Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 20th October 2025? Check out new documents from the field of the gas phase, especially GC and GC/MS techniques!<blockquote>👉 <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library">SEARCH THE LARGEST REPOSITORY OF DOCUMENTS ABOUT GCMS AND RELATED TECHNIQUES</a></blockquote><blockquote>👉 Need info about different analytical techniques? Peek into <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library">LabRulezLCMS</a> or <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library">LabRulezICPMS</a> libraries.</blockquote>This week we bring you applicaton notes by Agilent Technologies, EST Analytical, Shimadzu and Thermo Fisher Scientific!<h3>1. Agilent Technologies: FAMEs Analysis of Oils by GC-FID Coupled with Fully Automated Sample Preparation using a PAL3 Series 2 RTC</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_fame_oil_gc_pal3_5994_8543en_agilent_418da94d17.pdf">Full PDF for download</a></li></ul>The analysis of fatty acid methyl esters (FAMEs) is a widely used technique for characterizing lipid profiles in various food products, including oils, meats, and seeds. Fats are composed of a complex mixture of saturated, monounsaturated, and polyunsaturated fatty acids, each with varying carbon chain lengths.2 This type of analysis is routinely performed in governmental, quality control (QC), and contract research laboratories worldwide. The resulting data often informs product labeling. Among the analytical techniques available, gas chromatography (GC) with flame ionization detection (GC-FID) is one of the most common methods for determining fatty acid composition in&nbsp;foods.&nbsp;This application note describes the use of automated sample preparation and analysis of FAMEs using the PAL3 Series&nbsp;2 RTC Autosampler system coupled with Agilent 8890 GC system equipped with an FID. The results shown here focus on two different methods of derivatization for FAMEs extraction: (1) base catalyzed reactions using potassium hydroxide (KOH) (part&nbsp;number M5795-14000) and (2) base plus acid catalyzed reactions using boron trifluoride (BF3 ) 1 (part number M5795-14001). For ease of use, both processes have been transcribed into dedicated sample preparation methods. These methods are part of the Agilent automated sample preparation workflow suite of solutions. These workflows improve process safety, optimizes throughput, and minimizes&nbsp;errors.<h4>Experimental&nbsp;</h4>The 37 component FAME mix standard was purchased from Sigma-Aldrich (part number CRM47885), and three consumer oil products were purchased from a local grocery store. The samples were prepared and injected into the GC using the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=PAL3">PAL3 Series 2-RTC system</a>. The analysis was performed using an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=8890+GC">8890 GC</a> equipped with an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=DB%E2%80%91FastFAME">Agilent DB‑FastFAME GC column</a>, 30&nbsp;m × 250 µm, 0.25&nbsp;µm, (part number G3903‑63011) and configured with an FID using Agilent&nbsp;<a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=OpenLab+CDS+v2.7">OpenLab CDS v2.7+</a>.<h4>Conclusion&nbsp;</h4>In summary, the current study demonstrated excellent reproducibility and accuracy using automated sample preparation and analysis of FAMEs. Two different sample preparation methods were demonstrated, both delivering comparable and reliable results. The base-catalyzed method enables rapid analysis but is not suitable for samples containing free fatty acids. In contrast, the acid-catalyzed method, while more extensive, is compatible with a broader range of lipid classes, including free fatty acids, phosphoglycerides, and triglycerides. The Agilent automated sample preparation workflow suite of solutions deliver a comprehensive package by combining preconfigured hardware, optimized analytical methods, and the necessary consumables to ensure efficient and reliable results.<h3>2. EST Analytical: Unregulated Contaminant Monitoring Rule 3 for USEPA Method 524.3 and 524.4</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/Purge_and_Trap_Unregulated_Contaminant_Monitoring_Rule_3_for_USEPA_Method_524_3_and_524_4_b774e6ab4c.pdf">Full PDF for download</a></li></ul>The third Unregulated Contaminant Monitoring Rule (UCMR 3) was finalized in April of 2012. UCMR 3 requires public water systems to monitor for a specific list of 30 contaminants under three separate lists: list one, assessment monitoring, list two, screening survey, and list three, pre-screen testing. This application note will address the volatile organic compounds found in list one, assessment monitoring contaminants. USEPA Method 524.3 and 524.4 will be the methods evaluated for sampling and analysis.<h4>Discussion&nbsp;</h4>The amendments to the Safe Drinking Water Act (SDWA) require the EPA to list no more than 30 unregulated contaminants to be monitored by public water systems. Every five years, this list needs to be updated. List one contaminants include seven volatile organic compounds to be analyzed by USEPA Method 524.3. The detection limits for these compounds are much lower; therefore, Single Ion Monitoring (SIM) must be used for compound detection. USEPA Method 524.3 and 524.4 allow for modification of purge and trap parameters in order to take advantage of purge and trap improvements. Thus, method parameters can be modified in order to optimize purge and trap cycle times. Since the purge and trap parameters were established for these methods previously, refer to application note Drinking Water Analysis Conditions for USEPA Method 524.3 and the Newly Proposed Method 524.4, purge and trap method development was not required for this application. For this study, Helium and Nitrogen purge gases were compared utilizing the same purge volume then comparing experimental results for the linearity, precision, accuracy and overall compound response for the low level requirements set by UCMR 3.&nbsp;<h4>Experimental&nbsp;</h4>The <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2160">EST Analytical Encon Evolution purge and trap concentrator</a> and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2159">Centurion WS autosampler </a>were interfaced to an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7890%2F5975">Agilent 7890/5975 GC/MS</a>. The purge and trap concentrator was configured with a Vocarb 3000 (K) analytical trap. A chiller unit capable of keeping the sample vials cooled below 10°C was installed on the Centurion WS autosampler. The experimental parameters are listed in Tables 1 and 2.<h4>Conclusion</h4>The Encon Evolution and Centurion WS in conjunction with the Agilent 7890/5975 GC/MS performed very well using both the Helium and Nitrogen purge gases and employing SIM for compound detection. The Nitrogen and the Helium purge gases met USEPA Method 524.3 curve linearity criteria and produced comparable results for precision and accuracy at the low and mid-levels of the calibration curve. Overall, the principal difference between the two purge gases was exhibited in the compound response. When examining the overall compound response factors over the curve range, it is evident that the analytes’ responses are slightly lower with the Nitrogen purge gas as opposed to the Helium purge gas.<h3>3. Shimadzu: Comparison of Metabolites in Rice from Different Production Areas Using GC-MS/MS</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_01_01000_en_9c1d7cfe70.pdf">Full PDF for download</a></li></ul>Metabolomics is a research method for comprehensively analyzing metabolites contained in an organism. It is used for a wide variety of fields, such as medical science and food. Because food quality is affected by many components complexly, comprehensive analysis of metabolites can help improve food development and manufacturing processes. Rice contains metabolites, such as sugars, amino acids, and fatty acids. In recent years, development of more flavorful rice has been studied.&nbsp;This article describes simultaneous analysis of 502 metabolites and multivariate analysis of a variety of rice from different production areas. The <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=GCMS-TQ8040+NX">GCMS-TQ8040 NX</a> with the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=Smart+Metabolites+Database+ver.+2">Smart Metabolites Database Ver. 2</a> was used for measurement. <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=LabSolutions+Insight">LabSolutions Insight </a>was used for data processing, and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=eMSTAT+Solution">eMSTAT Solution</a> was used for multivariate analysis. The process flow, from pretreatment to data analysis, is shown in Fig. 1.<h4>eMSTAT Solution&nbsp;</h4>eMSTAT Solution is statistical analysis software that enables multivariate and discriminant analysis of chromatogram data. For multivariate analysis, it can discriminate between samples, and it can search for the marker peaks that contribute to those differences. For discriminant analysis, it can create a discriminant model based on training data and use the model for discriminant analysis. Users can easily switch both modes with just a single click. Workflow of the data analysis is shown in Fig. 2.<h4>Conclusion&nbsp;</h4>Metabolites in same variety of rice from different production areas were analyzed, and the differences between samples were identified by multivariate analysis. Score plots were used to visualize differences between the samples, and loading plots were used to confirm the characteristic compounds. Smart Metabolites Database Ver. 2, LabSolutions Insight, and eMSTAT Solution make metabolites analysis, data processing, and multivariate analysis easy for beginner users.<h3>4. Thermo Fisher Scientific: Automated, multi-parameter gasoline characterization using GC-VUV and ASTM D8071</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_003957_gc_vuv_trace_1610_vga_industrial_an003957_na_en_3c0a64e3b2.pdf">Full PDF for download</a></li></ul>Gasoline is a complex hydrocarbon blend whose composition directly impacts combustion behavior, emissions, and regulatory compliance. Accurately quantifying components such as aromatics, olefins, ethanol, and benzene is critical, but traditional ASTM methods require multiple techniques (FIA, GC-FID, GC-MS, etc.) to measure all relevant parameters. Table 1 summarizes several test methods and their respective scopes.&nbsp;ASTM D8071 introduces a consolidated method using GC-VUV, offering improved precision, spectral resolution, and reduced operational burden. This approach is now recognized as an EPA- and CARB-approved alternative to several legacy test methods, including ASTM D1319, D5599, D5769, and D3606.<h4>Experimental&nbsp;</h4>Gasoline samples were analyzed on the VUV Analyzer Platform for Fuels with no sample preparation required. The VUV Analyzer consists of the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/486">Thermo Scientific™ TRACE™ 1610 gas chromatograph</a> coupled to the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=3&amp;search=VGA-100">VGA-100™ spectrometer detector </a>(VUV Analytics, Inc.).&nbsp;Data are acquired and processed with the VUVision™ Software and VUV Analyze™ Software (VUV Analytics, Inc), respectively, specifically configured to run ASTM D8071.&nbsp;<h5>Workflow overview&nbsp;</h5>The VUV Analyzer Platform for Fuels performs gasoline PIONA class analysis using a streamlined five-step workflow:&nbsp;<ol><li>System validation – Verifies instrument performance using standard hydrocarbons.&nbsp;</li><li>Sample prep – No preparation required.&nbsp;</li><li>Data acquisition – Performed using VUVision Software.&nbsp;</li><li>Spectral matching – Automated deconvolution with VUV Analyze Software.&nbsp;</li><li>Quantitation – Volume % and mass % calculated with high accuracy using built-in response factors and density data.</li></ol><h4>Conclusion&nbsp;</h4>GC-VUV with ASTM D8071 enables complete hydrocarbon group and compound-level analysis of gasoline in a single method. Its ability to automate spectral deconvolution and report mass and volume percentages simplifies operations while meeting strict compliance standards. This solution not only enhances analytical accuracy and repeatability but also drastically reduces operating costs and lab complexity.&nbsp;<ul><li>Short analysis time with full gasoline class and compound profiling in 34 minutes&nbsp;</li><li>Faster throughput with full automation from injection to reporting&nbsp;</li><li>12× lower cost-per-analysis, due to reduced labor, no calibration standards, and consolidated workflow</li></ul>

News from LabRulezGCMS Library - Week 43, 2025

<h4>Abstract</h4>Strong or weak, light or dark, black or with cream; everyone who drinks coffee has a preference. Today, there are not only the choices of what you would like in your coffee, but also how you would like it brewed. Do you prefer the old fashioned percolator or the straight forward brewed coffee? Or do you like the new coffee by the cup makers or the instant coffees? There are so many options! This study will analyze four different instant coffee blends for some of their respective flavors using a purge and trap concentrator.<h4>Discussion</h4>Most of us who drink coffee know our preferences. We know which blend we like, what strength and definitely what we like in our coffee. However, most of us do not think about the flavors that go into our coffee that help us define our preferences. Coffee manufacturers, on the other hand, are working diligently to create a new blend or a more satisfying flavor that would make us want to choose their coffee over another maker.This study will look at four different blends of coffee and some of the compounds that contribute to the flavor of the blend. Using purge and trap sampling, the flavor compounds were purged out of the coffee and trapped onto an adsorbent trap. The analytes were then transferred to a Gas Chromatograph/Mass Spectrometer (GC/MS) for analysis. The study focused on six flavor compounds: the spicy smoky aroma of 2-methylfuran, the spicy caramel, almond odor of 5-methylfurfural, the buttery scent provided by the addition of 2,3-butanedione and 2,3-pentanedione, and the impact of the two and three methyl butanals giving the dark chocolate malty flavor to the coffee.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Purge_and_Trap_Analysis_of_Coffee_Flavors_by_Purge_and_Trap_Sampling_ca25beef60_1_acf9fc0b4f.jpg" alt="EST Analytical: Encon Evolution Purge and Trap Concentrator and Centurion WS Autosampler" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Purge_and_Trap_Analysis_of_Coffee_Flavors_by_Purge_and_Trap_Sampling_ca25beef60_1_acf9fc0b4f.jpg 197w," sizes="100vw" width="668" height="531"><h4>Experimental</h4>The EST Analytical <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2160">Encon Evolution Purge and Trap Concentrator</a> and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2159">Centurion WS Autosampler</a> were interfaced to a GC/MS. The Centurion WS was run in the soil mode and the purge and trap concentrator was configured with a Vocarb 3000 (K) analytical trap. The column selected for this study was an Rtx-1 60 m × 0.25 mm × 1 µm. Sampling method parameters and GC/MS parameters are listed below.<h5>Purge and Trap Parameters</h5><ul><li>Concentrator: EST Encon Evolution</li><li>Trap type: Vocarb 3000</li><li>Valve oven temperature: 150 °C</li><li>Transfer line temperature: 150 °C</li><li>Trap temperature: 35 °C</li><li>Moisture Reduction Trap (MoRT) temperature: 39 °C</li><li>Purge time: 11 min</li><li>Purge flow: 40 mL/min</li><li>Dry purge Temp.: Ambient</li><li>Dry Purge Flow: 50mL/min</li><li>Dry Purge Time: 1.0 min &nbsp;</li><li>Desorb pressure Control: ON</li><li>Desorb Pressure: 5psi</li><li>Desorb time: 0.5 min</li><li>Desorb preheat delay: 5 sec</li><li>Desorb temperature: 260 °C</li><li>MoRT bake temperature: 230 °C</li><li>Bake temperature: 260 °C</li><li>Sparge vessel bake temperature: 120 °C</li><li>Bake time: 8 min</li><li>Bake flow: 85 mL/min</li></ul><h5>Auto-Sampler (EST Centurion WS):</h5><ul><li>Sample type: Soil</li><li>Sample Fill Mode: loop</li><li>Sample Volume: 10mL</li><li>Sample Prime Time: 5 sec</li><li>Loop Equilibration Time: 10 sec</li><li>Sample Transfer Time: 15 sec</li><li>Sample Loop Rinse: Off</li><li>Sample Loop Sweep Time: 15 sec</li><li>Number of Sparge Rinses: 1</li><li>Rinse Volume: 5mL</li><li>Rinse Transfer Time: 20 sec</li><li>Rinse Drain Time: 20 sec</li><li>Number of Foam Rinse Cycles: 1</li><li>Water Heater Temp.: 85°C</li><li>Sample Preheat Temp.: 40°C</li><li>Soil Valve Temp.: 85°C</li><li>Soil Transfer Line Temp.: 150°C &nbsp;</li></ul><h5>GC/MS Parameters</h5><ul><li>System: <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7890%2F5975">Agilent 7890/5975</a></li><li>Inlet: Split mode, 200 °C, 20:1 split ratio, 16.041 psi head pressure</li><li>Column: Rtx-1 60m x 0.25mm I.D. 1.0µm film thickness</li><li>Oven program: 35 °C (1 min) → ramp 4 °C/min → 230 °C, total run time of 49.75 min</li><li>Column flow rate: 1 mL/min helium</li><li>Total flow: 26.0 mL/min</li><li>Source temperature: 230 °C</li><li>Quadrupole temperature: 150 °C</li><li>Transfer line temperature: 180 °C</li><li>Scan range: m/z 35–265, 3.12 scans/sec</li><li>Solvent delay: 0.0 min</li></ul>The GC column was acquired from Restek while the instant coffees were purchased at a local retailer. The four roasts chosen for this study ranged from light to dark. One half of a gram of each coffee was dissolved in 40 mL of de-ionized water at room temperature. The vials were shaken in order to fully dissolve the coffee. Next, 5 mL of each coffee mixture were run in the soil mode using the Centurion WS autosampler and the Encon Evolution purge and trap concentrator. Each coffee was run in triplicate in order to verify the results. Figures 1 through 3 display a bar graph comparison of the flavors in each coffee blend. Chromatograms of the coffee blends are shown in Figures 4 through 7.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analaytical_Figure_1_Buttery_Compound_Comparison_08f6fd5d05.jpg" alt="EST Analytical: Figure 1 Buttery Compound Comparison" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analaytical_Figure_1_Buttery_Compound_Comparison_08f6fd5d05.jpg 245w," sizes="100vw" width="905" height="544"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analaytical_Figure_2_Smoky_and_Spicy_Caramel_Compound_Comparison_6940d35e36.jpg" alt="EST Analytical: Figure 2 Smoky and Spicy Caramel Compound Comparison" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analaytical_Figure_2_Smoky_and_Spicy_Caramel_Compound_Comparison_6940d35e36.jpg 245w," sizes="100vw" width="905" height="545"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analaytical_Figure_3_Dark_Chocolate_Malty_Compound_Comparison_cbee579baf.jpg" alt="EST Analytical: Figure 3 Dark Chocolate - Malty Compound Comparison" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analaytical_Figure_3_Dark_Chocolate_Malty_Compound_Comparison_cbee579baf.jpg 245w," sizes="100vw" width="905" height="545"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analaytical_Figure_4_Light_Roast_Chromatogram_8380d110a6.jpg" alt="EST Analytical: Figure 4 Light Roast Chromatogram" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analaytical_Figure_4_Light_Roast_Chromatogram_8380d110a6.jpg 245w," sizes="100vw" width="953" height="375"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analaytical_Figure_5_Medium_Roast_Chromatogram_9a97a58a74.jpg" alt="EST Analytical: Figure 5 Medium Roast Chromatogram" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analaytical_Figure_5_Medium_Roast_Chromatogram_9a97a58a74.jpg 245w," sizes="100vw" width="886" height="401"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analaytical_Figure_6_Medium_Dark_Roast_Chromatogram_eb6a37cd16.jpg" alt="EST Analytical: Figure 6 Medium Dark Roast Chromatogram" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analaytical_Figure_6_Medium_Dark_Roast_Chromatogram_eb6a37cd16.jpg 245w," sizes="100vw" width="877" height="410"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analaytical_Figure_7_Dark_Roast_Chromatogram_79711f7858.jpg" alt="EST Analytical: Figure 7 Dark Roast Chromatogram" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analaytical_Figure_7_Dark_Roast_Chromatogram_79711f7858.jpg 245w," sizes="100vw" width="856" height="412"><h4>Conclusion</h4>The lightest roast had the most buttery and dark chocolate/malty flavors while the darkest roast had more of the smoky flavor. Surprisingly, the darkest roast and the medium roast had similar proportions of the flavor compounds with the exception of the smoky flavor. While the light roast had large amounts of the flavors tested for, the chromatography of the light roast was much simpler than that of the darker roasts. Overall, the Encon Evolution Purge and Trap Concentrator in conjunction with the Centurion WS Autosampler proved to be an excellent system for sampling coffee. The results were reproducible and provided a lot of information on the flavors of the respective coffees.

Analysis of Coffee Flavors by Purge and Trap Sampling

News from LabRulezGCMS Library - Week 44, 2025

Analysis of field samples in environmental laboratories can sometimes be complicated by how contaminated or “hot” the sample is. Many times “hot” samples have to be diluted in order to verify the level of contamination in the sample. The process of diluting samples is a time consuming process that can sometimes lead to human error when calculations are incorrect. A further problem is the loss of volatile organic compounds as the sample vial needs to be opened in order to perform the dilution.&nbsp;This poster will examine the benefits of automated dilutions. Since the syringe option of this system has the unique ability to dilute samples from two times to 400 times the original concentration, this study will examine the precision and accuracy for an array of dilutions in this comprehensive range. The dilution data will be compared to a manually prepared 50ppb calibration standard in order to determine the accuracy of the results. The precision will be established by examining four sequential dilutions and the percent relative standard deviation of the compounds’ respective area counts. Furthermore, in order to demonstrate the linearity of the dilutions, a calibration curve will be presented using the automated dilution option to prepare 200ppb standards for a calibration range of 0.5ppb (400x) to 200ppb (1x).<h4>Discussion&nbsp;</h4>Environmental laboratories often have to dilute field samples due to the analytes of interest having concentrations over the highest calibration level of the curve. In order to dilute these samples, the vial has to be opened and a portion of the sample has to be diluted manually and re-analyzed. Opening the vial can compromise the integrity of the sample as volatiles are lost when the seal of the vial is broken.&nbsp;EST Analytical has developed a syringe feature for the Centurion Autosampler that can dilute samples up to 400 times the original concentration. This feature is fully programmable and the sample vial does not have to be compromised in order to dilute the sample because the dilution process is automated. The sealed vial can be placed in the sample tray while the Centurion does all of the work.&nbsp;<h4>Experimental&nbsp;</h4>The <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2159">Centurion WS autosampler</a> was configured with an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2160">Encon Evolution concentrator</a>. A Vocarb 3000 (K) trap was installed in the Evolution. Finally, the sampling system was connected to a GC/MS for sample analysis. The GC column employed for this study was an Rxi-624Sil MS 30m x 0.25mm x 1.4µm. Dilution Factors, Purge and Trap, and GC/MS parameters are listed below.<h5>Standard Concentration &amp; Dilution Factors</h5><ul><li>100ppb: 2x</li><li>250ppb: 5x</li><li>500ppb: 10x</li><li>2.5ppm: 50x</li><li>5ppm: 100x</li><li>10ppm: 200x</li><li>20ppm: 400x</li></ul><h5>Purge and Trap Parameters</h5><ul><li>Concentrator: EST Encon Evolution</li><li>Trap type: Vocarb 3000</li><li>Valve oven temperature: 150 °C</li><li>Transfer line temperature: 150 °C</li><li>Trap temperature: 35 °C</li><li>Moisture Reduction Trap (MoRT) temperature: 39 °C</li><li>Purge time: 11 min</li><li>Purge flow: 40 mL/min</li><li>Dry purge Temp.: Ambient</li><li>Dry Purge Flow: 40mL/min</li><li>Dry Purge Time: 1.0 min &nbsp;</li><li>Desorb pressure Control: ON</li><li>Desorb Pressure: 5psi</li><li>Desorb time: 0.5 min</li><li>Desorb preheat delay: 5 sec</li><li>Desorb temperature: 260 °C</li><li>MoRT bake temperature: 230 °C</li><li>Bake temperature: 265 °C</li><li>Sparge vessel bake temperature: 120 °C</li><li>Bake time: 8 min</li><li>Bake flow: 40 mL/min</li></ul><h5>GC/MS Parameters</h5><ul><li>System: <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7890%2F5975">Agilent 7890/5975</a></li><li>Inlet: Split mode, 200 °C, 40:1 split ratio, 12.153 psi head pressure</li><li>Column: Rxi-624Sil MS 30m x 0.25mm I.D. 1.4µm film thickness</li><li>Oven program: 45 °C (1 min) → ramp 18 °C/min → 220 °C, hold for 0.3 min</li><li>Column flow rate: 1 mL/min helium</li><li>Total flow: 44.0 mL/min</li><li>Source temperature: 230 °C</li><li>Quadrupole temperature: 150 °C</li><li>Transfer line temperature: 180 °C</li><li>Scan range: m/z 35–265, 3.12 scans/sec</li><li>Solvent delay: 0.7 min</li></ul>A 9 point calibration curve was manually prepared and run from 0.5 to 200ppb with standards ordered from Restek. After a linear calibration curve was established, a 50ppb calibration standard was run to establish instrument response for the compounds being analyzed. Next, a series of dilutions were run and compared with the initial 50ppb calibration standard. Each dilution factor was run four times with blanks in between. The final concentration of each dilution was 50ppb. The precision and accuracy of the dilutions are listed in Tables 4 and 5 and Figures 1 and 2 display the chromatograms of two of the dilutions.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_1_Overlay_of_50ppb_1_X_and_2500ppb_50x_Standards_29d90b4107.jpg" alt="EST Analytical: Figure 1 - Overlay of 50ppb (1X) and 2500ppb (50x) Standards" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_1_Overlay_of_50ppb_1_X_and_2500ppb_50x_Standards_29d90b4107.jpg 245w," sizes="100vw" width="1023" height="383"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_2_Overlay_of_50ppb_1_X_and_10000ppb_200x_Standards_7f939589b9.jpg" alt="EST Analytical: Figure 2 - Overlay of 50ppb (1X) and 10000ppb (200x) Standards" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_2_Overlay_of_50ppb_1_X_and_10000ppb_200x_Standards_7f939589b9.jpg 245w," sizes="100vw" width="1073" height="383"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Table_4_Experimental_Results_2x_5x_10x_and_50x_dilutions_d81be1942f.jpg" alt="EST Analytical: Table 4 - Experimental Results (2x, 5x, 10x, and 50x dilutions)" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Table_4_Experimental_Results_2x_5x_10x_and_50x_dilutions_d81be1942f.jpg 150w," sizes="100vw" width="1173" height="1220"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Table_5_Experimental_Results_100x_200x_and_400x_dilutions_f29762c72e.jpg" alt="EST Analytical: Table 5 - Experimental Results (100x, 200x and 400x dilutions)" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Table_5_Experimental_Results_100x_200x_and_400x_dilutions_f29762c72e.jpg 124w," sizes="100vw" width="972" height="1226">Finally, a nine point calibration curve was run by setting up the system to do the dilutions. The curve was run using nine 40ml vials filled to volume with a 200ppb calibration standard and doing serial dilutions on the standards. For example, the 200ppb was diluted 400x for the 0.5ppb standard, 200x for the 1.0ppb standard, etc. See Table 6 for the curve dilutions and Table 7 for the curve linearity and compound responses.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Table_6_Syringe_Curve_Dilutions_4237e1d568.jpg" alt="EST Analytical: Table 6 Syringe Curve Dilutions" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Table_6_Syringe_Curve_Dilutions_4237e1d568.jpg 245w," sizes="100vw" width="785" height="381"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Table_7_Automated_Dilution_Curve_Results_356126f34f.jpg" alt="EST Analytical: Table 7 Automated Dilution Curve Results" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Table_7_Automated_Dilution_Curve_Results_356126f34f.jpg 138w," sizes="100vw" width="927" height="1050"><h4>Conclusions&nbsp;</h4>The Centurion WS with the syringe option displayed remarkable precision and accuracy from as low as the 2x dilution to as high as 400x dilution. On the whole, the average precision of the instrument was less than 5%RSD while the overall accuracy was 90% to 110%. The system also is capable of curve automation with the average %RSD of below 10% for a 9 point curve from 0.5ppb to 200ppb. The automated dilution feature of the Centurion WS with the syringe option would enable laboratories to run samples more efficiently and the since the samples would not need to be compromised in order to perform dilutions, the accuracy of the experimental results would improve.

Automated Dilutions Using the Centurion Autosampler

Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 10th November 2025? Check out new documents from the field of the gas phase, especially GC and GC/MS techniques!<blockquote>👉 <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library">SEARCH THE LARGEST REPOSITORY OF DOCUMENTS ABOUT GCMS AND RELATED TECHNIQUES</a></blockquote><blockquote>👉 Need info about different analytical techniques? Peek into <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library">LabRulezLCMS</a> or <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library">LabRulezICPMS</a> libraries.</blockquote>This week we bring you applicaton notes by Agilent Technologies, EST Analytical and Shimadzu!<h3>1. Agilent Technologies: Improved Thermal Stability Leads to Retention Time Stability and Data Accuracy for the Analysis of Pesticides</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_pesticide_gc_ms_5994_8447en_agilent_773f1f135b.pdf">Full PDF for download</a></li></ul>The analysis of trace-level pesticides is required by many governmental regulatory authorities at varying concentrations and can include hundreds of target analytes. As many of the matrices tested are complex and the analytes active, a robust and inert gas chromatography method is required.1 Heavy matrices can be difficult for analytical gas chromatography columns, and higher temperatures may be required to elute the matrix off of the column. To avoid damage from high temperatures and heavy matrix, a thermally stable and ultra inert analytical column phase is needed to successfully perform this analysis. The Agilent J&amp;W 5Q series of gas chromatography columns provide the most thermally stable column available and offer inertness for difficult analytes.2 The increased thermal stability not only dramatically reduces column bleed but also allows for less spectral interference at higher temperatures, leading to less need for background subtraction when searching analyte spectra against commercially available libraries.&nbsp;While column bleed is a normal phenomenon, the increase of the baseline due to column bleed is an indication of the column phase breaking down and leading to retention time shifts. Retention time shifting can be especially difficult with the analysis of pesticides, since sensitive detectors such as mass spectrometers and triple quadrupole systems collected in selected ion mode (SIM) or multiple reaction monitoring (MRM) mode are required to achieve lower limits of detection. In both SIM and MRM collection methods, time segment windows are stated for analytes of interest, and if a retention time shifts earlier, it can move out of the collection window and require time to update the analytical collection method. By using a GC column with increased thermal stability, such as the Agilent J&amp;W DB-5Q or the Agilent J&amp;W HP-5Q, the column will be more robust to thermal and matrix damage. These columns will also maintain consistent retention times over long periods of analytical stress.&nbsp;Retention time locking is a useful tool in the analysis of pesticides, as it can adjust column flow or pressure to normalize retention times, so that the retention times of the analytes are the same from system to system or column to column.3,4 When columns with identical selectivity are interchanged, after a single injection of a test mix, the analysis can be relocked and the column flow adjusted, based on the initial calibration, to be identical as in the original method. This eliminates the need to constantly update retention times in analytical methods for SIM or MRM windows or data processing methods when replacing analytical columns.&nbsp;When analyzing pesticides in heavy matrix, a guard column can serve two additional benefits. The guard column can help protect the analytical column from heavy matrix damage and can improve solvent and sample focusing. It is recommended to use nonpolar solvents when working with nonpolar column phases, such as the DB-5Q and HP-5Q columns. Recently it has become more common to prepare heavy matrices for pesticide analysis using QuEChERs-type preparations, with a final solvent of acetonitrile. Solvent-column phase polarity mismatch can lead to improper solvent focusing and wettability leading to improper peak shape, especially when working with columns that have low free silanol content on the deactivated surface of the fused silica. Use of a guard column can help to refocus the solvent and analytes to maintain proper peak shape.5&nbsp;The Agilent 7010D GC/TQ uses the new Agilent High Efficiency Source (HES) 2.0 equipped with a novel dipolar RF lens that redirects carrier gas and low mass ions by &gt;&nbsp;95%, helping to reduce noise and extend instrument robustness while maintaining sensitivity.6 When using DB-5Q and HP‑5Q columns in conjunction with the HES 2.0, it is possible to increase the overall robustness of the workflow for the analysis of pesticides over a wide dynamic range of analyte&nbsp;concentrations.&nbsp;<h4>Experimental&nbsp;</h4>An <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=8890">Agilent 8890 GC</a> coupled with an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=5977B">Agilent 5977B GC/MSD</a> with an Inert Extractor Source was used for acquisition of data and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=MassHunter+10.0+Qualitative+Analysis">MassHunter 10.0 Qualitative Analysis software</a> was used for data analysis. NIST20 library was used to confirm peak identification. A retention gap of one meter was used as a guard column to help protect the analytical column from heavy matrix and to aid in solvent focusing.<h4>Results and discussion&nbsp;</h4>The analysis of pesticides requires retention time stability as well as consistency from analytical column to analytical column. To compare the analytical performance of an Agilent J&amp;W DB-5Q to an Agilent J&amp;W DB-5ms UI GC column for the analysis of pesticides, a standard was first analyzed on a DB-5ms UI and the retention time locked for chlorpyrifosmethyl. The DB-5ms UI column was then replaced with a DB-5Q, and once the column was conditioned, the representative pesticide mix was again analyzed and relocked to the appropriate retention time for chlorpyrifos-methyl and analyzed again. Figure 1 demonstrates the identical selectivity of the DB-5ms UI to the DB-5Q phases and the ability to relock an existing analytical method when upgrading columns and compatibility with existing retention time locking libraries.&nbsp;Additionally, when comparing the baseline of the DB-5Q to the DB-5ms UI column at the upper temperature limit of the chromatographic method, the increased thermal stability of the DB-5Q allows for a significant decrease in column bleed at upper temperature limits (Figure 1).<h4>Conclusion&nbsp;</h4>This application note demonstrated that the Agilent J&amp;W DB-5Q column has identical selectivity to the Agilent J&amp;W DB-5ms UI column, allowing for seamless adoption and use with existing retention time locking methods. The robust DB-5Q column phase maintained retention time stability even when analyzing heavy matrices and temperature cycling. The increased thermal stability not only decreased the baseline at higher temperatures but also allowed for less spectral interference and high library match factor scores. The analytical performance of the Agilent J&amp;W DB-5Q column coupled with the Agilent 7010D with the HES 2.0 ion source allows for optimal sensitivity and wide dynamic range of pesticide compounds.<h3>2. EST Analytical: Automated Sampling of Methanol Extractions</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/Purge_and_Trap_Automated_Sampling_of_Methanol_Extractions_f521577cc4.pdf">Full PDF for download</a></li></ul>Environmental labs are required to perform methanol extractions on highly contaminated solid waste samples. Additionally, these extractions are used for difficult matrices, for example oily waste samples, that are also soluble in methanol. Due to the variety of matrices that can be extracted with methanol there are assorted hurdles to cross in order to automate the sampling process. One of these obstacles is how the matrix can absorb the extraction solvent. For example, many soil samples require more methanol; due to the soil expanding with the solvent addition. Adding more methanol aids in rectifying this issue however, when automating sampling, the added methanol coupled with the soil expansion needs to be accommodated. For this reason, EST Analytical created software for the Centurion WS that allows the user to program the needle depth to different distances. In doing this, laboratories are able to sample soils at higher depths in order to adjust for sample absorption and at lower depths for samples that do not require the added solvent. In order to test volatile compounds in methanol extractions, a portion of the extract needs to be sampled from the vial, diluted, and purged on a purge and trap concentrator. This examination will look at the automated sampling of three different soil matrices.&nbsp;<h4>Experimental:&nbsp;</h4>The <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2159">Centurion WS autosampler</a> with the syringe option and the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2160">Evolution purge and trap concentrator</a> were set up to run methanol extractions. Since this is a volatile analysis, a Vocarb 3000 (K) trap was used for the analytical trap. The sampling system was configured to an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1-10&amp;search=7890A">Agilent 7890A Gas Chromatograph (GC)</a> and an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1-10&amp;search=5975C">Agilent 5975C inert XL Mass Spectrometer (MS)</a>. The column selected for this analysis was a Restek Rxi®-624 Sil MS, with dimensions of 30m x 0.25mm I.D. x 1.4µm film thickness. Experimental parameters used for this analysis are listed in Tables 1 and 2.<h4>Conclusions:&nbsp;</h4>The system produced excellent results. The curve and the compound response factors met all of the method requirements. The overall precision was less than 5% RSD while the system showed an average recovery of 94%. When examining the expected analyte concentration to the extracted sand results, it was found that the average recovery was approximately 102%. Thus, the automated extraction performed extremely well. When comparing the three different matrices it was found that they all displayed similar recoveries, however the sand matrix did perform the best of the three as expected since sand tends not to absorb analytes as readily as other matrices. Finally, the ability to control the needle depth on extraction samples was a great benefit for the different matrices as the system exhibited no issues with needle clogging due to the higher needle depth when performing the potting soil extractions. As demonstrated from this study, the Centurion WS automated extraction capability would be an asset to any lab performing extractions.<h3>3. Shimadzu: Fatty Acid Analysis of Edible Oils by GC</h3>Comparing Helium and Hydrogen as Carrier GasesComparing Analysis by GC with a Simple Screening Analysis by LC-MS<ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_01_00852_en_e928ab40ea.pdf">Full PDF for download</a></li></ul>There are a variety of edible oils that are sold commercially for a range of uses. They are almost entirely composed of compounds called triacylglycerols (neutral lipids), which consist of three fatty acids bound to a glycerol molecule. Because fatty acids affect the functional characteristics of food, determining the fatty acid composition of food is an important area of analysis. In this Application News, the Brevis GC-2050 (GC-FID) is used to determine the fatty acid composition of commercially available edible oils, and the use of hydrogen as a carrier gas is examined and compared with helium. This Application News also analyzes the same edible oils analyzed by LC-MS in a previous Application News1) and comparesthe results.<h4>Equipment&nbsp;</h4>GC-FID analysis was performed using the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=Brevis+GC-2050">Brevis GC-2050</a> gas chromatograph (Fig.1) , which is designed to be highly compact, with an installation footprint 35 % smaller than the previous model. The Brevis GC-2050 is also equipped with a carrier gas saving mode that reduces carrier gas consumption. The carrier gas saving mode reduced the use of helium carrier gas by around 89 % and hydrogen carrier gas by around 79 % in the analyses described in this article. Hydrogen carrier gas also reduced analysis times by around 25 %.<h4>Results from Real-World Sample Analysis&nbsp;</h4>Edible oils were derivatized and analyzed using both helium and hydrogen carrier gases. Peaks that could not be identified with the calibration standard (37 FAME mixture) were analyzed by GC-MS to determine their carbon number and degree of unsaturation. (Labeled as isomer.) Fig. 4 shows the chromatograms (partial) obtained from analyzing linseed oil with helium and hydrogen carrier gases. Similar separation was achieved with both gases.<h4>Comparing GC-FID and FIA-MS&nbsp;</h4>Tables 5 and 6 compare the results of analyzing eight vegetable oils for fatty acids by FIA-MS (screening analysis) and GC-FID (a helium carrier). The results reveal characteristic features of the vegetable oils, such as the most abundant fatty acids, and that coconut oil contains fatty acids with relatively low carbon numbers. More information about the screening analysis performed with a single quadrupole mass spectrometer can be found in Shimadzu Application News 01-00674-EN. 1)<h4>Conclusion&nbsp;</h4>In this Application News, the Brevis GC-2050 was used to determine the fatty acid composition of edible oils. Fatty acid analysis is typically performed using helium as the carrier gas, but in this study, hydrogen was used. This reduced analysis times while producing results that compared favorably with helium. Given the current supply issues associated with helium, hydrogen should be considered as an alternative to helium.&nbsp;The results also show that fatty acid compositions determined by FIA-MS correlate well with results obtained by GC-FID. And because the sample pretreatment only requires sample dilution, analysis by FIA-MS is rapid, taking just 1 minute. Therefore, FIAMS seems particularly well-suited to the screening of large numbers of samples or when there is an urgent need to verify quality or safety

News from LabRulezGCMS Library - Week 46, 2025

Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 17th November 2025? Check out new documents from the field of the gas phase, especially GC and GC/MS techniques!<blockquote>👉 <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library">SEARCH THE LARGEST REPOSITORY OF DOCUMENTS ABOUT GCMS AND RELATED TECHNIQUES</a></blockquote><blockquote>👉 Need info about different analytical techniques? Peek into <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library">LabRulezLCMS</a> or <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library">LabRulezICPMS</a> libraries.</blockquote>This week we bring you applicaton notes by Agilent Technologies, EST Analytical and Shimadzu!<h3>1. Agilent Technologies: Accurate Identification and Quantification of Pesticide Residues in Ghee</h3>Analysis by QuEChERS with GC/MS/MS using the Agilent 8890 GC and Agilent 7010 GC/TQ<ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_pesticide_ghee_gc_5994_8399en_agilent_1cbd787002.pdf">Full PDF for download</a></li></ul>India is one of the largest producers of milk, contributing about 23% of global milk production.1 The dairy processing sector includes a wide range of products, such as milk, butter, cheese, ghee, yogurt, flavored milk, lactose-free dairy products, and value-added products like ice creams and yogurts. Amongst these, ghee production is significant because of its popularity, low cost of production, and versatile use. According to the Food Safety and Standards Authority of India (FSSAI), ghee is mentioned as a "product obtained exclusively from milk, cream or butter by a process that almost completely removes water and non-fat solids; it has a specially developed flavor and physical structure".2 Milk‑producing animals can be exposed to pesticides through their diet, such as feed and fodder containing pesticide residues, or through the direct application of pesticides for controlling ectoparasites on their bodies, in animal sheds, and in milk processing areas. Due to their persistent and lipophilic nature, pesticides tend to accumulate in the fat-rich tissues of animals. The FSSAI has specified maximum residue levels (MRLs) for 55 pesticides, and a tolerance limit of 0.01&nbsp;mg/kg for the remaining pesticides for which an MRL has not been&nbsp;fixed.&nbsp;Ghee consists of 98.9% fat, irrespective of the animal source. Among the short- and medium-chain saturated fatty acids, all samples contain butyric (C4:0), caproic (C6:0), caprylic (C8:0), and capric acid (C10:0).3 Since its introduction, the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=QuEChERS">QuEChERS method</a> has been widely used for the analysis of pesticides in several matrices. Some modifications to the original QuEChERS method have been introduced to ensure efficient extraction of pH-dependent compounds, to minimize degradation of susceptible compounds (such as base- and acid-labile pesticides), and to expand the spectrum of matrices covered. Ghee matrix has a very high lipid load, making it a difficult commodity for analysis pesticide residues. The primary challenge lies in obtaining an extract that contains the target analytes while minimizing the amount of fat. Co-extracted lipids in the extracts can be removed, to a high degree, by a freezing-out step or a C18 cleanup.&nbsp;During sample extraction, the sample is often diluted. To obtain a quantification limit of 0.01 mg/kg, the instrument should be able to detect the residues at a lower concentration. This application note addresses these requirements by combining a sample preparation technique covering multiclass pesticides, target-specific multiple reaction monitoring (MRM) data acquisition, and efficient software to simplify quantitative analysis. The Agilent 7010 triple quadrupole GC/MS system enabled trace-level detection and confident quantitation of 150 pesticides in ghee.<h4>Experimental&nbsp;</h4><h5>Equipment&nbsp;</h5>An Agilent <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=8890+GC">8890 GC</a> coupled to a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7010+GC%2FTQ">7010 GC/TQ</a> system equipped with high efficiency source was used for the analysis. The GC system was equipped with a multimode inlet with air cooling and midcolumn backflush based on an Agilent purged Ultimate union controlled by a pneumatic switching device. The method parameters are displayed in Table 1.<h4>Conclusion</h4>The limits of quantitation (LOQs) for the target list of over 150 compounds ranged from 2.5 to 5 mg/kg for the ghee matrix. To minimize interferences from the ghee matrix, numerous multiple reaction monitoring (MRM) transitions were employed. This approach helped to accurately identify and quantify the target compounds despite the complex sample matrix. The samples were diluted five-fold to ensure that the analytes were within the required detection range of the instrument. This dilution also helped in reducing the matrix effects, leading to more reliable results. The average analyte recoveries were between 70 and 130%, indicating that the method has good accuracy and precision. This range of recoveries demonstrates the method’s robustness and suitability for routine analysis of these compounds.<h3>2. EST Analytical: Analysis of Coffee Flavors by Purge and Trap Sampling</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/Purge_and_Trap_Analysis_of_Coffee_Flavors_by_Purge_and_Trap_Sampling_ca25beef60.pdf">Full PDF for download</a></li></ul>Most of us who drink coffee know our preferences. We know which blend we like, what strength and definitely what we like in our coffee. However, most of us do not think about the flavors that go into our coffee that help us define our preferences. Coffee manufacturers, on the other hand are working diligently to create a new blend or a more satisfying flavor that would make us want to choose their coffee over another maker.&nbsp;This study will look at four different blends of coffee and some of the compounds that contribute to the flavor of the blend. Using purge and trap sampling, the flavor compounds were purged out of the coffee and trapped onto an adsorbent trap. The analytes were then transferred to a Gas Chromatograph/Mass Spectrometer (GC/MS) for analysis. The study focused on six flavor compounds. The spicy smoky aroma of 2-methylfuran, the spicy caramel, almond odor of 5-methylfurfural, the buttery scent provided by the addition of 2,3-butanedione and 2,3- pentanedione and the impact of the two and three methyl butanals giving the dark chocolate malty flavor to the coffee.<h4>Experimental:&nbsp;</h4>The EST Analytical <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2160">Encon Evolution Purge and Trap Concentrator</a> and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2159">Centurion WS Autosampler </a>were interfaced to a GC/MS. The Centurion WS was run in the soil mode and the purge and trap concentrator was configured with a Vocarb 3000 (K) analytical trap. The column selected for this study was an Rtx-1 60m x 0.25mm x 1µm. Listed in Tables 1 and 2 are the experimental parameters used for this study.<h4>Conclusion:&nbsp;</h4>The lightest roast had the most buttery and dark chocolate/malty flavors while the darkest roast had more of the smoky flavor. Surprisingly, the darkest roast and the medium roast had similar proportions of the flavor compounds with the exception of the smoky flavor. While the light roast had large amounts of the flavors tested for, the chromatography of the light roast was much simpler than that of the darker roasts. Overall, the Encon Evolution Purge and Trap Concentrator in conjunction with the Centurion WS Autosampler proved to be an excellent system for sampling coffee. The results were reproducible and provided a lot of information on the flavors of the respective coffees.<h3>3. Shimadzu: Analysis of Ethanol in E10 Gasoline Using Polyarc Microreactor for GC</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_01_01033_en_d4ee66bd4f.pdf">Full PDF for download</a></li></ul>The flame ionization detector (FID) can detect almost all organic compounds, and the sensitivity of the obtained chromatograms displays a correlation with concentration and number of carbon atoms in the compound. However, as a weakness of FID, its sensitivity decreases when an organic compound contains oxygen atoms, asin the case of alcohols.&nbsp;The Polyarc microreactor improvessensitivity for alcohols and other compounds containing oxygen atoms (hereinafter, oxygenated compounds), allowing calibration using a single compound. Research and use of biofuels has accelerated in recent years, and more sensitive quantitative analysis of oxygenated compounds in multiple compoundsis now required.&nbsp;This Application News introduces an example of an analysis of a sample simulating E10 gasoline, in which 10 % ethanol by volume concentration was added to gasoline, demonstrating that enhanced sensitivity for oxygenated compounds can be achieved by adding Polyarc to the instrument configuration. The accuracy of the quantitative analysis was also verified using a general standard sample (alkane).<h4>Polyarc Microreactor</h4>Polyarc is a post-column type microreactor that is introduced between the column and the detector (FID). The organic compounds separated and eluted by the column are decomposed to methane by the Polyarc reactor in a two-stage oxidationreduction reaction (Fig. 1). Since the decomposed methane is detected by the FID, the uniform sensitivity for the carbon number can be obtained, regardless of the type of functional groups in a sample.<h4>Effective Carbon Number</h4>As mentioned above, the sensitivity of the FID detector varies depending on the types of functional groups in organic compounds. The detection sensitivity by the FID can be estimated based on the concept of the effective carbon number (ECN), which is an index showing how many carbon atoms in a compound function effectively. Depending on the type of functional groups contained in a compound, the carbon ratio in the molecule changes, and this causes changesin the sensitivity ofthe FID. For example, both ethane (C2H6) and ethanol (C2H5OH) contain the same number of carbon atoms of 2, but the sensitivity of the FID for ethanol is only 75 % of itssensitivity for ethane because the primary hydroxyl group (-OH) behaves as -0.5 carbon atoms in terms of its contribution to the ECN. This meansthe ECNof ethanol is 1.5. Table 1 shows several examples of other functional groups with ECNslowerthan the number of carbon atoms.<h4>Analysis Conditions</h4>In this Application News, sensitivity for ethanol when the Polyarc was added and when using only the FID was compared using an E10 sample, in which 10 v/v% ethanol was added to gasoline, simulating a biofuel which has attracted attention in recent years, and quantitativity for ethanol was confirmed. In the quantitative analysis, it was also carried out by the external standard method using a hydrocarbon (dodecane; C12) with a concentration of 1 w/v% as a standard sample. The analytical instrument was a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=GC-2030">GC-2030</a> (SPL/FID) model gas chromatograph with the Polyarc added (Fig. 2). Table 2 shows the analysis conditions.<h4>Conclusion</h4>E10 gasoline was analyzed using an FID detector and an added Polyarc microreactor, confirming that oxygenated compounds can be analyzed with high sensitivity. This study also confirmed that a uniform reaction of organic compounds can be obtained in the FID, and peak broadening can be suppressed by standardizing the response of sensitivity. Table 6 introduces several of the advantages that are possible by adding the Polyarc microreactor. The Polyarc converts all organic compounds to methane having the same number of carbon atoms (mol), enabling highsensitivity detection for compounds with low detection sensitivity by FID alone. In addition, since sensitivity is standardized, quantitation is possible using only one arbitrary calibration curve, regardless of the type of analysis compound. As a result, it is now possible to analyze compounds that were difficult to analyze by FID until now.

News from LabRulezGCMS Library - Week 47, 2025

<h4>Abstract&nbsp;</h4>The United States Environmental Protection Agency (USEPA) Method 8260 is used in order to ascertain volatile organic compounds in waters, soils and solid waste samples. Often times, soil and solid waste samples are so highly contaminated the sample needs to be dispersed in methanol. Sample collection for contaminated soils can be obtained in two ways. One, dispersing a bulk soil sample into a 40ml vial and adding methanol in the lab or two, sending preweighed vials with a septum sealed cap that already contains the pre-requisite methanol out in the field for soil sampling. No matter how the soil sample is dispersed in methanol, an aliquot of the methanol extract needs to be added to water and purged using USEPA Method 5030. This application will investigate automated sampling of methanol soil extractions.Introduction: Environmental labs are required to perform methanol extractions on highly contaminated solid waste samples. Additionally, these extractions are used for difficult matrices, for example oily waste samples, that are also soluble in methanol. Due to the variety of matrices that can be extracted with methanol there are assorted hurdles to cross in order to automate the sampling process. One of these obstacles is how the matrix can absorb the extraction solvent. For example, many soil samples require more methanol; due to the soil expanding with the solvent addition. Adding more methanol aids in rectifying this issue however, when automating sampling, the added methanol coupled with the soil expansion needs to be accommodated. For this reason, EST Analytical created software for the Centurion WS that allows the user to program the needle depth to different distances. In doing this, laboratories are able to sample soils at higher depths in order to adjust for sample absorption and at lower depths for samples that do not require the added solvent. In order to test volatile compounds in methanol extractions, a portion of the extract needs to be sampled from the vial, diluted, and purged on a purge and trap concentrator. This examination will look at the automated sampling of three different soil matrices.<h4>Experimental</h4>The <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2159">Centurion WS autosampler</a> with the syringe option and the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2160">Evolution purge and trap concentrator</a> were set up to run methanol extractions. Since this is a volatile analysis, a Vocarb 3000 (K) trap was used for the analytical trap. The sampling system was configured to an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7890A">Agilent 7890A Gas Chromatograph (GC) </a>and an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=5975C">Agilent 5975C inert XL Mass Spectrometer (MS)</a>. The column selected for this analysis was a Restek Rxi®-624 Sil MS, with dimensions of 30m x 0.25mm I.D. x 1.4µm film thickness. Experimental parameters used for this analysis are listed below.<h5>Purge and Trap Parameters</h5><ul><li>Concentrator: EST Encon Evolution</li><li>Trap type: Vocarb 3000</li><li>Valve oven temperature: 150 °C</li><li>Transfer line temperature: 150 °C</li><li>Trap temperature: 35 °C</li><li>Moisture Reduction Trap (MoRT) temperature: 39 °C</li><li>Purge time: 11 min</li><li>Purge flow: 40 mL/min</li><li>Dry purge Temp.: Ambient</li><li>Dry Purge Flow: 40mL/min</li><li>Dry Purge Time: 1.0 min &nbsp;</li><li>Desorb pressure Control: ON</li><li>Desorb Pressure: 6psi</li><li>Desorb time: 0.5 min</li><li>Desorb preheat delay: 15 sec</li><li>Desorb temperature: 260 °C</li><li>MoRT bake temperature: 210 °C</li><li>Bake temperature: 270 °C</li><li>Sparge vessel bake temperature: 120 °C</li><li>Bake time: 8 min</li><li>Bake flow: 85 mL/min</li></ul><h5>Purge and Trap Auto-Sampler: EST Centurion WS</h5><ul><li>Sample Type: Water</li><li>Water Volume: 5ml</li><li>Sample Prime Time: 5 sec</li><li>Loop Equilibration Time: 5 sec</li><li>Sample Transfer Time: 15 sec.</li><li>Syringe Rinse: On/6 ml</li><li>Number of Syringe Rinses: 2</li><li>Sample Loop Rinse: On/15 sec</li><li>Sample Sweep Time: 15 sec</li><li>Number of Sparge Rinses: On/2</li><li>Rinse Volume: 5 ml</li><li>Rinse Transfer Time: 15 sec</li><li>Rinse Drain Time: 25 sec</li><li>Internal Standard Vol.: 5 µl</li><li>Extraction: MeOH Prep A (Sand and Clay)</li><li>Extraction: MeOH Prep B (Potting Soil)&nbsp;</li></ul><h5>GC/MS Parameters</h5><ul><li>System: <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7890%2F5975">Agilent 7890/5975</a></li><li>Inlet: Split/splitless mode, 220 °C, 40:1 split ratio, 12.153 psi inlet head pressure</li><li>Column: Rxi-624Sil MS 30m x 0.25mm I.D. 1.4µm film thickness</li><li>Oven program: 45 °C (1 min) → ramp 15 °C/min → 220 °C, hold for 1.33 min, 14 min run time</li><li>Column flow rate: 1 mL/min helium</li><li>Total flow: 44.0 mL/min</li><li>Source temperature: 230 °C</li><li>Quadrupole temperature: 150 °C</li><li>Transfer line temperature: 180 °C</li><li>Scan range: m/z 35–300, 5.2 scans/sec</li><li>Solvent delay: 0.7 min</li></ul>The EPA method 8260 standards were acquired from Restek while the purge and trap grade methanol was procured from JTBaker. A nine point methanol curve was established from 0.5 to 200µg/L. Next Method Detection Limits (MDLs) were found running seven replicates of the low point on the curve. Precision and accuracy was determined by examining seven replicates of the 50µg/L standard. Table 3 displays the curve, MDL and precision and accuracy results. A set of three spiked sand matrix samples were used to establish the accuracy of the automated extraction at a 50µg/L concentration, see Table 4.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Table_3_Curve_MDL_and_Precision_and_Accuracy_Results_38f2c858a9.jpg" alt="EST Analytical: Table 3 - Curve, MDL and Precision and Accuracy Results." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Table_3_Curve_MDL_and_Precision_and_Accuracy_Results_38f2c858a9.jpg 159w," sizes="100vw" width="1102" height="1083"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Table_4_Results_of_Automated_Extraction_of_a_Sand_Matrix_3874d74191.jpg" alt="EST Analytical: Table 4 - Results of Automated Extraction of a Sand Matrix" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Table_4_Results_of_Automated_Extraction_of_a_Sand_Matrix_3874d74191.jpg 91w," sizes="100vw" width="741" height="1267">Finally, sand, clay and soil matrices were extracted in order to compare the chromatography of the automated extractions using different matrices. The matrix comparison required 5 grams of soil and 15mls of methanol due to the potting soils’ absorption of the methanol. Thus, in order to make a direct comparison, all of the matrices were spiked with the same volume of standard and extracted with 15mls of methanol. Figure 1 displays a comparison of the three matrices and their respective interaction with the extraction solvent and Figure 2 shows the chromatograms of the three matrices.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_1_Image_of_5g_of_soil_matrices_in_15mls_of_Methanol_fc02a00c9d.jpg" alt="EST Analytical: Figure 1 - Image of 5g of soil matrices in 15mls of Methanol" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_1_Image_of_5g_of_soil_matrices_in_15mls_of_Methanol_fc02a00c9d.jpg 185w," sizes="100vw" width="565" height="477"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_2_Chromatograms_of_Automated_Extraction_of_Sand_Clay_and_Soil_53e50f4fc4.jpg" alt="EST Analytical: Figure 2 - Chromatograms of Automated Extraction of Sand, Clay and Soil" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_2_Chromatograms_of_Automated_Extraction_of_Sand_Clay_and_Soil_53e50f4fc4.jpg 245w," sizes="100vw" width="1396" height="702"><h4>Conclusions</h4>The system produced excellent results. The curve and the compound response factors met all of the method requirements. The overall precision was less than 5% RSD while the system showed an average recovery of 94%. When examining the expected analyte concentration to the extracted sand results, it was found that the average recovery was approximately 102%. Thus, the automated extraction performed extremely well. When comparing the three different matrices it was found that they all displayed similar recoveries, however the sand matrix did perform the best of the three as expected since sand tends not to absorb analytes as readily as other matrices. Finally, the ability to control the needle depth on extraction samples was a great benefit for the different matrices as the system exhibited no issues with needle clogging due to the higher needle depth when performing the potting soil extractions. As demonstrated from this study, the Centurion WS automated extraction capability would be an asset to any lab performing extractions.

Automated Sampling of Methanol Extractions 

<h4>Abstract</h4>Desorb flow control was developed in order to help manage the moisture associated with the four minute desorb time required for USEPA method 524.2. An added benefit to this process is the reduction in helium consumption when using this technique. This application will explain the patented process of Desorb Flow Control (DFC) (United States Patent Office numbers: 8062905, 7951609, 7803635) for Helium conservation and moisture control.&nbsp;<h4>Introduction</h4>Helium has been an essential component in environmental testing for years. Since Helium is an inert gas with a similar diffusion speed as Hydrogen, it is ideal for using as a carrier gas in Gas Chromatography. In recent years, however, there has been an increasing shortage of Helium, leading laboratories to come up with different ways of conservation.&nbsp;Desorb Flow Control was developed to assist laboratories routinely running for USEPA Method 524.2. Method 524.2 requires a four minute desorb and laboratories are reporting issues with water when using the long desorb time. By using DFC, labs are now able to keep the required four minute desorb time and control the amount of water transferred to the GC by decreasing the flow through the trap during desorb while maintaining the desired split ratio at the GC inlet. Subsequently, DFC not only controls the amount of water transferred, but also decreases Helium consumption. See Figures 1 and 2.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_1_Traditional_GC_Flow_ebb2a6357c.jpg" alt="EST Analytical: Figure 1 - Traditional GC Flow" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_1_Traditional_GC_Flow_ebb2a6357c.jpg 245w," sizes="100vw" width="1106" height="553"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_2_GC_Flow_with_Encon_Evolution_using_DFC_5af219d179.jpg" alt="EST Analytical: Figure 2 - GC Flow with Encon Evolution using DFC" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_2_GC_Flow_with_Encon_Evolution_using_DFC_5af219d179.jpg 245w," sizes="100vw" width="1389" height="684"><blockquote>(NOTE: The Encon Evolution provides the increased flow after the trap during desorb at a set time in the desorb process.)&nbsp;</blockquote>The advent of more efficient purge and trap systems and more sensitive GC/MS systems has aided in laboratories’ production. However, water control is still an issue. Labs may pass an initial calibration curve, but as water builds up in the system, internal standard response drops over time, causing the laboratory to fail continuing calibration checks. In order to combat water, many labs use a high split rate. As a consequence, Helium consumption is much higher and sensitivity is decreased. Using DFC, labs can still achieve the moisture control required thus creating a more stable system and lowering Helium consumption by as much as 80%, depending on the experimental split rate. See Table 1. *The table below assumes a throughput of 72 samples per day.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Table_1_Daily_Helium_Consumption_ee240f3668.jpg" alt="EST Analytical: Table 1 - Daily Helium Consumption" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Table_1_Daily_Helium_Consumption_ee240f3668.jpg 245w," sizes="100vw" width="1454" height="323"><h4>Experimental</h4>The sampling system used for this study was the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2160">EST Analytical Encon Evolution concentrator</a> and the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2159">Centurion WS autosampler</a>. The concentrator was affixed with a Vocarb 3000 trap and connected to an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7890A">Agilent 7890A GC</a> and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=5975C">5975C inert XL MS</a>. The GC was configured with a Restek Rxi-624 Sil MS 30m x 0.25mm x 1.4µm column. Two different split ratios were used for comparison in this study, a 40:1 split rate was used for the baseline data and a 10:1 split rate was used for the DFC data. Experimental parameters used for this analysis are listed below.<h5>Purge and Trap Parameters</h5><ul><li>Concentrator: EST Encon Evolution</li><li>Trap type: Vocarb 3000</li><li>Valve oven temperature: 150 °C</li><li>Transfer line temperature: 150 °C</li><li>Trap temperature: 35 °C</li><li>Moisture Reduction Trap (MoRT) temperature: 39 °C</li><li>Purge time: 11 min</li><li>Purge flow: 40 mL/min</li><li>Dry purge Temp.: Ambient</li><li>Dry Purge Flow: 40mL/min</li><li>Dry Purge Time: 1.0 min &nbsp;</li><li>Desorb pressure Control: ON</li><li>Desorb Pressure: 13.5 psi</li><li>Desorb time: 4.0 min</li><li>Desorb preheat delay: 10 sec</li><li>Desorb temperature: 250 °C</li><li>MoRT bake temperature: 210 °C</li><li>Bake temperature: 260 °C</li><li>Sparge vessel bake temperature: 110 °C</li><li>Bake time: 8 min</li><li>Bake flow: 85 mL/min</li></ul><h5>Purge and Trap Auto-Sampler: EST Centurion WS</h5><ul><li>Sample Type: Water</li><li>Water Volume: 25ml</li><li>Internal Standard Vol.: 5 µl</li></ul><h5>GC/MS Parameters</h5><ul><li>System: <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7890%2F5975">Agilent 7890A/5975</a></li><li>Inlet: Split/splitless mode, 200 °C, 40:1 and 10:1 split ratio, 7.45 psi inlet head pressure</li><li>Column: Rxi-624Sil MS 30m x 0.25mm I.D. 1.4µm film thickness</li><li>Oven program: 40 °C (1.5 min) → ramp 8 °C/min → 100 °C, ramp 20 °C /min to 210 °C, hold for 1.25 min, 16.5 min run time</li><li>Column flow rate: 1 mL/min helium</li><li>Total flow: 13.8 and 43.8 mL/min</li><li>Source temperature: 230 °C</li><li>Quadrupole temperature: 150 °C</li><li>Transfer line temperature: 180 °C</li><li>Scan range: m/z 35–300, 3.12 scans/sec</li><li>Solvent delay: 1.0 min</li></ul>The USEPA Method 524.2 standards were acquired from AccuStandard. The linear ranges of the experiments were established by running eight point calibration curves from 0.5 to 100ppb. Table 4 displays curve linearity and compound response for the curves. Figure 3 displays chromatograms of the 20ppb calibration point with and without DFC. Finally, an experiment was run using Selective Ion Monitoring (SIM) of m/z 20 with and without DFC. This was done in order to show water control using D2O as the compound of interest so as not to SIM for water and overwhelm the MS. Figure 4 displays the results of this experiment.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Table_4_Curve_Linearity_and_Compound_Response_Summary_7303558674.jpg" alt="EST Analytical: Table 4 - Curve Linearity and Compound Response Summary" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Table_4_Curve_Linearity_and_Compound_Response_Summary_7303558674.jpg 107w," sizes="100vw" width="684" height="1003"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_3_20ppb_Chromatograms_With_and_Without_DFC_bebdb4c00f.jpg" alt="EST Analytical: Figure 3 - 20ppb Chromatograms With and Without DFC" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_3_20ppb_Chromatograms_With_and_Without_DFC_bebdb4c00f.jpg 245w," sizes="100vw" width="1383" height="518"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_4_Overlay_of_D2_O_mz_20_With_and_Without_DFC_701bb4011c.jpg" alt="EST Analytical: Figure 4 - Overlay of D2O mz 20 With and Without DFC" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_4_Overlay_of_D2_O_mz_20_With_and_Without_DFC_701bb4011c.jpg 143w," sizes="100vw" width="939" height="1026"><h4>Conclusions</h4>The results of this study show the patented Desorb Flow Control is an exceptional tool for conserving helium and creating a more stable system. The option of maintaining the desired split ratio at the GC inlet while decreasing the flow through the trap during desorb provides sensitivity while controlling the amount of moisture being sent onto the GC column. Furthermore, the split rate during the GC/MS run time is substantially lower than during the desorb time. Laboratories can have the advantage of running a higher split rate during the desorb process then maintaining a lower split during the rest of the GC/MS separation and analysis, thus providing laboratories with up to an 80% reduction in GC/MS helium use.

Benefits of Using Desorb Flow Control with the Encon Evolution

For more than 30 years, oxygenated compounds have been added to gasoline. The use of oxygenates provides two primary benefits: a reduction in pollution caused by vehicle emissions, as oxygenated gasoline burns more efficiently, and an improvement in overall engine performance.However, the prolonged use of oxygenated compounds has also led to environmental concerns. Increased contamination of groundwater has been observed, primarily due to leaks from underground storage tanks, allowing oxygenates to migrate into soil and water. In addition, because these compounds are highly soluble in water, analytical methods must be carefully optimized to achieve adequate detection limits.<h4>Discussion</h4>This application note investigates purge-and-trap experimental conditions to determine the most efficient and accurate approach for purging highly soluble fuel oxygenates. The study focuses on evaluating the effects of sample volume and purge temperature on analytical performance.The parameters examined include purge volumes of 5 mL, 10 mL, and 25 mL, as well as purge temperatures at room temperature and 60 °C. Experimental results were compared in terms of calibration range, linearity, method detection limits (MDLs), and compound response.A key feature of this study is the use of the EST Encon Evolution purge-and-trap concentrator, which provides enhanced control over moisture introduction into the GC system. Unlike conventional concentrators, the Encon Evolution employs an 8-port valve design that transfers analytes directly from the analytical trap to the GC via the transfer line, while excluding the Moisture Reduction Trap (MoRT) from the desorption pathway. This design is particularly advantageous when operating at elevated purge temperatures, as was required in this study. Flow paths for purge and desorption are illustrated in Figures 1 and 2.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Purge_and_Desrob_Flow_Path_f7c9fec3a8.jpg" alt="EST Analytical: Figure 1 &amp; 2: Purge and Desrob Flow Path" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Purge_and_Desrob_Flow_Path_f7c9fec3a8.jpg 245w," sizes="100vw" width="1141" height="568"><h4>Experimental</h4><h5>Instrumentation</h5>The sampling and concentration system consisted of an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2159">EST Analytical Centurion WS autosampler</a> coupled to an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2160">EST Encon Evolution purge-and-trap concentrator</a>. Experiments were conducted in water mode.The concentrator was configured with a VOCARB 3000 trap and interfaced to an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7890A">Agilent 7890A gas chromatograph</a> equipped with a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=5975C">5975 inert XL mass spectrometer</a>. GC/MS operating parameters were selected to support EPA Method 8260 analysis.<h5>Purge and Trap Parameters</h5><ul><li>Concentrator: EST Encon Evolution</li><li>Trap type: Vocarb 3000</li><li>Valve oven temperature: 150 °C</li><li>Transfer line temperature: 150 °C</li><li>Trap temperature: 35 °C</li><li>Moisture Reduction Trap (MoRT) temperature: 39 °C</li><li>Purge time: 11 min</li><li>Purge flow: 40 mL/min</li><li>Dry purge Temp.: Ambient</li><li>Dry Purge Flow: 40mL/min</li><li>Dry Purge Time: 1.0 min &nbsp;</li><li>Desorb pressure Control: ON</li><li>Desorb Pressure: 12 psi</li><li>Desorb time: 1.0 min</li><li>Desorb temperature: 250 °C</li><li>MoRT bake temperature: 150 °C</li><li>Bake temperature: 265 °C</li><li>Sparge vessel bake temperature: 130 °C</li><li>Bake time: 8 min</li><li>Bake flow: 40 mL/min</li></ul><h5>GC/MS Parameters</h5><ul><li>System: <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7890%2F5975">Agilent 7890A/5975</a></li><li>Inlet: Split/splitless mode, 200 °C, 40:1 split ratio, 17.311 psi inlet head pressure</li><li>Column: Rtx-624 20m x 0.18mm I.D. 1µm film thickness</li><li>Oven program: 45 °C (1 min) → ramp 18 °C/min → 220 °C, hold for 0.3 min</li><li>Column flow rate: 0.8 mL/min helium</li><li>Total flow: 38.8 mL/min</li><li>Source temperature: 230 °C</li><li>Quadrupole temperature: 150 °C</li><li>Transfer line temperature: 180 °C</li><li>Scan range: m/z 35–265, 3.12 scans/sec</li><li>Solvent delay: 0.7 min</li></ul><h4>Standards and Calibration</h4>Oxygenate standards were obtained from Restek. The California oxygenate mixture included:<ul><li>Diisopropyl ether (DIPE)</li><li>Ethyl tert-butyl ether (ETBE)</li><li>tert-Amyl methyl ether (TAME)</li><li>tert-Butyl alcohol (TBA)</li><li>Methyl tert-butyl ether (MTBE)</li></ul>Most ether compounds were prepared at 2000 µg/mL, while TBA was prepared at 10,000 µg/mL. Ethanol standards were also obtained from Restek at 10,000 µg/mL.Calibration curves consisted of nine concentration levels, ranging from 0.5 to 200 ppb for ether compounds and 2.5 to 1000 ppb for TBA and ethanol. Method detection limits were determined using seven replicate injections at low calibration levels.<h4>Results and Discussion</h4>Evaluation of purge volume and purge temperature demonstrated that increasing sample volume resulted in improved compound response. Additionally, the use of a heated purge at 60 °C significantly enhanced the response of polar compounds, particularly ethanol and TBA, with ethanol response more than doubling under heated purge conditions.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Table_3_Sample_Volume_and_Temperature_Experimental_Results_Summary_ace694091d.jpg" alt="EST Analytical: Table 3: Sample Volume and Temperature Experimental Results Summary" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Table_3_Sample_Volume_and_Temperature_Experimental_Results_Summary_ace694091d.jpg 245w," sizes="100vw" width="1600" height="372">While larger sample volumes generally increased sensitivity, the 10 mL sample volume combined with a 60 °C purge temperature provided the best balance of sensitivity, linearity, and chromatographic performance. This condition also produced the most consistent linear calibration range, especially for ethanol, which is traditionally difficult to analyze using purge-and-trap techniques.Chromatograms comparing room-temperature purge and heated purge conditions (Figures 3 and 4) clearly illustrate the improved peak response and signal stability achieved with heated purging.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_3_50ppb_Chromatogram_with_Room_Temperature_Purge_8ea1cd120f.jpg" alt="EST Analytical: Figure 3: 50ppb Chromatogram with Room Temperature Purge" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_3_50ppb_Chromatogram_with_Room_Temperature_Purge_8ea1cd120f.jpg 245w," sizes="100vw" width="1548" height="688"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_4_50ppb_Chromatogram_with_60_C_Purge_5246c294e6.jpg" alt="EST Analytical: Figure 4: 50ppb Chromatogram with 60 °C Purge" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_4_50ppb_Chromatogram_with_60_C_Purge_5246c294e6.jpg 245w," sizes="100vw" width="1513" height="773"><h4>Full 8260 and California Oxygenate Analysis</h4>Following optimization, a full EPA Method 8260 calibration and validation was performed using the selected conditions (10 mL sample volume, 60 °C purge). Method performance was evaluated for linearity, precision (%RSD), recovery, and detection limits across the complete compound list.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Table_4_Summary_of_8260_and_California_Oxygenate_Data_614adf67d6.jpg" alt="EST Analytical: Table 4: Summary of 8260 and California Oxygenate Data" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Table_4_Summary_of_8260_and_California_Oxygenate_Data_614adf67d6.jpg 211w," sizes="100vw" width="1600" height="1187"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_5_50ppb_Standard_of_8260_and_Fuel_Oxygenates_5edd5bd337.jpg" alt="EST Analytical: Figure 5: 50ppb Standard of 8260 and Fuel Oxygenates" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_5_50ppb_Standard_of_8260_and_Fuel_Oxygenates_5edd5bd337.jpg 245w," sizes="100vw" width="1219" height="560"><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/EST_Analytical_Figure_6_Extracted_Ion_Chromatogram_of_the_50_ppb_Standard_of_the_Fuel_Oxygenate_Compounds_in_the_8260_Mix_1e1684dbca.jpg" alt="EST Analytical: Figure 6: Extracted Ion Chromatogram of the 50 ppb Standard of the Fuel Oxygenate Compounds in the 8260 Mix" srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_EST_Analytical_Figure_6_Extracted_Ion_Chromatogram_of_the_50_ppb_Standard_of_the_Fuel_Oxygenate_Compounds_in_the_8260_Mix_1e1684dbca.jpg 245w," sizes="100vw" width="1188" height="561">Results demonstrated that the system met or exceeded all method performance criteria. Recoveries and precision were within acceptable limits for both volatile organic compounds and oxygenates, confirming suitability for regulatory compliance applications.<h4>Conclusions</h4>Overall, fuel oxygenate compounds exhibited higher responses with increased sample volume, while purge temperature had the greatest impact on polar analytes, particularly ethanol and TBA. The heated purge at 60 °C, combined with a 10 mL sample volume, produced optimal linearity and sensitivity.The EST Encon Evolution purge-and-trap system, equipped with a Moisture Reduction Trap (MoRT), proved to be highly effective for fuel oxygenate analysis. The system demonstrated excellent moisture control, robust analyte transfer, and reliable performance for both California oxygenates and full EPA 8260 compound lists. In all cases, method performance met or exceeded regulatory requirements.

California Oxygenates and 8260

Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 22nd December 2025? Check out new documents from the field of the gas phase, especially GC and GC/MS techniques!<blockquote>👉 <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library">SEARCH THE LARGEST REPOSITORY OF DOCUMENTS ABOUT GCMS AND RELATED TECHNIQUES</a></blockquote><blockquote>👉 Need info about different analytical techniques? Peek into <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library">LabRulezLCMS</a> or <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library">LabRulezICPMS</a> libraries.</blockquote>This week we bring you application notes by Agilent Technologies, EST Analytical and Shimadzu!<h3>1. Agilent Technologies: Analysis of Ethylene or Propylene Stream Cracking Gas Products</h3>Using the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=990+micro">Agilent 990 Micro GC</a><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_ethylene_propylene_stream_cracking_gas_products_5994_8803en_agilent_0cfe53e8f7.pdf">Full PDF for download</a></li></ul>Ethylene or propylene cracking gas products are produced from various feedstocks, including naphtha, light naphtha, atmospheric diesel, depressurized diesel, hydrotreating tail oils, ethane, and liquefied petroleum gas, among others.&nbsp;During gas cracking, yields of ethylene or propylene products should be monitored to measure the effectiveness of the process. The results of these analyses provide important process control data for optimizing cracking production and improving cracking yield—a key process parameter for cracking plants. Common cracking gas products are composed of hydrogen (H2 ), nitrogen (N2), and light hydrocarbons such as ethylene (C2H4), ethane (C2H6), propylene (C3H6), propane (C3H8), and 1-butene (C4H8), among&nbsp;others.&nbsp;The <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=990+micro">Agilent 990 Micro GC</a> enables fast and accurate detection of ethylene or propylene stream cracking gas products, a fundamental measure for determining the effectiveness of the cracking process. The system's demonstrated utility in refinery gas analysis further supports its suitability.<h4>Conclusion&nbsp;</h4>This study demonstrates the applicability of the Agilent 990 Micro GC for analyzing ethylene or propylene stream cracking gas products, providing essential process control data for optimizing cracking production and yield. Quantitation precision was evaluated through 10&nbsp;consecutive analyses of calibration standard gases, showing retention time (RT) repeatability (%RSD) less than 0.1% and area repeatability (%RSD) less than 1.0% for all compounds. These results confirm the instrument's excellent performance in reliably qualifying and quantifying these stream cracking gas&nbsp;products.<h3>2. EST Analytical: Purge and Trap Extraction of Tea Flavor Components</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/Purge_and_Trap_Tea_Flavor_Analysis_by_Purge_and_Trap_9bb392c2c1.pdf">Full PDF for download</a></li></ul>Purge and Trap (P&amp;T) sampling is a universally accepted technique for the analysis of volatile compounds in water. The United States Environmental Protection Agency (USEPA), the World Health Organization (WHO) and the American Society for Testing and Materials (ASTM) have all published methods using P&amp;T for water matrices. However, food and flavor manufacturers have yet to use this technique for the analysis of the volatile flavor components of their products. SPME has become the more accepted technique for flavor analysis.&nbsp;Both SPME and P&amp;T have their limitations. P&amp;T is recommended for volatile analytes and does not work when compounds have higher boiling points. Still, P&amp;T is a reliable technique that has the ability to purge out all of the volatile analytes of a system and detect very low concentrations of those analytes. On the other hand, SPME can be used for sampling a larger amount of semi-volatile compounds and fiber coating selection aids in better discrimination of analyte sampling. Yet, SPME is not an exhaustive sampling technique thus there are detection limitations to the technique. This application note will examine the analysis of white tea samples using P&amp;T sampling.&nbsp;<h4>Experimental</h4>The <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2160">EST Analytical Evolution Purge and Trap</a> was set up with a Vocarb™ 3000 trap while the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2159">Centurion WS autosampler </a>was set to run in soil mode. The sampling system was configured to an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7890">Agilent 7890A Gas Chromatograph (GC) </a>and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=5975C">5975C inert XL Mass Spectrometer (MS) </a>for separation and analysis. As the compounds of interest for this analysis were volatile, a Restek Rxi® 624 Sil MS 30m X 0.25mm X 1.8um column was affixed in the GC. Sampling and analysis parameters were optimized and are listed in Tables 1 and 2.<h4>Conclusions</h4>Using purge and trap to evaluate the flavor compounds of the tea samples was a reliable sampling technique. The findings were repeatable and the chromatography was excellent. The resulting flavor compounds were easily purged out of the tea matrix and as the technique is exhaustive, there was excellent detection of the flavor compounds in the system. This sampling technique established purge and trap to be an exceptional method for the determination of volatile analytes in tea.<h3>3. Shimadzu: Real-Time Measurement of CH4 and CO2 Concentrations for Estimating Methane Emissions from Rice Fields</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_01_00887_en_adf24e951d.pdf">Full PDF for download</a></li></ul><h5>User Benefits</h5><ul><li>The portability of this gas analyzer means the user can decide where to place it, such as near a rice field, to continuously measure CH4 and CO2 emissions.&nbsp;</li><li>The CGT-7100 analyzer unit has a built-in pump, filter, dehumidifier, and other sample pretreatment equipment, so it does not require other equipment to perform measurements.</li><li>Data can be stored on a USB flash drive for easy editing on a computer or sharing with other departments.</li></ul>CH4 is a gas that has a greenhouse effect about 28 times greater*1 than CO2. One source of CH4 gas emissions is flooded rice fields. They release the CH4 gases generated by microorganisms living in the soil into the atmosphere. Since CH4 emissions from rice fields account for a significant proportion of greenhouse gases emitted from the agriculture, forestry, and fishery industry, various measures are being implemented to reduce emissions, such as managing the water and soil used in rice fields and improvingthe fertilizers used.&nbsp;The closed chamber method measures variations in gas concentrations due to gases exchanged with plants, such as rice. 1) In this article, a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=CGT-7100">CGT-7100</a> portable gas analyzer measures the concentration of CH4 and CO2 generated inside a specialized chamber placed on the surface of rice paddy soil.<h4>CH4 Emitted from Rice Fields&nbsp;</h4>The amount of CO2 emitted from a rice field depends on the amount breathed (emitted) from the rice plant and photosynthesized (absorbed), whereas the amount of CH4 emitted depends on the microorganisms in the soil. Fig. 2 illustrates the process of CH4 emission from rice fields. The microorganisms generate CH4 by decomposing organic matter in the soil. When a rice field is flooded with water, the supply of oxygen to the soil stops and anaerobic microorganisms actively generate CH4. It is thought that the generated CH4 is emitted into the atmosphere via two pathways. One pathway is via the roots and stalks of the rice plants (pathway 1).2),3) Due to the functions of the microorganisms, CH4 concentrations in the soil become higher than inside the plant, resulting in a concentration gradient that dissolves into the root cells. The dissolved CH4 becomes a gas within the narrow gaps between cells and moves along the gaps to the leaf sheath above ground. Pores on the leaf surface then discharge the CH4 into the atmosphere. In the other pathway (pathway 2), CH4 in the soil forms bubbles that are released directly into the atmosphere without passing through the rice plant. Pathway 1 increases the CH4 concentration inside the chamber by a certain proportion, but the quantity and frequency of CH4 emissions via pathway 2 are not clearly known, so there is an element of uncertainty about the estimated quantity of CH4 emitted from rice fields4). Therefore, the frequency that bubbles formed was estimated by analyzing the CH4 concentration measurement results to determine how quickly the CH4 concentration increasedper unit area (methane flux).<h4><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=CGT-7100">CGT-7100 Portable Gas Analyzer&nbsp;</a></h4>The CGT-7100 is an all-in-one portable continuous gas concentration measuring system (Fig. 3). Because the compact main unit includes a pretreatment unit with a built-in electronic cooler for removing water moisture, a filter for removing dust, and a pump for suctioning sample gas into the analyzer system, the analyzer can be operated independently*2. Up to three components can be selected for measurement. In addition to two of the CO2, CO, and CH4 components being measured by the non-dispersive infrared absorption (NDIR) method, one component can also be selected for measurement by an O2 analyzer (optional), based on the limiting current type zirconia method. Changes in concentrations over time can be monitored with a wide range of measurements, from ppm to vol%. With the minimum sample gas flowrate of 100 mL/min (optional), gas concentrations can be measured in small sample quantities, and the sample gas flowrate can be varied within the range of 100 to 400 mL/min. As shown in the measurement process flow diagram below, samples can also be measured without losses by including a recirculation system that returns the sample gas discharged from the analyzer to the measurementlocation (inside the chamberin this case).<h4>Non-Dispersive Infrared Absorption (NDIR) Method&nbsp;</h4>The CGT-7100 uses the non-dispersive infrared absorption (NDIR) method for measurements. CO2 and other heteronuclear gases have unique infrared light absorption spectra. Gas concentrations can be measured selectively by passing infrared light through the sample gas and using the detector to measure the quantity of infrared light in the absorption band that is unique to a given type of gas. Robust and reliable measurements are achieved with the optical system in the NDIR unit, which has an excellent track record among online gas analyzers.<h4>Conclusion&nbsp;</h4>This article describes an example of using a CGT-7100 portable gas analyzer to estimate the amount of CH4 and CO2 emitted from a rice field by continuously measuring CH4 and CO2 concentrationsinside the chamberplaced in a rice paddy.&nbsp;Since the CGT-7100 is a continuous gas analyzer, it is ideal for measuringchangesin gas concentrationsin realtime. The CGT-7100 can be used to observe changes in the levels of CH4 and CO2 or the effects of bubble formation when implementing rice field water and soil management or fertilizer improvement measures.&nbsp;With its built-in sample gas pretreatment and sampling functionality, gas concentrations can be conveniently measured without the need for additional equipment, and the portability of the analyzer means it can measure gas concentrations in a wide variety of locations. If used with a communication unit, measurement data can be viewed and saved remotely via a computer or tablet to accommodate a wide range of testing and research applications.

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EST Analytical

European Symposium on Analytical Spectrometry (ESAS) 2026

2026 AOAC INTERNATIONAL Annual Meeting & Exposition

Shimadzu at 2026 AOAC Annual Meeting & Exposition

ICP-MS for Hybrid Photoelectrode Characterization

Modern Methods for Faster Microbial Analysis

Addressing LC Method Optimization - Scaling For Efficiency, Throughput And Reproducibility