<p><strong>Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 6th April 2026? Check out new documents from the field of the gas phase, especially GC and GC/MS techniques!</strong></p><blockquote><p><span style="font-size:20px;">👉 </span><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library"><span style="font-size:20px;"><strong>SEARCH THE LARGEST REPOSITORY OF DOCUMENTS ABOUT GCMS AND RELATED TECHNIQUES</strong></span></a></p></blockquote><blockquote><p><strong>👉 Need info about different analytical techniques?</strong> Peek into <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library"><strong>LabRulezLCMS</strong></a> or <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library"><strong>LabRulezICPMS</strong></a> libraries.</p></blockquote><p>This week we bring you application notes by <strong>Agilent Technologies, BaySpec, </strong>poster by <strong>MDCW / William &amp; Mary </strong>and<strong> </strong>brochure by<strong> Shimadzu!</strong></p><h3><strong>1. Agilent Technologies: High-Throughput BTEX Analysis in Nail Products by SPME and GC/TQ</strong></h3><p><strong>Minimal steps, maximum precision</strong></p><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_btex_analysis_nail_products_spme_gctq_5994_9009en_agilent_24ef32dd13.pdf"><strong>Full PDF for download</strong></a></li></ul><p>BTEX compounds—benzene, toluene, ethylbenzene, and xylenes—are volatile aromatic hydrocarbons widely used as solvents in industrial and consumer products. Among these, toluene is the most prevalent in nail polish formulations, where it serves as a solvent to dissolve resins and pigments, ensuring smooth application, uniform color dispersion, and rapid drying. Historically, these properties made toluene a preferred ingredient in nail coatings, including traditional polishes, gel formulations, and nail art products. However, its inclusion presents challenges for regulatory compliance and product reformulation. In response to these challenges, the California Department of Toxic Substances Control (DTSC) has listed nail products containing toluene as Priority Products under the Safer Consumer Products Regulations.1 Manufacturers selling such products in California must submit a Priority Product Notification and conduct an Alternative Analysis if toluene concentrations exceed the 100-ppm threshold.&nbsp;</p><p>To support compliance and ensure accurate monitoring of BTEX levels in nail products, robust analytical methods are essential. Solid phase microextraction (SPME) coupled with gas chromatography/triple quadrupole mass spectrometry (GC/TQ) has emerged as a preferred approach for volatile organic compound analysis due to its solvent-free sample preparation, high sensitivity, and compatibility with complex cosmetic matrices. The 8890 GC with 7000 Series GC/TQ offers enhanced detection capabilities through dynamic multiple reaction monitoring (dMRM), enabling precise quantification of BTEX compounds at trace levels, below regulatory thresholds. This platform provides the analytical rigor required for method validation, including limits of detection, recovery, and precision, ensuring compliance with California's stringent performance criteria and supporting industry efforts toward improving consumer product&nbsp;quality.&nbsp;</p><h4><strong>Experimental</strong></h4><h5><strong>GC/TQ analysis&nbsp;</strong></h5><p>Analyses were performed on an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=8890+GC"><strong>8890 GC</strong></a> coupled to a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7000"><strong>7000 Series GC/TQ </strong></a>equipped with an EI extractor ion source (Figure 2). The instrument operating parameters are listed in Table 2. The system was operated in splitless mode with an inlet temperature of 200&nbsp;°C, a purge flow of 3 mL/min, and a purge flow to split vent of 50&nbsp;mL/min at 2&nbsp;minutes. Carrier gas was helium at a constant flow of 0.693&nbsp;mL/min with a total flow of 53.7 mL/min. The chromatographic separation was accomplished on an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=DB-624+Ultra+Inert+column"><strong>Agilent J&amp;W DB-624 Ultra Inert column</strong></a> (20&nbsp;m × 0.18&nbsp;mm, 1&nbsp;µm, part number 121-1324UI). The oven program started at 40&nbsp;°C (hold 2&nbsp;minutes), ramped at 35&nbsp;°C/min to 160&nbsp;°C, and held for 2.58&nbsp;minutes, giving a total run time of 8.0&nbsp;minutes. The transfer line was maintained at 230&nbsp;°C, with the ion source at 230&nbsp;°C and quadrupoles at 150&nbsp;°C.</p><h4><strong>Conclusion&nbsp;</strong></h4><p>A rapid, high-throughput headspace‑SPME GC/TQ method was developed for quantifying BTEX in nail product matrices, using a 100-µm PDMS Agilent Smart SPME fiber on an Agilent 8890 GC with Agilent 7000 Series GC/TQ. The method provides solvent-free extraction, 8-minute chromatographic runs, and an ~11-minute total cycle time, enabling high-throughput analysis with robust selectivity in dMRM mode. Quality control results demonstrated mean recoveries of 100 to 107% with RSDs ≤ 8%, meeting method acceptance criteria for compliance-focused testing for toluene. Integration of Smart SPME automation and the intelligent features of the 8890 GC and 7000 Series GC/TQ allows a practical, defensible solution for routine laboratories monitoring BTEX in nail products. Calibration performance showed high linearity and low variance across the working ranges, with all compounds meeting initial calibration criteria via R² ≥ 0.995 or average RF RSD ≤ 20%. Combined with the short cycle time and automated fiber tracking, this workflow is ideally suited for routine compliance testing of BTEX in nail products using the 8890 GC and 7000&nbsp;Series GC/TQ.</p><h3><strong>2. BaySpec: Detection of residual pesticides on fruits and vegetables using Portability miniature mass s pectrometer</strong></h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/Bay_Spec_App_Note_Portability_Pesticides_4a7311fb3e.pdf"><strong>Full PDF for download</strong></a></li></ul><p>Pesticides are used in a variety of different ways during the production of food. Ranging from preventing crop damage by insects, rodents and molds during growth to prolonging storage of food after harvest. Because of the frequent usage, the residual pesticides are often found in many agricultural products and their monitoring and control is an important step in achieving and maintaining overall food safety in the modern society.&nbsp;</p><p>Mass spectrometry in connection with different separation techniques currently represents the main analytical approach for determination of residual pesticides in food. Traditionally, samples need to be collected and send to a laboratory for analysis using techniques such as GC-MS or HPLC-MS, which are costly and time-consuming. In addition, the conventional mass spectrometry usually requires laborious sample pretreatment, which does not allow for immediate in-situ sample determination. Presented here is an application of Thermal Desorption ElectroSpray Ionization (TD-ESI) for pesticide screening coupled to a portable mass spectrometer.&nbsp;</p><p>TD-ESI is a mass spectrometry technique from the family of ambient ionization methods that utilizes very simple probing of different surfaces with no or limited sample pretreatment while it is still noted for its selective and sensitive detection capabilities. In TD-ESI a solid surface or a liquid sample is touched by a simple metallic probe that absorbs the analyte. The probe is then inserted into a heated tube and the desorbed analyte is carried by gas flow into an orthogonally mounted electrospray. The electrospraty plume extracts the analyte and further ionization and ion introduction follows the conventional electrospray mechanism.&nbsp;</p><p><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2219"><strong>Bayspec’s Portability mass spectrometer</strong></a> is less than 10kg highly portable and battery operated linear ion trap mass spectrometer with atmospheric pressure inlet (API). When TD-ESI is combined with PortabilityTM then it is possible to perform fast in-field detection of analytes including residual pesticides, directly of the surfaces of fresh food products without any sample pre-treatment. Fast pesticide screening by Portability mass spectrometer can immediately disclose fake organic food products as well as to discover elevated levels of residual pesticides.&nbsp;</p><p>TD-ESI-MS was used to rapidly screen residual pesticides on the surfaces of different fruits and vegetables. Direct sampling probe was used to introduce analytes from surfaces of unprocessed samples. Due to short analysis times (1-5s a sample), the technique allows for fast screening for applications in food and environmental safety. MS (as well as MS/MS) analyses can be performed on surface-residual pesticides at ppm and sub-ppm levels. The miniaturized TD-ESI ion source compatible with Portability is available from BaySpec. This ion source mounts on the Portability front inlet and does not require any additional support, external power or gases. The simple intuitive software interface is operated by touch screen and makes the instrument extremely easy to control. The external TD-ESI source is fully integrated into the main software environment and the hyphenated system is thus very user-friendly, does not require excessive training and can be operated by persons with no previous mass spectrometry experiences.</p><h3><strong>3. MDCW / William &amp; Mary: Volatile Characterization of American Foulbrood Disease Using Comprehensive Two-Dimensional Gas Chromatography</strong></h3><ul><li>Poster</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/P_15_Christensen_39521e3391.pdf"><strong>Full PDF for download</strong></a></li></ul><p>American foulbrood (AFB) is a deadly disease spread by Paenibacillus larvae bacterial spores, targeting the brood stage of Apis mellifera honey bees. Broods perish in a matter of days after exposure to the spores, forming infected colloidal scales in the hive that adult bees cannot remove. 1,2 The spores are extremely persistent and resistant to typical treatment methods, which standardized the immediate euthanasia of bees and destruction of the hive and associated equipment by burning. 3 In an effort to expedite identification of the spores, scent-detection dogs have been trained for use in apiaries. Furthermore, gammairradiation has been tested as a proposed treatment method as it would offer a nondestructive alternative to sterilization.</p><p>The goals of this study were to use comprehensive two-dimensional gas chromatography – time-of-flight mass spectrometry (GC×GC-TOFMS) to characterize the volatiles associated with AFB disease for understanding scent detection and to measure the effectiveness of gamma-irradiation in sterilizing these volatiles.</p><h4><strong>Methods</strong></h4><p>Samples included blanks, material from healthy comb, aged unsterilized diseased scales, fresh unsterilized diseased scales, and diseased scales sterilized with the proposed treatment method of gamma-irradiation. These samples were stored in headspace vials (Figure 3) in the freezer when not in use. No sample preparation was required before injection with solidphase microextraction using the LPAL-3 (CTC Analytics).</p><p>Analysis was performed using a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/37"><strong>Pegasus BT4D</strong></a> (LECO Corporation) according to the parameters described below in Table 1. <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/41"><strong>ChromaTOF software</strong></a> (LECO Corporation) was used to analyze the chromatographic data. Preliminary identifications were assigned to peaks using a minimum signal to noise of 200 and a minimum stick count of 3.</p><h4><strong>Conclusions</strong></h4><p>GC×GC-TOFMS can be used to distinguish the volatile profiles of A. mellifera samples at different stages of infection with AFB disease. Future Directions for Research:&nbsp;</p><ul><li>Discrimination of volatiles specific to AFB from non-specific volatiles&nbsp;</li><li>Characterization of AFB-specific volatiles for scent-detection purposes&nbsp;</li><li>Measurement of gamma-irradiation sterilization success in removing AFB volatiles</li></ul><h3><strong>4. Shimadzu: Screening System for Phthalate Esters, Brominated Flame Retardants and Other Regulated Substances Py-Screener Ver.3</strong></h3><ul><li>Brochure</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/c146_e507_45f041b0d7.pdf"><strong>Full PDF for download</strong></a></li></ul><p>The <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=Py-Screener"><strong>Py-Screener™ Ver. 3</strong></a> can screen for 7 types of phthalate esters and brominated flame retardants (PBBs, PBDEs), including substances regulated under the RoHS Directive. In addition, it can also test for PIP (3:1), which is regulated under the US TSCA (Toxic Substances Control Act), as well as UV-328, Dechlorane Plus (DP), and short-chain chlorinated paraffins (SCCPs) and medium-chain chlorinated paraffins (MCCPs), which are regulated under the Stockholm Convention (POPs Convention) on Persistent Organic Pollutants (POPs). These regulated compounds, thermally extracted from the sample by Pyrolysis-GC-MS (Py-GC-MS), are selectively detected and quantified. Py-Screener Ver. 3 consists of dedicated software for easy screening, special standard samples, and a sampling tool kit, making it simple to operate even for first-time users.</p><h5><strong>Shimadzu Corporation’s Solutions for Complying with International Hazardous Substance Regulations</strong></h5><p>When manufacturing and exporting products, it is necessary to comply with the chemical and hazardous substance regulations established by each country. Products contain many parts and use various materials and substances. Therefore, it is the manufacturer’s responsibility to manage the entire supply chain to ensure that harmful substances are not contained. Shimadzu Corporation provides analysis solutions that comply with these regulations.</p><h5><strong>Applicable Systems and Software</strong></h5><ul><li><strong>GC-MS: </strong><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=GCMS-QP2020+NX"><strong>GCMS-QP™2020 NX</strong></a>, <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=GCMS-QP2020"><strong>GCMS-QP2020,</strong></a> <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=GCMS-QP2010+Ultra"><strong>GCMS-QP2010 Ultra</strong></a></li><li><strong>Pyrolyzer:</strong> <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=42&amp;search=EGA%2FPY-3030D"><strong>EGA/PY-3030D</strong></a> multi-shot pyrolyzer</li><li><strong>Autosampler:</strong> AS-2020E, <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=42&amp;search=AS-1020E"><strong>AS-1020E auto-shot sampler&nbsp;</strong></a></li><li><strong>GC-MS Workstation:</strong> <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=GCMSsolution"><strong>GCMSsolution</strong></a>™ (Ver. 4.60SP2 or later) + <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=LabSolutions+Insight"><strong>LabSolutions Insight</strong></a>™ (Ver. 5.0 or later)</li><li><strong>Py Workstation:</strong> EGA-PY3030 program (Ver. 1.54 or later)</li></ul>

News from LabRulezGCMS Library - Week 15, 2026

<p><strong>This study describes the development and validation of a dual-column, dual-detector HS-GC-FID/FID method for the forensic analysis of ethanol and other low-molecular-weight volatile compounds in biological samples. The method demonstrated excellent linearity, low detection limits, high precision, and accuracy, and was successfully verified through international proficiency testing.</strong></p><p>In addition to routine forensic application, the study reviews current practices in forensic alcohol analysis and highlights the lack of globally harmonized analytical standards. The authors propose essential methodological recommendations to improve the reliability and evidential value of ethanol determination in forensic toxicology.</p><blockquote><h4><strong>The original article</strong></h4><h4><a target="_blank" rel="noopener noreferrer" href="https://www.mdpi.com/2039-4713/16/3/80"><strong>Dual-Column HS-GC-FID/FID Method for In-Depth Analysis of Low-Molecular-Weight Volatile Alcohols in Postmortem Biological Material&nbsp;</strong></a></h4><p>Paweł Szpot, Olga Wachełko, Kaja Tusiewicz and Marcin Zawadzki</p><p>J. Xenobiot. 2026, 16(3), 80</p><p><a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.3390/jox16030080">https://doi.org/10.3390/jox16030080</a></p><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/"><strong>CC-BY 4.0</strong></a></h6></blockquote><p><strong>Selected sections from the article follow. Formats and hyperlinks were adapted from the original.</strong></p><div><p>The determination of low-molecular-weight volatile alcohols in <span>postmortem</span> material using headspace gas chromatography (HS-GC) is routinely performed in forensic laboratories. These analyses are important not only for law enforcement agencies in the broad sense, but also for insurance companies that decide on the payment of compensation under insurance policies. Typically, routine determination of alcohols such as methanol, ethanol, isopropanol, n-propanol, and n-butanol is sufficient to establish whether death occurred as a result of poisoning with these substances. In forensic toxicology practice, however, there are also situations in which the determination of additional chemical compounds in biological material proves to be essential. One such compound is acetone, the determination of which is crucial not only in cases of acetone or isopropanol poisoning (since acetone is a metabolite of the aforementioned alcohol) [<a target="_blank" rel="noopener noreferrer" href="https://www.mdpi.com/2039-4713/16/3/80#B1-jox-16-00080">1</a>], but also in the diagnosis of ketosis caused by diabetes, hypothermia, or starvation [<a target="_blank" rel="noopener noreferrer" href="https://www.mdpi.com/2039-4713/16/3/80#B2-jox-16-00080">2</a>]. Criminal cases can be complex, and therefore, to achieve a better understanding of the circumstances preceding death, toxicological analyses are sometimes extended to also include other compounds, such as acetaldehyde [<a target="_blank" rel="noopener noreferrer" href="https://www.mdpi.com/2039-4713/16/3/80#B3-jox-16-00080">3</a>].</p><p><span>Postmortem</span> blood toxicological analysis is of particular importance because it plays a key role in determining the cause of death, especially in cases of unexplained sudden death and deaths occurring under suspicious circumstances. Even a simple screening for volatile chemical compounds can, at an early stage, allow determination of whether death resulted from poisoning or was a consequence of an underlying disease suffered by the deceased (e.g., untreated diabetes) [<a target="_blank" rel="noopener noreferrer" href="https://www.mdpi.com/2039-4713/16/3/80#B4-jox-16-00080">4</a>].</p><p>One of the fundamental assumptions in forensic toxicological investigations is that their results must have evidential value and withstand scrutiny in court. Only such results can be used, for example, to reconstruct the circumstances preceding death, determine the time of substance intake or the dose of a toxic agent, or assess whether the deceased was intoxicated. This is particularly important in cases of traffic accidents, occupational accidents, drownings, domestic violence, and deaths occurring during police custody. It is worth emphasizing that the interpretation of <span>postmortem</span> toxicological results requires particular caution due to the multitude of “confounding” factors, such as interindividual variability, substance stability, endogenous formation, the postmortem interval (PMI), and the circumstances of death. To avoid introducing additional variables that could further complicate interpretation, the applied analytical method must be reliable, i.e., accurate, selective, resistant to interference, and preferably verified through independent proficiency testing [<a target="_blank" rel="noopener noreferrer" href="https://www.mdpi.com/2039-4713/16/3/80#B5-jox-16-00080">5</a>].</p><p>In gas chromatographic analysis of low-molecular-weight alcohols, either direct injection or the headspace technique is employed [<a target="_blank" rel="noopener noreferrer" href="https://www.mdpi.com/2039-4713/16/3/80#B6-jox-16-00080">6</a>]. In the past, even highly invasive approaches were used, such as the direct injection of whole blood into the gas chromatograph injector [<a target="_blank" rel="noopener noreferrer" href="https://www.mdpi.com/2039-4713/16/3/80#B7-jox-16-00080">7</a>]. However, the headspace technique has become the most widely used technique for the determination of alcohols in forensic laboratories. This preference can be attributed to several well-established advantages, most notably that the method allows the sample to be analyzed with minimal or no preparatory steps, irrespective of the biological matrix (e.g., without extraction or protein precipitation). Additional benefits include practically negligible matrix effects, elimination of the need for inlet liners, thereby minimizing the risk of contamination or carryover within the analytical system, and reduced deterioration of the chromatographic column compared with direct injection.</p><p>However, it should be noted that in the context of postmortem samples (particularly those collected from putrefied cadavers), the impact of decomposition on analyte partitioning cannot be precisely assessed. While headspace analysis generally exhibits negligible matrix effects, pre-death specimens from the same individual are rarely available for direct comparison, making it difficult to determine the extent to which postmortem changes might influence measurements. Moreover, the blood samples are subjected to multiple dilutions with an internal standard, which further minimizes potential matrix effects.</p><p>Despite numerous established methods for the determination of volatile alcohols in postmortem biological samples, current standard approaches often face limitations that can compromise forensic reliability. Single-column analyses may be prone to co-elution and interferences from structurally similar compounds, while reliance on a single detector increases the risk of undetected fluctuations and errors. Additionally, inappropriate selection of internal standards and postmortem formation of endogenous alcohols and other volatile compounds can further bias quantification. These issues highlight a critical gap, as widely adopted methods that integrate redundant analytical controls with validated procedures to minimize errors and ensure evidential reliability remain limited.</p><p>The aim of this study was to develop a method for the determination of methanol, acetone, ethanol, n-propanol, isopropanol, and n-butanol using headspace gas chromatography with dual columns and dual-flame ionization detectors. The practical applicability of the method was demonstrated using authentic forensic samples, including putrefaction fluid and antemortem blood. This study addresses the aforementioned gap by employing a dual-column/dual-FID approach, which allows cross-verification across two independent chromatographic conditions, thereby enhancing both the accuracy and reproducibility of forensic alcohol analysis. Furthermore, this paper aims to draw the attention of toxicologists worldwide to several critical factors that can significantly influence measured ethanol concentrations, potentially leading to legal and financial consequences, such as denial of compensation due to falsely elevated ethanol levels.</p><h4><strong>2. Materials and Methods</strong></h4><h5><strong>2.4. Apparatus</strong></h5><p>A <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=2010"><strong>Shimadzu GC-2010</strong></a> Plus AF IVD system (Kyoto, Japan), fitted with an advanced flow controller (AFC), a split/splitless (SPL) inlet, and two flame ionization detectors (FID), was employed. Samples were processed and introduced via a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=HS-20"><strong>Shimadzu HS-20 static headspace autosampler</strong></a> (Kyoto, Japan), with transfer to the GC through a single SPL inlet. The HS effluent was split equally (1:1) using a SilFlow<sup>®</sup> microfluidic platform (SHI-980-10593, Trajan, Ringwood, VIC, Australia) and directed onto two capillary columns: <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=50&amp;search=Zebron-BAC1"><strong>Zebron-BAC1</strong></a> (30 m × 0.32 mm i.d., 1.8 μm film; Phenomenex, Torrance, CA, USA) and Zebron-BAC2 (30 m × 0.32 mm i.d., 1.2 μm film; Phenomenex, Torrance, CA, USA). Each column fed an independent FID channel, allowing concurrent acquisition from both separations. Headspace settings and chromatographic conditions for alcohol congener analysis followed those reported previously in [<a target="_blank" rel="noopener noreferrer" href="https://www.mdpi.com/2039-4713/16/3/80#B8-jox-16-00080">8</a>].</p><h4><strong>3. Results</strong></h4><p>Validation results are shown in <a target="_blank" rel="noopener noreferrer" href="https://www.mdpi.com/2039-4713/16/3/80#table_body_display_jox-16-00080-t002">Table 2</a>. All presented values fall within the acceptable range for toxicological analysis of biological materials, in accordance with the recommendations of the German Society of Toxicological and Forensic Chemistry (GTFCh) [<a target="_blank" rel="noopener noreferrer" href="https://www.mdpi.com/2039-4713/16/3/80#B10-jox-16-00080">10</a>]. Quality-control samples were prepared at three concentrations (low, medium, and high relative to the calibration range) by spiking blank samples. Relative error (RE) values within ±15% and precision expressed as relative standard deviation (RSD) ≤ 15% were considered acceptable, in accordance with GTFCh recommendations. The method, developed in 2019, has been subjected to international proficiency testing for ETB Ethanol in blood (ARVECON) and has consistently achieved positive results in each test. Additionally, the developed method for the determination of ethyl alcohol in blood was evaluated and achieved positive results in other proficiency tests, namely: the AXIO LGC Proficiency Testing Scheme in Drugs in blood Quantitative analyte selection, PT-TX-BLD (accreditation ISO/IEC 17043) (LGC Group Limited, Guildford, UK). Furthermore, the HS-GC-FID/FID method has been successfully implemented for routine toxicological analysis in our laboratory during the past 6 years.&nbsp;</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/J_Xenobiot_2026_16_3_80_Table_2_Validation_results_for_six_quantified_volatile_compounds_methanol_ethanol_acetone_isopropanol_n_propanol_and_n_butanol_64ddd30e8d.jpg" alt="J. Xenobiot. 2026, 16(3), 80: Table 2. Validation results for six quantified volatile compounds: methanol, ethanol, acetone, isopropanol, n-propanol, and n-butanol. " srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_J_Xenobiot_2026_16_3_80_Table_2_Validation_results_for_six_quantified_volatile_compounds_methanol_ethanol_acetone_isopropanol_n_propanol_and_n_butanol_64ddd30e8d.jpg 180w," sizes="100vw" width="1238" height="1073"></p><p>Chromatograms of all compounds analyzed using the presented method, collected on two columns (Zebron ZB-BAC1 and Zebron ZB-BAC2), are shown in <a target="_blank" rel="noopener noreferrer" href="https://www.mdpi.com/2039-4713/16/3/80#fig_body_display_jox-16-00080-f001">Figure 1</a>. During routine toxicological examinations, we analyzed various biological fluids, including standard matrices such as whole blood, serum, plasma, vitreous humor, and urine, as well as less commonly studied matrices such as bile, putrefaction fluid, and gastric contents.&nbsp;</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/J_Xenobiot_2026_16_3_80_Figure_1_Chromatograms_of_ISTD_and_LOQ_of_volatile_compounds_obtained_from_two_columns_3826b6b870.jpg" alt="J. Xenobiot. 2026, 16(3), 80: Figure 1. Chromatograms of ISTD and LOQ of volatile compounds obtained from two columns (Zebron ZB-BAC1 and Zebron ZB-BAC2) and two flame ionization detectors. The retention time of tert-butanol (ISTD) on the first column was 2.848, and on the second it was 3.131. " srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_J_Xenobiot_2026_16_3_80_Figure_1_Chromatograms_of_ISTD_and_LOQ_of_volatile_compounds_obtained_from_two_columns_3826b6b870.jpg 236w," sizes="100vw" width="1600" height="1056"></p><p>Chromatograms from representative authentic cases are shown in <a target="_blank" rel="noopener noreferrer" href="https://www.mdpi.com/2039-4713/16/3/80#fig_body_display_jox-16-00080-f002">Figure 2</a>, including putrefaction fluid (containing 0.4‰ of ethanol) compared with a standard whole blood sample containing 1.38‰ ethanol.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/J_Xenobiot_2026_16_3_80_Figure_2_A_Chromatograms_of_putrefaction_fluid_with_ethanol_concentration_of_0_4_B_chromatograms_of_antemortem_blood_sample_with_ethanol_concentration_of_1_38_fe782ce3d1.jpg" alt="J. Xenobiot. 2026, 16(3), 80: Figure 2. (A) Chromatograms of putrefaction fluid (with ethanol concentration of 0.4‰); (B) chromatograms of antemortem blood sample (with ethanol concentration of 1.38‰). Results were provided for both columns: Zebron ZB-BAC1 and Zebron ZB-BAC2." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_J_Xenobiot_2026_16_3_80_Figure_2_A_Chromatograms_of_putrefaction_fluid_with_ethanol_concentration_of_0_4_B_chromatograms_of_antemortem_blood_sample_with_ethanol_concentration_of_1_38_fe782ce3d1.jpg 245w," sizes="100vw" width="1600" height="453"></p><h4><strong>5. Conclusions</strong></h4><p>The findings presented in this study demonstrate that reliable forensic determination of ethanol and other volatile compounds requires a comprehensive analytical strategy that extends beyond routine instrumental analysis. Despite the long-standing use of alcohol determinations in forensic practice, significant methodological limitations persist, particularly with respect to selectivity, internal standard selection, and control of pre-analytical and analytical variables. Based on a critical evaluation of currently published methods and supported by experimental evidence and authentic forensic casework, several key methodological principles emerge as essential for ensuring the evidential reliability of ethanol analysis in forensic toxicology. These principles are summarized below:</p><div><ul><li>Using two columns with different polarities combined with two detectors.</li><li>Avoiding internal standards such as n-propanol, n-butanol, and other substances that are formed <span>postmortem</span> in forensic investigations.</li><li>Utilizing tert-butanol as an internal standard in forensic toxicological practice.</li><li>Analysis of quality-control (QC) concentrations defined by law for DUI threshold limits, with verification that precision and accuracy remain within acceptable ranges.</li><li>Ensuring that sample preparation is performed in facilities free from exposure to airborne organic solvent vapors, particularly methanol and ACN (which are routinely used for protein precipitation in other toxicological analyses).</li><li>Preparation of analytical batches including two replicates of each sample, analyzed in a forward- and reverse-order sequence (e.g., samples 1–5 followed by 5–1) to verify analytical consistency.</li><li>Verification of internal standards and blank samples in each batch to ensure the absence of contamination during the pre-analytical phase.</li><li>Ensuring compliance with the acceptance criterion of a maximum 5% deviation between results, based on four measurements per sample.</li><li>Careful chromatographic evaluation and critical assessment of peak shape, symmetry, and resolution to minimize the risk of undetected interferences, particularly when using detectors such as FID, where retention time is the sole discriminating parameter.</li><li>Routine performance of independent proficiency tests to assess whether the method meets required accuracy and precision standards.</li><li>Biological fluids intended for forensic toxicology testing should be collected in tubes containing sodium fluoride (NaF) and stored under controlled conditions in a refrigerator maintained at 2–8 °C.</li></ul></div></div>

Dual-Column HS-GC-FID/FID Method for In-Depth Analysis of Low-Molecular-Weight Volatile Alcohols in Postmortem Biological Material

<p><strong>Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 13th July 2026? Check out new documents from the field of the gas phase, especially GC and GC/MS techniques!</strong></p><blockquote><p><span style="font-size:20px;">👉 </span><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library"><span style="font-size:20px;"><strong>SEARCH THE LARGEST REPOSITORY OF DOCUMENTS ABOUT GCMS AND RELATED TECHNIQUES</strong></span></a></p></blockquote><blockquote><p><strong>👉 Need info about different analytical techniques?</strong> Peek into <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library"><strong>LabRulezLCMS</strong></a> or <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library"><strong>LabRulezICPMS</strong></a> libraries.</p></blockquote><p>This week we bring you posters by <strong>Agilent Technologies / ASMS,&nbsp;</strong> <strong>MDCW / William &amp; Mary, </strong>and<strong> Thermo Fisher Scientific</strong> <strong>/ ASMS </strong>and technical note by <strong>Shimadzu!</strong></p><h3><strong>1. Agilent Technologies / ASMS: Comprehensive PFAS Analysis in Textiles Using Triple Quadrupole GC/MS and LC/MS Workflows</strong></h3><ul><li>Poster</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/po_pfas_textiles_gc_tq_lc_tq_wp_414_asms_2026_en_agilent_a1d50ab96c.pdf"><strong>Full PDF for download</strong></a></li></ul><section><div><div><div><div><div><div><p>Per- and polyfluoroalkyl substances (PFAS) are widely used in textiles to provide water-, stain-, and oil-repellent functionality. Increasing evidence of environmental and human-health risks has led to heightened global regulatory pressure, including REACH/POPs restrictions, and strengthened requirements from industry frameworks such as ZDHC, OEKO-TEX®, AFIRM, and Bluesign. These initiatives demand highly sensitive, reliable, and standardized analytical workflows capable of quantifying both volatile and non-volatile PFAS in diverse textile matrices. This study demonstrates end-to-end PFAS solutions aligned with EN 17681-1:2025, comprising heat- and ultrasound-assisted (HUA) extraction followed by GC/TQ and LC/TQ determination of volatile and non-volatile PFAS, respectively. The workflow enables robust quantification of a comprehensive PFAS panel in T-shirts, waterproof shorts, and socks.</p><h4><strong>Experimental</strong></h4><h5><strong>Instrumentation&nbsp;</strong></h5><p>A dual-platform analytical approach combining GC/TQ and LC/TQ systems was used to quantify over 100 PFAS across 14 chemical classes (Figure 1). More than 30 volatile PFAS were analyzed using an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=8890"><strong>Agilent 8890 GC</strong></a> coupled to a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7010D"><strong>7010D TQ</strong></a> and a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=DB-624"><strong>DB-624 column</strong></a>. Over 70 non-volatile PFAS were determined using an <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library?mainauthorItems=10&amp;search=6475"><strong>Agilent 6475 LC/TQ</strong></a> paired with a <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library?mainauthorItems=10&amp;search=1290+infinity+III"><strong>1290 Infinity III UHPLC </strong></a>and a <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library?mainauthorItems=10&amp;search=ZORBAX+RRHD+Eclipse+Plus+C18"><strong>ZORBAX RRHD Eclipse Plus C18</strong></a> column.</p><h4><strong>Conclusions</strong></h4><ul><li>A dual-platform approach deploys Agilent 8890 GC coupled with 7010D TQ and Agilent 1290 Infinity III LC with 6475A TQ system for volatile and non-volatile PFAS in textiles.&nbsp;</li><li>Fast and simplified workflow: Utilizes a streamlined protocol based on EN 17681-1:2025. The method enhances lab productivity by eliminating tedious evaporation and reconstitution steps.&nbsp;</li><li>Regulatory compliance: Effectively addresses increasing textile industry focus on PFAS monitoring and supports compliance with various regulatory standards and limit requirements for PFAS detection in textiles.</li></ul><h3><strong>2. MDCW / William &amp; Mary: The Effect Of Using Low-Bleed Columns In The First Dimension For Comprehensive Two-Dimensional Gas Chromatographic Analyses</strong></h3><ul><li>Poster</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/Webb_MDCW_Poster_2026_1_5657991949.pdf"><strong>Full PDF for download</strong></a></li></ul><section><div><div><div><div><div><div><p>In gas chromatography, the presence of column bleed impacts peak data quality. As siloxanebased stationary phase components fragment, they release bleed artifacts into the mass spectrometer (MS), producing interference and decreasing signal-to-noise ratios (S/N) of analytes. <sup>1</sup> When using comprehensive twodimensional gas chromatography (GC×GC), a secondary column with an orthogonal stationary phase is used in providing improved separation between column bleed and analytes. However, it also introduces more stationary phase that can be degraded to produce more bleed artifacts.</p><p>The goal of this research was to define how replacing the primary column in a GC×GC-MS system impacts the resulting S/N and analyte identification quality, in order to clarify how column bleed impacts analytes that appear to be chromatographically resolved from column artifacts in GC×GC output. This will demonstrate the advantage that low-bleed columns can provide for future analyses.</p><h5><strong>Methods</strong></h5><p>Samples analyzed were the Century Mix2 , containing approximately 100 different analytes within different classes (i.e. Century Mix2) and a 52- component Indoor Air Standard. Both were assessed using a 5% phenyl/95% dimethylsiloxane standard column in the first dimension and a (50%-phenyl)-methylpolysiloxane standard column in the second dimension. Samples were then reanalyzed with a low-bleed column replacement in the first dimension.</p><p>Analysis of the samples was performed using the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/37"><strong>Pegasus BT4D GC×GCTOFMS</strong></a> with a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/44"><strong>quad-jet dual-stage cryogenic modulator</strong></a><strong> </strong>(LECO Corporation). <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/41"><strong>ChromaTOF software</strong></a><strong> </strong>(LECO Corporation) was used to analyze the chromatographic data.</p><h4><strong>Conclusions</strong></h4><p>This work demonstrated that samples run with the low-bleed first dimension column showed a reduction in the presence of column bleed components identified and maintained or improved the quantitative signal-to-noise ratios of components compared to the samples run on standard first dimension columns. This showed that that low concentration analytes were more reliably detected in the absence of column bleed, even when contour plots showed physically resolved components. In the future, this can be applied to improve the resolution of complex samples and increase analyte signal.</p><h3><strong>3. Shimadzu: Dimethyl carbonate as a green organic modifier in supercritical fluid extraction of pesticide residue analysis in apple samples</strong></h3><ul><li>Technical note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/c190_e347_869b9e2ade.pdf"><strong>Full PDF for download</strong></a></li></ul><p>According to the Green Analytical Chemistry (GAC) principles[1], a highly promising strategy to minimize the side effects of analytical methods involves replacing potentially toxic solvents and/or obtained by non-renewable sources with more environmentally friendly alternatives. In this frame, dimethyl carbonate (DMC) is an environmentally friendly, non-corrosive, safe handling, and biodegradable chemical, extensively used in several application fields, such as pharmaceuticals, coatings, and lithium-ion battery electrolytes [2]. Additionally, instead of the historical use of toxic and corrosive phosgene as a carbonate source, simple and direct synthesis routes from carbon dioxide (CO2) have been proposed [3]. Thus, also falling within the “carbon capture and utilization” processes, ensuring the reduction of atmospheric CO2 concentration and its conversion into useful chemical products.&nbsp;</p><p>Firstly introduced in the second edition of the GlaxoSmithKline’s solvent selection guide, DMC has been included among the “few issues” solvents, along with water [4]. Thereafter, it has attracted widespread attention as a valuable chemical and/or solvent, and substantial research efforts have been made in the scientific community. Its potential as a green alternative to conventional solvents in both reversed-phase liquid chromatography [5–7] and supercritical fluid chromatography [8] has been explored. The extraction capabilities of DMC toward different target molecules have been also investigated. In 2022, Alfieri et al. optimized an ultrasoundassisted extraction of two lignans from Linum species [9]. The extraction performances of a panel of green solvents and two natural deep eutectic solvents (in combination with water in a solvent/water ratio of 80:20) were tested versus methanol and chloroform (used for comparison with published studies). The results showed that, in terms of purity and recovery, DMC was the optimal media for the 6-methoxypodophyllotoxin extraction. DMC has been also employed in an in-syringe extraction coupled to solid phase extraction to assess nicotine in environmental water and sportspersons’ urine samples [10]. Extracts enriched in oleanolic acid were obtained by solid-liquid extraction of grape pomace using DMC compared to other tested solvents (ethyl acetate, acetone, n-butanol) [11]. In addition to the highest obtained recovery value, the lowest co-extraction of other matrix components was also achieved.&nbsp;</p><p>Supercritical fluid extraction (SFE) represents a reliable alternative to conventional solvent-based extraction methods. Several advantages are provided when CO2 is employed as supercritical fluid due to its non-toxicity, non-flammability, abundancy, renewability (as a by-product of industrial processes, as fermentation or combustion), recyclability, and cost-effectiveness. Supercritical CO2 has a polarity similar to that of n-hexane; thus, the addition of a co-solvent is necessary for the extraction of polar molecules [12, 13].&nbsp;</p><p>This work aims to expand the use of DMC that, to the best of the author’s knowledge, is here firstly proposed as an organic modifier in SFE. The extraction efficiency and selectivity of DMC toward conventional solvents, such as acetonitrile (ACN) and bio-ethanol (EtOH) obtained from edible renewable feedstocks, has been evaluated for multi-residue analysis of pesticides (64 pesticides, representing diverse chemical classes, polarities, and molecular weights) in apple samples. Considering the sustainable and nontoxic nature of CO2 and DMC, the use of DMC in SFE represents a win-win combination. Thus, improving the overall sustainability and automation of the extraction process closely align with the GAC principles. Furthermore, in this research, always following the GAC principles, a low-pressure gas chromatography-tandem mass spectrometry (LP-GC-QqQMS) method was employed, allowing a greater sample loadability and a higher optimal linear velocity allowed by the vacuum conditions of the system, effectively reducing the analysis time at about 10 minutes [14, 15].</p><h4><strong>2. Materials and methods</strong></h4><h5><strong>2-3. Instrumentation</strong></h5><h5><strong>Low‑pressure gas chromatography triple quadrupole mass spectrometry&nbsp;</strong></h5><p>The LP-GC-QqQMS analyses were performed using a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=GC-2010"><strong>GC-2010 Plus system</strong></a> (Shimadzu Corporation, Kyoto, Japan) coupled with a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=8040"><strong>triple quadrupole mass spectrometer (TQ8040</strong></a>, Shimadzu). Injection was performed using an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=AOC-20i"><strong>AOC-20i autosampler</strong></a><strong> </strong>and<strong> </strong>a split/splitless injector (injection temperature 280 °C) equipped with a focus liner (volume: 810 μL). The injection was performed in splitless mode (3 μL) using the high-pressure injection mode function (290 kPa for 0.5 min).&nbsp;</p><p>To avoid that sub-ambient pressure conditions reach the injector, an uncoated column (0.48 m × 0.1 mm ID) was installed before the separation column, a non-polar Equity-5 [poly(5% diphenyl/95% dimethyl siloxane)] of the following dimension: 5 m × 0.53 mm ID × 0.53 μm df. Both the columns were provided by Merck KGaA. The oven was temperature programmed as follows: 40 °C (2 min) to 320 °C raised at 30 °C min−1. Helium was used as carrier gas with an average constant linear velocity of 100 cm s−1 (into the separation column).&nbsp;</p><p>Electron ionization was performed at 70 eV. The interface and ion source temperatures were 320 and 280 ˚C, respectively. The collision gas was argon at a pressure of 200 kPa. The targeted analyses were carried out in the multiple reaction monitoring (MRM) acquisition mode (acquisition frequency: 3.3 Hz). To ensure univocal identification, two different MRM transitions (quantifier and qualifier) were monitored for each compound (Table S1). The SCAN analysis was performed with an acquisition frequency of 3.3 Hz and a mass range of 50–600 m/z. The GCMS Solution v.4.45 software (Shimadzu) was used for data collection and processing.</p><h4><strong>4. Conclusions&nbsp;</strong></h4><p>Under the optimized extraction conditions, the use of DMC as a co-solvent in SFE demonstrated promising performance in the analysis of pesticide residues in apple samples. The method achieved an average extraction yield of 85% across the 64 analyzed pesticides, spanning a broad range of chemical classes, polarities, and molecular weights. Notably, DMC provided cleaner extracts with significantly lower amounts of co-extracted matrix components compared to conventional solvents like ACN and EtOH. Despite the recovery for certain analytes being below 70%, the results remained within acceptable precision limits according to SANTE guidelines. Overall, DMC not only fulfills the analytical requirements for pesticide residue determination but also offers a greener, more sustainable alternative that supports enhanced instrument maintenance and aligns with the principles of GAC.</p><h3><strong>4. Thermo Fisher Scientific / ASMS: Improved detection capabilities for polychlorinated dibenzo-p-dioxins/furans (PCDD/Fs) using GC Orbitrap MS</strong></h3><ul><li>Poster</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/po_004693_lsms_pcdd_fs_exploris_gc_efs_po004693_asms2026_na_en_68e4d9e8b3.pdf"><strong>Full PDF for download</strong></a></li></ul><p>Polychlorinated dibenzo-p-dioxins/furans (PCDD/F) analysis requires ultra-high sensitivity and selectivity due to their toxicity at trace levels. Regulatory compliance requires laboratories to adhere to strict analytical criteria (Figure 1). Through the integration of NVAEI source (NVAEI) with HRAM Thermo Scientific Orbitrap mass spectrometer, the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/2419"><strong>Orbitrap Exploris GC S </strong></a>delivers mass resolution and accuracy that far exceed those required while delivering enhanced sensitivity required for pg/g (part per trillion (ppt)) detection within food and feed matrices.</p><h4><strong>Conclusions&nbsp;</strong></h4><p>Enhanced sensitivity of the NeverVent AEI ion source coupled to the Orbitrap Exploris GC S delivers accurate quantitation down to 2 fg/μL (10 fg on column) of TCDD while meeting analytical criteria required for Dioxin analysis compliance.&nbsp;</p><p>Response of 2 fg/μL (10 fg on column) of TCDD standard remained stable over a 185-injection sequence of food/feed extract, demonstrating robust performance of the NeverVent AEI at maintaining trace level sensitivity.&nbsp;</p><p>Good agreement in the analysis of food and feed extracts preformed by GC-HRMS magnetic sector demonstrates the Orbitrap Exploris GC S can deliver accurate quantitation at and below regulatory limits.</p></div></div></div></div></div></div></section></div></div></div></div></div></div></section>

News from LabRulezGCMS Library - Week 29, 2026

Can Temperature and UV Exposure Alter the Antimicrobial Properties of the Essential Oils? An Investigation of Origanum vulgare, Cymbopogon citratus, Syzygium aromaticum, and Lippia sidoides

<p><span><strong>This study evaluates headspace gas chromatography–ion mobility spectrometry (HS-GC-IMS) for characterizing the volatile profiles of five </strong></span><i><span><strong>Origanum</strong></span></i><span><strong> species and detecting blends with nonoregano leaves. MS-supported compound identification revealed species-specific differences, particularly in carvacrol/thymol and sesquiterpene profiles, while the method showed good repeatability and stable profiles over six weeks.</strong></span></p><p><span>Authenticity experiments using oregano blended with marjoram, myrtle, thyme, olive, and hoary rock-rose showed that potential marker compounds could be identified for marjoram and myrtle. The results demonstrate that HS-GC-IMS offers a sensitive and cost-effective approach for </span><i><span>Origanum</span></i><span> characterization and selected oregano adulteration screening.</span></p><blockquote><h4><strong>The original article</strong></h4><h4><a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/afsthl/article/doi/10.1021/acsfoodscitech.6c00607/5428045/Gas-Chromatography-Ion-Mobility-Spectrometry-for"><strong>Gas Chromatography-Ion Mobility Spectrometry for Characterizing Different Species of Origanum and Detecting Blends of Its Products</strong></a></h4><p>Modestus Wigger* ; Phil Carbow; Daria Garder; Silke Hillebrand; Ursula Telgheder; Stefanie Sielemann*</p><p>ACS Food Sci. Technol. (2026)&nbsp;</p><div><a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1021/acsfoodscitech.6c00607">https://doi.org/10.1021/acsfoodscitech.6c00607</a></div><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/"><strong>CC-BY 4.0</strong></a></h6></blockquote><p><strong>Selected sections from the article follow. Formats and hyperlinks were adapted from the original.</strong></p><div><div><div><div><div><div><div><p>Gas chromatography-ion mobility spectrometry (GC-IMS) has emerged as a complementary technique to GC-MS for food-aroma analysis and offers several advantages for aroma profile characterization. Applications include the authentication of olive oils, (<a href="javascript:;">14</a>) monofloral honeys, (<a href="javascript:;">15</a>) and many more. (<a href="javascript:;">16</a>)</p></div><div><p>Many GC-IMS approaches in food analysis use HS sampling. (<a href="javascript:;">16</a>) It eliminates the need for sample preparation and is optimal for transferring the compounds of interest into the GC system. After GC separation, IMS provides an additional dimension via drift time. Furthermore, it is a very sensitive, less costly method compared to a conventional quadrupole MS. Unfortunately, the capabilities for identifying compounds in IMS are limited, as it lacks the powerful databases that MS have. Therefore, in the analytical setup used, a quadrupole MS is installed on a separate flow line, as described by Budzyńska et al. (<a href="javascript:;">17</a>) and Augustini et al. (<a href="javascript:;">18</a>) Coupled with the NIST MS database and the peak-assignment approach of Augustini et al., (<a href="javascript:;">18</a>) this method enables reliable identification of most GC-IMS signals. Using this HS-GC-MS/-IMS configuration, it is demonstrated how GC-IMS can characterize <i>Origanum</i> volatilomes by analyzing five (sub)species, including one species represented by material from two geographic origins. To minimize environmental effects on volatile expression, reference seeds were grown under identical conditions in an indoor greenhouse prior to analysis. This approach helps to compare chemotypic differences among taxa and origins under controlled growth conditions.</p></div><div><p>Beyond chemotaxonomy and quality control, a further motivation for robust analytical fingerprinting of <i>Origanum</i> is the widespread issue of oregano adulteration. According to the European Spice Association, only the leaf product derived from <i>Origanum vulgare</i> ssp. <i>hirtum</i> and <i>Origanum onites</i> may be called oregano, while the International Organization for Standardization defines oregano in ISO 7925:1999–10 as leaves from the genus <i>Origanum</i> except <i>Origanum majorana</i>. ISO also specifies that the proportion of stalks and other plant parts shall not exceed 3% and that extraneous matter shall not exceed 1%, a requirement often violated in commercial oregano for economic reasons. Maquet et al. (<a href="javascript:;">19</a>) reported that 48% of oregano samples collected across the supply chain in the European Union were adulterated. Common adulterants include leaves from <i>Cistus</i> spp. for a dark green color, from olive (<i>Olea europaea</i>), and myrtle (<i>Myrtus communis</i>) for financial reasons. Another possibility could be an accidental admixture with other herbs, such as marjoram (<i>O. majorana</i>) or thyme (<i>Thymus spp</i>.). (<a href="javascript:;">20</a>) These types of food fraud are challenging for consumers and regulatory authorities to identify. One possibility is to analyze leaf material macroscopically or microscopically for foreign matter. (<a href="javascript:;">21</a>) However, a variety of analytical approaches have been developed to detect oregano adulteration. Fourier-transform infrared (FT-IR) spectroscopy has been used to screen for olive, myrtle, sumac, hoary rock-rose, and hazelnut leaf adulterants. (<a href="javascript:;">22</a>) Flügge et al. (<a href="javascript:;">23</a>) combined next-generation sequencing (NGS) with nuclear magnetic resonance (NMR) spectroscopy to detect olive, myrtle, hazelnut, and pink rock-rose (<i>Cistus</i>) leaves. Liquid chromatography–mass spectrometry (LC-MS) targeting oleuropein has been developed specifically to identify olive leaf adulteration (<a href="javascript:;">24</a>) and is also used by Maquet et al. (<a href="javascript:;">19</a>) as an analytical method for an EU-wide control of adulteration. Rocomora-Rivera et al. (<a href="javascript:;">25</a>) were the first to apply GC-IMS for the detection of oregano adulteration. Using orthogonal partial least-squares discriminant analysis (OPLS-DA), they identified admixtures containing olive leaves, but they did not test other potential adulterants. They also applied the method to commercially available oregano samples. However, their results were not verified by other analytical techniques. In the presented study, the feasibility of GC-IMS for detecting common adulterants in oregano, namely the leaves of hoary rock-rose, olive, myrtle, thyme, and marjoram, is tested by identifying marker compounds. Because only one authentic oregano type and no commercially adulterated samples were available, blends were prepared by combining oregano with candidate adulterant leaf material to simulate adulteration scenarios.</p></div><div><p>The objectives of this study are to evaluate HS-GC-IMS for volatilome profiling of five <i>Origanum</i> (sub)species grown under controlled conditions and assess the technique’s ability to detect common leaf adulterants in oregano blends.</p></div><h4><strong>2. Material and Methods</strong></h4><h5><strong>2.3. Analysis</strong></h5><div><p>An <a target="_blank" rel="noopener noreferrer" href="https://labrulez.com/en-us/gcms/library?mainauthorItems=1&amp;search=AOC5000"><strong>AOC5000</strong></a> (Shimadzu Corporation, Kyoto, Japan) HS sampler incubating for 30 min at 120 <span>°</span>C was used for the static HS analysis of the samples. 500 μL of the HS was injected into a <a target="_blank" rel="noopener noreferrer" href="https://labrulez.com/en-us/gcms/library?mainauthorItems=1&amp;search=2010"><strong>GC 2010-Plus</strong></a> (Shimadzu Corporation), equipped with two split injectors with a split of 1:20 and two identical analytical columns (HP-5 MS UI 30 m × 0.25 mm × 0.5 μm; Agilent, Santa Clara, CA, USA), each leading to one spectrometer (IMS or MS). A constant flow rate (35 cm/s) of helium 5.0 (Messer Industriegase, Siegen, Germany) was used. The GC temperature program started at 40 <span>°</span>C, held for 4 min, then heated with 3 <span>°</span>C/min to 150 <span>°</span>C, then heated 10 <span>°</span>C/min to 220 <span>°</span>C, held for 12.33 min, for a total program time of 60 min.</p></div><div><p>One analytical column was connected to the <strong>quadrupole MS QP-2010 Ultra</strong> (Shimadzu Corporation) in scan mode (<i>m</i>/<i>z</i> 32–300 at 3.3 Hz) with electron ionization (70 eV) and the other to the ion mobility spectrometer (G.A.S. Gesellschaft für analytische Sensorsysteme mbH, Dortmund, Germany). The drift tube (dimensions: 15.2 mm × 53 mm; temperature: 80 <span>°</span>C) was flushed with 75 mL/min drift gas (nitrogen 5.0, produced by an in-house generator), and ionization was performed by atmospheric-pressure chemical ionization with a <sup>3</sup>H source. The field strength was 500 V/cm.</p><h4><strong>3. Results and Discussion</strong></h4><h5><strong>3.1. Identification of Volatiles in Origanum</strong></h5><div><p>For the characterization of the volatilome of different <i>Origanum</i> species, it is necessary not only to detect compounds sensitively using HS-GC-IMS but also to identify them. For identification, HS-GC-MS was used in addition to HS-GC-IMS. The HS-GC-MS enables identification of unknowns through database comparison of fragmentation patterns.</p></div><div><p><a href="javascript:;">Figure 1</a> shows the total ion current (TIC) chromatograms for both HS-GC-IMS and HS-GC-MS of a fresh leaf from <i>O. vulgare</i> ssp. <i>hirtum</i>, with retention time on the <i>x</i>-axis, the integrated ion current for the IMS, and the intensity for MS on the <i>y</i>-axis. The <i>y</i>-axis of the HS-GC-MS chromatogram is logarithmically scaled, because it shows significant intensity differences (3 orders of magnitude between baseline and the highest peak), and linear scaling would discriminate small peaks in visualization. Most analytes are properly separated within the 60 min analysis time. When comparing the signals in both chromatograms, it is noticeable that they are shifted by several minutes. For example, an analyte (marked with an arrow), eluting at 35.8 min in the IMS flow line, elutes at 27.6 min in the MS flow line. However, the shift in retention times does not allow direct peak assignment. Using the 2-alkanone standard mixture as a reference, the retention times can be converted to retention indices using <a href="javascript:;">eqs 1</a> and <a href="javascript:;">2</a>, which can then be used to derive retention times for the GC-MS. An example calculation is provided in the <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/afsthl/article-supplement/5428045/pdf/fs6c00607_si_001/">Supporting Information</a>. To demonstrate the effectiveness of this method, the TIC chromatograms shown in <a href="javascript:;">Figure 1</a> are replotted in <a href="javascript:;">Figure 2</a>, with the calculated retention index on the <i>x</i>-axis instead of the retention time. The marked substance in <a href="javascript:;">Figure 1</a> is visible at a retention index of 992 in the HS-GC-IMS and 986 in the HS-GC-MS, corresponding to a deviation of only 6 RI units (≈0.6%), indicating very good assignment between the two methods. It is noticeable that, due to the logarithmic scaling of the intensity in the HS-GC-MS chromatogram, the peak pattern resembles that of the HS-GC-IMS. The IMS exhibits a nonlinear response over the measured intensity range. Therefore, logarithmic scaling of the MS signal intensity provides a representation that more closely matches the response characteristics of the IMS. Although the retention index still shows a slight shift, peak assignments are possible by comparing peak patterns. Additionally, within the retention index range of 600 to 700 (highlighted in gray), it is noticeable that the HS-GC-IMS exhibits more intense peaks than the HS-GC-MS. Peaks with a retention index above 700 become broader in the HS-GC-IMS, which can be explained by a less heated transfer and detector setup. Regarding sensitivity and separation power, the HS-GC-IMS is therefore more suitable for higher volatiles, while the HS-GC-MS is more suitable for lower volatiles, as it is also shown in Schanzmann et al. (<a href="javascript:;">33</a>) The results show that the IMS has comparable analytical power to the MS, but is more cost-effective, as it requires no vacuum and less maintenance.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ACS_Food_Sci_Technol_2026_Figure_1_Total_ion_current_TIC_chromatogram_of_a_leaf_from_O_vulgare_ssp_hirtum_cover_fc6d9adaee.jpg" alt="ACS Food Sci. Technol. (2026): Figure 1. Total ion current (TIC) chromatogram of a leaf from O. vulgare ssp. hirtum measured by headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) (upper part) and HS-GC mass spectrometry (HS-GC-MS) (lower part). The intensity of the HS-GC-MS-TIC is given on a log10 scale for better visualization, since the intensity range is 3 orders of magnitude and small peaks would not be visible in linear scaling." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ACS_Food_Sci_Technol_2026_Figure_1_Total_ion_current_TIC_chromatogram_of_a_leaf_from_O_vulgare_ssp_hirtum_cover_fc6d9adaee.jpg 201w," sizes="100vw" width="1600" height="1247"></p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ACS_Food_Sci_Technol_2026_Figure_2_Total_ion_current_TIC_chromatogram_of_a_leaf_from_O_vulgare_ssp_hirtum_bb33b1d86a.png" alt="ACS Food Sci. Technol. (2026): Figure 2. Total ion current (TIC) chromatogram of a leaf from O. vulgare ssp. hirtum measured by headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) (upper part) and HS-GC mass spectrometry (HS-GC-MS) (lower part) with the calculated retention index based on 2-alkanones on the x-axis. The intensity of the HS-GC-MS-TIC is given on a log10 scale for better visualization, since the intensity range is 3 orders of magnitude and small peaks would not be visible in linear scaling." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ACS_Food_Sci_Technol_2026_Figure_2_Total_ion_current_TIC_chromatogram_of_a_leaf_from_O_vulgare_ssp_hirtum_bb33b1d86a.png 201w," sizes="100vw" width="2508" height="1946"></p></div><h5><strong>3.4. Comparison of the Species</strong></h5><p>The first main topic of this study is to investigate species-specific variations in the volatilome. The HS-GC-IMS chromatograms for each species are illustrated in <a href="javascript:;">Figure 6</a>, where all <i>Origanum</i> species can be compared visually. Distinct differences in peak pattern and intensity between the samples are evident.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ACS_Food_Sci_Technol_2026_Figure_6_Headspace_gas_chromatography_ion_mobility_spectrometry_HS_GC_IMS_chromatograms_962a045868.png" alt="ACS Food Sci. Technol. (2026): Figure 6. Headspace gas chromatography-ion mobility spectrometry (HS-GC-IMS) chromatograms of five different species, one from two origins, Germany (DE) and Greece (GR), with the drift time on a reactant ion peak (RIP) relative scale (RIP position: ∼4.9 ms), the retention time in seconds on the y-axis, and the intensity in V on a color scale." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ACS_Food_Sci_Technol_2026_Figure_6_Headspace_gas_chromatography_ion_mobility_spectrometry_HS_GC_IMS_chromatograms_962a045868.png 152w," sizes="100vw" width="1254" height="1289"></p><p>It can be seen that the species <i>O. vulgare</i> ssp. <i>hirtum</i> contains more monoterpenes/monoterpenoids, especially carvacrol, than <i>O. vulgare</i> ssp. <i>vulgare</i>, which shows higher amounts of sesquiterpenes. This comparison provides insight into the profile of each species, as even two different plants of the same species can exhibit distinct profiles.</p><h5><strong>3.5. Detection of Blends in Oregano</strong></h5><p>After investigating the volatilomes of different <i>Origanum</i> species, the potential of this technique to detect food fraud can be demonstrated by comparing the volatilomes of oregano and its adulterants. The capabilities and limitations of GC-IMS for identifying oregano adulteration were assessed within this feasibility study by using self-made blends, as no intentionally fraudulent samples were available. For this purpose, common adulterants for oregano, namely leaves from olive, thyme, marjoram, myrtle, and hoary rock-rose, were added in different mass ratios (10%, 30%, and 50%) to ground oregano known to be pure and from <i>O. vulgare</i> ssp. <i>hirtum</i>. The sample material is shown in <a href="javascript:;">Figure 9</a> as a photograph.</p><p><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ACS_Food_Sci_Technol_2026_Figure_9_Photograph_of_the_sample_material_80493b7a68.png" alt="ACS Food Sci. Technol. (2026): Figure 9. Photograph of the sample material: Oregano (O. vulgare ssp. hirtum), olive (O. europaea L.), thyme (Thymus vulgaris L.), marjoram (O. majorana L.), myrtle (M. communis L.), hoary rock-rose (C. incanus L.)." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ACS_Food_Sci_Technol_2026_Figure_9_Photograph_of_the_sample_material_80493b7a68.png 245w," sizes="100vw" width="1254" height="291"></p><div><p>These pure samples were analyzed by HS-GC-IMS, and the chromatograms in the <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/afsthl/article-supplement/5428045/pdf/fs6c00607_si_001/">Supporting Information</a> generally show lower numbers and lower intensities of volatiles in olive leaves and hoary rock-rose than in oregano. In contrast to oregano, the volatilome of thyme and marjoram is comparably complex, with thyme exhibiting a very similar pattern with high proportions of thymol/carvacrol and a variety of monoterpenes and sesquiterpenes. Marjoram also contains many monoterpenes and some sesquiterpenes, but no carvacrol/thymol. The chromatogram of myrtle shows some monoterpenes, but not in the same numbers and intensity as oregano.</p></div><div><p>Potential marker substances were identified by analyzing all individual signals in the blending material and excluding those present in dried oregano or the fresh leaves of the different <i>Origanum</i> plants. Additional GC-MS measurements, the previously described peak assignment, and the NIST database enabled tentative identifications.</p></div><div><p>In marjoram piperityl acetate (RI = 1305, DT = 6.15 ms) is found, which has been tentatively identified by the described procedure. The peak intensity has a coefficient of variation of 29.9% for the lowest blend (10% marjoram in oregano) in technical triplicate. The high variation can be explained by coelution of the peak with the dominant carvacrol. The limit of detection (LOD) for marjoram in oregano using piperityl acetate as the marker was estimated at 4.1% based on the signal-to-noise (S/N) approach of Schanzmann et al. (<a href="javascript:;">33</a>) The S/N was determined for the 10% blend, and the blend ratio corresponding to S/N = 3 was calculated assuming proportionality between signal intensity and blend level. Creydt et al. identified blumeatin as a marker for marjoram adulterations using liquid chromatography–mass spectrometry and established a LOD of approximately 5%. (<a href="javascript:;">41</a>) Consequently, both volatile and nonvolatile analytes yielded comparable detection limits.</p></div></div></div></div></div></div></div></div>

Gas Chromatography-Ion Mobility Spectrometry for Characterizing Different Species of Origanum and Detecting Blends of Its Products

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