Determination of Chemical Mixtures in Environmental, Food, and Human Samples Using High-Resolution Mass Spectrometry-Based Suspect Screening Approaches

Ergot alkaloids (EAs) are common contaminants in cereals such as rye, wheat, and barley, posing food safety challenges worldwide. Their quantification, according to EN 17425:2021, relies on HPLC-MS/MS analysis of six primary EAs and their epimers. However, accurate quantification is often hindered by complex food matrices and the lack of suitable internal standards.To overcome these limitations, a semisynthetic approach was developed to produce stable isotope-labeled analogs of all major EAs. Building on previous work, native ergotamine was N6-demethylated and remethylated using ^13CD₃-iodomethane. The resulting labeled standards were validated against native compounds using HPLC-HR-MS/MS, exhibiting identical chromatographic and mass spectral properties. These new standards significantly improve accuracy, reproducibility, and comparability of EA analyses, strengthening food safety monitoring.<blockquote><h4>The original article</h4><h4><a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.jafc.5c03345">Semisynthesis of Stable Isotope-Labeled Ergot Alkaloids for HPLC-MS/MS Analysis</a></h4>Sven-Oliver Herter, Hajo Haase, and Matthias Koch*J. Agric. Food Chem. 2025, 73, 29, 18412–18419<a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1021/acs.jafc.5c03345">https://doi.org/10.1021/acs.jafc.5c03345</a><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/">CC-BY 4.0</a></h6></blockquote>Selected sections from the article follow. Formats and hyperlinks were adapted from the original.Ergot alkaloids (EAs) are a group of naturally occurring toxic alkaloids produced by fungi of the genus Claviceps, with Claviceps purpurea being the most prevalent in Europe. <a href="javascript:void(0);">(1)</a> They grow on various cereals, but primarily on rye, wheat, and triticale. <a href="javascript:void(0);">(2,3)</a> When a floret is infected with a spore of ergot fungi, the spore mimics a pollen grain growing into the ovary during fertilization, thus destroying the plant ovary and connecting to the vascular bundle of the plant. The ergot fungi produce asexual spores that are released with a sugary honeydew and dispersed by insects to other florets. In preparation for winter, a hardened mycelium (sclerotia) is formed inside the husk of the floret, and alkaloids and lipids are accumulated in the sclerotium. <a href="javascript:void(0);">(4)</a> The harvest of infected cereal leads to the introduction of sclerotia into the food chain. Mechanical techniques for the removal of sclerotia from grain are effective; however, they do not eliminate contamination completely. Residual sclerotia, in the form of dust or fragments, are ground with grain to flour and thereby introduce toxic EAs into foodstuffs. <a href="javascript:void(0);">(4,5)</a> A defining characteristic of EAs is the tetracyclic ring structure, known as ergoline (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.jafc.5c03345#fig1">Figure 1</a>). Naturally occurring EAs diverge structurally from ergoline due to the methylation of the N6-atom and various substituents attached to the C8-atom. <a href="javascript:void(0);">(6)</a> Additionally, most EAs possess a double bond between the C9- and C10-atoms in the ergoline structure. <a href="javascript:void(0);">(7)</a> They can be divided into three different groups based on their structural characteristics: lysergic acid and its simple amides, the ergopeptines, and the ergoclavines. <a href="javascript:void(0);">(6)</a> They all share an R-configuration at the C8-position of the ergoline structure. Epimerization at the C8-atom of simple lysergic acid amides and ergopeptines via keto–enol tautomerism is observed when these EAs are exposed to heat, UV light, or high/low pH. <a href="javascript:void(0);">(8,9)</a> However, ergoclavines, such as lysergine and lysergole, do not undergo epimerization due to the absence of a carboxyl group at the C8-atom.In parallel with the establishment of the maximum levels, the European Standard Method (ESM) EN 17425 for the determination of ergot alkaloids in cereals and cereal-based products was published. <a href="javascript:void(0);">(14)</a> The method describes the extraction of EAs from cereals and the subsequent cleanup of the extract using dispersive solid-phase extraction. The determination of EAs is performed with high-performance liquid chromatography coupled to tandem mass spectrometry (HPLC-MS/MS). However, the European Committee for Standardization (CEN) has indicated that the method cannot be considered satisfactory for levels below 24 μg/kg for the sum of the priority EAs due to an increase in interlaboratory uncertainties observed during the method validation study. <a href="javascript:void(0);">(14)</a> HPLC-MS/MS is susceptible to various forms of interference when used for quantification. A common challenge is the effect of coeluting molecules on the ionization yield of the analyte molecules. These matrix-dependent signal suppression or enhancements impact the analyte signal and cause the measured concentration to be different from its true value. <a href="javascript:void(0);">(15,16)</a> To overcome this problem, matrix-matched calibration can be employed. This involves the use of a calibration solution whose matrix matches the sample matrix, except for the analyte. However, these specific matrices are rarely available in environmental and food analytical studies. Alternatively, an internal standard (ISTD) can be used to reduce the impact of the matrix on the analyte signal. A suitable ISTD has comparable physio-chemical properties to the analyte, e.g., retention time, ionization response, and fragmentation pattern. Because of the need for an appropriate ISTD for each analyte of interest, this approach is costly and time-consuming. Therefore, in HPLC-MS/MS, ISTDs are typically stable isotope-labeled analogs (2H, 13C, and 15N) of the analyte. <a href="javascript:void(0);">(17)</a> For EAs, only ergometrine-13CD3 and its epimer ergometrinine-13CD3 are currently commercially available, due to their less complex structure compared to the ergopeptides. <a href="javascript:void(0);">(15,18)</a> However, a comprehensive set of all isotopically labeled priority EAs is required to enhance the current ESM and thus to reliably control the EA maximum level in food for infants and young children at 20 μg/kg. In our previous work, we described a straightforward two-step semisynthesis of the ergopeptines 13CD3-ergotamine and 13CD3-ergotaminine, starting from native ergotamine. <a href="javascript:void(0);">(19)</a> The general approach for the two-step semisynthesis of isotopically labeled EAs is illustrated in <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.jafc.5c03345#fig2">Figure 2</a>. In the first step, native EA is demethylated at the N6-position via an iron-catalyzed dealkylation reaction to yield the corresponding Norergot alkaloid (Nor EA). Subsequent methylation at the N6-atom with an isotopically labeled methylating reagent, e.g., iodomethane, yields the isotopically labeled EA.Given that all priority EAs share the methyl group at the N6-atom, we investigated the possibility of synthesizing all isotopically labeled EAs via a two-step synthesis.<h4>Materials and Methods</h4><h5>HR-MS/MS Measurements</h5>High-resolution tandem mass spectra (HR-MS/MS) were measured on a <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library?mainauthorItems=55&amp;search=TripleTOF+6600">Quadrupole time-of-flight 6600 mass spectrometer</a> (Sciex, Darmstadt, Germany). The purified solution, comprising either the native EA or Nor EA, was injected directly into the mass spectrometer via a syringe pump for analysis. For HPLC-HR-MS/MS analysis, the QTOF was coupled to a <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library?mainauthorItems=10&amp;search=1290+Infinity+II">1290 Infinity II</a> system (Agilent, Waldbronn, Germany). For the measurements, a Phenomenex Gemini C6–Phenyl (150 × 2.0 mm; 3 μm) column was used. For the MS/MS experiments, an inclusion list with the exact m/z ratio [M + H]+ for the native and isotopically labeled EAs was created. <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acs.jafc.5c03345/suppl_file/jf5c03345_si_001.pdf">Table S6</a> presents the QTOF parameters, and <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acs.jafc.5c03345/suppl_file/jf5c03345_si_001.pdf">Table S7</a> presents the HPLC parameters that were used for the HPLC-HR-MS/MS measurement. The predicted sum formulas for the most abundant product ion m/z ratios were calculated using a threshold of ±5 ppm deviation (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acs.jafc.5c03345/suppl_file/jf5c03345_si_001.pdf">Tables S9–S14</a>).<h4>Results</h4><h5>HR-MS/MS of Norergot Alkaloids</h5>The successful N6-demethylation of the EAs to the Nor EAs was confirmed by HR-MS/MS. Purified samples containing either the native EA or the associated Nor EA were introduced into the QTOF mass spectrometer for measurement via direct infusion. The HR-MS/MS spectra of the native EAs and Nor EAs were compared, and specific fragment ions were assigned to the major peaks in the mass spectra. <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.jafc.5c03345#fig4">Figure 4</a> shows the comparison of the fragment spectra of native ergocristine and the demethylated product norergocristine. The HR-MS/MS spectra of ergocristine coincide with previously reported data in the literature. <a href="javascript:void(0);">(20,21)</a> Upon comparison of the spectra of ergocristine and norergocristine, a similar fragmentation pattern is evident. The observed differences in the intensities of certain fragment ions can be attributed to the lower energy required for the fragmentation of norergocristine. For fragment ions containing the N6-atom, a shift in the m/z ratio for norergocristine compared to ergocristine was observed. This m/z shift corresponds to the loss of the methyl group at the N6-atom and is observed for the fragment ions of ergocristine/norergocristine with the m/z ratios of 348.1711/334.1545, 268.1451/254.1280, and 223.1234/209.1073. The differences in the m/z are 14.0166, 14.0171, and 14.0164, respectively, and match with the m/z ratio of the neutral loss of CH2, which is 14.0157 (cf. <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.jafc.5c03345#fig4">Figure 4</a>).&nbsp;<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/J_Agric_Food_Chem_2025_73_29_18412_18419_Figure_4_Positive_ESI_HR_MS_MS_spectra_M_H_of_a_ergocristine_and_b_norergocristine_3403f0b9e7.jpg" alt="J. Agric. Food Chem. 2025, 73, 29, 18412–18419: Figure 4. Positive ESI-HR-MS/MS spectra [M + H]+ of (a) ergocristine and (b) norergocristine. In addition to the measured accurate m/z ratio, a suggestive structure is provided for the precursor ion and the major fragment ions along with their calculated exact m/z ratio." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_J_Agric_Food_Chem_2025_73_29_18412_18419_Figure_4_Positive_ESI_HR_MS_MS_spectra_M_H_of_a_ergocristine_and_b_norergocristine_3403f0b9e7.jpg 245w," sizes="100vw" width="2078" height="1106">The fragmentation of the amide bond between the lysergic acid moiety and the cyclic tripeptide corresponds to the fragment ions with m/z ratios of 223.1234/209.1070 and 268.1451/254.1280. Fragmentation of the cyclic tripeptide ring results in the fragment ions with m/z ratios of 348.1711/334.1545. The fragment ion with an m/z ratio of 325.1546 is indicative of the fragment ion of the tricyclic peptide. Given that no modifications were introduced to the cyclic tripeptide ring structure, the spectra of ergocristine and norergocristine both exhibit this specific fragment ion. The HR-MS/MS spectra for the Nor EAs of ergometrine, ergocornine, ergotamine, α-ergocryptine, and ergosine compared to the native EAs are presented in the Supporting Information, <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acs.jafc.5c03345/suppl_file/jf5c03345_si_001.pdf">Figures S7, S9, S11, S13, S15</a>. The related structure of all investigated ergopeptines results in a comparable fragmentation pattern, similar to the one observed for ergocristine and norergocristine. In contrast, the representatives of the lysergic acid derivatives, ergometrine and norergometrine, exhibit a less complex product ion spectrum. Based on the measured accurate m/z ratios, we were able to make a structural proposal for all major product ions of the EAs and Nor EAs.<h4>Synthesis of Stable Isotope-Labeled Ergot Alkaloids</h4>To verify the successful synthesis of all 12 isotopically labeled priority EAs, they were spiked at a concentration of 25 ng/mL to a standard with a concentration of 25 ng/mL containing all unlabeled native EAs in acetonitrile and analyzed via HPLC-HR-MS/MS. <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acs.jafc.5c03345#fig5">Figure 5</a> depicts the extracted-ion chromatogram (XIC) for the specific fragment ion of the native (m/z 223.1235) and isotopically labeled (m/z 227.1458) EAs. <a href="javascript:void(0);">(22)</a><img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/J_Agric_Food_Chem_2025_73_29_18412_18419_Figure_5_Extracted_ion_chromatogram_M_H_XIC_of_a_25_ngm_L_standard_70f2a2760a.jpg" alt="J. Agric. Food Chem. 2025, 73, 29, 18412–18419: Figure 5. Extracted-ion chromatogram [M + H]+ (XIC) of a 25 ng/mL standard for (a) 12 native priority EAs and (b) 12 stable isotope-labeled priority EAs. An inclusion list containing the exact m/z values of each native and stable isotope-labeled EA [M + H]+ was created, and the sample was analyzed in parallel reaction monitoring (PRM) mode on a QTOF mass spectrometer." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_J_Agric_Food_Chem_2025_73_29_18412_18419_Figure_5_Extracted_ion_chromatogram_M_H_XIC_of_a_25_ngm_L_standard_70f2a2760a.jpg 245w," sizes="100vw" width="2079" height="1198"><h4>Discussion</h4>The quantification of EAs in complex food matrices using HPLC-MS/MS is challenging, primarily due to matrix effects and the lack of stable isotope-labeled standards. To address this gap, a semisynthetic approach was developed that targets the N6-atom of the lysergic acid moiety, a structural feature shared among all investigated native priority EAs.The demethylation of the N6-atom to the corresponding Nor EAs was achieved via an iron-catalyzed reaction, and the structure of the Nor EAs was confirmed by HR-MS/MS. A structural assignment for the most intense product ions of the Nor EAs was proposed based on the measured accurate m/z ratios and correlated with specific HR-MS/MS fragments of the native compounds. The characteristic loss in the m/z value associated with the demethylation was observed only for fragment ions of the Nor EAs that contain the N6-atom, thereby confirming successful and selective demethylation for all investigated EAs.For the subsequent remethylation of the Nor EAs, 13CD3-iodomethane was utilized and resulted in the formation of the isotopically labeled C8-R and C8-S epimers of the respective EAs. Overall yields ranged from 8.1% for 13CD3-ergocristine/-inine and up to 29.5% for 13CD3-ergocryptine/-inine. Due to the limited availability of starting material, no yield could be determined for 13CD3-ergometrine/-inine and 13CD3-ergosine/-inine. The epimer ratio (R%:S%) of the ergopeptines ranged between 58:42 for 13CD3-ergocornine/-inine and 45:55 for 13CD3-ergocristine/-inine. Although the synthesis started from a compound with the 8R-configuration, both stable isotope-labeled epimers were obtained in approximately equal amounts. This outcome is favorable as it provides sufficient quantities of both stable isotope-labeled epimers from a single epimeric pure starting material. In contrast, the simpler lysergic acid amide 13CD3-ergometrine/-inine showed less epimerization, with an epimer ratio of 69:31. The structures of the synthesized labeled EAs were confirmed using HPLC-HR-MS/MS. Therefore, a mixture containing all 12 native priority EAs and their corresponding labeled analogs was analyzed. As anticipated for deuterium-labeled compounds, the isotopically labeled EAs showed slightly shorter retention times (1–3 s) compared to their native counterparts. The precursor and fragment ions containing the isotopically labeled methyl group at the N6-position exhibited a shift in the m/z ratio of 4 Da. In contrast, fragment ions without this structural feature were present in the MS/MS spectra of both labeled and unlabeled EAs. With the measured accurate m/z ratios of the precursor and product ions, we were able to predict a sum formula and match specific fragment ions for each major signal in the HR-MS/MS spectrum. Due to the limited availability of the native EAs, only small amounts of the 13CD3-labeled analogs were synthesized, which precluded structural elucidation by NMR. However, the identical fragmentation patterns and signal intensities between labeled and unlabeled EAs, in conjunction with the same retention time in HPLC, provided unambiguous confirmation of the structures for all 12 synthesized stable isotope-labeled priority EAs.For the first time, the procedure described herein enabled the semisynthesis of a complete set of stable isotope-labeled priority EAs. In future work, these standards will be implemented in the ESM and facilitate an enhanced methodology for the quantification of these mycotoxins in food and feed.

Semisynthesis of Stable Isotope-Labeled Ergot Alkaloids for HPLC-MS/MS Analysis

Multidrug-resistant Acinetobacter baumannii (MDR AB) poses a critical global health challenge due to limited treatment options and robust resistance mechanisms. Targeting bacterial bioenergetics, particularly ATP synthase, represents a promising alternative approach inspired by the success of bedaquiline against Mycobacterium tuberculosis.In this study, a library of trisubstituted pyridines was synthesized and evaluated for ATP synthase inhibition in A. baumannii. Four lead compounds demonstrated potent and selective inhibition, exhibiting strong antibacterial activity against both susceptible and MDR clinical isolates. Furthermore, these compounds acted synergistically with colistin, underscoring their potential as novel antibiotics to combat resistant A. baumannii infections.<blockquote><h4>The original article</h4><h5><a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c06380">Synthesis and Evaluation of Pyridine-Based Antibacterial Agents that Inhibit ATP Synthase in Acinetobacter baumannii</a></h5>Angelina L. Dennison, Armaan Singh, Toni A. Marchlewski, Sierra N. Ghee, Kevin C. Gence, lAva G. Hammock, Sabrina Liu, Shaylla Wilson, Alexander P. L. Williams, Katie T. Ward, Thomas E. Meigs, P. Ryan Steed*, and Amanda L. Wolfe*ACS Omega 2025, 10, 39, 45823–45839<a target="_blank" rel="noopener noreferrer" href="https://doi.org/10.1021/acsomega.5c06380">https://doi.org/10.1021/acsomega.5c06380</a><h6>licensed under <a target="_blank" rel="noopener noreferrer" href="https://creativecommons.org/licenses/by/4.0/">CC-BY 4.0</a></h6></blockquote>Selected sections from the article follow. Formats and hyperlinks were adapted from the original.Antimicrobial resistance─a leading cause of death globally─was responsible for &gt;4 million premature deaths in 2019, with projections suggesting this number could rise to over 10 million by 2050. <a href="javascript:void(0);">(1,2)</a> The nosocomial ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumonia, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp.) contribute significantly to these deaths. Multidrug resistant A. baumannii (MDR AB), an opportunistic Gram-negative pathogen, poses a serious challenge due to a multitude of resistance pathways, including a robust outer membrane (OM), active efflux pumps, and exiguous aperture porins. Moreover, AB is considered one of the most difficult-to-treat ESKAPE pathogens due to its resistance to safety net antibiotics (including colistin, tigecycline, and carbapenems), which demonstrates the dire need for development of novel antimicrobials. <a href="javascript:void(0);">(3)</a>Recently, efforts in antibiotic discovery and development have shifted toward identifying new bacterial targets to overcome current resistance mechanisms in pathogens. One emerging target is ATP synthase, an essential enzyme in bacterial bioenergetics and all life (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c06380#fig1">Figure 1</a>A). <a href="javascript:void(0);">(4−6)</a> F1Fo ATP synthase is a protein complex comprised of two rotary motors that catalyzes the final step in oxidative phosphorylation. <a href="javascript:void(0);">(7)</a> In bacteria, the membrane-embedded Fo motor is composed of stator ab2 subunits adjacent to a homooligomeric ring of c subunits (c10 in AB). <a href="javascript:void(0);">(8)</a> Rotation of the c-ring, driven by an electrochemical gradient of H+, is coupled to rotation of a central stalk within the cytoplasmic F1 motor (composed of α3β3γδε), which catalyzes phosphorylation of ADP to ATP. ATP synthase has proven to be a druggable antibiotic target through the success of the FDA-approved antitubercular drug bedaquiline (BDQ). <a href="javascript:void(0);">(9)</a> BDQ inhibits ATP production in Mycobacterium tuberculosis (MT) by binding to the H+ binding site at the subunit ac interface in Fo, halting ATP synthesis in the F1 complex and causing cell death. <a href="javascript:void(0);">(10−12)</a> BDQ was the first antibiotic to target bacterial energy metabolism and the first drug approved for MDR MT in over four decades. <a href="javascript:void(0);">(13)</a>Due to the success of BDQ against MT, our group <a href="javascript:void(0);">(14−17)</a> and others <a href="javascript:void(0);">(18−21)</a> have begun to explore whether functionalized quinolines can inhibit ATP synthase in other bacterial pathogens via a similar binding interaction with the Fo c subunit and act as antibiotics against resistant strains. One challenge of targeting ATP synthase in Gram-negative pathogens, like AB specifically, is that the Fo complex of ATP synthase is embedded in the inner membrane. Therefore, the drugs must first penetrate the negatively charged OM and then embed in the hydrophobic inner membrane to inhibit the enzyme. Recently, we have developed and interrogated a series of functionalized quinolines that are able to inhibit ATP synthase in AB and penetrate the OM to act as antibiotics against MDR AB strains. <a href="javascript:void(0);">(17)</a> Specifically, the quinoline core was substituted with a benzyl sulfide at the C1 position and a flexible and basic nitrogen-containing side chain at C2. Functionalization on the western portion of the quinoline increased enzyme inhibition and overall antibacterial activity against both susceptible and MDR AB clinical isolates. However, increasing steric bulk beyond a certain threshold decreased both enzymatic and bacterial activity significantly, which was attributed to overall larger steric bulk limiting the interactions with the c subunit and reducing membrane permeability. Quinoline WSA 261 (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c06380#fig1">Figure 1</a>B) demonstrated the most potent antibacterial activity against both susceptible and MDR AB of the series. <a href="javascript:void(0);">(17)</a> To explore the necessity of the quinoline core and to interrogate the limitations on molecular flexibility and size on AB ATP synthase inhibition more broadly, we have synthesized a library of 34 novel trisubstituted pyridine analogs (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c06380#fig1">Figure 1</a>C) and evaluated this library in enzymatic, antibacterial, and cytotoxicity assays to assess the viability of this series as potential antibacterial agents for treating AB infections.<h4>Methods</h4>Reagents and solvents were purchased reagent-grade and used without further purification. All reactions were performed in flame-dried glassware under an Ar or N2 atmosphere. Evaporation and concentration in vacuo was performed at 40–45 °C. TLC was conducted using precoated SiO2 60 F254 glass plates from EMD with visualization by UV light (254 or 366 nm). NMR (1H or 13C) were recorded on an Varian INOVA-400 MHz spectrometer or a Bruker AVANCE-400 MHz spectrometer at 298 K. Residual solvent peaks were used as an internal reference (CDCl3 with 0.1% TMS). Coupling constants (J) (H,H) are given in Hz. Coupling patterns are designated as singlet (s), doublet (d), triplet (t), multiplet (m) or quintet (qu). IR spectra were recorded on a <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library?mainauthorItems=1&amp;search=IRSpirit">Shimadzu IRSpirit FT-IR spectrophotometer</a> and measured neat. Low-resolution mass spectral data were acquired on a <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library?mainauthorItems=1&amp;search=LCMS-2020">Shimadzu single quadrupole LCMS-2020.</a> High-resolution mass spectral Samples were analyzed with a <a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/library?mainauthorItems=3&amp;search=Q+Exactive+HF-X">Q Exactive HF-X</a> (ThermoFisher, Bremen, Germany) mass spectrometer. Samples were introduced via a heated electrospray source (HESI) at a flow rate of 10 μL/min. HESI source conditions were set as: nebulizer temperature 400 °C, sheath gas (nitrogen) 20 arb, auxiliary gas (nitrogen) 0 arb, sweep gas (nitrogen) 0 arb, capillary temperature 320 °C, RF voltage 45 V. The mass range was set to 100–1000 m/z. All measurements were recorded at a resolution setting of 120,000. Solutions were analyzed at 0.1 mg/mL or less based on responsiveness to the ESI mechanism.<a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/products/1758"> Xcalibur</a> (ThermoFisher, Breman, Germany) was used to analyze the data. Molecular formula assignments were determined with Molecular Formula Calculator (v 1.3.0). All observed species were singly charged, as verified by unit m/z separation between mass spectral peaks corresponding to the 12C and 13C12Cc-1 isotope for each elemental composition.<h4>Results and Discussion</h4><h5>ATP Synthase Inhibition</h5>Once synthesized, the pyridine compounds were tested for their ability to inhibit ATP synthase activity using our previously reported luciferin/luciferase assay. <a href="javascript:void(0);">(17)</a> Briefly, endogenous electron transport chains of inverted inner membrane vesicles were energized with NADH to generate a proton gradient and to drive ATP synthesis. ATP was measured via luminescence from the luciferase-catalyzed oxidation of d-luciferin. Luminescence activities across increasing inhibitor concentrations were corrected for gradient independent background sources of ATP by comparison with a control containing the protonophore CCCP (carbonyl cyanide 3-chlorophenylhydrazone). The data were then fit to a four-parameter logistic dose–response curve, from which IC50 values and Hill coefficients were determined using a nonlinear least-squares regression.Assessing the SAR of ATP synthase inhibition, pyridines with H or Br at C4 exhibited the lowest inhibitory activity across all amine series (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acsomega.5c06380/suppl_file/ao5c06380_si_001.pdf">Table S1</a>, <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c06380#fig2">Figure 2</a> and <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acsomega.5c06380/suppl_file/ao5c06380_si_001.pdf">S1</a>). Among compounds having C4 phenyl groups, the 4-methoxyphenyl, 3-fluoro-4-methoxyphenyl, and 4-methylphenyl analogs showed potent IC50 values across all amine types, while the 2,4-difluorophenyl, phenyl, and 4-fluorophenyl substituents generally demonstrated weaker inhibitory activity. Compounds WSA 290, 289, 275, 288, and 305 showed the strongest inhibitory activity among the pyridines, with IC50 values between 190 and 270 ng/mL. These in vitro IC50 values are significantly lower than that of WSA 261 (IC50 = 770 ng/mL), suggesting that the pyridine scaffold improves AB ATP synthase inhibitory activity. WSA 290, 289, and 288 all belonged to the C2 cyclopentyl piperidine substituted series, while WSA 275 belonged to the methyl piperazine series and WSA 305 belonged to the ethyl piperidine series. WSA 290 and WSA 275, the strongest performing compounds in their amine series, contained 3-fluoro-4-methoxyphenyl at C4; similarly, WSA 297 (IC50 = 270 ng/mL) with the same 3-fluoro-methoxyphenyl C4 substituent was the strongest performing compound within the benzyl pyrrolidine series. WSA 288 and WSA 305 had methoxyphenyl C4 substituents, and WSA 289 contained a methylphenyl group off C4. The presence of a methoxy group, in both ortho disubstituted and monosubstituted forms, on the C4 phenyl seems to confer stronger inhibition.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ACS_Omega_2025_10_39_45823_45839_Figure_2_Potent_inhibition_of_ATP_synthesis_activity_86ae703368.jpg" alt="ACS Omega 2025, 10, 39, 45823–45839: Figure 2. Potent inhibition of ATP synthesis activity. ATP synthesis activities of inverted membrane vesicles in the presence of 0–16 μg/mL inhibitor (log2 scale) are plotted relative to the DMSO control containing no inhibitor. Replicate measurements are shown as dots. The fitted dose response curves are shown as solid lines, and the dashed lines indicate the 95% confidence bounds of the fit." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ACS_Omega_2025_10_39_45823_45839_Figure_2_Potent_inhibition_of_ATP_synthesis_activity_86ae703368.jpg 245w," sizes="100vw" width="4151" height="2101"><h5>Computational Docking</h5>Computational docking was performed using GNINA and PLIP (see <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c06380#sec4">Methods</a>). The protein (PDB ID: <a target="_blank" rel="noopener noreferrer" href="http://doi.org/10.2210/pdb7P2Y/pdb">7P2Y</a>) <a href="javascript:void(0);">(22)</a> was assigned protonation states using the H++ server, <a href="javascript:void(0);">(23)</a> compounds were protonated at pH 7 using Open Babel, <a href="javascript:void(0);">(24)</a> and both were prepared for docking using Autodock Tools. Docking was performed using GNINA with a fixed grid box centered around cAsp60. Poses from GNINA were then input into PLIP 2.3.0 to extract interaction level data.The strong inhibitors WSA 290, 289, 275, 288, and 305 all formed salt-bridges between their secondary or tertiary amines and cAsp60 (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/suppl/10.1021/acsomega.5c06380/suppl_file/ao5c06380_si_001.pdf">Table S2</a>). The conformations adopted also allowed for hydrogen bonding with the backbones of cPhe53, cGly57 (WSA 290), cMet64 (WSA 275), and aLeu257 (WSA 305). Additionally, cIle65, cLeu71, aIle242, aLeu245, aIle246, and aLeu257 formed a hydrophobic binding pocket that consistently interacts with these compounds. The enriched binding pocket for high affinity compounds is shown in <a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c06380#fig3">Figure 3</a>A, where residue-ligand contacts were computed using PLIP on the chosen GNINA poses for each compound. This binding pocket overlaps substantially with that predicted for our previous quinoline scaffold (<a target="_blank" rel="noopener noreferrer" href="https://pubs.acs.org/doi/10.1021/acsomega.5c06380#fig1">Figure 1</a>A), supporting a conserved binding mode centered around the cAsp60-mediated salt-bridge and a hydrophobic cavity across both chemotypes.<img src="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/ACS_Omega_2025_10_39_45823_45839_Figure_3_A_The_putative_binding_site_in_the_ac_interface_of_A_baumannii_ATP_synthase_25731daecd.jpg" alt="ACS Omega 2025, 10, 39, 45823–45839: Figure 3. (A) The putative binding site in the ac interface of A. baumannii ATP synthase (PDB ID: 7P2Y) is shown at the interface of subunit a (left, pale cyan) and the c-ring (right, light blue). Residues in the binding pocket are colored by enrichment score, defined here as frequency of binding to strong inhibitors divided by frequency of binding to weak inhibitors, where strong inhibitors are those with IC50 &lt; 500 ng/mL and weak inhibitors are those with IC50 &gt; 5000 ng/mL. The residues shown as sticks are those with enrichment &gt;1 (i.e., frequent interaction with strong inhibitors) and cAsp60 (a key salt-bridge forming residue). (B) Computed binding poses of compounds WSA 276 (cyan), WSA 278 (yellow), and WSA 280 (magenta) in the methyl piperazine series with 4-dimethylamino, 4-methoxyphenyl, and 4-methylphenyl western fronts. (C) Computed binding poses of compounds WSA 288 (cyan), WSA 289 (magenta), and WSA 302 (yellow) in the cyclopentyl piperidine series with 4-methoxyphenyl, 4-methylphenyl, and phenyl western fronts, respectively. (D) Computed binding poses of compounds WSA 297 (yellow), WSA 298 (cyan), WSA294 (orange), and WSA296 (purple) of the benzyl pyrrolidine series, with 2,4-fluoromethoxyphenyl, 4-fluorphenyl, 4-phenyl, and 4-methoxyphenyl C4 substituents respectively." srcset="https://storage.googleapis.com/labrulez-bucket-strapi-h3hsga3/thumbnail_ACS_Omega_2025_10_39_45823_45839_Figure_3_A_The_putative_binding_site_in_the_ac_interface_of_A_baumannii_ATP_synthase_25731daecd.jpg 159w," sizes="100vw" width="1868" height="1838"><h4>Conclusions</h4>As discussed, development of new antibiotics that overcome bacterial resistance in MDR AB is a critical need globally due to the rising rate of bacterial infections caused by this pathogen. Bacterial bioenergetics are underexplored drug targets that if properly and selectively inhibited could provide a robust area for antibiotic development, helping to slow the rate of resistance emergence. While the quinoline scaffolds derived from the antitubercular ATP synthase inhibitor BDQ have been the standard for inhibitor development of this type to date, limitations in molecular design and synthesis require new scaffolds to be explored.Through biochemical and antibacterial evaluation of our trisubstituted pyridine library we have demonstrated that the traditional quinoline core is not required for ATP synthase inhibition in AB, opening a new area of drug development from a more readily available starting material. Specifically, we explored the SAR of AB ATP synthase inhibition and found that enzyme inhibition is driven by both molecular size and interaction with key residues in the proposed binding site of the ac interface of Fo. However, despite the increase in enzyme inhibition compared to the traditional quinoline series, antibacterial activity was limited, and the most potent compounds were cytotoxic against mammalian cells indicating that there is room for improvement using strategic molecular design. Four pyridines, WSA 276, WSA 288, WSA 289, WSA 298, with variations at C2 and C4 but similar overall molecular size and flexibility demonstrated potent antibacterial activity against both susceptible and MDR AB clinical isolates due to selective inhibition of AB ATP synthase in ng/mL concentrations. Additionally, this set had the most favorable preliminary toxicity ratio when dosed in combination with colistin, making them the basis for future studies to improve activity and selectivity of the class.

Synthesis and Evaluation of Pyridine-Based Antibacterial Agents that Inhibit ATP Synthase in Acinetobacter baumannii

In the week of November 3, the following webinars await you in the field of gas / solid phase and especially Raman, FTIR, GC and GC/MS.<blockquote><h4><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinars">👉 DETAILS AND REGISTRATION IN THE WEBINARS SECTION</a></h4>👉 Search and filter in the largest global database with over 5 000 GC, LC, MS and spectroscopy webinars.</blockquote><div><div><div><div><div><div><h5>1. Wiley: Discover Hidden Trends in Spectral &amp; Chromatographic Datasets</h5><ul><li>Tu, 4.11.2025 14:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinar/5604">Registration</a></li></ul>Learn how KnowItAll’s new Trendfinder tool uses Principal Component Analysis (PCA) to uncover hidden relationships and trends in large spectral and chromatographic datasets.<h5>2. Wasson-ECE Instrumentation: Rotary Valve Training</h5><ul><li>Tu, 4.11.2025 21:30 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinar/5525">Registration</a></li></ul>Gain hands-on insights into rotary valve operation, maintenance, and troubleshooting to ensure optimal performance in chromatographic and analytical systems.<h5>3. Phenomenex: Clear Signals – Navigating Baseline Challenges in GC</h5><ul><li>We, 5.11.2025 10:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinar/5609">Registration</a></li></ul>Join Duilio Romanello to master GC baseline troubleshooting. Learn to diagnose noise and drift issues, improve stability, and optimize GC method performance.<h5>4. Technology Networks: Enhancing Pharmaceutical Manufacturing Using Raman Spectroscopy</h5><ul><li>We, 5.11.2025 17:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinar/5563">Registration</a></li></ul>Discover how Raman spectroscopy enables fast, non-destructive pharmaceutical testing. Improve process efficiency, ensure compliance, and explore future innovations.<h5>5. Thermo Fisher Scientific: Mastering Mass Spectrometry with Chromeleon CDS – Expert Tips and Tricks</h5><ul><li>We, 5.11.2025 20:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinar/5386">Registration</a></li></ul>Learn advanced Chromeleon 7.4 features to optimize mass spectrometry workflows. Boost data quality, streamline configuration, and explore new MS performance tools.<h5>6. Agilent Technologies: Power Ahead with Ammonia</h5><ul><li>Th, 6.11.2025 07:30 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinar/5542">Registration</a></li></ul>Explore how Agilent GC systems ensure ammonia purity and support hydrogen generation through cracking for safe, efficient energy and mobility applications.<h5>7. Waters Corporation: Analysis, Mitigation, and Monitoring in Modern Data Governance</h5><ul><li>Th, 6.11.2025 16:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinar/5658">Registration</a></li></ul>Learn how advanced data governance strategies improve compliance, quality, and resilience across analytical and regulatory systems.</div></div></div></div></div></div>

Webinars LabRulezGCMS Week 45/2025

In the week of November 3, the following webinars await you in the field of liquid phase and especially HPLC and LC/MS.<blockquote><h4><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinars">👉 DETAILS AND REGISTRATION IN THE WEBINARS SECTION</a></h4>👉 Search and filter in the largest global database with over 5 000 GC, LC, MS and spectroscopy webinars.</blockquote><h5>1. SelectScience: Expert Tips to Mastering Polar Analyte Separation</h5><ul><li>Mo, 3.11.2025 17:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5603">Registration</a></li></ul>Dr. Chris Collins (Waters) reveals key retention mechanisms for polar analytes and guides you in choosing the optimal column for seamless LC separations.<h5>2. Wiley: Discover Hidden Trends in Spectral &amp; Chromatographic Datasets</h5><ul><li>Tu, 4.11.2025 14:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5604">Registration</a></li></ul>Learn how KnowItAll’s Trendfinder tool applies PCA to uncover patterns and correlations in complex spectral and chromatographic datasets.<h5>3. Restek Corporation: Why the Biphenyl Column Is a Great Tool for Environmental LC Analysis</h5><ul><li>Tu, 4.11.2025 14:30 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5656">Registration</a></li></ul>Explore biphenyl LC column applications for environmental testing of air, soil, and water. Learn method development strategies for complex contaminant matrices.<h5>4. Wiley: From Molecular Complexity to Synthetic Simplicity</h5><ul><li>Tu, 4.11.2025 15:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5605">Registration</a></li></ul>See how computer-assisted retrosynthesis is reshaping synthetic chemistry, enabling faster, smarter route design in academia and industry.<h5>5. Waters Corporation: Back to Basics Advanced – Biologics: Proteins &amp; Peptides</h5><ul><li>Tu, 4.11.2025 15:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/4780">Registration</a></li></ul>Discover the newest innovations in LC columns and detection for proteins and peptides, and explore automated workflows in waters_connect.<h5>6. Waters Corporation: The Art of Separation – SEC for Biotherapeutic Proteins and Peptides</h5><ul><li>Tu, 4.11.2025 16:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5657">Registration</a></li></ul>Master SEC, SEC-MALS, and SEC-MS techniques for analyzing protein size variants and CQAs in biotherapeutic development workflows.<h5>7. Technology Networks: Unlocking High-Value Targets – Chemoproteomics &amp; Covalent MS</h5><ul><li>Tu, 4.11.2025 16:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5634">Registration</a></li></ul>Learn how Evotec’s high-throughput MS and chemoproteomics accelerate covalent inhibitor discovery while reducing off-target effects.<h5>8. Bruker: The Ever-Increasing Challenge of PFAS Analysis</h5><ul><li>Tu, 4.11.2025 16:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5606">Registration</a></li></ul>Explore advanced PFAS workflows using DART, ion mobility, and HRMS to improve completeness, speed, and contamination control.<h5>9. SelectScience: Automation and Integrated QC in Long-Read Sequencing</h5><ul><li>Tu, 4.11.2025 17:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5635">Registration</a></li></ul>Discover how Agilent and PacBio technologies integrate automation and QC to enhance long-read sequencing and variant detection accuracy.<h5>10. Thermo Fisher Scientific: Safeguard Dataset Quality in LC-MS Analysis (SST/IRC)</h5><ul><li>Tu, 4.11.2025 17:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5583">Registration</a></li></ul>Learn how Chromeleon software’s SST/IRC features improve LC-MS system suitability, data integrity, and run control.<h5>11. Waters Corporation: Hidden Threats – Detect Aggregates in Biotherapeutics</h5><ul><li>Tu, 4.11.2025 17:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5562">Registration</a></li></ul>Use high-throughput DLS and BMI workflows to identify oligomers and aggregates for improved biologic safety and stability.<h5>12. Bruker: Flow Chemistry Meets AI and NMR for Next-Gen API Production</h5><ul><li>Tu, 4.11.2025 17:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5561">Registration</a></li></ul>See how AI, NMR, and flow chemistry integrate in real time for scalable, sustainable API manufacturing in the PIPAc project.<h5>13. Separation Science: Automated Sample Prep – Transforming PFAS Analysis</h5><ul><li>We, 5.11.2025 11:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5610">Registration</a></li></ul>Discover Biotage® PrepXpert-8 SPE automation for PFAS analysis, offering high throughput and reproducible sample preparation.<h5>14. Waters Corporation: Method Adjustment Across UHPLC and HPLC Systems</h5><ul><li>We, 5.11.2025 17:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5590">Registration</a></li></ul>Learn practical method adjustment for scaling between UHPLC and HPLC while maintaining analytical performance and accuracy.<h5>15. Thermo Fisher Scientific: Mastering Mass Spectrometry with Chromeleon CDS</h5><ul><li>We, 5.11.2025 20:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5386">Registration</a></li></ul>Explore new Chromeleon 7.4 features to optimize MS workflows, configuration, and performance. Includes live Q&amp;A with Thermo Fisher experts.<h5>16. SCIEX: Applying QTRAP Technology in Quantitative and Qualitative Workflows</h5><ul><li>Th, 6.11.2025 11:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5558">Registration</a></li></ul>Understand SQ, TQ, and QTRAP MS modes. Learn how SIM, MRM, and MRM³ scans enhance quantitation and qualitative depth.<h5>17. Waters Corporation: Becoming a DLS and Dynamics Expert – Part 3</h5><ul><li>Th, 6.11.2025 11:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5336">Registration</a></li></ul>Compare cumulants vs. regularization for DLS data analysis and learn how to choose the right model for your samples.<h5>18. SCIEX: Reporting and Data Export Strategies</h5><ul><li>Th, 6.11.2025 11:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5085">Registration</a></li></ul>Master advanced reporting and data export tools in SCIEX OS software to streamline results and boost data impact.<h5>19. Waters Corporation: Analysis, Mitigation, and Monitoring in Modern Data Governance</h5><ul><li>Th, 6.11.2025 16:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5658">Registration</a></li></ul>Discover how data governance improves risk management, compliance, and data quality in analytical laboratories.<h5>20. Waters Corporation: Cutting-Edge Bioprocessing Analytics for Cell Culture Media</h5><ul><li>Th, 6.11.2025 16:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5637">Registration</a></li></ul>See how bioprocessing analytics provide deeper insights into cell metabolism and process optimization through live demonstration.<h5>21. Thermo Fisher Scientific: From Complexity to Clarity – Smarter PFAS Identification Workflows</h5><ul><li>Th, 6.11.2025 17:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5612">Registration</a></li></ul>Explore how Compound Discoverer 3.5 streamlines non-targeted PFAS identification with faster, more confident results.<h5>22. Waters Corporation: Pushing the Limits of N-1 for Long RNA</h5><ul><li>Th, 6.11.2025 17:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5601">Registration</a></li></ul>Gain insights into sgRNA analysis and LC-MS workflows from Eli Lilly and Waters experts to ensure RNA quality and consistency.<h5>23. Waters Corporation: Becoming a DYNAMICS Expert – Part 4</h5><ul><li>Fr, 7.11.2025 20:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://lcms.labrulez.com/webinar/5338">Registration</a></li></ul>Join Dr. Andy Meyer to explore high-throughput DLS applications for optimizing formulation and stability workflows.

Webinars LabRulezLCMS Week 45/2025

In the week from November 3, the following webinars await you in the field of atomic and molecular spectroscopy and spectrometry<blockquote><h4><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/webinars">👉 DETAILS AND REGISTRATION IN THE WEBINARS SECTION</a></h4>👉 Search and filter in the largest global database with over 5 000 GC, LC, MS and spectroscopy webinars.</blockquote><h5>1. Wiley: Discover Hidden Trends in Spectral &amp; Chromatographic Datasets</h5><ul><li>Tu, 4.11.2025 14:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/webinar/5604">Registration</a></li></ul>Learn how KnowItAll’s Trendfinder uses Principal Component Analysis (PCA) to reveal hidden correlations and trends in large analytical datasets.<h5>2. Bruker: Exploring Multi-Field Layer Thickness Capabilities with Micro-XRF in SEM</h5><ul><li>Tu, 4.11.2025 17:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/webinar/5627">Registration</a></li></ul>Explore the principles of micro-XRF-based layer thickness analysis. Learn how to calculate and interpret layer thickness directly in the scanning electron microscope.<h5>3. Bruker: Flow Chemistry Meets AI and NMR for Next-Gen API Production</h5><ul><li>Tu, 4.11.2025 17:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/webinar/5561">Registration</a></li></ul>Discover how AI, NMR, and flow chemistry integration revolutionize API manufacturing through real-time monitoring, scalability, and sustainable automation.<h5>4. Agilent Technologies: Avoiding Double Charged Interferences on Single Quadrupole ICP-MS</h5><ul><li>Tu, 4.11.2025 21:30 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/webinar/2769">Registration</a></li></ul>Learn how to configure half-mass measurements in your ICP-MS software to minimize double-charged ion interferences and improve analytical accuracy.<h5>5. Technology Networks: Enhancing Pharmaceutical Manufacturing Using Raman Spectroscopy</h5><ul><li>We, 5.11.2025 17:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/webinar/5563">Registration</a></li></ul>See how Raman spectroscopy enhances pharmaceutical manufacturing with fast, non-destructive testing to improve process control and regulatory compliance.<h5>6. Anton Paar: Effortless Particle Size Analysis – See the Difference</h5><ul><li>We, 5.11.2025 18:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/webinar/5636">Registration</a></li></ul>Experience the Anton Paar Litesizer DIF 500 for laser diffraction. Learn how modular Quick-Click design and Kalliope™ software simplify particle size analysis.<h5>7. Bruker: Quantitative CEST MRI – From Principles to Applications in Cancer and Neuroimaging</h5><ul><li>Th, 6.11.2025 10:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/webinar/5397">Registration</a></li></ul>Explore CEST MRI fundamentals, correction techniques, and applications in cancer and neuroimaging, bridging preclinical and clinical research.<h5>8. Bruker: Catch Up with eWARP – Unmatched EBSD Performance</h5><ul><li>Th, 6.11.2025 17:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/webinar/5628">Registration</a></li></ul>Discover how eWARP’s hybrid pixel sensor advances EBSD analysis, offering unmatched speed, resolution, and performance for materials characterization.

Webinars LabRulezICPMS Week 45/2025

Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 3rd 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 Thermo Fisher Scientific and poster by Shimadzu!<h3>1. Agilent Technologies: Estimation of Methyl Bromide Residues in Food</h3>Using the Agilent 8890 GC and Agilent 7010 triple quadrupole GC/MS system with Agilent 8697 headspace sampler<ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_methyl_bromide_food_8890_gc_7010_tq_8697_hs_5994_8499en_agilent_35c0751a37.pdf">Full PDF for download</a></li></ul>Bromomethane (methyl bromide) is a halogenated hydrocarbon with a boiling point of 3.6 °C. It is widely used as a fumigant due to its strong fumigation and penetration effects, effectively controlling pests.1 However, methyl bromide is harmful to the ozone layer, causes environmental pollution, and is harmful to humans.2 By 2015, most countries phased out its production and application, except for essential uses such as port quarantine. China stopped agricultural use of methyl bromide by the end of 2018.2 Despite its high volatility, residues of methyl bromide can persist in foods such as nuts and seeds. Therefore, quantitative methods for determining these residues are important. Gas chromatography (GC) is commonly used for analysis, either directly with headspace sampling, or with sample pretreatment methods including solvent extraction and solid phase microextraction. Various detectors are used with GC, such as the flame ionization detector, electron capture detector, and electron ionization. Detection can also be performed by mass spectrometer, using an electron ionization (EI) source. The maximum residue limit for methyl bromide in the EU is 10&nbsp;ng/g, according to EU Regulation number 396/2005.&nbsp;In this application note, an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1-10&amp;search=8697+headspace+">Agilent 8697 headspace sampler</a> was used for sample introduction to an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1-10&amp;search=8890">Agilent 8890 GC system</a> coupled with an <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=10&amp;search=7010">Agilent 7010 triple quadrupole GC/MS</a> for quantification of methyl bromide residues.<h4>Results and discussion&nbsp;</h4><h5>Calibration&nbsp;</h5>Figures 1 through 3 show the linearity of the methyl bromide calibration curve in rice, cumin powder, and red chili powder, respectively. The R2 obtained was above 0.998.&nbsp;<h5>Repeatability&nbsp;</h5>The repeatability of this method was demonstrated by injecting six replicates of rice, cumin, and red chili powder spiked with 10 ng/g of methyl bromide. The area %RSD and retention time %RSD results are shown in Table 3.&nbsp;<h5>Recovery&nbsp;</h5>Methyl bromide was spiked in samples of rice, cumin, and red chili powder at concentration levels of 10 ng/g. Acceptable recoveries were obtained by quantification through prespike matrix-based calibration. Results are highlighted in Table 4.<h4>Conclusion&nbsp;</h4>An accurate and rugged method was developed which meets the requirements of the EURL for the maximum residue limit of methyl bromide in foodstuffs. This ranges from 10 to 100 ng/g, depending on the commodity (Reg. (EC) number 396/2005) for the analysis of pesticides in rice, cumin powder, and red chili powder. The LOQ of the method was demonstrated at 5 ng/g for all tested matrices. Repeatable results were found for six successive replicates of matrix‑based standards at 10 ng/g concentration levels. Sufficient recoveries were obtained in all tested matrices at 10 ng/g spiked concentration levels. Thus, this study demonstrates the applicability of this method for routine analysis of food samples for methyl bromide at trace levels.<h3>2. EST Analytical: Effect of Split Ratio on USEPA Method 8260 Compounds</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_Effect_Split_Ratio_on_USEPA_8260_Compounds_2b7339c7c7.pdf">Full PDF for download</a></li></ul>Injection size on a GC column is dictated by the diameter of the GC column. Packed columns are usually shorter in length and larger in diameter and are usually filled with a packing coated with stationary phase. Due to their large diameter, packed columns can handle much larger injections. However, since packed columns are shorter in length, compound resolution is more difficult. Capillary columns, on the other hand, are much longer with much smaller diameters. A capillary column has a stationary phase that is coated onto the column wall which in turn makes the diameter even smaller. Overloading is a common problem with capillary columns, thus smaller injections and higher dilutions are required when using a capillary column.&nbsp;The benefit of a capillary column is that it has substantially more theoretical plates than a packed column. Increasing the number of theoretical plates enhances column efficiency because peaks are narrowed and peak resolution is improved. The disadvantage of the capillary column is column overloading. This is where a split injection is greatly beneficial. A split injection can limit sample overload while taking advantage of the efficiency of the capillary column.&nbsp;<h4>Discussion:&nbsp;</h4>Purge and trap sampling is the method used for purging volatile compounds out of a water matrix for USEPA Method 8260. Due to the large number of analytes and the lower detection limits required in this method, a capillary column is needed for detection and separation. Split injections provide a method to control moisture from the purge and trap sampling while preventing column overloading with the capillary column. However, due to the detection limits required of the method, if the split injection is too large, the detection limits of the method may not be met. On the other hand, if the split injection is too small, there can be moisture problems with the mass spectrometer. This application will provide a comparison of several different split rates and their effect on compound detection for USEPA Method 8260.<h4>Experimental:&nbsp;</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 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=1-10&amp;search=7890A">Agilent 7890A GC</a> and <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1-10&amp;search=5975C">5975C </a>inert XL MS. The GC was configured with a Restek Rxi-624 Sil MS 30m x 0.25mm x 1.4µm column. Three different split ratios were used for this study. Refer to Table 1 for the sampling method parameters and Table 2 for GC/MS parameters.<h4>Conclusions:&nbsp;</h4>As USEPA Methods require lower and lower detection limits, split ratios will play a large factor in reaching these new requirements. This study demonstrated that all three split ratios met USEPA Method 8260 requirements for linearity, compound response and method detection limits. However, there was a remarkable difference in compound detection limits as the split ratio was increased. The 40 to 1 split rate had much lower detection limits due to an increase in compound response. The Encon Evolution purge and trap concentrator has a unique feature for moisture control using an eight port valve to avoid desorbing through the moisture trap. This feature enables better moisture control when using a lower split rate, thus using a larger split rate to control moisture is unnecessary.<h3>3. Shimadzu / AOAC: Simultaneous analysis of residual contaminants in drinking water using Programmed Temperature Vaporization (PTV) for Large Volume Injection (LVI) and GC-MS/MS</h3><ul><li>Poster</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/labrulez-bucket-strapi-h3hsga3/aoac_2025_w016_04bda0b617.pdf">Full PDF for download</a></li></ul>This study aimed to develop a single analytical method for the simultaneous analysis of over 60 residual contaminants, including Poly-Aromatic Hydrocarbons (PAH), Poly-Chlorinated Biphenyls (PCB), and pesticides, in drinking water. Traditionally, multiple methods are being employed for analyzing these contaminants. Most common ones include, extraction using solvents in large separating funnel or SPE cartridge followed by volume concentration by evaporation. These methods require huge sample and solvent quantities. Due to these factors like large sample size handling, concentration steps etc., method may show poor reproducibility.&nbsp;By utilizing Programmed Temperature Vaporization (PTV) for Large Volume Injection (LVI), the method significantly reduces the initial sample amount required for preparation, pre-treatment steps, and solvent consumption compared to conventional approaches, while eliminating the need for final sample concentration. The optimized procedure achieved limits of quantification (LOQs) as low as 0.005 ppb and 0.05 ppb, demonstrating high sensitivity without compromising efficiency. Validation parameters like specificity, linearity, recovery and precision were studied as per SANTE guidelines[1] . For linearity and recovery study, matrix match calibration was used.<h4>Materials and methods&nbsp;</h4>For this study, reference standard mixtures of over 60 contaminants regulated in drinking water were procured from Restek® Corporation. It included PAH, PCB and GC amenable pesticides. Drinking water sample was extracted and used to prepare matrix-matched calibration standards and spiked samples. This method was validated for criteria mentioned in SANTE Guidelines. <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/library?mainauthorItems=1&amp;search=GCMS-TQ8040+NX">GCMS-TQ8040 NX</a> (Figure 2), manufactured by Shimadzu Corporation Japan, was used to quantify residual contaminants in drinking water sample.<h4>Conclusion</h4><ul><li>This study shows that the extraction of reduced sample quantity combined with LVI of 50 μL on GC-MS/MS system is a reliable and efficient tool to simultaneously quantify residual contaminants like PAH, PCB and pesticides in drinking water sample.</li><li>Also, highly sensitive Shimadzu GC-MS/MS allows trace level detection even without the need of evaporating &amp; concentrating the sample. This helps in ruggedness resulting in reproducible detection of analytes.</li><li>The combination of sensitive instrument and reproducible extraction method enables its use in testing laboratories for residual contaminants analysis in drinking water.</li></ul><h3>4. Thermo Fisher Scientific: Automated liquid-liquid extraction workflow for direct ultra-trace analysis of pesticides and PAHs in water matrices 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_003943_gc_autosampler_triplus_rsh_smart_environmental_an003943_na_en_b9980f4e3e.pdf">Full PDF for download</a></li></ul>Ensuring high standards of water quality is a fundamental priority within the European Union. This is highlighted through stringent EU regulations, such as the Water Framework Directive and the Drinking Water Directive,1 where protection of the environment and safeguarding public health are of utmost importance. As such, regular monitoring of both surface and drinking water for hazardous semi-volatile organic compounds, such as polyaromatic hydrocarbons (PAHs) and pesticides, is needed.1,2&nbsp;To meet regulatory compliance, laboratories are required to reach ultra-trace levels (i.e., parts per-trillion (ng/L)), while maintaining analytical method performance criteria outlined under EU Directive 2020/2184.3 To reach required concentration limits, laboratories typically need to extract large sample volumes using solvent (i.e., liquid-liquid) or sorbent-based (i.e., solid-phase) extraction techniques with additional preconcentration.Such techniques involve manual operations, which are costly in terms of consumables and time. However, automated sample preparation and extraction can reduce such costs while helping to eliminate systematic errors to improve data quality and lab efficiency.&nbsp;The aim of this work was to evaluate the sensitivity, precision, and robustness of the TriPlus RSH SMART autosampler in performing automated liquid-liquid extraction and on-line analysis of polyaromatic hydrocarbons (PAHs) and pesticides in drinking and surface water using triple quadrupole GC-MS/MS. This study will demonstrate that the developed automated workflow is compliant with EU regulation criteria and greatly increases laboratory productivity by reducing laboratory costs and time.<h4>Experimental</h4><h5>Instrument and method setup&nbsp;</h5>A <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/486">Thermo Scientific™ TRACE™ 1610 GC </a>equipped with a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/1744">Thermo Scientific™ TraceGOLD™ TG5-SilMS</a> (30 m × 0.25 mm I.D. × 0.25 µm film) capillary column with a 5 m integrated SafeGuard retention gap (P/N 26096-1425) was used to perform the chromatographic separation. The <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/422">TriPlus RSH SMART autosampler</a> was configured to perform automated sample preparation, liquid-liquid extraction, and on-line injection for GC-MS/MS analysis. The automated workflow was designed using the Thermo Scientific™ TriPlus™ RSH Sampling Workflow Editor Software (P/N 1R77010-1200) and imported into the <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/76">Thermo Scientific™ Chromeleon™ 7.3.2 Chromatography Data System (CDS) software</a>. This integration allows sample preparation, acquisition, and data processing to be carried out within a single software. The automated workflow involved the following steps: internal standard addition, extraction solvent addition (pentane) and vortexing for extraction, addition of solvent for emulsion removal (isopropyl alcohol), addition of syringe standard prior to analysis, and large volume injection into the GC-MS. Parameter settings for the automated workflow are outlined in Table 1 with a visual overview provided in Figure 1. A list of accessories needed to configure the TriPlus RSH SMART autosampler is provided in the appendix (Table A2).&nbsp;After sample extraction was completed, a 30 μL aliquot of the pentane layer was directly injected into a programmable temperature vaporization (PTV) inlet. Injection and oven program conditions can be found described in Tables 1 and 2. Data acquisition was carried out using selected reaction monitoring (SRM) with a <a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/products/485">Thermo Scientific™ TSQ™ 9610 triple quadrupole GC-MS</a> equipped with an Advanced Electron Ionization (AEI) source. Method parameters for data acquisition are summarized in Table 2 with optimized SRM transitions outlined in the appendix (Table A3).<h4>Conclusions&nbsp;</h4>Maintaining water quality is of both human and environmental health importance. However, due to the physical chemical properties of various organic substances, analytical methods require ultra-trace sensitivity and accuracy to quantify hazardous risks within both drinking and environmental surface waters. The results presented demonstrate that the developed automated workflow for online liquid-liquid extraction and analysis of water samples can meet these requirements:&nbsp;<ul><li>Ultra-trace sensitivity combining large volume injection with highly sensitive triple quadrupole GC-MS/MS, with over 70% of targeted analytes having limits of quantification below 2 ng/L&nbsp;</li><li>Compliant extraction recovery at part per trillion concentrations&nbsp;</li><li>Robust method precision over extended analysis time&nbsp;</li><li>Improved laboratory efficiency and productivity while reducing environmental impact with limited solvent consumption&nbsp;</li><li>Workflow customization capability through the Sampling Workflow Editor software</li></ul>

News from LabRulezGCMS Library - Week 45, 2025

News from LabRulezLCMS Library - Week 45, 2025

Our Library never stops expanding. What are the most recent contributions to LabRulezICPMS Library in the week of 3rd November 2025? Check out new documents from the field of spectroscopy/spectrometry and related techniques!<blockquote>👉 <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library">SEARCH THE LARGEST REPOSITORY OF DOCUMENTS ABOUT SPECTROSCOPY/SPECTROMETRY 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://gcms.labrulez.com/library">LabRulezGCMS</a> libraries.</blockquote>This week we bring you application notes by LECO and Shimadzu and poster by Thermo Fisher Scientific!<h3>1. LECO: Determination of Carbon, Hydrogen, and Nitrogen in Biomass</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/labrulez-bucket-strapi-h3hsga3/CHN_828_CARBON_HYDROGEN_NITROGEN_BIOMASS_203_821_665_bccca204f2.pdf">Full PDF for download</a></li></ul>Carbon, Hydrogen, and Nitrogen determination is part of the ultimate analysis of solid biofuel materials. Determining the content of these elements can help to characterize the materials and provide information that can be utilized in calculating material/energy balances. In addition, this information may be used to calculate efficiencies, as well as emissions potentials, for solid biofuel materials.&nbsp;<h4>Instrument Model and Configuration&nbsp;</h4>The <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library?mainauthorItems=24&amp;search=CHN828">LECO CHN828</a> is a combustion Carbon, Hydrogen, and Nitrogen determinator that utilizes a pure Oxygen environment in a vertical quartz furnace, ensuring complete combustion and superior analyte recovery. Combustion gases are swept from the furnace through an afterburner containing a reagent to scrub Sulfur compounds from the gas stream prior to collection in the ballast volume. The combustion gases are collected in a ballast where they equilibrate and mix before a representative aliquot (3 cm3 or 10 cm3 volume) of the gas is extracted and introduced into a flowing stream of inert gas (Helium or Argon) for analysis. The aliquot gas is carried to an infrared cell (IR) for the detection of Carbon (CO2) and a thermal conductivity cell (TC) for the detection of Nitrogen (N2). A separate portion of the ballast gas is transferred to an IR cell for the detection of Hydrogen (H2O).&nbsp;Thermal conductivity detectors work by detecting changes in the thermal conductivity of the analyte gas compared to a reference/carrier gas. The greater the difference between the thermal conductivity of the carrier gas and the analyte gas, the greater the sensitivity of the detector. The CHN828 supports either the use of Helium or Argon as the instrument's carrier gas. When used as a carrier gas, Helium provides the highest sensitivity, and the best performance at the lower limit of the Nitrogen range. Argon can also be used as a carrier gas. However, the thermal conductivity difference between Argon and Nitrogen is not as great as the thermal conductivity difference between Helium and Nitrogen, therefore the detector is inherently less sensitive when using Argon as a carrier gas.&nbsp;<h4>TYPICAL RESULTS&nbsp;</h4>Data was generated utilizing a linear, full regression calibration for Carbon determination, and linear, force through origin calibrations for Hydrogen and Nitrogen determination, using fractional masses (~0.07 g to ~0.15 g) of 502-642 (Lot 1019) LCRM Phenylalanine (65.47% C, 6.74% H, 8.46% N). The calibration was verified using LECO 502-896 (Lot 1003) LCRM EDTA (41.08% C, 5.52% H, 9.58% N). An atmospheric blank was determined using ground sucrose and was utilized to compensate for entrapped atmosphere. A moisture value for the samples was obtained utilizing a LECO TGM800 on the day of analysis and entered into the software to correct for moisture. Results are reported on a dry basis.<h3>2. Shimadzu: Ultrasonic Fatigue Test for Hourglass-shaped Metal Test Specimens with Parallel Sections</h3><ul><li>Application note</li><li><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/labrulez-bucket-strapi-h3hsga3/an_01_00889_en_6ce0f2e7e9.pdf">Full PDF for download</a></li></ul><h4>User Benefits</h4><ul><li>The ultrasonic fatigue tester is capable of testing at a repetition rate of 20 kHz and can complete tests with 109 cycles (1 billion cycles) in only about 14 hours.</li><li>It is possible to test hourglass-shaped test specimens with parallel sections specified in the Chinese National Standard GB/T 43896 “Metallic materials-Very high cycle fatigue-Ultrasonic fatigue test method.”&nbsp;</li></ul>Fatigue is a fracture phenomenon caused by repeated loads, even within the elastic region. It is said that about 70 % of structural fracture phenomena are caused by metal fatigue. For most structural steels, there is a fatigue limit where fatigue failure does not occur even after repeated loading if the stress is less than a certain value, and the number of cycles is about 106 to 107. However, in high-strength steels such as chromium molybdenum steel, it is known that fatigue failure occurs in the ultra-high cycle range of 108 to 109 cycles, exceeding 107 cycles, due to inclusions in the material. Therefore, the standard of 107 repetitions as the maximum number of repetitions used in general fatigue tests is not sufficient, and fatigue tests with more than 109 cycles are required. On the other hand, a fatigue test with more than 109 cycles would take more than 3 years at a 10 Hz load. The ultrasonic fatigue tester used in this study is capable of testing at 20 kHz and can complete tests with 109 cycles in about 14 hours, making it ideal for measuring ultra-high cycle fatigue.&nbsp;In previous reports1,2), we conducted tests on standard hourglass specimens. In November 2024, the National Standard GB/T 43896 of the People's Republic of China (Metallic materials- Very high cycle fatigue-Ultrasonic fatigue test method) was issued, so Shimadzu has added a new dimension calculation function for hourglass-shaped specimens with parallel sections to its USF2000A dedicated software, Super Sonic. In this paper, we introduce an example of measurement of an hourglass-shaped specimen with a parallel section in compliance with GB/T 43896 using SNCM439, a type ofstructuralsteel.<h4>Instruments&nbsp;</h4>The <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/library?mainauthorItems=1&amp;search=USF-2000A">USF-2000A</a> was used in this test. Table 1 shows the testing equipment and Fig. 1 shows the test setup. In the ultrasonic fatigue test, a longitudinal wave vibration generated by a piezo actuator causes the specimen to resonate, and stresses are applied to the specimen. The cyclic stress is not measured using a load cell, but is calculated based on the displacement of specimen's end face. In this test, an eddy current displacement meter was used to measure the displacement of the end face.&nbsp;In the ultrasonic fatigue test, internal heat generation occurs due to the high repetition rate. According to GB/T 43896, the surface temperature of the high-stress part of specimen is measured, and the specimen temperature during the test is required to be within room temperature +10 °C. In order to suppress the temperature rise of the specimen, an air cooler was employed to blow cooling air onto the heated region, and intermittent operation was performed as described below.<h4>Conclusion&nbsp;</h4>In these tests, ultrasonic fatigue tests were conducted on SNCM439 hourglass-shaped specimens with a parallel section in accordance with the Chinese National Standard GB/T 43896, “Metallic materials-Very high cycle fatigue-Ultrasonic fatigue test method,” and S-N diagrams were obtained.<h3>3. Thermo Fisher Scientific: Benefits of coupling a high-speed laser ablation system to Quadrupole Inductively Coupled Plasma Mass Spectrometry (ICP-MS)</h3><ul><li>Poster</li><li><a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/labrulez-bucket-strapi-h3hsga3/po_12348_high_speed_laser_ablation_system_po12348_en_9c310f2096.pdf">Full PDF for download</a></li></ul>Laser Ablation (LA) coupled with ICP-MS is a well-established way to directly analyze solid samples. The main advantages of laser ablation include the ability to avoid lengthy and potentially contamination prone sample preparation protocols and the ability to obtain information about the spatial resolution of an analyte in a sample.&nbsp;The interest in so-called mapping techniques has increased in recent years, calling for laser ablation systems to develop methods to improve sample transfer and therefore speed of mapping experiments. New laser-ablation systems dedicated to high-speed mapping are commercially available and can be easily coupled to quadrupole ICP-MS for such applications.With the improvement in sample transfer and washout times from laser ablation systems, the time available to analyze discrete packets of sample from a laser pulse is drastically reduced. The limit for lateral resolution using a sequential ICP-MS, such as a quadrupole ICP-MS, is dependent on the dwell times chosen for each measured m/z channel. This has a direct impact on the signal-tobackground ratio achievable for each m/z channel; therefore, a direct impact on the final image contrast for each mapped m/z channel.<h4>MATERIALS AND METHODS</h4><h5>Instrumentation&nbsp;</h5>A Teledyne Photon Machines Iridia Laser Ablation System fitted with a Cobalt lowdispersion ablation chamber was directly coupled with a <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/products/1206">Thermo Scientific™ iCAP™ TQ ICP-MS</a>. Data was acquired using <a target="_blank" rel="noopener noreferrer" href="https://icpms.labrulez.com/products/1489">Thermo Scientific™ Qtegra™ Intelligent Scientific Data Solution™ (ISDS) Software</a> and processed using Teledyne Photon Machines HDIP Mass Spectrometry Data Analysis Software.<h4>CONCLUSIONS&nbsp;</h4>Through careful optimization of laser ablation and ICP-MS parameters, it is possible to generate high quality multi-elemental images at a fast rate. The use of new low-dispersion laser ablation cells and aerosol transfer technology is not limited to simultaneous mass spectrometers and is also applicable to sequential scanning mass spectrometers such as Quadrupole ICP-MS.&nbsp;The major limitation of coupling low-dispersion Laser Ablation systems to sequential mass spectrometers is the limited number of elements that can be scanned; however, this is offset by the sensitivity and the specificity of, especially, triple quadrupole ICP-MS systems for the reduction of interferences on select analytes.&nbsp;Most imaging experiments can be reduced to three or four analytes of interest, and in these cases LA-ICP-MS coupled to Triple Quadrupole ICP-MS using a low-dispersion, fast imaging setup can provide the analytical data quality required to answer challenging research questions.

News from LabRulezICPMS Library - Week 45, 2025

In the week of November 10, the following webinars await you in the field of gas / solid phase and especially Raman, FTIR, GC and GC/MS.<blockquote><h4><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinars">👉 DETAILS AND REGISTRATION IN THE WEBINARS SECTION</a></h4>👉 Search and filter in the largest global database with over 5 000 GC, LC, MS and spectroscopy webinars.</blockquote><div><div><div><div><div><div><h5>1. Wasson-ECE Instrumentation: Calibration Techniques for Accurate Data</h5><ul><li>Tu, 11.11.2025 09:30 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinar/5526">Registration</a></li></ul>Learn best practices for GC calibration, including multi-point curve generation, standard preparation, and maintaining data integrity for precise analytical results.<h5>2. Metrohm: Through-Container Raman for Chemicals, Raw Materials, and Field Response</h5><ul><li>Th, 13.11.2025 15:00 CET</li><li><a target="_blank" rel="noopener noreferrer" href="https://gcms.labrulez.com/webinar/5665">Registration</a></li></ul>Discover how through-container Raman spectroscopy identifies chemicals directly through opaque containers, improving safety, compliance, and workflow efficiency.</div></div></div></div></div></div>

Webinars LabRulezGCMS Week 46/2025

Article

Product

Events

Webinars

Application

Academy

Video

Poster

Scientists

Plastics

Environment

Food

Water

Health

Presentation

Scientific article

Interview

Toxicology

Popularization

Science and research

Software

Covid-19

Career

Laboratories

Various

PFAS 

Zaměření

Type of News

Focus

Everything from the world of analytical chemistry in one place. We connect people in solving their problems. At Labrulez you will find all the necessary information easily, quickly and clearly. Stop searching and start finding.

Webinars LabRulezGCMS Week 46/2025

News from LabRulezICPMS Library - Week 45, 2025

News from LabRulezLCMS Library - Week 45, 2025

News from LabRulezGCMS Library - Week 45, 2025

Webinars LabRulezICPMS Week 45/2025

Webinars LabRulezLCMS Week 45/2025

Webinars LabRulezGCMS Week 45/2025

Synthesis and Evaluation of Pyridine-Based Antibacterial Agents that Inhibit ATP Synthase in Acinetobacter baumannii

Semisynthesis of Stable Isotope-Labeled Ergot Alkaloids for HPLC-MS/MS Analysis

Determination of Chemical Mixtures in Environmental, Food, and Human Samples Using High-Resolution Mass Spectrometry-Based Suspect Screening Approaches

Upcoming events

Analytical Insights Tour: From Food to Nutraceuticals

LECO Training Course Pegasus BT/BT4D BTX/BTX4D

LECO Training Course CS-744/844 Series & ON/ONH-736/836 Series

Webinars

Extending the power of LC MS/MS: advanced workflows with QTRAP®

Liner selection and injection techniques in GC

Future Days: Catalysts, What Will Define the Next Decade of Catalysis?