News from LabRulezGCMS Library - Week 32, 2025

Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 4th August 2025? Check out new documents from the field of the gas phase, especially GC and GC/MS techniques!

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This week we bring you poster by Agilent Technologies / ASMS, application note by Shimadzu, presentation by PSL RESEARCH UNIVERSITY / MDCW and technical note by Thermo Fisher Scientific!

1. Agilent Technologies / ASMS: Investigation and Profiling of the Aroma Components by GC-SICRIT-QTOF 

• Poster
• Full PDF for download

Volatile aroma components possess significant value in flavor research. Conventional GC-MS analysis, reliant on the NIST library, is more adept at identifying known components. In contrast, LC-QTOF which exhibits strong identification capabilities, demonstrates limited ionization efficiency for volatile substances.

GC-SICRIT-QTOF, a hybrid technique, synergizes the separation capabilities of GC for volatiles, the ionization strength of SICRIT for alkenes and enols, and the powerful identification capacity of QTOF, highly suitable for the detection and profile of volatile aroma components.

Experimental

• Agilent 6546 Q-TOF Mass Spectrometer
• SICRIT ion source (Plasmion GmbH, Germany
• Agilent 8860 GC System

Results and Discussion

Target Extraction and Confirmation 

Without sample preparation, volatile aroma components can be directly analyzed 6546 QTOF equipped with the SICRIT ion source, obtain MS and Auto MS/MS spectra within 1 min. For example, in positive ion mode, we can observe [M+H]+ and [M+NH₄ ]⁺ ions for common organic solvents such as water, alcohol, acetonitrile and so on. If we spike ethanol vapor to nitrogen gas, less than 0.1% can be detected with 10e4~5 intensity (Figure 1). 

It is also possible to find volatilizable components in complex mixtures. Figure 2 shows some examples. Butanediol is a major component in essence. Besides of alcohol, it is also possible to find esters in Chinese liquor. Alkenes and enols are main aroma components in Sichuan pepper. Their formulas are proved by accurate mass and isotope patterns.

GC Coupling for isomers separation

 Pepper samples contain many isomers with the same formula but different aromas. We use 8860 GC to separate these isomers, combined with SICRIT-QTOF for ionization and acquiring mass spectra. The system demonstrates a robust response to the volatile gas components of Sichuan pepper, with a significant number of signals observed in the total ion chromatogram (TIC, Figure 3). 

For the known volatile components, the GC-SICRIT-QTOF system can identify many isomers by quasi-molecular ion extraction. For example, C10H16, includes myrcene with peppery aroma, limonene with the flavor and fragrance of oranges, sabinene with woody and spicy aroma. RT, MS and MS/MS spectra can be used for identification by the support of reference and PCDL database. 

Conclusions

GC-SICRIT-QTOF is a powerful tool for volatile aroma component analysis. It combines the separation capabilities of GC, the ionization strength of SICRIT for low polar components, and the identification power of QTOF. 

Compare to GC-MS, this system shows quasi-molecular ions, which can be used in identification and discover new component using non-targeted extraction. Soft ionization is also suitable for fast screening and profiling without preparation. 

GC-SICRIT-QTOF facilitates the analysis of complex mixtures. It was demonstrated in the research of Sichuan pepper, including the target extraction, unknown analysis and profiling. It will contribute to the development of new food products, fragrances, and other applications in the flavor industry.

2. PSL RESEARCH UNIVERSITY / MDCW: TOWARDS A BETTER UNDERSTANDING OF THE BODY VOLATOLOME: FOCUS ON ENDOGENOUS PARAMETERS INFLUENCING BODY VOLATOLOME COMPOSITION 

• Presentation
• Full PDF for download

The human body emits a wide range of volatile organic compounds (VOCs), collectively known as the body volatolome. This study aimed to better understand how endogenous parameters—such as age, sex, and anatomical sampling site—influence the composition of these compounds. Using skin sampling devices (SkinVOCs®) and comprehensive GC×GC-TOF-MS, researchers profiled VOCs from different body areas of volunteers while controlling for exogenous factors like deodorants or perfumes.

Principal Component Analysis (PCA) and Partial Least Squares Discriminant Analysis (PLS-DA) revealed clear distinctions in VOC profiles based on sampling site and age. For instance, armpit VOCs showed age-dependent differences, particularly in the levels of steroids and known odor-active molecules like E-3-methyl-2-hexenoic acid. Interestingly, left-right body symmetry was confirmed, suggesting that bilateral samples from the same person can be used as replicates. Some molecules were identified as gender-specific, and although some trends contradicted literature findings, most supported age and sex influence on volatolome composition.

The study concludes that age- and gender-matched sampling is essential in clinical volatolomics research to avoid confounding variables. These findings pave the way for developing personalized diagnostics and deeper understanding of skin VOCs in health and disease.

3. Shimadzu: Multiresidue Pesticides Analysis in Cumin Seeds Using GCMS-TQ8040 NX 

• Application note
• Full PDF for download

Cumin (Cuminum cyminum) has been used as a natural medicine for over 2000 years. It shows anti-inflammatory property and supports the immune system. Cumin seeds (Figure 1) have been widely used as a spice in many food preparations. To fulfil the high-demand of such spices, pesticides are widely used. But their overuse may cause acute and permanent health problems in humans. Therefore, to protect human health, the European Union has set maximum residue limits (MRLs) for the presence of pesticides in cumin seeds[1]. Thus, increasing the importance of having analytical method for determination of residual pesticides present in it.

This study reports a validated method for the determination of 169 pesticides in cumin seeds of Indian origin using Shimadzu GCMS-TQ8040 NX (Figure 2). The multi-residue extraction was performed using QuEChERS extraction method[2].

Materials and Methods 

The reference standards for this study were procured from Restek with below catalogue number: GC multi-residue pesticides kit – 32562 Cumin seeds procured from local market, were used to prepare matrix-matched calibration standards and spiked samples. This method is validated for criteria as mentioned in SANTE Guidelines[3]. GCMS-TQ8040 NX, manufactured by Shimadzu Corporation Japan, was used to quantify residual pesticides in cumin seeds sample.

Conclusion 

A validated method was developed as per SANTE guidelines for determination of 169 pesticidesin cumin seeds. QuEChERS’ extraction was used for quantifying residual pesticides in this complex spice matrix containing essential oils, cuminaldehyde, pigments etc. The instrumental MRM method was effortlessly created using Smart Pesticides Database. The combination of highly sensitive Shimadzu GC-MS/MS and reliable method showed reproducibility < 20% (as per SANTE guidelines) at LOQ levels. This enables its use in testing laboratories for multi-residue analysis in cumin seeds.

4. Thermo Fisher Scientific: What is the benefit of high mass resolving power on the Orbitrap Exploris GC Series? 

• Technical note
• Full PDF for download

Why do I need high mass resolving power from Orbitrap technology? 

• Resolve target analytes from interfering compounds and matrix ions of similar mass. 
• Achieve sub-ppm mass accuracy to give data certainty in compound identification. 
• Sub-ppm mass accuracy enables narrow mass extraction windows (± 5 ppm) to give high selectivity, which in turn makes peak detection algorithms efficient. 
• Easily increase scope of analysis through full scan accurate mass data acquisition (Figure 1). 
• Quickly and confidently propose elemental compositions for the identification of unknown features. 
• Retrospective data processing of samples long after data acquisition. 
• Have high mass resolving power and sensitivity. No compromise. 

With resolving power of up to 240,000 and consistent sub-ppm mass accuracy, the Thermo Scientific™ Orbitrap Exploris™ GC 240 mass spectrometer is a unique laboratory tool for targeted and discovery workflows, where screening, quantitation, compound identification, and structural elucidation applications are required. 

High-resolution Orbitrap mass spectrometry has been available with both liquid and gas chromatography for many years and has proven to be a highly valuable analytical technique.1-4 More recently, the technology in gas chromatography moved to join the Thermo Scientific Orbitrap Exploris Mass Spectrometer series. This new platform of a benchtop hybrid quadrupoleOrbitrap mass spectrometer opens up research opportunities in a system with a significantly reduced footprint, saving both energy and raw materials. The benchtop hybrid quadrupole-Orbitrap mass spectrometer provides new possibilities for increased mass accuracy, sensitivity, and selectivity for GC-amenable compounds. Figure 2 shows how the resolving power is in the ideal range for volatile small molecules, with resolving power increasing with lowering m/z.

The impact of mass resolution on selectivity for targeted analysis 

High-resolution, accurate-mass (HR/AM) experiments typically provide a full scan analysis of a sample, and for small molecule analyses, the scan range is typically 50–600 Da. Orbitrap technology provides the required selectivity to resolve the target compound from other compounds or from matrix ions of similar mass. For targeted compound analysis, the accurate mass of the diagnostic ion is extracted with a narrow mass extraction window (typically < 5 ppm). This narrow window is possible only when the instrument provides sufficient mass accuracy, for which high mass resolving power is essential. However, when two mass profiles overlap, the measured mass profile is the sum of the two individual profiles. This overlap results in the incorrect assignment of the mass of the target compound. The problem is demonstrated in Figure 3, where a QuEChERS leek extract in acetonitrile was analyzed four times at resolving powers of 15K, 30K, 60K, and 120K (m/z 200). 

Being able to separate two compounds that are close in mass is one of the significant advantages of high-resolution accurate mass. This is demonstrated in Figures 4A-C where the compounds flurenol methyl ester C₁₅H₁₂O₃ m/z = 240.0781 and dimetilan C₁₀H₁₆N₄O₃ m/z = 240.1217 were analyzed at equal intensity at three different resolving power levels of 30,000, 60,000, and 240,000. The zoomed spectra show excellent separation at all resolution levels, with improvements at 60K and 240K showing the clear benefits. When analyzed at 10:1 ratio (Figure 5), there is still good separation and mass accuracy. The latter reflects the real world where compounds will be at varying intensities, and it is essential that mass accuracy is maintained to make confident identifications.