News from LabRulezGCMS Library - Week 6, 2025

Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 3rd February 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 applications and other documents by Shimadzu, Agilent Technologies and Thermo Fisher Scientific!

1. Analysis of Essential Oils Using Comprehensive Two-Dimensional Gas Chromatography (GC × GC) and High-Resolution Mass Spectrometer

• Application note
• Full PDF for download

The analysis of complex samples such as essential oils can benefit substantially from comprehensive two-dimensional gas chromatography (GC × GC), which provides a high degree of chromatographic separation due to the second dimension. Combining GC × GC with high-resolution accurate mass measurement increases the number of identifiable components and enhances confidence in the results.

The focus of this study was to establish a workflow for the analysis of essential oils using GC × GC with a reverse flow modulator (RFM) combined with a high-resolution quadrupole time-of-flight (GC/Q-TOF) mass spectrometer.

Experimental

The samples were separated on an Agilent 8890 GC using a GC × GC configuration with an RFM and analyzed using a high-resolution accurate mass Agilent 7250 GC/Q-TOF MS as well as an FID. A "normal" column set, combining a nonpolar primary column and a polar secondary column, was used. This set consisted of a 20 m × 0.1 mm, 0.1 μm Agilent DB-1ms column (100% dimethylpolysiloxane) and a 5 m × 0.25 mm, 0.15 μm Agilent DB-17ms column (equivalent to (50%-phenyl)-methylpolysiloxane).

To decrease flow to the MS, and to add an FID to the configuration as a second detector, the column flow must be split at the end of the secondary column by connecting it to a splitter. Two splitter types, purged and unpurged, have been explored to highlight the benefits and limitations of each configuration. In the case of a purged splitter, the column flow mixes with the makeup flow before splitting between the two detectors. In contrast, an unpurged splitter does not use makeup flow when splitting the column effluent between the two restrictors connected to the two detectors. A second FID (monitor, or vent) channel was added for method optimization and troubleshooting.

Conclusion

In this application note, a method for the analysis of essential oils using several comprehensive GC × GC configurations with a reverse flow modulator (RFM) and a high-resolution Agilent 7250 GC/Q-TOF system was developed. Method optimization was performed using a diesel sample. Essential oil components, separated by GC × GC, were reliably identified using the Unknowns Analysis tool. Agilent Mass Profiler Professional (MPP) software successfully determined the differences in chemical composition between the essential oils.

2. Utilizing hydrogen carrier gas for sensitive analysis of pesticides in food using gas chromatography mass spectrometry

• Poster / ASMS
• Full PDF for download

Purpose: To demonstrate the performance of the Thermo Scientifc HeSaver-H2Safer kit for iConnect split-splitless (SSL) injection module for trace analysis of pesticides using H2 as a carrier gas as a safe and sustainable solution for laboratory operations.

Methods: In this study, hydrogen was used as a carrier gas for GC-MS/MS analysis of trace levels of pesticides in food. The GC was fitted with a new hydrogen safer split/splitless injector, with chromatographic separation performed on a TG-5 SIL MS(30 m × 0.25 mm, 0.25 μm) capillary GC column. The chromatographic conditions applied ensured critical pair separation was achieved. The GC-MS/MS system was equipped with an advanced electron ionization (AEI) source to increase sensitivity for analyte detection. Quantification and assessment of critical regulatory requirements, such as linearity and sensitivity, were performed in a single software.

Conclusions

• The use of the HeSaver-H2Safer technology allows for a safe and compliant use of hydrogen as an alternative carrier gas in GC/GC-MS applications without the need to install a hydrogen sensor and removes any risk of unwanted reactions with the sample in the hot SSL injector.
• When used with hydrogen, the limited carrier gas consumption offered by the HeSaver-H2Safer mode permits a very controlled system demand for hydrogen, making this solution ideal for laboratories working with hydrogen generators.
• Migrating the GC-MS/MS method from helium to hydrogen requires an adaptation of method parameters to address (i.e., retention time shift and different fragmentation patterns).
• 97% of pesticides in baby food and 98% in honey showed a linear response in the concentration range 0.005–0.500 mg/kg and the relative standard deviation for N=5 repeats of each sample type at 0.01 mg/kg was equal or lower than 10% for 98% of the evaluated compounds.

3. Analysis of VOC and SVOC Emissions from Automotive Interior Materials Using GCMS-QP2050 in Accordance with ISO 12219-11

• Application note
• Full PDF for download

User Benefits

• The GCMS-QP2050 features a new interface that enables good peak shape and sensitivity even when analyzing compounds with high boiling points.
• When used with the TD-30R thermal desorption system, it can analyze compounds in accordance with ISO 12219-11.
• The TVOC Calculation Tool can calculate in a simple manner quantitative emissions (toluene and hexadecane equivalents) in accordance with ISO 12219-11.

Introduction

In recent years, measures to reduce the use of organic compounds in automotive interiors have progressed, the ISO 12219-11 standard is being developed for the analysis of volatile organic compounds (VOCs) and semi-volatile organic compounds (SVOCs) that are emitted from automotive interior materials. The ISO 12219-11 analytical procedure involves filling a thermal desorption (TD) glass tube with a sample of materials, heating the tube using TD, and loading the VOCs (up to C25) and SVOCs (C14 to C32) that were emitted from the sample into a GC-MS system for analysis. Although this standardized procedure enables simple and quick analysis of VOC and SVOC emissions from these materials, contamination of the MS system caused by the simultaneous loading of compounds with high boiling points is a problem.

As shown in Fig. 1, the GCMS-QP2050 is equipped with a new contamination-resistant ion optical system that effectively minimizes contamination of the MS. Featuring a new interface (Fig. 2) that enables good peak shape and sensitivity even for compounds that are typically prone to adsorption, it is optimally suited to analyzing SVOCs, including those with high boiling points.

TD-30R and GCMS-QP2020 NX will be listed as examples for suitable test equipment on ISO 12219-11. This Application News describes analyzing VOC and SVOC emissions from the materials of vehicle interiors in compliance with ISO 12219-11 using the GCMS-QP2050 together with the NexisTM GC-2030 and the TD-30R thermal desorption system.

Conclusion

Using the new GCMS-QP2050, it was possible to consistently analyze SVOCs and other compounds with high boiling points. By combining this system with the TD-30R thermal desorption system and the TVOC Calculation Tool, even inexperienced users can rapidly analyze automotive interior materials and quantify emissions (i.e., calculate toluene and hexadecane equivalents) in compliance with ISO 12219-11.