News from LabRulezGCMS Library - Week 43, 2024

Our Library never stops expanding. What are the most recent contributions to LabRulezGCMS Library in the week of 21st October 2024? Check out new documents from the field of the gas phase, especially GC and GC/MS techniques!

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👉 Need info about different analytical techniques? Peek into LabRulezLCMS or LabRulezICPMS libraries.

This week we bring you applications by Agilent Technologies, Thermo Fisher Scientific, and Shimadzu and a presentation by James Little - Mass Spec Interpretation Services!

1. Shimadzu: Ethylene Oxide and 2-Chloroethanol in Various Rice Samples by Dynamic Headspace and GC- MS/MS

• Application

User Benefits

• Simple sample preparation procedure, direct sample analysis
• Sample recovery within 70 % to 130 % without matrix-matched calibration curves

Introduction

Ethylene oxide (EO) is sometimes used as a fumigant on food products to control pests and insects during storage and transportation. However, residue of EO might remain in the products, raising concerns about the potential health risks associated with it. Therefore, it is essential to monitor and analyze ethylene oxide levels in food product to ensure compliance with safety regulations and protect consumer health. In this study, both ethylene oxide (EO) and 2-chloroethanol (2-CE) in rice were analyzed. 2-CE, a potential byproduct of EO fumigation, is also a compound of interest due to its toxicity and potential health implications. By utilising dynamic headspace and GC-MS/MS, precise and sensitive detection of both EO and 2-CE residues in rice samples can be achieved. The limit of quantitation is 5 ng/g with area %RSD (n=5) for EO and 2-CE at 5.6 % and 4.9 %, respectively. The spike recovery study at concentrations of 10 ng/g, 25 ng/g and 100 ng/g yielded recoveries within 70 %-130 %. This comprehensive analytical approach enables accurate quantification and identification of these compounds, significantly contributing to the overall safety and quality assurance of the food supply chain.

Conclusion

An internal standard method was successfully developed for the analysis of EO and 2-CE in rice using HS-20 NX Trap with GCMS-TQ8050 NX. The dynamic headspace technique and GC-MS/MS were employed, simplifying the sample preparation process and maximizing the sensitivity. Good linearity (R2 value > 0.997) and recovery within 70 % to 130 % were achieved for all the samples analyzed in this experiment, even without the use of matrix-matched calibration curves.

2. Thermo Fisher Scientific: Supporting exposomics research with the Orbitrap Exploris GC 240 mass spectrometer

• Application

What is exposomics?

The exposome, which is defined as the cumulative effect of environmental exposures and corresponding biological responses, helps to provide a comprehensive measure for evaluating non-genetic causes of disease. Exposomics is the study of the exposome that seeks to understand and quantify the totality of a human's lifetime exposure to various environmental factors, including chemical, physical, and biological agents. In essence, it involves assessing and analyzing the complex interactions between environmental exposures and an individual's genetic makeup, lifestyle, and other factors to understand their impact on human health and disease. By examining the cumulative effects of multiple exposures over time, exposomics provides valuable insights into the underlying mechanisms of disease development and can inform strategies for prevention and intervention.¹

Summary

The ability to measure the complexity of the exposome has been limited by the available analytical technology to detect complex exposures patterns at varying concentrations. By using untargeted approaches with high-resolution mass spectrometry, it is possible to detect and identify ongoing exposures that may have not been expected or characterized.

• High-resolution, full scan mass spectrometry using Orbitrap technology provides a solution for:
• Detection and quantification of compounds using an untargeted full scan acquisition that is both highly selective and sensitive.
• Identification and elucidation of the chemical composition of unknown compounds.
• Retrospective analysis of samples long after data acquisition.

The combined capability of both the Orbitrap Exploris GC 240 mass spectrometer and Compound Discoverer software with spectral libraries is an excellent tool to support exposomics research.

3. Agilent Technologies: Comparison of Sample Preparation Methods for Pesticide Analysis in Botanical Dietary Supplement Materials

• Application

Abstract

This application note presents a novel streamlined sample preparation method for liquid chromatography/triple quadrupole mass spectrometry (LC/MS/MS) and gas chromatography/triple quadrupole mass spectrometry (GC/MS/MS) multiresidue pesticide (over 440) analysis. This treamlined sample preparation enables analysis in botanical dietary supplement (BDS) materials using the EMR mixed‑mode passthrough cleanup with Agilent Captiva EMR with Carbon S cartridges. Various BDS samples are extracted by traditional QuEChERS extraction, followed by appropriate Captiva EMR cartridge cleanup. The selected Captiva EMR cartridges, based on the BDS sample matrix complexity and pigment intensity, include Captiva EMR–GPD for green tea and peppermint tea, Captiva EMR–LPD for barberry root, and Captiva EMR–GPD + EMR–GPF for curcumin complex. The developed method provides a simple and unified sample preparation workflow for both LC/MS/MS and GC/MS/MS pesticide detection. This method demonstrates acceptable performance, i.e., recovery of 70 to 120% and RSDs < 20%, in representative BDS samples for over 82% of the total 447 pesticides analyzed. Compared to the traditional approach that requires multiple sample preparation methods, the newly developed method demonstrates a more one‑size‑fits‑most approach for efficient cleanup. This approach increases the instrument uptime and reduces both
consumables and labor resources. The direct comparison of new method versus old method on actual samples analysis demonstrates acceptable equivalence on reporting results.

Conclusion

A simple, rapid, and reliable method using Agilent Bond Elut QuEChERS extraction followed by EMR mixed‑mode passthrough cleanup using Agilent Captiva EMR with Carbon S cartridges was developed. The results of this method were verified for over 440 pesticides in botanical dietary supplement extracts and products by LC/MS/MS and GC/MS/MS. The EMR mixed‑mode passthrough cleanup method provided a convenient and simplified cleanup method after sample extraction for selective and efficient matrix removal in BDS matrices and acceptable quantitation recovery and reproducibility in large panel pesticide quantitation. The detailed proficiency test confirmed the acceptable method performance for practical
sample analysis.

The ability to streamline sample preparation into a single method allows for a reduction in the total amount of sample preparation consumables and reduces the preparation time. The reduced organic solvent, especially the toxic solvent used per sample, made the entire procedure greener while being more people and environmentally friendly. Also, having one sample to be prepped in a single day allows for much greater traceability regarding shared analytes between LC and GC analyses. This single sample preparation also helps simplify the results and documentation. Consolidating sample preparation documentation into a single packet, as opposed to two packets, minimizes time spent by reviewing staff.

4. James Little - Mass Spec Interpretation Services: KnowItAll Quantitative Software for EI GC-MS

• Application

Table of content:

• Files Used for Demonstration
• More Information on Files from North Dakota Website
• Final Result Page from Demonstration
• Quantitation Workflow
• Wiley KnowItAll Training Resources