Screening for 926 Pesticides and Endocrine Disruptors by GC/MS with Deconvolution Reporting Software and a New Pesticide Library

Significance of the Topic

Pesticide and endocrine disruptor screening is essential to ensure food and environmental safety by detecting trace-level residues that may impact human health and ecosystems. The combination of retention time–locked gas chromatography–mass spectrometry (GC/MS), deconvolution reporting software, and an expanded spectral library enables rapid and reliable identification of a broad range of contaminants.

Objectives and Study Overview

This study presents the development and application of the new G1672AA Pesticide and Endocrine Disruptor Database containing 926 entries, including 359 additional compounds compared to the previous library. The expanded library is used with Agilent’s Deconvolution Reporting Software (DRS) to screen food, water, and environmental samples. Key aims include evaluating library performance in real samples, comparing screening results from the original 567-compound library to the new 926-compound version, and demonstrating improved identification of coeluting or low-abundance analytes.

Methodology and Instrumentation

The analytical workflow integrates three software components: the ChemStation for targeted quantification, AMDIS for spectral deconvolution and retention time–filtered library searching, and the NIST MS Search for confirmation against a comprehensive mass spectral library. Retention time locking ensures reproducible elution times across laboratories. Samples are injected in split/splitless or PTV mode with a 30 m HP-5ms column and analyzed by an Agilent 6890N GC coupled to a 5975 inert mass selective detector, operating in scan mode from m/z 50–550. Deconvolution yields purified component spectra that are matched against the RTL database and subsequently confirmed by NIST ’05.

Key Results and Discussion

Deconvolution enabled the detection of analytes buried under co-eluting matrix interferences, exemplified by the identification of norflurazon within a complex chromatogram. Comparison of library versions using 17 surface water extracts revealed that the original 567-compound database identified 37 target analytes, while the 926-compound database detected an additional 99 contaminants, including pesticide metabolites, flame retardants, and stimulants like caffeine. Processing time increased modestly from 20 minutes to 32 minutes for all samples, compared to approximately 8 hours required for manual chemist screening.

Benefits and Practical Applications

The new database and deconvolution approach deliver rapid screening (≈2 minutes per sample), higher confidence through retention time and spectral matching, and reduced false positives. The method supports high-throughput monitoring in food safety laboratories, environmental testing, quality control, and regulatory compliance. Laboratories can customize or extend libraries to meet specific application needs.

Future Trends and Opportunities

Further expansion of spectral libraries to cover emerging contaminants, integration with high-resolution mass spectrometry and machine learning–based deconvolution algorithms, and automation of data processing workflows will enhance throughput and detection capabilities. Coupling these advancements with isotopic standards and multidimensional chromatography will further improve sensitivity and selectivity.

Conclusion

The updated G1672AA Pesticide and Endocrine Disruptor Database, combined with Agilent’s Deconvolution Reporting Software, significantly enhances the speed, breadth, and reliability of GC/MS screening for a wide spectrum of target compounds. The workflow reduces manual review time, uncovers otherwise undetectable contaminants, and strengthens confidence in identifications across diverse laboratory settings.

Instrumentation Used

• Gas chromatograph: Agilent 6890N with 30 m × 0.25 mm HP-5ms column
• Inlet: Programmable temperature vaporization (solvent vent) or split/splitless
• Injection: 15 µL, PTV or split/splitless
• Carrier gas: Helium, constant pressure mode with retention time locking
• Oven program: 70 °C (2 min) ramp to 150 °C at 25 °C/min, then to 200 °C at 3 °C/min, then to 280 °C at 8 °C/min (10–15 min final hold)
• Mass spectrometer: Agilent 5975 inert MSD, scan range m/z 50–550
• Software: ChemStation G1701DA, Deconvolution Reporting Software G1716AA, AMDIS 2.62+, NIST MS Search with NIST ’05 library

References

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