GC/MS solutions for environmental and food testing

Importance of Topic

Environmental and food matrices present complex analytical challenges due to the diversity and low levels of contaminants such as per- and polyfluoroalkyl substances (PFAS), phthalates, semivolatile organic compounds (SVOCs), pesticides, disinfection by-products (DBPs), polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), flame retardants and other industrial pollutants.
High-performance gas chromatography/mass spectrometry (GC/MS) workflows are essential to ensure public health and regulatory compliance by providing sensitive, reliable and high-throughput methods for trace-level detection.

Objectives and Study Overview

This compendium of Agilent application notes demonstrates advanced GC/MS solutions to address environmental and food testing needs:

• High-resolution GC/quadrupole time-of-flight (GC/Q-TOF) for broad PFAS screening and nontarget discovery.
• GC/MS with hydrogen carrier gas and HydroInert source for phthalate analysis under helium shortages.
• Automated sample preparation using PAL3 robotic tool change (RTC) for EPA 8270E SVOC analysis.
• Novel DB-5Q column chemistries and high-efficiency ion source (HES 2.0) to improve sensitivity, data accuracy and robustness.
• Accurate mass personal compound database and library (PCDL) development for PFAS and integrated nontarget workflows using NIST and public libraries.

Methodology and Instrumentation

• GC/Q-TOF: Agilent 7250 with DB-624 and DB-5ms columns, full-spectrum accurate mass EI, target/nontarget screening with PCDL, MassHunter Unknowns Analysis.
• GC/MSD with Hydrogen: Agilent 8890 GC coupled to 5977C MSD using Hydrogen carrier and HydroInert source, monitored according to IEC 62321-8.
• Automated LLE: PAL3 RTC for liquid–liquid extraction of water, SPE cocktails, calibration prep and parallel GC/TQ analysis on 7000 series triple quadrupole.
• Column Innovations: DB-5Q low-bleed, inert polysiloxane phase with enhanced thermal stability; HES 2.0 ion source with RF dipolar lens reduces background.
• Library Development: Collection of over 150 EI accurate mass PFAS spectra, annotation and PCDL creation; integration of NIST23 and MassBank.us for comprehensive contaminant screening.

Main Results and Discussion

• PFAS GC/Q-TOF: Headspace-SPME extraction and target screening enabled detection of volatile PFAS (e.g., 6:2 FTOH) in soil and plants. Nontarget recalls also identified PCBs, PBDEs, PAHs, pesticides and flame retardants.
• Phthalate GC/MS: Hydrogen carrier and HydroInert source mitigated hydrogenation artifacts, delivering stable quantitative performance (R2 > 0.99) and detection limits <4 mg/kg in polymers.
• Automated SVOC Prep: PAL3 RTC GP/TQ workflow produced linear calibration (0.01–20 µg/mL), MDLs 1.8–3.7 mg/kg, recoveries 89–101%, with robust QC and high throughput under EPA 8270E.
• Column Chemistry & HES 2.0: DB-5Q columns exhibited <10% baseline bleed at 340 °C, preserved peak shapes for active phenolic and halogenated analytes, maintained chromatography after 200 soil extract cycles with minimal retuning.
• Accurate Mass PCDL & Nontarget: PFAS PCDL enabled rapid suspect screening in drinking water extracts; integration with NIST23 and MassBank.us revealed DBPs, personal care by-products, pharmaceuticals and pesticides with high confidence via retention indices and accurate mass match.

Benefits and Practical Applications

• Enhanced Sensitivity: Accurate mass GC/Q-TOF and inert columns lower detection limits for volatile and semivolatile contaminants.
• Improved Data Quality: Reduced column bleed and source background, stable retention times and peak symmetry improve quantitation accuracy.
• Greater Robustness: High thermal stability of column chemistries and hydro-inert ion source sustain prolonged sample loads and challenging matrices.
• Automated Workflows: PAL3 RTC systems streamline sample prep, reduce manual errors, conserve solvents and increase lab productivity.
• Comprehensive Screening: Targeted PCDLs combined with nontarget library searches expand contaminant coverage in a single analysis without reinjection.

Future Trends and Possibilities

• Expanded Libraries: Growth of accurate mass PCDLs for emerging PFAS, novel pesticides and industrial chemicals will broaden suspect screening scopes.
• AI-Powered Data Mining: Machine learning for automated deconvolution, spectral matching and anomaly detection will accelerate nontarget discovery.
• Green Diagnostics: Hydrogen-based chromatography and miniaturized sample prep will reduce environmental footprint.
• Integrated Platforms: Coupling GC/Q-TOF, GC/TQ and robotic prep under unified software ecosystems will enable on-demand, real-time monitoring in environmental and food safety labs.

Conclusion

Agilent GC/MS solutions—from high-resolution GC/Q-TOF with accurate mass libraries to innovative column and source chemistries, combined with automated robotic sample prep—provide a comprehensive, sensitive and robust platform for environmental and food contaminant analysis. These integrated workflows meet stringent regulatory requirements, streamline high-throughput testing, and adapt readily to evolving pollutant landscapes.

References

1. Williams AJ, et al. Assembly and Curation of Lists of PFAS to Support Environmental Research. Front. Environ. Sci. 2022.
2. Sunderland EM, et al. A Review of Pathways of Human Exposure to PFAS. J. Expo. Sci. Environ. Epidemiol. 2019.
3. EPA Method 8270E: Semivolatile Organic Compounds by GC/MS, Revision 6, 2018.
4. IEC 62321-8: Determination of Certain Substances in Electrotechnical Products—Part 8: Phthalates, 2017.
5. MassBank of North America (MassBank.us).
6. Wong L, et al. Accurate Mass Library for PFAS Analysis in Environmental Samples. Agilent application note, 2023.
7. Van Gansbeke W, et al. Semi-Automated GC/Q-TOF Screening with AssayMAP Bravo. Agilent application note, 2023.