Analyzing Multi-Class Persistent Organic Pollutants (OCPs, PCBs, PBDEs, and PAHs) in Food Matrices in a Single Injection by APGC-MS/MS

Significance of the Topic

Persistent organic pollutants (POPs) such as organochlorine pesticides, PCBs, PBDEs and PAHs resist environmental breakdown and accumulate in food, posing health risks. Reliable monitoring at trace levels is crucial to enforce regulations and safeguard public health.

Objectives and Study Overview

This study aimed to develop and validate a single-injection method using atmospheric pressure gas chromatography coupled to tandem mass spectrometry (APGC-MS/MS) to quantify 141 multi-class POPs in various food matrices, including milk, infant formula, meats and fish, using a generic sample preparation.

Methodology and Instrumental Setup

Sample Preparation

• Homogenized samples (10-12 g) spiked with isotopically labeled standards were extracted with ethyl acetate after rehydration and QuEChERS salts (MgSO4, NaCl).
• Extracts underwent gel permeation chromatography (GPC) cleanup with dichloromethane, followed by silica gel column cleanup and concentration.

Instrumental Conditions

• GC system: Agilent 7890A with splitless injection at 300 °C on a DB-5 column.
• Ionization: Atmospheric pressure gas chromatography (APGC) with corona discharge source enabling charge and proton transfer.
• MS detection: Waters Xevo TQ-S operating in positive mode, multiple reaction monitoring (MRM) with MassLynx and TargetLynx software.

Main Results and Discussion

The method achieved excellent recovery (66–122%) and repeatability (%RSD <20%) across six matrices at fortification levels down to parts-per-trillion. Limits of detection were below 1 µg/kg for all analytes. The softer APGC ionization provided abundant molecular ions, improving sensitivity (e.g., signal-to-noise ratios for BDE-17 and BDE-28 increased over threefold compared to conventional EI). Calibration curves exhibited linearity (R² >0.99) over 2–25 µg/kg.

Benefits and Practical Applications

• Simultaneous quantification of four POP classes in a single run reduces analysis time and cost.
• Generic sample preparation simplifies workflow for diverse food matrices.
• Enhanced sensitivity and selectivity allow reliable trace-level monitoring.
• Method accredited under ISO 17025, supporting regulatory compliance.

Future Trends and Potential Applications

Emerging opportunities include extending APGC-MS/MS to environmental and biological samples, incorporating automated sample cleanup, and adapting the approach for novel or less studied POPs. Continued refinement of soft ionization techniques will further improve molecular ion detection and reduce fragmentation.

Conclusion

This validated APGC-MS/MS method offers a robust, sensitive, and efficient approach for multi-class POP analysis in food, meeting regulatory demands and improving laboratory throughput.

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