Determination of Brominated Flame Retardants (BFRs) in Fish Tissue using an Optimized Extraction/Cleanup Procedure and the Agilent 7000 Triple Quadrupole GC/MS System

Significance of the topic

Fish is a valuable dietary source of omega-3 fatty acids, but it can also accumulate lipophilic pollutants such as brominated flame retardants (BFRs). Monitoring these contaminants in fish tissue is essential to protect public health and comply with regulatory limits published by the EU and other authorities. A rapid, sensitive, and cost-effective analytical protocol enables laboratories to generate reliable data for food safety control and respond swiftly to contamination alerts.

Objectives and overview of the study

This work aimed to develop and validate a streamlined extraction and cleanup procedure followed by tandem GC-MS quantification of 21 BFRs, including eight priority polybrominated diphenyl ether (PBDE) congeners and five newer alternative flame retardants. The method targets sub-µg/kg levels in fish muscle while reducing solvent consumption, operator time, and instrument run time.

Methodology and instrumentation

The sample preparation combines a simple liquid-liquid partition in ethyl acetate/water with salting out, followed by silica gel minicolumn cleanup to remove lipids. Key steps:

• Homogenize 10 g fish tissue with surrogate standard (BDE 37).
• Add 5 mL water and 10 mL ethyl acetate; shake and salt out with MgSO4 and NaCl.
• Centrifuge, collect organic layer, evaporate, reconstitute in n-hexane.
• Purify on 1 g silica gel minicolumn; elute with hexane/dichloromethane (3:1).
• Evaporate eluate, reconstitute in isooctane with syringe standards (BDE 77, 13C-BDE 209).

Instrumental analysis employs an Agilent 7890A gas chromatograph fitted with a DB-XLB capillary column (15 m × 0.18 mm × 0.07 µm), coupled to an Agilent 7000B triple quadrupole mass spectrometer in electron ionization multiple reaction monitoring (EI-MRM) mode. Calibration covers 0.05–500 ng/mL (extended to 1,000 ng/mL for highly brominated congeners).

Main results and discussion

The method achieved overall recoveries of 78–115% and repeatability (RSD) below 14% at fortification levels of 1 and 5 µg/kg. Limits of quantification ranged from 0.005 µg/kg for lower-brominated PBDEs up to 1 µg/kg for decaBDE and OBIND. High chromatographic efficiency on a short column and selective MRM transitions resolved coeluting isomers and minimized interferences. Total analysis time per sample (including GC run) was under 12 minutes, improving throughput compared to conventional 30 m NCI-GC methods.

Benefits and practical applications

This approach offers:

• High sensitivity and selectivity for a broad panel of BFRs.
• Streamlined sample prep with reduced solvent use and waste.
• Increased laboratory throughput and cost efficiency.
• Compliance with EU and international food safety requirements.

Future trends and potential applications

Ongoing developments may integrate automated extraction systems, miniaturized cleanup formats, and high-resolution mass spectrometry for non-target screening of emerging BFRs. Adapting the protocol for other fatty food matrices (e.g., dairy, meat) and environmental samples will broaden its utility in contamination surveillance.

Conclusion

The optimized extraction/cleanup workflow combined with Agilent triple quadrupole GC/MS delivers a robust, high-throughput method for quantifying a comprehensive suite of BFRs in fish tissue. The validation confirms its suitability for routine food safety monitoring at low (sub-µg/kg) levels.

References

• European Commission. Directive 2003/11/EC of 6 February 2003 amending Council Directive 76/769/EEC on pentabromodiphenyl ether and octabromodiphenyl ether.
• Bromine Science and Environmental Forum (BSEF). Brominated flame retardants on the market. 2012.
• Covaci A, Harrad S, Abdallah MAE, et al. Novel brominated flame retardants: A review of their analysis, environmental fate and toxicological properties. Environmental International. 2011;37:532–556.
• European Commission Rapid Alert System for Food and Feed (RASFF). Accessed June 2012.
• Kalachova K, Pulkrabova J, Drabova L, Cajka T, Kocourek V, Hajslova J. Fast determination of BFRs in fish muscle by ethyl acetate extraction and GC-MS/MS. Analytica Chimica Acta. 2011;707:84–91.
• EFSA CONTAM Panel. Advice on monitoring levels of brominated flame retardants in food and feed. EFSA Journal. 2006;328:1–4.
• EFSA Scientific Opinion on polybrominated diphenyl ethers in food. EFSA Journal. 2011;9(5):2156.
• SANCO/12495/2011. Stakeholder guidance on pesticide residue method validation and quality control procedures.
• Kalachova K, Cajka T, Sandy C, Hajslova J, Pulkrabova J. High-throughput GC-MS/MS analysis of flame retardants in fatty matrices. Talanta. 2013;105:109–116.