The VetDrugs Explorer Collection: screening and quantitation of multi-class veterinary drug residues in animal matrices with a comprehensive workflow solution

Significance of the Topic

This study addresses the critical need for efficient, sensitive, and comprehensive screening of veterinary drug residues in food matrices. Ensuring compliance with global regulatory limits and mitigating risks such as antimicrobial resistance and human exposure to banned substances drives the development of robust analytical workflows.

Objectives and Overview

The primary goal was to establish a unified LC-MS/MS workflow capable of detecting, confirming, and quantifying over 160 veterinary drugs across diverse chemical classes in bovine muscle, fish fillet, and milk. The workflow integrates streamlined sample preparation, high-throughput chromatography, and triple quadrupole mass spectrometry with automated data processing to meet stringent EU and other international residue requirements.

Methodology and Instrumentation

• Sample Preparation: Modified QuEChERS protocol incorporating ammonium oxalate/EDTA buffering, acetonitrile extraction, sodium sulfate drying, and CEC18 dispersive SPE for matrix clean-up.
• Chromatography: Vanquish Flex Binary UHPLC with Accucore VDX column (100 × 2.1 mm, 2.6 µm) at 40 °C, 17-minute gradient from 2 % to 100 % organic modifier.
• Mass Spectrometry: Thermo Scientific TSQ Altis triple quadrupole operating in timed-SRM mode with positive/negative H-ESI switching, optimized collision energies, and 546 transitions managed by TraceFinder software.

Results and Discussion

The workflow achieved detection limits well below EU maximum residue limits across all matrices. Recoveries averaged 75–80 % with relative standard deviations ≤ 15 % at screening target concentrations (STCs). Representative examples include:

• Ethyl Violet in salmon: linear calibration from 0.2–5 ng/g, MDL ~0.03 ng/g.
• Sulfamethazine in bovine: calibration from 10–250 ng/g, MDL ~0.6 ng/g.
• Ractopamine in milk: calibration from 2–50 ng/g, MDL ~0.19 ng/g.

Chromatographic performance and SRM peak shapes remained stable over 500 injections, demonstrating method robustness for routine high-throughput testing.

Benefits and Practical Applications

This integrated solution provides laboratories with:

• A single-method approach for multi-class screening and quantitation.
• Fast sample throughput with only 2 µL injection volume and 17-minute runs.
• Regulatory compliance to EU Decision 2002/657/EC and related MRL regulations.
• Automated data processing and QC checks via TraceFinder software.

Future Trends and Potential Applications

Advancements are expected in areas such as higher-resolution multiplexed MS techniques, enhanced automated sample handling, and expanding compound coverage to emerging veterinary pharmaceuticals and metabolites. Integration with laboratory information management systems (LIMS) and machine-learning-based data review may further streamline compliance workflows.

Conclusion

The VetDrugs Explorer Collection workflow delivers a robust, sensitive, and user-friendly LC-MS/MS solution for comprehensive multi-residue veterinary drug analysis in food matrices. Its combination of modified QuEChERS sample preparation, rapid UHPLC separation, and timed-SRM quantitation ensures reliable performance under regulatory demands while maximizing laboratory efficiency.

References

• George E., Beck J., Yang C. et al. The VetDrugs Explorer Collection: screening and quantitation of multi-class veterinary drug residues in animal matrices with a comprehensive workflow solution. Thermo Fisher Scientific Application Brief 65118.