Xevo TQ-S cronos for the Analysis of Banned Veterinary Drug Residues: Determination of Nitrofuran Metabolites and Chloramphenicol in Chicken Muscle at Regulatory Limits

Significance of Topic

The monitoring of banned veterinary drug residues in food of animal origin is critical to ensure consumer safety and regulatory compliance. Compounds such as chloramphenicol and nitrofuran metabolites are strictly prohibited due to their toxicity and potential health risks. Sensitive and reliable analytical methods are essential for routine control laboratories to detect these substances at or below established Reference Points for Action (RPAs).

Objectives and Study Overview

This study evaluates the performance of an ACQUITY UPLC I-Class PLUS System coupled with a Xevo TQ-S cronos tandem quadrupole mass spectrometer for quantitative determination of four nitrofuran metabolites and chloramphenicol in chicken muscle. The primary goals were to demonstrate linearity, sensitivity, precision, and robustness at EU RPA levels and to assess instrument uptime under extended runs.

Methodology and Instrumentation

Sample Preparation and Cleanup:

• Chicken muscle extracts were prepared by solvent extraction followed by solid-phase extraction (SPE) in trap-and-elute mode.
• Oasis HLB cartridges were used for chloramphenicol cleanup; Oasis MCX cartridges were applied for nitrofuran metabolites.
• Derivatization of nitrofurans was typically required, but pre-derivatized standards were used for performance assessment.

UPLC-MS/MS Conditions and Instrumentation:

• UPLC system: ACQUITY UPLC I-Class PLUS with FTN Sample Manager.
• Column: BEH C18, 1.7 µm, 2.1 × 100 mm operated at 45 °C.
• Mobile phase A: 0.5 mM ammonium formate; Mobile phase B: methanol; flow rate 0.45 mL/min.
• Mass spectrometer: Xevo TQ-S cronos with electrospray ionization; positive mode for nitrofurans, negative mode for chloramphenicol.
• Desolvation temperature: 600 °C; source temperature: 150 °C; optimized cone voltages and collision energies for each analyte.

Main Results and Discussion

Calibration and Sensitivity:

• Linearity across three orders of magnitude with R² > 0.99 for all analytes at concentrations down to the EU RPAs (0.15 µg/kg for chloramphenicol, 0.5 µg/kg for nitrofuran metabolites).
• Sensitivity and residuals within 15–20% across calibration ranges.

Matrix Effects and Quantitation:

• Matrix effects were evaluated and controlled using isotopically labelled internal standards and matrix-matched calibration.
• Ion ratios and retention times remained within regulatory tolerances (±0.2 min, ion ratio deviations per Commission Decision 2002/657/EC).

Precision and Robustness:

• Inter-day repeatability assessed over 36 hours (three analytical batches, n = 36) yielded %RSD values well below 15%.
• No source cleaning or maintenance was required during extended runs, demonstrating instrument robustness.

Benefits and Practical Applications

• Reliable routine quantitation of banned residues at or below EU regulatory limits.
• High throughput with 10 min total run times and clear chromatographic separation.
• Minimal operator intervention maximizes uptime and laboratory efficiency.
• Compatibility with standard SPE workflows for food safety testing in compliance laboratories.

Future Trends and Opportunities

• Integration of high-resolution mass spectrometry for broader screening of emerging residues.
• Automation of sample preparation and data processing using advanced software algorithms.
• Expansion to additional food matrices (e.g., aquaculture, dairy) and multi-class contaminant panels.
• Development of miniaturized and portable platforms for on-site screening.

Conclusion

The combination of an ACQUITY UPLC I-Class PLUS System with a Xevo TQ-S cronos mass spectrometer provides a robust, sensitive, and precise method for the determination of chloramphenicol and nitrofuran metabolites in chicken muscle at regulatory threshold levels. The system’s design features ensure long-term stability and low maintenance requirements, supporting routine food safety monitoring.

Reference

1. EU Commission Regulation (2019/1871) on Reference Points for Action for Non-Allowed Pharmacologically Active Substances in Food of Animal Origin. Official Journal of the European Union, L289/41-46 (2019).
2. EU Commission Regulation (2017/625) on Official Controls to Ensure the Application of Food and Feed Law. Official Journal of the European Union, L95/1-142 (2017).
3. U.S. Food and Drug Administration. Guidance for Industry on Veterinary Drug Residue Monitoring (Accessed April 6, 2021).
4. Codex Alimentarius Commission. Maximum Residue Limits for Veterinary Drugs in Foods (Accessed April 6, 2021).
5. FAO/WHO JECFA. Veterinary Drug Residues Evaluation Reports (Accessed April 6, 2021).
6. Cooper KM, Kennedy DG. Nitrofuran Antibiotic Metabolites Detected at Parts per Million Concentrations in Retina of Pigs. The Analyst 130, 466–468 (2005).
7. Waters Application Note 720006637EN. Multi-Residue Pesticide Analysis by UPLC-MS/MS in Fruits, Vegetables, and Rice (2019).
8. Waters Application Note 720006701EN. Robustness of Xevo TQ-S cronos for Acrylamide Determination in Processed Potato Chips (2019).
9. Waters Application Note 720007202EN. Best Practice for Xevo TQ-S cronos in Triphenylmethane Dye Analysis in Seafood (2021).
10. EU Commission Decision 2002/657/EC on Performance of Analytical Methods and Interpretation of Results. Official Journal of the European Union, L221/8-29 (2002).