Liquid Chromatography-Tandem Mass Spectrometry System
The 36 target veterinary drugs encompass diverse chemical classes and exhibit a wide range of physicochemical properties. Some compounds are highly polar and readily soluble in water, whereas others are strongly lipophilic. Tetracyclines readily chelate metal ions and exhibit relatively poor stability. Quinolones and sulfonamides also show substantial differences in polarity. Simultaneous multi-residue analysis may therefore lead to issues such as peak co-elution, ion suppression/enhancement, and quantitative result drift. In addition, animal-derived food matrices are complex and contain high levels of proteins, lipids, and phospholipids, resulting in significant matrix interference.
Liquid chromatography–tandem mass spectrometry (LC-MS/MS) using a triple quadrupole mass spectrometer offers high selectivity and sensitivity and is therefore a preferred confirmatory analytical technique for the determination of veterinary drug multi-residues.
Test Results
Calibration Curves and Limits of Quantification
The figure shows the calibration curves for selected compounds. The correlation coefficients (r) for all compounds were greater than 0.99, demonstrating excellent linearity and ensuring the accuracy and reliability of the analytical results.
Conclusion
In this study, a simultaneous trace-level analytical method was successfully developed for the determination of 36 veterinary drug residues across multiple chemical classes using the AccuraSys QuantEX 6250 triple quadrupole mass spectrometry platform, in accordance with GB 31658.17-2021. By optimizing a multi-component-compatible chromatographic gradient, differentiated multiple reaction monitoring (MRM) mass spectrometric parameters, and the sample pretreatment and cleanup procedures, together with comprehensive matrix-effect correction and full-process quality control strategies, efficient separation and accurate quantification of 36 veterinary drugs, including quinolones, sulfonamides, and tetracyclines, were achieved.
The developed method exhibited excellent linearity and high sensitivity. Its accuracy and precision met the technical requirements of the national standard for trace-level multi-component analysis. The method demonstrated strong resistance to matrix interference and excellent system stability. In addition, the procedure is simple to operate, provides comprehensive analyte coverage, and has broad applicability. It can be widely applied to the simultaneous monitoring of 36 veterinary drug residues in livestock and poultry meat samples, providing stable and reliable technical support for food safety risk monitoring and routine laboratory testing.
