Quantitative Analysis of Veterinary Drugs Using the Shimadzu LCMS-8050 Triple Quadrupole Mass Spectrometer

Significance of the Topic

Veterinary drug residues in food products such as meat and seafood pose a potential risk to consumers and are regulated by maximum residue limits. A rapid, sensitive method capable of detecting a wide range of residues in a single analytical run supports compliance monitoring and food safety enforcement.

Objectives and Study Overview

This study evaluates a streamlined workflow combining QuEChERS extraction with Shimadzu LCMS-8050 triple quadrupole mass spectrometry for simultaneous quantitation of 89 veterinary drugs in cattle, poultry, and fish samples. The goal is to maintain high sensitivity and reproducibility while reducing sample preparation complexity.

Methodology and Instrumentation

Sample Preparation:

1. Homogenize 100 g of sample (chicken, pork, salmon, shrimp).
2. Weigh 10 g of homogenate into a 50 mL tube and add 5 mL water.
3. Add acidified acetonitrile with QuEChERS salts, shake, and centrifuge.
4. Collect the organic layer, filter, and prepare for injection.
5. Co-inject 2 µL of extract with 10 µL water using the autosampler to improve peak shape.

Instrumentation:

• System: Shimadzu LCMS-8050 triple quadrupole MS with ESI in positive/negative modes.
• Column: Shim-pack XR-ODSⅡ, 75 mm × 2.0 mm, 2.2 µm.
• Mobile Phase A: 0.1% formic acid in water; B: acetonitrile with 0.1% formic acid gradient.
• Flow Rate: 0.2 mL/min; Column Oven: 40 °C.
• Injection: 2 µL sample + 10 µL water; Ion source settings: interface 400 °C, DL 200 °C, block 400 °C.

Main Results and Discussion

Co-injection of water effectively prevented peak splitting for polar compounds, yielding sharp chromatographic peaks. Limits of quantitation for most analytes ranged from 0.01 to 1 µg/L. Comparison of neat and matrix-matched standards showed minimal matrix effects, with LOQs and calibration linearity maintained. Recovery experiments across shrimp, chicken, pork, and salmon matrices demonstrated that over 90% of compounds recovered between 70% and 120%. Extraction efficiency averaged 80%, though highly polar tetracyclines and quinolones showed reduced recoveries, suggesting the need for tailored extraction protocols for these classes. Continuous analysis over three days confirmed instrument robustness, with low relative standard deviations for typical compounds.

Benefits and Practical Applications

The simplified QuEChERS-based workflow eliminates time-consuming cleanup steps while enabling comprehensive screening and quantitation of veterinary drugs in food matrices. This approach enhances laboratory throughput and supports routine monitoring programs for regulatory compliance.

Future Trends and Potential Applications

Ongoing developments may include integration of automated sample handling, expansion to high-resolution mass spectrometry for non-targeted screening, and adaptation of the workflow to additional residue classes and environmental samples. Combining multi-residue methods with data-processing advances will further improve monitoring capabilities.

Conclusion

The presented QuEChERS-LCMS-8050 method provides a robust, sensitive, and efficient platform for multi-residue analysis of veterinary drugs in complex food matrices, meeting the demands of modern food safety laboratories.