Analysis of Veterinary Drugs

Importance of the Topic

The widespread use of veterinary antimicrobials in livestock production raises significant concerns regarding drug residues in food products and the acceleration of antimicrobial resistance.
Robust analytical platforms capable of broad-spectrum, high-throughput screening are critical for ensuring food safety, regulatory compliance, and environmental monitoring.

Objectives and Study Overview

This application note presents a non-targeted LC-TOF-MS workflow for simultaneous analysis of over 40 veterinary antibacterial and antimicrobial agents.
The goal is to achieve rapid chromatographic separation, high detection sensitivity, and comprehensive coverage of diverse drug classes in a single run.

Methodology and Instrumentation

A reversed-phase gradient method was developed using a metal-free C18 column and formic acid-modified mobile phases.
Key method parameters:

• Column: Shim-pack Scepter C18-120, 150 mm × 2.1 mm I.D., 3 µm particle size
• Mobile phase A: 0.1 % formic acid in water; B: 0.1 % formic acid in acetonitrile
• Gradient: 1 % B to 15 % B (0–1 min), to 40 % B (1–6 min), to 100 % B (6–15 min), back to 1 % B (15.01–18 min)
• Flow rate: 0.2 mL/min; Column temp.: 40 °C; Injection: 2 µL (co-injection of 10 µL water)

Used Instrumentation

• LC system: Shimadzu Nexera X3 UPLC
• MS detector: Shimadzu LCMS-9030 high-resolution TOF-MS, m/z range 100–1000
• Nebulizing gas: 3.0 L/min; Drying gas: 10.0 L/min; Heating gas: 10.0 L/min
• Interface temp.: 250 °C; DL temp.: 250 °C; Block heater temp.: 400 °C

Main Results and Discussion

The method successfully resolved all target antimicrobials—quinolones, sulfonamides, diaminopyrimidines, and related compounds—within an 18-minute cycle.
Use of a metal-free column minimized analyte–surface interactions, improving peak shape and reproducibility.
TOF-MS detection provided accurate mass measurement and full scan data for retrospective non-target screening.

Benefits and Practical Applications

The single-run protocol streamlines multi-class veterinary drug monitoring in food and environmental matrices.
High mass accuracy and full scan capability enable trace-level quantitation and identification of unexpected residues.
The rapid gradient reduces analysis time, increasing laboratory throughput and cost-effectiveness.

Future Trends and Opportunities

Integration of data-independent acquisition and advanced software can enhance non-target compound discovery.
Coupling with automated sample preparation will further improve workflow efficiency in routine surveillance.
Expanding the method to include emerging veterinary drugs and transformation products will support evolving regulatory requirements.

Conclusion

This study demonstrates a versatile, high-throughput LC-TOF-MS approach for comprehensive veterinary drug screening.
The optimized reversed-phase gradient, metal-free column, and high-resolution detection deliver robust performance for food safety and environmental analysis.

Reference

Application News an_01-00461, Shimadzu Corporation, First Edition Aug. 2023