A comprehensive evaluation of the clean-up step in the QuEChERS procedure for the determination of six groups of veterinary drugs in poultry using ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS)

The primary aim of this study is to establish a reliable, quick, and cost-effective QuEChERS method for extracting and cleaning six groups of veterinary drugs from poultry feed for subsequent analysis. Several factors were explored, including the type of solvent used for extraction, clean-up process optimization using graphitized carbon black (GCB), ethyl acetate, n-heptane, and temperature suitable for the concentration process. Prior research was considered to choose the best extraction solvent, and a mix of 0.1 M EDTA-McIlvaine buffer, acetonitrile (ACN), and methanol (MeOH) was used. After thorough analysis, a solvent composition called OSC-B, containing 10 mL ACN and 4 mL MeOH, was preferred due to its superior extraction properties for specific drugs. GCB was added during the clean-up process, and 15 mg was found to be the most effective amount. Ethyl acetate and n-heptane were added to reduce matrix interference from the feed, resulting in three distinct layers during extraction. The optimal sample volume to withdraw from the second layer was 7 mL, consistently producing clear samples suitable for analysis. The solution concentration process was optimized at different temperatures, with 45°C selected as the ideal temperature due to its shorter evaporation time and acceptable analyte peak shapes. The recovery of all six groups is close to 100%, indicating trustworthy results. This study comprehensively optimizes extraction and clean-up processes, offering a robust methodology for analyzing five groups in the positive mode and one group in the negative mode of veterinary drug residue in poultry feed. This study is vital in ensuring the safety and quality of poultry products for consumers.