Ahmad Talhah Suhaimi, Marni Sapar And Muhd Fauzi Safian
An analytical method was developed and validated for simultaneous analysis of 23 veterinary drugs belonging to 7 different classes. The method was based on QuEChERS (quick, easy, cheap, effective, rugged, and safe) extraction. The sample preparation included ultrasonication with a mixture of acetonitrile, methanol and McIlvaine buffer followed by phase separation with magnesium sulphate and sodium chloride addition. The supernatant was extracted with ethyl acetate and mixed with hexane to ensure fat removal from the matrix. It was then cleaned by using a primary-secondary amine, octadecylsilane (C18) and graphitised carbon black. Detection and quantification was by a single analytical run using ultra-per formance liquid chromatography coupled with electrospray ionisation and tandem mass spectrometry (UPLC?ESI?MS/MS) operating in both positive and negative multiple reaction monitoring (MRM). Chromatographic separation was on a C18 column using methanol and 2 mM ammomium acetate in water (pH4) and 2 mM ammonium acetate in methanol as the mobile phase. Validation was in accordance with international guidelines. Good linearity was obtained for the analytes with correlation coefficients higher than 0.9735. The limit of detection and limit of quantification of all drugs were 0.05 to 0.93 mg/kg and 0.15 to 3.11 mg/kg, respectively. Average analyte recoveries ranged from 83.7 to 109.9%, and the repeatability was lower than 9.9%. The validation results demonstrate that the described LC-MS/MS method is sensitive, repeatable and reliable for safety monitoring and control of veterinary drug use in poultry feed.