Development and validation of an HPLC method for the determination of penicillin antibiotics residues in bovine muscle according to the European Union Decision 2002/657/EC

A high-performance liquid chromatographic method was developed for the determination of five penicillins: penicillin G (PENG), penicillin V (PENV), oxacillin (OX), cloxacillin (CLO), and dicloxacillin (DICLO), in bovine muscle. Samples were macerated with a mixture of H2O/CH3CN (1:1) and purified using RP-8 Adsorbex SPE cartridges after centrifugation, with mean recovery from spiked samples higher than 89%. The separation of the examined penicillins was achieved on an analytical column, an Inertsil C8 5 mu m, 250 x 4 mm(2), at ambient temperature. The mobile phase consisted of 0.1% TFA/ACN 50:50 v/v delivered isocratically at a flow rate of 1.1 mL/ min. Analytes were monitored at 240 nm. The procedure was validated according to the European Union Decision 2002/657/EC by means of selectivity, stability, decision limit, detection capability, accuracy, and precision. Method's LOQ values achieved were 54 mu g/kg for PENG and DICLO, 46 mu g/kg for PENV, 16 mu g/kg for OX, and 43 mu g/ kg for DICLO. The detection capabilities (CC beta) were 73.6 mu g/kg for PENG, 29.1 mu g/kg for PENV, 350.6 mu g/kg for OX, 379.9 mu g/kg for CLO, and 355.8 mu g/kg for DICLO. The method was applied to various samples from the local market. Two penicillins were identified by photodiode array (PDA) detection and quantified.