Abstract: A high performance liquid chromatography (HPLC) method for the determination of four penicillin residues in foods of animal origin was developed.?Ampicillin trihydrate was used as the internal standard. Samples were extracted with a mixture of acetonitrile and water (10:1, V/V), and the extract was then cleaned up on an HLB solid-phase extraction cartridge. Penicillin G, oxacillin, nafcillin and dicloxacillin were separated on a C18 column by gradient elution with a mobile phase consisting of monopotassium phosphate (0.02 mol/L) and acetonitrile. The calibration curves were linear over the concentration range of 0.01–2 μg/mL with correlation coefficients of more than 0.999. The limits of detection (RSN > 3) (LOD) and quantification (RSN>10) (LOQ) were 3 and 10 μg/kg for all the analytes, respectively. The average recoveries were between 69.9% and 100.3% with relative standard deviations (RSDs) of 1.58%–9.15% (n = 6). The method is simple, rapid, sensitive and accurate and can meet the requirements for practical analysis. It has been applied with satisfactory results to detect penicillin residues in pork, beef, chicken and fish.

Key words: penicillin, animal origin foods, high performance liquid chromatography