A dual column chromatographic method for simultaneous quantifying aminoglycosides and coccidiostats in milk

A rapid and simple approach to the simultaneous LC-MS/MS determination of polar and non-polar veterinary drugs in milk is proposed. The determination is based on a robust dual column system including two standard HPLC columns (C18 and HILIC) coupled successively into a single line. 14 veterinary drugs, including cocci-diostats and aminoglycosides, with logP varying from -8.30 to 8.74 were separated. The developed method was validated by spiking blank milk samples with different concentrations of the analytes. The intra-day and inter-day precision of the procedure were estimated in terms of relative standard deviations. The LOQs of examined analytes ranged from 1 to 50 mu g kg-1. Relative standard deviations for most of the substances were <20 %. The data indicate good sensitivity and reliability of the proposed method.