Simultaneous HPLC-MS/MS Determination of 35 Veterinary Drugs in Animal Derived Food

A method of HPLC-MS/MS for the simultaneous determination of 35 veterinary drugs in food of animal origin was proposed. The sample was extracted with acetonitrile (containing 1% by vol. of acetic acid) and purified by the QuEChERS method. Zobax Eclipse Plus C18 column was used as stationary phase in chromatographic separation, and the mixture of 0.1% (φ) formic acid solution and acetonitrile mixed in different ratio was used as mobile phase in gradient elution. ESI+ and multi-reaction monitoring were adopted in MS/MS. Linear relationships between values of peak area and mass fraction of the 35 compounds were kept in the same range of 1-50 μg·kg-1, with detection limits (3S/N) in the range of 0.02-1.07 μg·kg-1 and lower limits of determination (10S/N) in the range of 0.08-3.58 μg·kg-1. On the base of blank sample, test for recovery was made by standard addition method; values of recovery found were in the range of 45.6%-121%, with RSD′s (n=6) in the range of 2.4%-24%.