Determination of Residual Amounts of 20 Veterinary Drugs in Pork by Hyphenation of HPLC with QuadrupoleTOFMS

The method of HPLC in hyphenation with quadrupoleTOFMS was applied to the determination of residual amounts of 20 veterinary drugs, including 16 sulphonamides and 4 βrecepter agonists. The pork sample (2.00 g) was first treated by the method of matrix solidphase dispersion and then extracted twice with 20 mL (in each extraction) of a mixture of CH3CNHCOOH (99+1). The supernatants were combined and evaporated to near dryness by N2blowing, the concentrate was dissolved in 1.0 mL of CH3OHH2O (1+9) mixture, and used for HPLCTOFMS analysis after filtration. Linearity ranges for the 20 drugs were found same between 0.2-400 μg·L-1, with lower limits of determination (10S/N) in the range of 0.4-15 μg·kg-1. Test for recovery was made by standard addition method at 3 concentration levels, giving values of recovery in the range of 70.4%-109% and values of RSD′s (n=6) ranged from 6.7% to 19%.