HPLC-MS/MS Determination of Praziquantel and Propangite in Fish with Sample Treatment by Matrix Solid Phase Dispersion Extraction

Sample of fish (2.0 g) was treated by MSPD extraction (with 10 mL of CH3CH), homogenized for 1 min by mixing at a rate of 6 000 r·min-1, and then mixed with 4 g of anhydrous MgSO4 and 1.5 g of NaCl. The mixture was centrifuged for 3 min at a rate of 5 000 r·min-1. One mL of the supernatant was mixed with 50 mg each of N-propyl-ethylene diamine and C18 powder. The mixture was centrifuged for 3 min at a rate of 10 000 r·min-1 and 0.5 mL of supernatant was mixed with 0.5 mL of water and analyzed by HPLC-MS/MS under prescribed conditions. Tests for recovery were made by addition of mixed standard solution at 3 concentration levels to matrixes of 3 kinds of fishes, giving results of recovery in the ranges of 83.7%-93.2% for praziquantel and 85.2%-92.8% for propargite, with values of RSD′s (n=5) ranged from 3.7% to 9.3% and 2.1% to 9.6% respectively. Values of detection limits (3S/N) were found same as 0.3 μg·kg-1.