HPLC-MS/MS Determination of Residual Amounts of 26 Pesticides in TCM Hypericum Augustinnii N. Robson with Solid-Phase Extraction

A method of HPLC-MS/MS for the determination of residual amounts of 26 pesticides in hypericum augustinnii N. Robson was proposed. The sample was extracted oscillatorily with acetonitrile, and the extract was purified by NH2-solid phase extraction column. Shim-packXR-ODS column was used as chromatographic column, and positive electrospray ionization as well as multiple reactions monitoring mode was used in the detection. Linear relationships between values of peak area and mass concentration of 26 pesticides were kept in the range of 0.01-2.5 mg·L-1, with detection limits (3S/N) in the range of 4.16×10-5-2.85×10-4mg·kg-1. Tests for recovery and precision were made by addition of standard solution at 3 different concentration levels, which were then analyzed by the proposed method. Values of recovery found were in the range of 78.4%-112%, and values of RSD′s (n=5) found were in the range of 1.2%-11%.