RP-HPLC Determination of Residual Amounts of Abamectin in Muscle Tissues of Shrimps

It was reported that residual amount of abamectin in muscle tissues of shrimps was determined by RP-HPLC. Samples were extracted with ethyl acetate, and defatted with n-hexane. After centrifugation, an aliquot of the lower layer was taken for separation by passing through Hypersil C18 column (150 mm×4.6 mm, 5 μm). A mixture of methanol and water mixed in the ratio of 86 to 14 (by volume) was used as mobile phase; and UV-detection at 245nm was used in the determination. Linear relationship between values of peak area and mass concentration of the abamectin was kept in the range of 0.005-2 mg·L-1, with detection limit (3S/N) of 0.002 mg·kg-1. Test for recovery was made by addition of standard abamectin at 3 different concentration levels to samples of muscle tissues of shrimps as matrixes, values of recovery found were in the range of 89.4% to 102.4%. Values of intraday and interday relative standard deviation (n=6) found were in the ranges of 2.1%-7.2% and 5.5%-8.4% respectively.