样品中阿维菌素经乙腈提取所得滤液过滤后,经氯化钠固体振荡,取乙腈相于60 ℃水浴中氮气吹干,残留物用甲醇定容至2.0 mL,用Symmetry C18柱色谱分离,以甲醇-水(90+10)溶液为流动相进行洗脱,流量为1.0 mL·min-1,紫外检测波长为245 nm,外标法定量.在0.01~2.0 mg·L-1范围内,阿维菌素标准工作溶液的色谱峰高与质量浓度呈线性关系,龙眼中阿维菌素的添加回收率为87%~92%,测定结果的相对标准偏差(n=5)在1.79%~4.89%之间,检出限(3S/N)为0.005 mg·kg-1.

Abamectin in longan was extracted with acetonitrile and fitered. The extract was shaked with solid NaCl. An aliquot of the acetonitrile phase was taken,and evaporated to dryness by N2-blowing in a hot water bath at 60 ℃. The residue was taken and made up to 2.0 mL with methanol,and the solution obtained was used for HPLC determination. The Symmetry C18 column was used as stationary phase,and mixture of methanol and H2O (90+10) was used as mobile phase with flow-rate of 1.0 mL·min-1. UV detection at 245 nm was adopted in the measurement. Linear relationship between values of peak area and concentration of abamectin was obtained in the range of 0.01-2.0 mg·L-1,and detection limit (3S/N) of the method found was 0.005 mg·kg-1. Eight samples of longan were analyzed by the proposed method,and recovery was tested by adding standard solution of abamectin to these samples,values of recovery found were in the range of 87%-92%,and values of RSD′s (n=5) of the results were in the range of 1.79%-4.89%.