Determination of spinosad and spinetoram residues in soil by ultra performance liquid chromatography(UPLC)

An ultra performance liquid chromatography(UPLC) method was established for the determination of spinosad(A and D) and spinetoram(J and L) residues in soil. The soil samples were extracted with acetonitrile-5% NaCl-1 mol/L KOH and purified by SPE tube. The final extract was injected into UPLC and quantified by external standard method. According to the results of experiments, the limits of quantification(LOQs) were 0.1 and 0.05 mg/kg for spinosad and spinetoram respectively, and the limits of detection of spinosad and spinetoram were 8.0×10-7 and 2.8×10-7 g respectively. The recoveries of spinosad spiked in soil were 89%-96% with the relative standard deviations(RSDs) ranging from 2.1% to 4.9%, and the recoveries of spinetoram spiked in soil were 86%-93% with the RSDs ranging from 1.2% to 8.1%. The results have demonstrated that the proposed method is sensitive and accurate for the determination of spinosad and spinetoram in soil.