Simultaneous Determination of Six Insecticides in Okra (Abelmoschus esculentus L. Moench) by UHPLC-MS/MS

Abstract

The sensitive analytical method using quick, easy, cheap, effective, rugged and safe (QuEChERS) method for simultaneous determination of six insecticides in Okra was developed by UHPLC -MS-MS. The six insecticides were extracted from Okra matrices using acetonitrile and subsequently clean up using only octadecylsilance as sorbent prior to LC-MS-MS analysis. The determination of the target compounds were achieved in less than 2.0 min using an electrospray ionization source in positive mode (ESI+) for imidacloprid, acetamiprid, thiacloprid, thiamethoxam, clothianidin and negative mode (ESI-) for flonicamid. The method showed that the limits quantification (LOQ) ranged from 0.13 to 5.9 μgkg-1 in all matrices. The matrix-matched standard gave satisfactory recoveries (72.4%-105.1%) and relative standard deviation (2.2 - 20.0%) values in different matrices at three spiked levels (0.01, 0.1, and 1 mgkg-1) for Okra.