Abstract:

A new method was developed with ultra-performance liquid chromatography-tandem mass spectrometry (UPLCMS/MS) to determine indoxacarb pesticide residue in vegetables and fruits. Samples were extracted by acetonitrile and cleaned up on a solid-phase extraction (SPE)-PAK C18 cartridge column. The reconstituted sample solution was analyzed by UPLC-MS/MS under positive ion mode. Waters BEH C18 was taken as the analytical column, and 20 mmol/L ammonium acetate aqueous solution containing 0.1% formic acid-acetonitrile containing 0.1% formic acid was taken as the mobile phase. When fresh cabbage was the matrix, the spike recoveries of indoxacarb were 89.5% to 101.2% (n = 6), and the average recovery was 93.45%. When freezedried cabbage was the matrix, the spike recoveries of indoxacarb were 82.4% to 105.3% (n = 6), and the average recovery was 90. 6%. Both the within-day and inter-day RSDs (n = 6) were less then 5.0%. The detection limit of indoxacarb by this method was 0.05 μg/L (S/N = 3).

Key words: indoxacarb, ultra-performance liquid chromatography-mass spectrometry (UPLC-MS/MS), SPE, vegetables, fruits