Determination of imidacloprid in vegetable samples by gas chromatography-mass spectrometry

A method for the determination of imidacloprid involving hydrolysis in basic medium followed by gas chromatography-mass spectrometry and selected ion monitoring was developed, The hydrolysis product which was extracted with chloroform was found to be suitable for gas chromatographic analysis, Further, clean-up is not necessary using the selected ion monitoring mode, [H-2(10)]Anthracene was used as an internal standard, The applicable concentration range was 12.5-250.0 mu g kg(-1), the detection limit was 2.5 mu g kg(-1) (98 pg) and the relative standard deviation at the 125.0 mu g kg(-1) level was 0.7%, The method,vas applied to the determination of the imidaclorpid in vegetable samples (tomato, cucumber, pepper and green beans). Recovery levels were between 94.3% and 105.8%.