Determination of Imidacloprid in Vegetable Samples by Gas Chromatography–Mass Spectrometry

Abstract

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. [ ² H ₁₀ ]Anthracene was used as an internal standard. The applicable concentration range was 12.5–250.0 µg kg ^{- 1} , the detection limit was 2.5 µg kg ^{- 1} (98 pg) and the relative standard deviation at the 125.0 µg kg ^{- 1} level was 0.7%. The method was 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%.