Determination of Pyrethroid Insecticides in Vegetables with Liquid Chromatography Using Detection by Electrospray Mass Spectrometry

Liquid chromatography with electrospray mass spectrometry (LC-ES-MS) instrumentation equipped with a single quadrupole mass filter has been used to determine several pyrethroid insecticides (fenpropathrin, lambda-cyhalothrin, deltamethrin, fenvalerate, permethrin, tau-fluvalinate and bifenthrin). The applicability of the method to the determination of insecticides in spiked cucumber, green bean, tomato and aubergine was evaluated. Samples were extracted into dichloromethane without a clean-up step. Interferences due to the matrix effect were overcome using matrix matched standards. The limits of detection ranged from 4–8 ng mL−1 (3 and 6 ng g−1 in the vegetable samples), with relative standard deviations < 6.8%, using blank vegetable extract. Mean recoveries ranged from 80.1–109.8%.