Development of a rapid detection method for seven pesticides in cucumber using hollow fibre liquid phase microextraction and ion mobility spectrometry

摘要

A novel method based on hollow fibre liquid phase microextraction coupled with a hand-held ion mobility spectrometer was developed for determination of seven pesticides in cucumber samples. The hollow fibre liquid phase microextraction (LPME) sample preparation method is used to preconcentrate pesticide residues present in cucumber samples. The extracted pesticide residues are detected by IMS under optimized operating conditions. During the tests, the instrument is operated in the positive mode at ambient pressure using ~(63)Ni as the ionization source, with dry, clean air as the drift gas which circulates in a closed loop system. The IMS detection limits for propoxur, carbofuran, atrazine, cyanatryn, metolachlor, prometryn and tebuconazole were 5, 5, 1, 5, 5, 10 and 50 ng respectively. The analysis via IMS takes less than 10 s. The mean recoveries were in the range of 60-89% with an acceptable reproducibility (RSD < 12%). The results obtained reveal that the method is of great potentiality for rapid screening and detection of seven pesticide residues contained in agricultural products.