Multiresidue analysis of 16 pesticides in jujube using gas chromatography and mass spectrometry with multiwalled carbon nanotubes as a sorbent.

Although jujube is a minor crop and very few pesticides are registered on it, the application of pesticides during the growth stage of jujube is inevitable to control the pests or diseases. This situation has led to pesticide misuse. A modified quick, easy, cheap, effective, rugged, and safe method using a novel sorbent, multiwalled carbon nanotubes, as a dispersive solid-phase extraction sorbent combined with gas chromatography with mass spectrometry, was developed for the determination of 16 pesticides in jujube. Under the optimized conditions, recoveries of 76.7-112.4% were obtained for the target analytes at three spiked concentration levels. The relative standard deviations ranged from 1.2 to 12.3%. Limits of detection and limits of quantification for 16 pesticides ranged from 1 to 10 and 3 to 30 μg/kg, respectively. The residues of chlorpyrifos, hexaconazole, tebuconazole, and cyhalothrin were detected from samples obtained from the market.