title: [Determination of 14 pesticide residues in sulfur-containing vegetables by gas chromatography-negative chemical ionization mass spectrometry].
abstract: A gas chromatography-negative chemical ionization mass spectrometric (GC-NCI/ MS) method has been developed for analyzing 14 pesticide residues in sulfur-containing vegetables (scallion, garlic, garlic bolt, leek, etc.). The samples were first heated in a microwave oven to eliminate most of the sulfur-containing interfering impurities and then extracted with acetonitrile. The extracts were further cleaned-up by gel permeation chromatography (GPC) and a primary-secondary amine (PSA) cartridge. The target analytes were determined using GC-NCI/MS in the selected ion monitoring (SIM) mode. The recoveries of all the pesticides (at spiked level of 50 microg/kg) were from 49.2% to 113.1% with the relative standard deviations between 1.42% and 8.70%. The detection limits (S/N = 3) were in the range of 0.5-10.0 microg/kg. The method is selective without interference and suitable for the determination and confirmation of pesticides in the sulfur-containing vegetables.
authors.affiliation: Shaoxing Entry-Exit Inspection and Quarantine Bureau, Shaoxing 312000, China. hubeizhen_002@yahoo.com.cn
authors.forename: Beizhen
authors.initials: B
authors.lastname: Hu
authors.forename: Weihua
authors.initials: W
authors.lastname: Song
authors.forename: Liping
authors.initials: L
authors.lastname: Xie
authors.forename: Tiefeng
authors.initials: T
authors.lastname: Shao
mesh_terms: D005504:Food Analysis / Q000379:methods*; D005506:Food Contamination / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D057230:Limit of Detection; D016014:Linear Models; D008872:Microwaves; D010573:Pesticide Residues / Q000032:analysis* / Q000302:isolation & purification; D015203:Reproducibility of Results; D013455:Sulfur / Q000378:metabolism*; D014675:Vegetables / Q000737:chemistry* / Q000378:metabolism*
chemical_list: D010573:Pesticide Residues; D013455:Sulfur