气相色谱-负离子化学电离质谱法对咖啡中8种有机氯农药的检测

Determination of 8 Organochlorine Pesticides in Coffee by Gas Chromatography-Negative Chemical Ionization Mass Spectrometry

An efficient and selective analytical method for the determination of 8 organochlorines pesticides residues(α-666,β-666,γ-666,δ-666,op’-DDT,pp’-DDT,pp’-DDD,pp’-DDE) in coffee has been developed.The coffee samples were extracted with hexane-acetone(1 ∶1,by volume) according to a selective extraction step using accelerated solvent extraction(ASE),followed by a clean-up by gel permeation chromatography(GPC) and a column combined with Florisil and GCB.Identification and quantification were performed using gas chromatography with negative chemical ionization mass spectrometric detection(GC-NCI MS).The method detection limits varied between 0.002 and 0.069 ng/g.The calibration curves showed a good linearity for all OCPs(r≥0.999 5) under a concentration of 0.20-50.0 μg/L.When the spiked levels were 0.5 μg/L and 5 μg/L,the average recoveries were range of 94%-110% with RSD of 3.5%-10.6%.The method was accurate,sensitive and suitable for the analysis of pesticides.