关键词: 固相萃取, GC-MS, 杀虫剂, 杀菌剂, 除草剂, 有机氯农药, 有机磷农药

Abstract: Fifteen pesticides were determined by solid-phase extraction and gas chromatograph-mass spectrum(SPE-GC-MS), and these pesticides were α-HCH, β-HCH, γ-HCH, δ-HCH, 4,4’-DDE, 2,4’-DDT, 4,4’-DDD, 4,4’-DDT, dimethoate, pirimicarb, acetochlor, malathion, triadimefon, triadimenol and deltalmethrin. The precisions of SPE-GC-MS ranged from 1.15% to 9.80% with mostly lower than 5%. The recoveries were 77.78%-112.00% with the detection limits in the range of 0.77-10.34 μg·L^-1, which demonstrated it was a good method. SPE-GC-MS was used to determine pesticide residues of barley from Jiangsu, Sichuan, Xinjiang, Yunnan, Heilongjiang, Inner Mongolia, Gansu. All of them didn't exceed its national standard. Fifteen pesticides were classified into two groups, according to content levels. Four pesticides in one group were high in level but lower than national standard level, including 4,4’-DDT (≤ 0.032 mg·kg^-1), β-HCH (≤ 0.039 mg·kg^-1), triadimefon (≤ 0.093 mg·kg^-1) and dimethoate(≤ 0.030 mg·kg^-1). Furthermore, residues of dimethoate have only been detected in Jiangsu. The other group including 11 pesticides was much lower than national standard level or even non-detection. The low residues may be related to the high resistance to diseases and pests of barley．

Key words: solid-phase extraction, GC-MS, insecticide, fungicide, herbicide, organochlorine, organophosphorus