啤酒大麦中十五种农药残留检测方法的建立及应用

建立固相萃取—气相色谱—质谱联用技术法,并检测了大麦中六六六(α-六六六、β-六六六、γ-六六六、δ-六六六)、滴滴涕(p,p'-滴滴伊、o,p’-滴滴涕、p,p’-滴滴滴、p,p’-滴滴涕)、乐果、抗蚜威、乙草胺、马拉硫磷、三唑酮、三唑醇、溴氰菊酯15种农药残留。该方法的精密度在1.15%～ 9.80%,大部分低于5.00%；回收率在77.78%～112.00%；检出限在0.77～10.34 μg/L,表明该检测方法准确可靠。利用该方法检测国内7个地区(江苏、四川、新疆、云南、黑龙江、内蒙古、甘肃)的大麦农残,所有的农残含量均未超标。根据农残水平可将15种农药划分为两大类：一类是残留相对较高但未超标,包括4种化合物p,p’-滴滴涕(≤ 0.032 mg/kg)、β-六六六(≤ 0.039 mg/kg)、三唑酮(≤ 0.093 mg/kg)和乐果(≤ 0.030 mg/kg)。其中乐果除了江苏地区外其他地区均未检出；另一类是残留未检出或远远低于国家限量标准(最大残留限量)的农药。

Establishment and application of detection methods for 15 pesticide residues in beer barley

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．