Pang Guo-Fang, Cao Yan-Zhong, Fan Chun-Lin, Jia Guang-Qun, Zhang Jin-Jie, Li Xue-Min, Liu Yong-Ming, Shi Yu-Qiu, Li Zeng-Yin, Zheng Feng, Lian Yu-Jing
Qinhuangdao Entry-Exit Inspection and Quarantine Bureau, 39 Haibin Rd, Qinhuangdao, Hebei, People's Republic of China.
J AOAC Int. 2009 May-Jun;92(3):933-40.
The paper reports the study of gel permeation chromatography (GPC), gas chromatography/mass spectrometry (GS/MS), and column chromatography tandem MS (LC/MS/MS) for 839 pesticides and chemical contaminants, through which a GPC data bank has been established for 744 pesticides, a GC/MS data bank for 541 pesticides, and an LC/MS/MS data bank for 464 pesticides. On the basis of this study, a new method for quantitative determination of 587 pesticide residues in animal muscles such as beef, mutton, pork, chicken, and rabbit has been established using GPC cleanup followed by GC/MS and LC/MS/MS. In the method, 10 g animal samples were mixed with 20 g sodium sulfate and extracted twice with 35 mL cyclohexane-ethyl acetate (1 + 1) by blender homogenization followed by centrifugation, filtration, and concentration. An equivalent of 5 g sample was injected into a 400 x 25 mm S-X3 GPC column, with cyclohexane-ethyl acetate (1 + 1) as the mobile phase at a flow rate of 5 mL/min. The 22-40 min fraction was collected for subsequent analysis. For the 478 pesticides determined by GC/MS, the portions collected from GPC were concentrated to 0.5 mL and exchanged twice with 5 mL hexane. For the 379 pesticides determined by LC/MS/MS, the portions collected from GPC were dissolved with acetonitrile-water (60 + 40) after taking the extract to dryness with nitrogen gas. At the limit of quantification (LOQ) and 10 LOQ fortification levels of 0.1-16 000 microg/kg, recoveries were within 40-130%, among which 563 pesticide recoveries were between 60 and 130%, accounting for 96% of the compounds; 24 analytes were recovered between 40 and 60%, accounting for 4% of the compounds. The relative standard deviation was below 30% for all 587 pesticides. The limits of detection for the method were 0.1-1600 microg/kg. In comparison with GC/MS, LC/MS/MS increased the detection sensitivity 2-1000 times for 236 pesticides.
该论文报道了采用凝胶渗透色谱法（GPC）、气相色谱/质谱联用法（GC/MS）和柱色谱串联质谱法（LC/MS/MS）对839种农药及化学污染物进行的研究，据此建立了包含744种农药的GPC数据库、541种农药的GC/MS数据库以及464种农药的LC/MS/MS数据库。基于此项研究，建立了一种测定牛肉、羊肉、猪肉、鸡肉和兔肉等动物肌肉中587种农药残留的新方法，该方法先用GPC净化，再采用GC/MS和LC/MS/MS进行测定。在该方法中，将10 g动物样品与20 g硫酸钠混合，用35 mL环己烷 - 乙酸乙酯（1 + 1）通过搅拌器匀浆，然后离心、过滤并浓缩，重复提取两次。取相当于5 g的样品注入400×25 mm的S - X3 GPC柱中，以环己烷 - 乙酸乙酯（1 + 1）为流动相，流速为5 mL/min。收集22 - 40 min的馏分用于后续分析。对于通过GC/MS测定的478种农药，从GPC收集的部分浓缩至0.5 mL，并用5 mL己烷交换两次。对于通过LC/MS/MS测定的379种农药，从GPC收集的部分在氮气吹干提取物后，用乙腈 - 水（60 + 40）溶解。在0.1 - 16 000 μg/kg的定量限（LOQ）和10倍LOQ加标水平下，回收率在40% - 130%之间，其中563种农药的回收率在60% - 130%之间，占化合物总数的96%；24种分析物的回收率在40% - 60%之间，占化合物总数的4%。所有587种农药的相对标准偏差均低于30%。该方法的检测限为0.1 - 1600 μg/kg。与GC/MS相比，LC/MS/MS对236种农药的检测灵敏度提高了2 - 1000倍。
