固相萃取-气相色谱法对河水与海水中36种农药残留的同时测定

应用固相萃取和气相色谱技术建立了河水和海水中36种常用农药(7种有机氯、11种有机磷、8种拟除虫菊酯、4种酰胺、2种苯胺和4种唑类杂环)的分析方法.采用Oasis HLB柱为水样富集萃取柱,考察了洗脱溶剂、上样体积、pH值和离子强度等因素对萃取效果的影响,采用无水硫酸钠和NH2柱进行除水和净化.目标农药在0.9 ～2 600 μg/L范围内线性良好;以PCB103为内标物,2,4,5,6-四氯间二甲苯、环氟菌胺和氟丙菊酯为替代物,实际河水、海水的加标回收率分别为62% ～124%、64% ～132%,相对标准偏差(n=3)分别为0.2% ～9.6%、0.1% ～12.2%;方法检出限为0.10 ～1.0 ng/L.方法快速、灵敏、准确,已成功应用于福建九龙江入海口表层水样的分析.

Simultaneous Determination of 36 Pesticides in River Water and Sea Water Using Solid Phase Extraction-Gas Chromatography

A method for simultaneous determination of 36 pesticides(7 organochlorines,11 organophosphorous,8 pyrethrins,4 amides,2 nitrodiphenylamines and 4 heterozoles) in river water and sea water was established by combination of solid phase extraction and gas chromatography(SPE/GC).Oasis HLB cartridge was selected to extract and enrich target pesticides.Effect of experimental conditons,such as elution solvents,loading speed,penetration volume,cleanup cartridges,pH and salinity on extraction efficiency were investigated.Under the optimized conditions,the calibration curves showed good linearity between 0.9 and 2 600 μg/L for targeted compounds.With PCB103 as internal standard,2,4,5,6-tetrachloro-m-xylene,cyflufenamid and acrinathrin as surrogates,recoveries of 36 pesticides from river water and sea water at two spiking levels were in the range of 62%-124% and 64%-132%,respectively,their relative standard deviations(n=3) were 0.2%-9.6% and 0.1%-12.2%,respectively.Method detection limits ranged from 0.10 to 1.0 ng/L.The method was fast,sensitive,accurate,and was successfully applied in the analysis of pesticide in surface waters of Jiulong River estuary,Fujian province.