固相萃取-气相色谱-串联质谱法同时测定饮用出厂水中202种农药

Simultaneous determination of 202 pesticides in potable water from water factory by solid phase extraction-gas chromatography-tandem mass spectrometry

目的 建立固相萃取(solid phase extraction, SPE)-气相色谱-串联质谱(gas chromatography-tandem mass spectrometry, GC-MS/MS)测定饮用出厂水中202种农药的方法。方法 优化了预处理方法,采用填料为二乙烯苯和N-乙烯基吡咯烷酮共聚物(divinylbenzene and N-vinylpyrrolidone copolymer, HLB)的SPE柱富集1 L水样,3 ml甲醇和15 ml乙酸乙酯洗脱,氮吹定容至1.0 ml后GC-MS/MS测定,外标法定量。结果 202种农药在2.5×10^(3)-2.0×10^(5) ng/L范围内线性关系良好,相关系数0.9954~0.9999,方法检出限2~20 ng/L。其中181种农药的定量下限(limit of quantitation, LOQ)为10~50 ng/L,回收率为59.5%~119.3%,相对标准偏差为2.1%~42.6%;另有21种农药的LOQ暂时无法确立。结论 该方法准确、灵敏,经实际样品测试,适用于生活饮用水中农药残留的高通量筛查与检测。

Objective To establish a method for determining 202 kinds of pesticides in potable water from water factory by solid phase extraction(SPE)-gas chromatography-tandem mass spectrometry(GC-MS/MS). Methods The pretreatment method was optimized. The SPE column filled with divinylbenzene and N-vinylpyrrolidone copolymer(HLB) was used to enrich 1 L water sample, and then eluted with 3 ml of methanol and 15 ml of ethyl acetate. The elution solvents were concentrated to 1.0 ml, then determined by GC-MS/MS and quantified by external standard method. Results The callibration curves for 202 pesticides were linear in the range of 2.5×10^(3)-2.0×10^(5) ng/L with correlation coefficients from 0.9954 to 0.9999, and the limits of detection were in the range of 2 ng/L-20 ng/L. The limits of quantification(LOQs) for 181 pesticides were from 10 ng/L to 50 ng/L, and the recoveries were between 59.5% and 119.3%, with the relative standard deviations of 2.1%-42.6%. The LOQs for the other 21 pesticides could not be established temporarily. Conclusion The proposed method is accurate and sensitive for high-throughput screening and detection of pesticide residues in potable water.