加速溶剂萃取-气相色谱-质谱法同时测定污泥中37种有机磷类及10种拟除虫菊酯类农药

Simultaneous Determination of 37 Organophosphorus and 10 Pyrethroid Pesticides in Sludge by GC-MS after Extraction with ASE

建立了加速溶剂萃取(ASE)-气相色谱-质谱法(GC-MS)测定污水处理厂污泥中的37种有机磷类农药(OPPs)和10种拟除虫菊酯类农药的方法。将污泥样品冷冻干燥后,加入装有硅藻土的萃取池中,以体积比为1∶1的正己烷-丙酮混合溶液为萃取溶剂,在110℃,10.0 MPa下循环萃取2次,萃取液经减压浓缩后转移至石墨化炭黑固相萃取小柱中,用体积比为1∶1的正己烷-丙酮混合溶液洗脱,控制洗脱流量为4 mL·min^(-1),洗脱液经减压浓缩后过0.22μm有机滤膜。吸附在DB-1701P色谱柱上的滤液中的目标物在用程序升温条件分离后,用配有电子轰击离子源(EI)的质谱仪进行检测,用基质匹配混合标准溶液系列制作标准曲线。结果显示:47种目标物的质量浓度均在2.00-100.0 mg·L^(-1)内与其对应的峰面积呈线性关系,检出限(3.143s)为0.04-0.19 mg·kg^(-1);对实际样品进行加标回收试验,所得回收率为58.0%-118%,测定值的相对标准偏差(n=6)为0.80%-7.4%。方法用于分析污水处理厂的污泥样品,检出了毒死蜱(0.23 mg·kg^(-1))、二嗪农(0.39 mg·kg^(-1))、安硫磷(0.71 mg·kg^(-1)),低于GB 36600-2018规定的限值。

A method was developed for the simultaneous determination of 37 organophosphorus and 10 pyrethroid pesticides in sludge from sewage treatment plant by GC-MS after extraction with ASE.After freeze-drying,the sludge sample was extracted twice by the mixed solution of acetone and n-hexane with volume ratio of 1∶1 in the extraction tank with diatomaceous earth at 110℃and 10.0 MPa.After the extraction solution was concentrated under reduced pressure,purified by graphitized carbon black solid phase extraction cartridge with mixed colution of acetone and n-hexane with volume ratio of 1∶1 as eluant at a flow rate of 4 mL·min^(-1).Analytes in the eluate adsorbed on the DB-1701 pchromatographic column were separated under programmed temperature,detected by MS with EI.Matrix matching mixed standard solution series were used to make standard curves.The results showed that mass concentrations of the 47 target compounds were linearly related with respective peak areas in the range of 2.00-100.0 mg·L^(-1),with limits(3.143s)of detection in the range of 0.04-0.19 mg·kg^(-1).The spiked recovery test was made on the actual samples,giving values of recovery in the range of 58.0%-118%,and RSDs(n=6)of the determined values ranged from 0.80%to 7.4%.The proposed method was used to analyze sludge samples from sewage treatment plants,chlorpyrifos(0.23 mg·kg^(-1)),diazinon(0.39 mg·kg^(-1)),and amphion(0.71 mg·kg^(-1))were detected,with their contents all less than those specified by GB 36600-2008.