全自动加速溶剂萃取-超高效液相色谱-串联质谱法测定土壤中7种杀线虫剂的残留量

Determination of Residues of 7 Nematocides in Soil by Ultra-High Performance Liquid Chromatography-Tandem Mass Spectrometry with Automatic Accelerated Solvent Extraction

通过优化提取、净化条件,提出了题示方法测定土壤样品中棉隆、噻唑膦、灭线磷、丰索磷、杀线威、丁硫环磷、除线磷等7种杀线虫剂的含量。随机采集土壤样品,风干,粉碎后过筛,分取10.0 g,加入硅藻土15.0 g,用体积比2:1的甲醇和三氯甲烷混合溶液进行加热加压全自动萃取;萃取液过活化好的HLB固相萃取柱,用10 mL体积比1∶1的甲醇和乙腈混合溶液洗脱。洗脱液于45℃氮吹至近干,残留物用1 mL乙酸乙酯溶解,过0.22μm滤膜,滤液采用超高效液相色谱-串联质谱法测定。结果显示:7种杀线虫剂的质量浓度在0.005~2.0 mg·L^(-1)内与峰面积呈线性关系,检出限(3S/N)为4~25μg·kg^(-1);按照标准加入法进行回收试验,回收率为87.2%~101%,测定值的相对标准偏差(n=6)为1.5%~3.8%;方法用于实际样品分析,检出了棉隆、噻唑膦、灭线磷、丰索磷、除线磷,检出量为14.81~124.03μg·kg^(-1)。

By optimizing the extraction and purification conditions,the method mentioned by the title was proposed to determine 7 nematocides in soil samples,including dazomet,fosthiazate,ethoprophos,fensulfothion,oxamyl,fosthietan and dichlofenthion.Soil sample was collected randomly,dried by air,crushed and sieved.An aliquot(10.0 g)was taken,and 15.0 g of diatomaceous earth was added.The mixture was extracted automatically under heating and pressure conditions with the mixed solution of methanol and trichloromethane at volume ratio of 2∶1.The extract was passed through the activated HLB solid phase extraction column for elution by 10 mL of the mixed solution of methanol and acetonitrile at volume ratio of 1∶1.The eluent was blown to near dryness by nitrogen at 45℃,and the residue was dissolved in 1 mL of ethyl acetate.The solution obtained was passed through a 0.22μm filter membrane,and the filtrate was determined by ultra-high performance liquid chromatography-tandem mass spectrometry.It was shown that linear relationships between values of the mass concentration and the peak area of the 7 nematocides were kept in the range of 0.005-2.0 mg·L^(-1),with detection limits(3S/N)in the range of 4-25μg·kg^(-1).Test for recovery was made according to the standard addition method,giving recoveries in the range of 87.2%-101%,and RSDs(n=6)of the determined values in the range of 1.5%-3.8%.The proposed method was used for the analysis of actual samples,and dazomet,fosthiazate,ethoprophos,fensulfothion and dichlofenthion were detected with detection amounts ranged from 14.81μg·kg^(-1)to 124.03μg·kg^(-1).