加速溶剂萃取-气相色谱-串联质谱法同时测定种植土壤中7种常见除草剂的残留量  

Simultaneous Determination of Residues of 7Common Herbicides in Planting Soil by Gas Chromatography-Tandem Mass Spectrometry with Accelerated Solvent Extraction

作　　者：李旭霞 LI Xuxia(Shandong Tai Ke Environmental Monitoring Co.,Ltd.,Linyi 276007,China)

机构地区：[1]山东科泰环境监测有限公司,临沂276007

出　　处：《理化检验（化学分册）》2023年第5期532-536,共5页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

摘　　要：采集表层往下约20 cm种植土壤样品,除杂、自然风干、研磨后过孔径0.18 mm筛。分取样品10 g,和弗罗里硅土10 g、硅藻土5 g混合,以体积比1∶1的乙酸乙酯-丙酮混合溶液作萃取溶剂,于90℃进行加速溶剂萃取。收集全部萃取液,于70℃水浴氮吹至约2 mL,过活化好的弗罗里硅土固相萃取柱,用10 mL体积比1∶1的丙酮-正己烷混合溶液洗脱。收集全部洗脱液,于70℃水浴氮吹至近干,用丙酮稀释至1.0 mL,过0.22μm滤膜,滤液进入气相色谱-三重四极杆质谱仪,在DB-5MS石英毛细管色谱柱上进行程序升温分离,以电子轰击离子源电离,多反应监测模式检测,外标法定量分析苯磺隆、环草敌、烯禾啶、禾草灭、伏草隆、精吡氟禾草灵、丁氟消草等7种常见除草剂。结果显示,7种除草剂的质量浓度在0.02~5.0 mg·L^(-1)内与对应的峰面积呈线性关系,方法检出限(3s)为0.008~0.017μg·kg^(-1)。按标准加入法进行回收试验,回收率为87.3%~102%,测定值的相对标准偏差(n=6)均小于5.0%。方法用于水稻、小麦、玉米、苹果和葡萄种植土壤样品的分析,在水稻、小麦、苹果和葡萄种植土壤中分别检出了伏草隆、苯磺隆、烯禾啶和精吡氟禾草灵,检出量分别为32.15,14.22,11.62,27.15μg·kg^(-1)。The planting soil samples about 20cm below the surface were collected,removed from impurities,naturally dried by air,ground,and passed through a sieve with pore size of 0.18mm.An aliquot(10g)of the sample was taken and mixed with 10g of Florisil and 5g of diatomaceous earth.The mixture was pretreated by accelerated solvent extraction with ethyl acetate-acetone mixed solution at volume ratio of 1∶1at 90℃.All the extract was collected and blown to about 2mL in 70℃water bath by nitrogen.The solution obtained was passed through Florisil solid phase extraction column activated beforehand,and elution was carried out by 10mL of acetone-n-hexane mixed solution at volume ratio of 1∶1.The eluate was collected,blown to near dryness in 70℃water bath by nitrogen,and diluted to 1.0mL by acetone.The resulting solution was passed through a 0.22μm filter membrane,and the filtrate was introduced into the gas chromatography-triple quadrupole mass spectrometer.Seven common herbicides,including bensulfuron methyl,cyclochlor,dimefop,pochlor,vochlor,flufop-p-ethyl,and bufloxacin,were separated by programmed temperature on the DB-5MS quartz capillary chromatographic column,ionized by the electron impact ion source,detected by the multiple reaction monitoring mode,and quantitatively analyzed by external standard method.As found by the results,linear relationships between values of the mass concentration and respective peak area of the 7herbicides were kept in the range of 0.02-5.0mg·L^(-1),with detection limits(3s)of method in the range of 0.008-0.017μg·kg^(-1).Test for recovery was made by standard addition method,giving recoveries in the range of 87.3%-102%,and RSDs(n=6)of the determined values were less than 5.0%.The proposed method was applied to the analysis of the rice,wheat,corn,apple,and grape-planting soil samples,and vochlor,bensulfuron methyl,dimefop,and flufop-p-ethyl were detected in rice,wheat,apple,and grape-planting soil samples,with detection amounts of 32.15,14.22,11.62,27.15μg·kg^(-1),respectively.

关 键 词：加速溶剂萃取 气相色谱-串联质谱法 常见除草剂 残留量 种植土壤 

分 类 号：O657.63[理学—分析化学]