加速溶剂萃取-气相色谱-质谱法测定土壤中5种硝基麝香的含量

Determination of 5 Nitro-Musks in Soil by Gas Chromatography-Mass Spectrometry with Accelerated Solvent Extraction

取约20g土壤样品,加入适量硅藻土,混匀后研磨至流砂状,按照设置好的萃取条件进行加速溶剂萃取:萃取溶剂为体积比1∶1的正己烷-丙酮混合溶液,萃取温度100℃,静态萃取时间5min,静态萃取次数2次。收集萃取液,过无水硫酸钠(10.0g)柱进行脱水。收集流出液,氮吹至1.0mL,全部过活化好的硅胶净化小柱,弃去流出液,用7mL体积比1∶9的二氯甲烷-正己烷混合溶液洗脱。收集洗脱液,氮吹至近1mL,加入10.0μL 100mg·L^(-1)菲-d10内标溶液,用正己烷定容至1.0mL,供气相色谱-质谱仪分析,内标法定量。结果表明:5种硝基麝香(葵子麝香、伞花麝香、西藏麝香、二甲苯麝香和酮麝香)的质量浓度均在100~2 000μg·L^(-1)内与其和内标的峰面积比值呈线性关系,检出限(3.143s)为1.1~1.2μg·kg^(-1);按照标准加入法进行回收试验,回收率为74.9%~94.9%,测定值的相对标准偏差(n=6)为2.4%~9.8%;方法用于香料厂修复场地不同深度的土壤样品以及周边土壤样品的分析,在香料厂修复场地不同深度的土壤样品中检出了葵子麝香、二甲苯麝香和酮麝香,且检出量随着土壤深度的增大而减小。

About 20 g of soil sample was taken,and appropriate amount of diatomaceous earth was added.After mixing well,the mixture was ground to a flowing sand state,and accelerated solvent extraction was carried out according to the set extraction conditions as follows:the mixed solution of n-hexane and acetone at volume ratio of 1:1 as extraction solvent,the extraction temperature of 10o C,the static extraction time of 5 min,and the static extraction number of 2 times.The extract was collected,and passed through anhydrous sodium sulfate(1o.O g)column for dehydration.The effluent was collected,and blown to 1.O mL by nitrogen.The solution obtained was passed through the silica gel column activated beforehand,and the effluent was discarded.Elution was made by 7 mL of the mixed solution composed of dichloromethane and n-hexane at volume ratio of 1:9,and the eluate was collected,and blown to nearly 1 mL by nitrogen.After 10.0μL of 100 mg·L^(-1) phenanthrene-dio internal standard solution was added into the concentrate,the volume of the mixed solution was made up to l.0 mL by n-hexane for gas chromatograph-mass spectrometer analysis,and internal standard method was used for quantification.It was shown that linear relationships between values of the mass concentration of the 5 nitro-musks(musk ambrette,musk cymene,musk Tibetene,musk xylene and musk ketone)and the peak area ratio of 5 nitro-musks to internal standard were kept in the range of 100-2000μg·L^(-1),with detection limits(3.143s)ranging from 1.1μg·kg^(-1) to 1.2μg·kg^(-1).Test for recovery was made according to standard addition method,giving recoveries in the range of 74.9%-94.9%,and RSD(n=6)of the determined values ranged from 2.4%to 9.8%.The proposed method was applied to the analysis of soil samples at different depths of the spice factory remediation site and surrounding soil sample,musk ambrette,musk xylene and musk ketone were detected in soil samples at different depths of the spice factory remediation site,and the detection amounts decreased with the increase of soil depth.