地下水中21种半挥发性有机物测定方法的优化研究

Study on optimization of determination method for 21 semi-volatile organic compounds in groundwater

为研究建立同时测定地下水中21种半挥发性有机物的固相萃取-气相色谱-串联质谱(SPE-GC/MS)法,采用C 18和HLB固相萃取柱对地下水样品进行富集萃取,DB-5MS毛细管柱(30 m×0.25 mm×0.25μm)进行气相分离,单离子监测(SIM)扫描模式进行分析,并对进样速率、洗脱剂和pH等样品前处理条件进行优化,建立了固相萃取-气相色谱-质谱测定地下水中21种半挥发性有机物的检测方法。研究结果显示:21种半挥发性有机物的标准曲线在0.1~1μg/mL范围内,线性关系良好。平均回收率基本在80%~120%之间,精密度在1.70%~8.79%之间,检出限在0.022~0.045μg/L之间,均低于《地下水质量标准》(GB/T 14848—2017)一类水限值。研究结果表明,本方法操作简便、有机试剂消耗量少、灵敏、准确,可用于地下水中多种半挥发性有机物的同时检测。

In order to study establishing the method of solid phase extraction-gas chromatography-tandem mass spectrometry(SPE-GC/MS)for determinating 21 semi-volatile organic compounds in groundwater at the same time,the groundwater samples are enriched and extracted by C18 and HLB solid phase extraction columns and then the gas phase separation is carried out by DB-5MS capillary column(30 m×0.25 mm×0.25μm),while the single ion monitoring(SIM)scanning mode is adopted for the relevant analysis.Moreover,the sample pretreatment conditions,i.e.the sample-injection rate,eluent,pH.etc.,are optimized,thus the method for solid phase extraction-gas chromatography-mass spectrometry for determinating 21 semi-volatile organic compounds in groundwater is established.The study result exhibits that all the standard curves of the 21 semi-volatile organic compounds are within the range of 0.1-1μg/mL with better linear relationships;for which the mean recovery rates are between 80%and 120%with the precisions of 1.70%-8.79%and the detection limits are between 0.022-0.045μg/L,which are all lower than those of the limits for the water of Class I specified in the Standard for Groundwater Quality(GB/T 14848—2017).The study result shows that this method is simple and easy to be handled with less consumption of organic reagent,while it is sensitive and accurate,thus can be used for the simultaneous determination of several semi-volatile organic compounds.