Needle trap-顶空进样-气相色谱法分析地下水中的苯系物

Analysis of Benzene Series in Groundwater by Gas Chromatography with Needle trap-Headspace Sampling

摘要: 利用Needle trap集现场采样、无溶剂提取和热解吸进样等多功能为一体的特点,针对密闭的20 mL顶空样品瓶(10 mL样品),通过优化提取温度、样品平衡时间、注射器推杆循环抽拉体积、加盐量及现场采样保存时间等条件,确定了Needle trap吸附提取地下水中7种苯系物的最佳条件,用顶空进样气相色谱法测定,方法加标回收率为84.27%~115.03%,检出限为0.06~0.09 μg/L,精密度(RSD,n＝7)＜7%,符合EPA相关标准。建立的方法表明Needle trap适用于地下水中苯系物的提取分析。

Abstract: A method for the determination of 7 benzene series in groundwater samples by gas chromatography with Needle trap-headspace sampling was developed, which represents the integrated features of on-site sampling, solvent-free extracting and thermal desorption. The experiment conditions such as extraction temperature, sample-equilibration time, pump volume of syringe plunger, additive amount of salt and sample storage time were tested and optimized. The detection limits of the method for 7 benzene series were 0.06~0.09 μg/L and the recoveries were 84.27%~115.03% with precision of lower than 7%RSD(n＝7), which is consistent with relevant criteria of US EPA. The method is suitable for the determination of these benzene series in groundwater samples.