静态顶空-气相色谱/质谱法同时检测环境水体中59种挥发性有机物

摘要

The headspace sampling ( HS) method is a simple, environmentally friendly method. The measurement of 59 kinds of volatile organic compounds ( VOCs ) in environmental water using HS coupled gas chromatography/mass spectrometry (GC/MS) was discussed. Under the optimal headspace sampling conditions, a detector gain of 1. 00 kV, a sample salinity of 40%, an equilibrium temperature of 80℃, an equilibrium time of 10 min, an equilibrium pressure of 0. 103 4 MPa, a pressure equilibration time of 45 s, a loop equilibration time of 20 s, a loop inject time of 3 min were get up, and the obtained detection limits were 0. 06 ~7. 6 μg/L, with r>0. 998. The obtained average recovery ratios were 60% ~110% (n=6) in spiked samples from drinking source and sewage plants, with a RSD of 0. 33% ~22% (n=6). The HS-GC/MS method with automatic water pretreatment can be applied to the simultaneous measurement of 59 VOCs in water samples with high efficiency.%静态顶空法是一种简单、环保的样品前处理方法.通过对比试验,优化了影响静态顶空进样方法灵敏度的主要因素,确定了较佳的样品盐度(40%)、平衡温度(80℃)、平衡时间(10 min)、平衡压力(0.1034 MPa)、定量环平衡时间(20 s)、进样时间(3 min)等前处理方法参数.采用优化后水样前处理条件及1.00 kV的检测器电压,59种挥发性有机物在特定的线性范围内,标准曲线线性相关系数均大于0.998,方法检出限为丙烯腈4.4μg/L、硝基苯7.6μg/L,其余挥发性有机物(VOCs)介于0.06~1.4μg/L,饮用水源水及污水处理厂进水实际样品加标回收率为60%~110%,精密度(RSD)为0.33%~22%(n=6).建立的静态顶空-气相色谱/质谱法(HS-GC/MS)水样前处理过程自动化,可同时对水中59种挥发性有机物进行检测.