吹扫捕集–气相色谱–质谱法同时测定环境水中101种挥发性有机物

建立吹扫捕集–气相色谱–质谱联用法测定环境水中101种常见挥发性有机物(VOCs)的方法。通过加热吹扫,样品水中的VOCs富集于捕集管中,以DB–624(60 m×0.25 mm,1.4μm)色谱柱分离,内标法定量。结果表明,101种挥发性有机物(VOCs)色谱分离效果良好,质量浓度在0.5~50 ng/mL范围内与色谱峰面积均呈线性关系,高沸点VOCs线性范围较窄。方法定量限(10 S/N)为0.11~0.77 ng/mL,均低于GB 3838–2002《地表水环境质量标准》、GB 5749–2006《生活饮用水卫生标准》及国外相关标准的限值。平均加标回收率在70.3%~123.6%之间,测定结果的相对标准偏差不大于8.8%(n=6)。该方法快速、简便,适用于环境水中挥发性有机化合物的分析检测。

Determination of 101 Kinds of Volatile Organic Compounds in Ambient Waters by Purge and Trap-Gas Chromatography-Mass Spectrometry

A method for the determination of 101 kinds of volatile organic compounds (VOCs) in waters by using purge–and–trap coupled with gas chromatography–mass spectrometry was established. Samples were heated and purged, and VOCs were enriched in capture tube. The target ingredients were separated by DB–624 column (60 m×0.25 mm, 1.4 μm), internal standard quantitation method was used. The method presented perfect performance in chromatographic separation. The mass concentration of 101 kinds of VOCs was linear with chromatographic peak area in the range of 0.5–50 ng/mL, high boiling point compounds presented a narrow linear range. The limits of quantification were 0.11–0.77 ng/mL, which were lower than guidance value in the domestic standard (GB 3838–2002, GB 5749–2006) and international laws and regulations. The recoveries ranged from 70.3%to 123.6%,and the relative standard deviations of detection results were less than 8.8%(n=6). This method is fast,accurate and convenient,it is suitable for the determination of VOCs in waters in routine tests.