采用顶空-气相色谱-质谱法测定地表水和废水中55种挥发性有机物的含量。选择顶空平衡温度和时间分别为65 ℃和50 min。在气相色谱分离中用DB-624色谱柱为固定相,在质谱分析中采用全扫描和选择离子监测模式。以氟苯和1,2-二氯苯-D4为内标物。55种挥发性有机物的线性范围均为10.0~400 μg·L-1。全扫描模式下,检出限在0.8~6.8 μg·L-1之间,加标回收率在81.3%~116%之间,测定值的相对标准偏差(n=6)在0.40%~15%之间。在选择离子监测模式下,检出限在0.2~1.1 μg·L-1之间,加标回收率在81.0%~117%之间,测定值的相对标准偏差(n=6)在0.40%~6.5%之间。

Headspace-GC-MS was applied to the determination of 55 volatile organic compounds in suface water and waste water. The equilibrium temperature and time of headspace sampling were set at 65 ℃ and 50 min, respectively. DB-624 chromatographic column was used for GC separation, and full-scanning mode and the selected ion monitoring mode were adopted in MS determination. Fluobenzene and 1,2-dichlorobenzene-D4 were used as internal standards. Linearity ranges of the 55 volatile organic compounds were found same between 10.0-400 μg·L-1. Under the full-scanning mode, values of detection limits found were in the range of 0.8 to 6.8 μg·L-1; and values of recovery found by standard addition method were found in the range of 81.3%-116%, with values of RSD′s (n=6) ranged from 0.40%-15%. Under the selected ion monitoring mode, values of detection limits found were in the range of 0.2-1.1 μg·L-1; and values of recovery found by standard addition method were in the range of 81.0%-117%, with values of RSD′s (n=6) ranged from 0.40%-6.5%.