顶空—气相色谱—质谱法测定地表水和废水中25种挥发性有机物的含量

Headspace-GC-MS determination of 25 volatile organic compounds in surface water and waste water

采用顶空—气相色谱—质谱法测定地表水和废水中25种挥发性有机物的含量。选择NaCl的加入量为4 g,顶空平衡温度70℃,顶空平衡时间40 min。在质谱分析中采用选择离子扫描模式,采用平均相对响应因子法进行定量。25种挥发性有机物在一定的浓度范围内与其响应值呈线性关系,线性相关系数均大于0.995。方法的检出限为0.18~0.48μg/L,加标回收率为67.0%~115.0%,测定值的相对标准偏差为1.7%~13.8%(n=7)。在实际样品测定中,地表水水样加标回收率为56.6%~110.0%,废水水样加标回收率为72.9%~103.1%。该方法简便、自动化程度高、检测结果能满足地表水和废水的分析要求。

HS-GC-MS was applied to the determination of 25 volatile organic compounds in surface water and waste water. The amount of NaCl added was 4 grams, the equilibrium temperature and time of headspace sampling were set at 70 C and 40 min. The selected ion monitoring mode was used in mass spectrometry, the mean relative response factor method was used for quantification. Linear relationships between response values and concentration of the 25 volatile organic compounds were kept in definite ranges and with linear correlation coefficient more than 0.995. The detection limit was 0.18-0.48 ^g/ L, the average recovery rate was 67.0%-115% and the relative standard deviation of determination results was 1.7%-13.8%（n=7）. In the determination of actual samples, the average recovery rate of surface water was 56.6%-110%, and 72.9%-103% of the waste water. The method is simple, high degree of automation and the results is in consistent with the requirements of detection of surface water and waste water.