捕集阱顶空气相色谱/质谱法测定水中的二氯一溴甲烷

建立了捕集阱顶空气相色谱/质谱测定水中二氯一溴甲烷的方法。采用正交实验设计对平衡温度、平衡时间、循环次数3个参数进行了优化,在平衡温度70 ℃、平衡时间20 min、循环次数2次的优化条件下,对水中的二氯一溴甲烷进行测定。结果显示,在0.1～10.0 μg/L范围内,二氯一溴甲烷的质量浓度和峰面积呈良好的线性关系,相关系数为0.9991。方法的检出限(S/N=3)为0.03 μg/L,定量限(S/N=10)为0.1 μg/L,回收率为83.1%～111.3%,相对标准偏差为1.7%～5.2%(n=6)。将该方法应用于水中二氯一溴甲烷的定性定量分析,效果良好。

Determination of dichlorobromomethane in water by headspace-trap gas chromatography/mass spectrometry

A novel method was developed for the determination of dichlorobromomethane in water using headspace-trap gas chromatography/mass spectrometry (GC/MS). Three parameters of headspace-trap including thermostatic temperature, time and cycle number were optimized by orthogonal experiment analysis. Dichlorobromomethane in water samples was analyzed under the optimized conditions of 70 degrees C and 20 minutes with the cycle number of two. The results showed that the calibration curve was linear in the range of 0.1 - 10.0 microg/L, and the correlation coefficient was 0.999 1. The detection limit was 0.03 microg/L. The average recovery was 83.1% - 111.3% with the relative standard deviation (RSD) not more than 5.2% (n = 6). This method is rapid, sensitive and reproducible for the routine detection of the low concentration of dichlorobromomethane in water.