毛细管气相色谱法检测大气中三氯甲烷和四氯化碳

目的建立大气中三氯甲烷、四氯化碳的溶剂解吸毛细管气相色谱测定方法。方法大气样品用活性炭管采样,丙酮解析,毛细管气相色谱法测定。结果线性测定范围为三氯甲烷5.0×10-4～1.0×10-1mg/m3、四氯化碳1.9×10-4～1.0×10-2 mg/m3;样品在炭管中可保存7天;方法的重现性好,不同浓度的相对标准偏差为三氯甲烷0.41%～1.54%,四氯化碳0.31%～1.03%。方法的检出限为三氯甲烷1.5×10-3ng,四氯化碳5.8×10-4 ng。不同浓度的回收率为三氯甲烷88.5%～98.6%,四氯化碳91.0%～99.0%;采样效率为三氯甲烷93.7%～99.2%,四氯化碳90.6%～99.2%。空气中可能共存的结构相近性质相似的挥发性卤代烃在该方法条件下不干扰测定。结论该方法简便快速,灵敏度高,适用于大气中三氯甲烷、四氯化碳的监测。

Determination of chloroform and carbon tetrachloride in residential air by capillary gas chromatography

Objective To establish solvent desorption capillary gas chromatography method for determination of chloroform and carbon tetrachloride in residential air.Methods The sample was absorbed by active carbon glass tube,then desorbed by Acetone and determined by Capillary Gas Chromatography.Results Linear range of this method: 5.0 × 10-4-1.0 × 10-1 mg /m3 for chloroform,1.9 × 10-4-1.0 × 10-2 mg /m3 for carbon tetrachloride.The sample could be stored in the active carbon glass tube for 7 days.The re-occurrence rate of this method is good.RSD is:0.41%-1.54% for chloroform,0.31%-1.03% for carbon tetrachloride.Detection limit of this method:1.5 × 10-3 ng for chloroform,and 5.8 × 10-4 ng for carbon tetrachloride.Recovery rate for different concentrations:88.5%-98.6% for chloroform,and 91.0%-99.0% for carbon tetrachloride.Sampling efficiency: 93.7%-99.2% for chloroform,and 90.6%-99.2% for carbon tetrachloride.Other Volatile halogenated hydrocarbons with similar structures and similar nature in the residential air do not interfere the measurement.Conclusion The method was easy and quick,with high sensibility.It was applicable to monitor the chloroform and carbon tetrachloride in residential air.