顶空气相色谱法测定大气中甲醇含量

摘要

In this paper,pure water was used to absorb methanol in the air,followed by using headspace gas chromatography analysis of the methanol concentration in the absorption solution.Thereby,the optimization method of determination of methanol in air and waste gas by headspace gas chromatography with capillary column was established.The results show that when the sampling volume is 24 L and the absorption solution is 5 mL,the detection limits of the proposed method for methanol is 0.1 mg/m3,the relative standard deviation is between 2.1％ and 5.3％,and the recovery rate ranges from 95％ to 108％ with a relative standard sample added.The headspace gas chromatography (HS-GC) is simple,sensitive and accurate.The sample pretreatment and chromatographic analysis can be conducted continuously,because of its high degree of automation.%首先使用纯水为吸收液,吸收空气中的甲醇,再采用顶空气相色谱法分析吸收液中甲醇浓度,由此建立了自动顶空毛细管气相色谱法测定空气和废气中甲醇的方法,并对自动顶空进样条件进行了优化.结果表明,当采样体积为24 L、吸收液体积5 mL时,该方法的最低检出浓度为0.1 mg/m3,相对标准偏差为2.1％～5.3％,加标回收率为95％ ～ 108％.该法操作简单,具有较好的灵敏度和可靠的准确度,自动化程度高,可连续完成样品的前处理、样品进样和色谱分析.