气相色谱法测定氨气中的甲硫醇及甲硫醚

Determination of Methyl Mercaptan and Dimethyl Sulfide in Ammonia Gas by Gas Chromatography

建立了测定氨气中甲硫醇及甲硫醚的气相色谱分析方法。样品充入高纯氮气后 ,通过磷酸吸收液脱除氨气 ,有机硫化物由氨气转移到高纯氮气中 ,收集这部分气体 ,取 1 0～ 2 0mL采用火焰光度检测填充柱气相色谱法进行分析。方法的相对标准偏差小于 7% ,甲硫醇和甲硫醚的加标回收率分别为 92 1%和 87 6 % ,最低检出量分别为 0 11ng和 0 17ng ,最低检出质量浓度分别为 0 11μg/L和 0 17μg/L。

A method was developed for the determination of methyl mercaptan and dimethyl sulfide in ammonia gas. The samples were mixed first with high purity nitrogen and then washed with phosphoric acid absorption solution to remove ammonia. The organic sulfur compounds were transferred from ammonia gas into high purity nitrogen. 1.0～2.0 mL of the prepared gas was analyzed by flame photometric detecting packed column gas chromatography. The relative standard deviation of the method is below 7%,the recoveries of the marked methyl mercaptan and dimethyl sulfide are 92 1% and 87 6% respectively, and the minimum detection mass concentrations are 0.11 μg/L and 0.17 μg/L respectively.