加入EDTA改进硫化氢吸收液的方法探讨

The Discussion about Improving Air Hydrogen Sulfide Absorption Liquid by Adding EDTA

在分析硫化氢的方法中,稳定地保存捕集在捕集液里的硫化氢的硫离子是很重要的。对加入EDTA隐蔽铁等金属离子来防止氢氧化钠溶液中硫离子氧化的方法进行了讨论。结果是在1.0×10-5mol.L-1硫化氢标准溶液里,如果加入10mmol.L-1浓度的EDTA,硫化氢标准溶液放置在暗处至少可以稳定地保存一周。结论是通过在氢氧化钠吸收液中加入少量EDTA,成功地提高了溶液中硫离子的稳定性,使测定大气中微量硫化氢的荧光分析法更加实用。

It was very important to retain sulfur ion of hydrogen sulfide which was collected in entrapment liquid. Adding EDTA as masking agent to eliminate the interference of metal ions and to prevent sulfur ions to be oxidized in sodium hydroxide solution was discussed. The result was that hydrogen sulfide standard solution （1.0×10 5mol·L-1） could preserve stably for one week in dark place if 10mmol·L-1 EDTA was added. It was concluded that the stability of sulfur ions in sodium hydroxide solution could be improved by adding small amount of EDTA, and this would make the fluorophotometry be more practical which was applied to determine the hydrogen sulfide in air.