摘要
《工作场所空气有毒物质测定 无机含氮化合物》为标准测定氨的方法改进,以 0.005 mol/L的硫酸作为吸收液,研究氨的保存时间优化,以纳氏试剂作为显色剂,在 420 nm波长下测定吸光度,根据《职业卫生标准制定指南第 4部分:工作场所空气中化学物质测定方法》(GBZ/T 210.4-2008)样品准确度和稳定性试验规定,研究保存时间对其结果的影响.经试验证明,工作场所空气中氨以 0.005 mol/L硫酸溶液作为吸收液,用大型气泡吸收管采集,在碱性溶液中,氨与纳氏试剂反应生成黄色络合物,在 420 nm波长下测定吸光度,采集样品的保存时间至少可延长至7d.
Abstract
The method for determining ammonia based on the standard Determination of Inorganic Nitrogen Compounds in Workplace Air Toxic Substances was improved.0.005 mol/L sulfuric acid was used as the absorption solution to study the optimization of ammonia storage time.Nessler's reagent was used as the color reagent to measure absorbance at a wavelength of 420 nm.According to the Guidelines for the Development of Occupational Health Standards Part 4:Methods for the Determination of Chemical Substances in Workplace Air(GBZ/T 210.4-2008)sample accuracy and stability test regulations,the influence of storage time on its results was studied.Through experiments,it has been proven that ammonia in the workplace air is absorbed by a 0.005 mol/L sulfuric acid solution,collected using a large bubble absorption tube.In an alkaline solution,ammonia reacts with Nessler's reagent to form a yellow complex,and the absorbance is measured at a wavelength of 420 nm.The storage time of the collected samples can be extended to at least 7 days.
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