【摘要】 目的:探讨国家职业卫生标准中工作场所中空气氨的测定方法。方法:采用经稀释酸度后的吸收液,并加入酒石酸钾钠溶液,纳氏试剂显色,分光光度法测定。结果:经试验,本法最低检测氨的含量为1.0μg,若短时间采样标准体积为7.5 L时,最低检出浓度为0.67 mg/m3。高中低三浓度标准溶液的加标回收率介于95%～103%,相对标准偏差(RSD)均小于5%,不确定度分别为24.0μg±0.3μg、10.2μg±0.3μg、2.1μg±0.2μg(k=2)。结论:经改进后,该法操作简便、准确,能满足工作场所中空气氨的测定。更多还原

【Abstract】 Objective:To study the method for determination of ammonia in the workplace air from the Chinese occupation health standard.Methods: The aqueous-diluted acid solution was selected as absorption liquid,the colour reaction was realized by Nessler′s reagent after adding potassium sodium tartrate solution and spectrophotometric method was employed for the determination of ammonia in the workplace air.Results: After the experiment,the minimum detectable ammonia concentration of this method was 1.0 μg.In instantaneous sampling(sampling volume 7.5 L),the lowest density reached 0.67 mg/m3.The recoveries of the high-mid-low concentration ranged from 95% to 103%,the RSDs were less than 5%and the uncertainties were 24.0 μg±0.3 μg,10.2 μg±0.3 μg and 2.1 μg±0.2 μg(k=2),respectively.Conclusion: Based on the modified method,it is simple,accurate and able to meet a requirement for the determination of ammonia in the workplace air.更多还原