乙酰丙酮甲醛分光光度法测定车间空气中氨

Determination of ammonia in workplace air by acety1 acetone and formaldehyde spectrophotometry

目的：建立不受甲醛、硫化氢干扰的测定车间空气中氨的新型分光光度测定法。方法：用0.01 mol/L H2SO4溶液的气泡吸收管采集空气中的氨,在加热100℃条件下,于pH4.5～5.0的乙酸-乙酸钠缓冲介质中,氨与乙酰丙酮、甲醛反应生成黄色化合物,于405 nm比色定量。结果：本法线性范围为0.20～10.00μg/ml,相对标准偏差为1.40%～5.07%,加标回收率为95.3%～104.5%,方法检测限为0.13 mg/m3。结论：本法简便、快速、不受甲醛、硫化氢干扰,用于实际车间空气样品中氨的测定,结果满意。

Objective：To develop a new spectrophotometric method to detect ammonia in workplace air.Methods：Ammonia in the workplace air was absorbed by 0.01mol/L sulfuric acid in a bubbling absorption tube.With 100℃ of water bath and pH4.5-5.0 of buffer solution of acetic acid-sodium acetate,the ammonium in the solution reacted with acety1 acetone and formaldehyde to form a yellow product which has a maximum absorbance of 405 nm.Results：This method produced a linear range of.0.20~10.00 μg/ml.The detection limit was 0.13 mg/m3.The extraction recoveries of the method ranged from 95.3% to 104.5%,with 1.4%~5.07% of relative standard deviations.Conclusion：The method is simple,rapid and safe.The common coexisting substances in the workplace do not interfere with the determination.The precision and accuracy can satisfy the requirements of the determination of ammoniain in workplace air.