摘要
采用HJ535-2009《水质氨氮的测定纳氏试试剂分光光度法》测定水样氨氮时,当水样浑浊或有颜色时用蒸馏法对样品进行预处理,但该处理方法测定结果偏低,远远超出误差允许范围。提出以0.45μm滤膜过滤样品后进行测定,并在比色过程用过滤水样作色度校准。方法改进后对标准样品进行测定,测定结果与标准值相一致。采用改进后的方法对实际样品进行测定,加标回收率为96.7%,测定结果的相对标准偏差为3.60%(n=6)。该法测试数据稳定、结果可靠,适合于汛期地表水中氨氮的测定。
In determination of ammonia nitrogen of water specimen by HJ 535-2009 Water Quality-Determination of Ammonia Nitrogen-Nessler＇ s Reagent Spectrophotometry, it is necessary to pretreat the water specimen if it is muddy or colorful, but the test results of the method are less than the standard value, and far exceed the range which error allowed. It is suggested that filtering the specimen with 0.45 μm filter membrane before testing, and using filtered specimen as chromaticity calibration in colorimetric procedure. The calibration specimen were detected by the improved method, the result was accordance with reference value. The practical samples were detected by the improved method, the adding recovery was 96.7%, relative standard deviation was 3.60%（n=6）. The improved method has the advantages that results are stable and reliable, so the method is suitable for ammonia nitrogen determination of the surface water in flood season.
出处
《化学分析计量》
CAS
2013年第3期91-93,共3页
Chemical Analysis And Meterage
关键词
纳氏试剂法
氨氮
预处理
蒸馏法
地表水
Nessler＇ s reagent spectrophotometry
ammonia nitrogen
pretreatment
steam distillation
surface water
