纳氏试剂分光光度法测定水质氨氮预蒸馏方法的改进  

Improvement of the Pre Distillation Method for Determining Ammonia Nitrogen in Water Quality Using Nessler’s Reagent Spectrophotometry

作　　者：柴江君 Chai Jiangjun(Wanzijian Testing Technology(Shanghai)Co.,Ltd.,Shanghai 201800,China)

机构地区：[1]万子健检测技术(上海)有限公司,上海201800

出　　处：《皮革制作与环保科技》2023年第12期29-31,43,共4页Leather Manufacture and Environmental Technology

摘　　要：根据《水质氨氮的测定纳氏试剂分光光度法》(HJ 535-2009)[1],如果水样浑浊或有颜色时可用预蒸馏的方法处理。该标准使用50 mL硼酸溶液(浓度:20 g/L)作为预蒸馏的吸收液。由于吸收液的酸度对比色测定结果有重要影响,因此需进行中和处理,十分不方便。在实际检测过程中,经常会遇到测定结果偏低的情况。为了解决水中氨氮预蒸馏方法测定结果偏低的问题,本文使用90 mL硼酸溶液(浓度:2.5 g/L)作为吸收液,同时对预蒸馏前处理的流程做了优化,简化了操作。比色测定时不需要调节吸收液的酸度就可以得到满意的结果。该改进法的实验结果表明:实际水样的加标回收率均在95%~105%之间,相对标准偏差<2%;标准样品测定结果均在标准值范围以内,相对标准偏差<2%,采用标准曲线计算和采用工作曲线计算结果没有明显差别。According to the"Determination of Ammonia Nitrogen in Water Quality by Nessler's Reagent Spectrophotometer"(HJ 535-2009)[1],if the water sample is turbid or has color,pre distillation can be used for treatment.This standard uses 50 mL boric acid solution(concentration:20g/L)as the pre distilled absorption solution.Due to the signifi cant impact of the acidity of the absorption solution on the color measurement results,neutralization treatment is required,which is very inconvenient.In the actual detection process,low measurement results are often encountered.In order to solve the problem of low determination results of ammonia nitrogen in water by pre distillation method,this article uses 90 mL boric acid solution(concentration:2.5 g/L)as the absorption solution,and optimizes the pre distillation pretreatment process to simplify the operation.During colorimetric determination,satisfactory results can be obtained without adjusting the acidity of the absorption solution.The experimental results of this improved method indicate that the actual recovery rates of the water samples are between 95%and 105%,with a relative standard deviation of less than 2%;The measurement results of the standard samples are all within the standard value range,with a relative standard deviation of less than 2%.There is no signifi cant difference between the results calculated using the standard curve and the results calculated using the working curve.

关 键 词：氨氮 纳氏试剂法 预处理 蒸馏法 水质 

分 类 号：TS5[轻工技术与工程—皮革化学与工程]