连续流动-次溴酸盐氧化法测定海水氨氮的研究  

Determination of Ammonia Nitrogen in Seawater by Continuous Flow Analysis-Hypobromate Oxidation Method

作　　者：仇镇武 QIU Zhenwu(Zhongshan Ecological Environment Monitoring Station of Guangdong Province,Zhongshan 528400,China)

机构地区：[1]广东省中山生态环境监测站,广东中山528400

出　　处：《环境科学与技术》2025年第2期112-118,共7页Environmental Science & Technology

基　　金：2024年度中山市第一批社会公益与基础研究项目(2024SYF03);中山市入海河流沉积物中特征金属元素的调查研究(240424075208605)。

摘　　要：GB 17378.4-2007次溴酸盐氧化法使用的试剂对环境友好,是测定海水氨氮抗盐度干扰最好的监测方法,但因其手工操作、步骤繁琐,且低空白值较难控制导致适用性不强。该文根据该方法化学原理建立连续流动-次溴酸盐氧化法测定海水氨氮,目的是要保留次溴酸盐氧化法抗干扰能力强的优点,再利用连续流动分析法的特点改善手工法的不足。结果显示:连续流动-次溴酸盐氧化法测定海水氨氮的误差与氧化效率(R)密切相关,拟制出修正公式,利用修正公式检验氨氮测定结果的回收率是91.0%~105.6%,说明修正公式正确度良好。方法的校准曲线在0.020~0.500 mg/L质量浓度范围内,氧化效率大于80%,相关系数大于0.999,方法检出限0.000 3 mg/L,相对标准偏差0.8%~3.9%,不同基体标准样品的测定结果在标准值范围,实际样品测定结果与手工法比较相对误差是0.7%~4.3%,加标回收率是95.3%~101.3%。连续流动-次溴酸盐氧化法适用于快速测定海水氨氮,利用修正的计算公式可提高测量精度,其线性范围、检出限、精密度、正确度性能指标较优,其高效的自动化监测、抗干扰能力强等特点可替代现有国标的手工法,值得推广应用。The reagents used in GB 17378.4-2007“Bromate Oxidation Method”are environmental friendly.The method is the best for determining the salinity resistance of seawater ammonia nitrogen,but it is not widely applicable since the low blank value is difficult to control.Based on the chemical principle of the method,a continuous flow hypobromate oxidation method was established for the determination of ammonia nitrogen in seawater,then the characteristics of continuous flow analysis method are used to improve the deficiency of manual method.Results indicated that the error of the continuous flow hypobromate oxidation method for the determination of ammonia nitrogen in seawater is closely related to the oxidation efficiency(R).The modified formula is worked out,and the recovery of ammonia-nitrogen was 91.0%~105.6%by modified formula,which shows that the modified formula is correct.The calibration curve was in the range of 0.020~0.500 mg/L.The oxidation efficiency was more than 80%and the correlation coefficient was more than 0.999.The detection limit was 0.0003 mg/L and the relative standard deviation was 0.8%~3.9%,the results of different matrix standard samples were in the range of standard values.The relative error between the actual samples and manual method was 0.7%~4.3%,and the recoveries were 95.3%~101.3%.The continuous flow hypobromate oxidation method is suitable for the rapid determina-tion of ammonia nitrogen in seawater,its linear range,detection limit,precision and accuracy are better,and its high-effi-cient automatic monitoring,high anti-interference ability can replace the existing manual method,which is worth populariz-ing and applying.

关 键 词：连续流动 次溴酸盐 海水 氨氮 环境友好 

分 类 号：X830.2[环境科学与工程—环境工程]