锌-镉法测定天然水中硝酸盐的盐误差及其解决方法  

MODIFICATION ON THE DETERMINATION OF NITRATE IN NATURAL WATER BY Zn-Cd REDUCTION METHOD

作　　者：于志刚[1] 姚庆祯[1] 张经[1] 

机构地区：[1]青岛海洋大学海洋化学系,青岛266003

出　　处：《理化检验（化学分册）》1998年第11期496-497,共2页Physical Testing and Chemical Analysis(Part B:Chemical Analysis)

基　　金：山东省自然科学基金(Q95B0314)资助项目

摘　　要：研究了锌-镉法测定天然水中硝酸盐的盐误差,发现水中含盐量对还原率有重大影响,但在盐度为1%以后还原率基本不变;加入人工海盐(1.5g/50ml水样)可消除盐误差.由此建立了没有盐误差的新的锌-镉法.方法相对标准偏差小于3%,回收率为98%～102%,与镉-铜法对比,两种方法的相对偏差小于8%.It is observed that the salt content of natural water has a profound influence on the determination of nitrate by the Zn-Cd reduction method. But it is found that when the salinity is greater than 1% , the rate of re-duction by Zn-Cd becomes constant. Thus the interference of salinity in the determination of nitrate can be elimi-nated by adding 1. 5g of artificial sea salt to each 50 ml of the water sample. The recovery of the modified Zn-Cd reduction method is 98%-102% with a relative standard deviation of 3% at 4-60μmol level of nitrate.

关 键 词：锌-镉法 硝酸盐 分析 天然水 水质监测 

分 类 号：X832.02[环境科学与工程—环境工程]