摘要
基于NO-3 在酸性介质中被锌粉还原后 ,溶液紫外吸收光谱将发生显著变化的原理 ,建立了测定水中NO-3浓度的还原紫外分光光度法。该方法采用的波长为 2 0 2 .0nm ,水样的 pH值控制为 7,以试样还原前后在该条件下的吸光度变化值ΔA对NO-3 溶液的浓度进行标定。还原紫外分光光度法测定NO-3 浓度的线性范围为 0～ 8.5mg/L ,最低检出限为 0 .0 2mg/L ,且F-、Cl-以及HCO-3 等常见离子对测定不产生干扰。地下水、自来水、雪水以及湖水等实际水样的测定结果及加标回收实验结果表明 ,该方法的相对标准偏差小于 2 .5 % ,加标回收率在 96 .3%～10 3.1% ,相对于标准方法 (紫外分光光度法 )的偏差为 - 4 .0 %～ 4 .0 %。该方法的精密度、准确度和灵敏度均较高 ,且操作简便 ,适用于饮用水以及污染较轻的湖水和地下水中NO-3 含量的测定。
Because there is a great difference of absorption spectrum before and after reduction of nitrate solution by zinc powder, a reduction ultraviolet spectrophotometric method for determinating the concentration of nitrate in water is proposed. Nitrate solution and its production after reduction are determined at a wave length of 202.0 nm when the pH value of solution is 7.0. The linear range of the concentration of nitrate is 0～8.5 mg/L, and the recovery of nitrate is 96.3%～103 1%. The vulgar ions, such as F -,Cl -,HCO - 3, can not interfere the determination of nitrate by this method. The relative standard deviation is less than 2.5%. This method has been checked with practical water samples and synthetic samples. The satisfactory results are obtained. This method is well suit for determinating the content of nitrate in drinking water and natural water.
出处
《石油大学学报（自然科学版）》
CSCD
北大核心
2002年第2期88-90,共3页
Journal of the University of Petroleum,China(Edition of Natural Science)
基金
"九五"中国石油天然气集团公司攻关项目 (970 60 7)
