紫外分光光度法测定生活饮用水中硝酸盐氮初步研究

目的 :旨在寻找一种较国标法更简单、快速、准确的生活饮用水中硝酸盐氮检测方法 ,以紫外分光光度法测定生活饮用水中硝酸盐氮。方法 :用 1mol/L盐酸酸化水样后 ,直接用紫外分光光度计测定水样中硝酸盐氮含量。结果 :本法标准曲线线性关系好 ,相关系数r =0 .9998,最低检出浓度为 0 .0 11mg/L ,RSD均 <5 %。标准质控样测定值与已知定值的相对偏差为 - 0 .6 0 %～ 0 .75 % ,平均加标回收率为 10 0 .7% ,与国标法(二磺酸酚法 )比较 ,差异无显著性 ,P >0 .0 5。结论 :本法简便快速、准确、灵敏度高 ,推荐本法为生活饮用水中硝酸盐氮检测方法。

Determination of Nitrate-nitrogen in Drinking Water with Ultra Violet Spectrophotometry

In order to establish a new method of determination of nitrate-nitrogen in drinking water, ultra violet spectrophotometry was applied. After water sample was acidified with hydrochloric acid, concentration of nitrate-nitrogen in water samples was directly determined with ultra violet spectrophotometry. Linear relation of standard curve was good, coefficient of correlation r=0.9998. The minimum detection concentration was 0.011 mg/L. The RSD was all less than 5%. The relative deviation between measured value and certified value of the standard quality control sample was between -0.60% and 0.75%. The average recovery rate was 100.7%. The method had no significant difference(P>0.05) as compared with national standard test GB5750-85(disulfonic acid phenol method). The method was simple, fast, accurate, high specificity. It suggested that this method be a useful tool for determination of nitrate-nitrogen in life drinking water.