水杨酸法检测水质氨氮的改进方法

该氨氮检测方法是对水杨酸分光光度法的改进,通过将50 g/L的水杨酸改为150 g/L的水杨酸钠,将有效氯为3. 5 g/L的次氯酸钠溶液改为5 g/L的二氯异氰尿酸钠溶液,增加了检测试剂的稳定性和贮存时间,同时将氨氮测定上限从1 mg/L提高至2. 5 mg/L,并将显色时间从60 min优化为30 min,使得此方法更为便捷。该方法的氨氮标准曲线线性关系良好,相关系数为0. 999 6,准确性和精密度高,加标回收率良好,适用于不同类型水质中氨氮的检测。

The Improvement of Salicylic Acid Method to Determine Ammonia Nitrogen in Water

The method of ammonia nitrogen determination in this study is an improvement of the salicylic acid spectrophotometry. The stability and storage time of detection reagents were increased by substitute 150 g/L sodium salicylate for 50 g/L salicylic acid and 5 g/L sodium dichloroisocyanurate for sodium hypochlorite solution of 3.5 g/L available chlorine. Meanwhile, the upper limit of ammonia nitrogen detection was increased from 1 mg/L to 2.5 mg/L, and the color reaction time was optimized to 30 min from 60 min. Therefore, the improvement method is much more convenient than before. There was a good linearity for the standard curve equation of ammonia nitrogen, and the correlation coefficient was 0.9996. The method was of high accuracy and precision, and the standard recovery rate was good. The method might apply to ammonia nitrogen determination with different types of water quality.