In view of the problems existed in total nitrogen determination in water quality by UV Spectrophotometry, the absorbance value of blank correction was on the high side. The influencing factors impact on total nitrogen determination respectively from experimental water selection, potassium persulfate reagent selection, preparation and storage and the problems of digestion process were analyzed, optimization suggestions was proposed. The different processing methods, including flocculation precipitation, digestion after centrifugation, digestion after filtration by 0.45 μm, centrifugation after digestion and the filtration by 0.45 μm after digestion respectively on the turbid water samples, were discussed. It was showed that the centrifugation after digestion or the filtration by 0.45 μm after digestion could effectively eliminate the turbidity interference and improve the accuracy of determination of total nitrogen through comparing the analysis of the effect of different pretreatment methods on the result accuracy.%结合碱性过硫酸钾消解紫外分光光度法水质总氮测定过程中总氮空白值偏高的问题,从实验用水的选择、过硫酸钾试剂的选择和配制储存以及消解过程的问题等方面探讨了其影响因素以及优化建议.对浑浊水样探讨了不同处理方法包括絮凝沉淀法、离心后消解法、0.45 μm滤膜过滤后消解法、消解后离心法和消解后0.45 μm滤膜过滤法等分别对其总氮结果的准确性影响,通过比对分析得出消解后离心分离法和消解后0.45 μm滤膜过滤法都能快速有效地去除浊度干扰,提高总氮测定的准确度.
展开▼
