连续流动分析法测定环境水体中总氮实验条件探讨

Study on experimental conditions for determination of total nitrogen in environmental water by continuous flow analysis

目的探讨连续流动分析法测定地表水和污水处理厂出水中的总氮实验条件对测定结果的影响。方法优化试剂浓度、蠕动泵转速、进样时间和清洗时间等实验条件,测定两种环境水体中的总氮。结果在0.20~10.00 mg/L范围内,总氮浓度与吸光度呈现出良好的线性关系,相关系数(r)为0.9998,方法检出限为0.051 mg/L,标准偏差(RSD)为1.4%~1.6%,水样加标回收率为90.0%~102.5%。结论优化后的连续流动分析法测定总氮含量具有准确性高和重现性好的优点,适宜在地表水和污水处理厂出水中应用。

Objective To study the influence of experimental conditions on the determination of total nitrogen in surface water and effluent from sewage treatment plant by continuous flow analysis.Methods Experimental conditions such as reagent concentration,peristaltic pump speed,injection time and cleaning time were optimized to determine the total nitrogen in two kinds of environmental water.Results In the range of 0.20-10.00 mg/L,there was a good linear relationship between total nitrogen concentration and absorbance,the correlation coefficient(r)was 0.9998,the detection limit of the method was 0.051 mg/L,the RSD was 1.4%-1.6%,and the standard recovery of water sample was 90.0%~102.5%.Conclusions The optimized continuous flow analysis method has the advantages of high accuracy and good reproducibility for the determination of total nitrogen content,and is suitable for surface water and effluent water of sewage.