用去离子水替代无氨水测定氨氮的研究

[目的]在满足准确度和精密度要求的前提下,探索缩短水环境检测的时间、减少试剂消耗的方法。[方法]采用70型离子交换纯水器制取去离子水,代替无氨水测定氨氮,通过数理统计检验此法的可行性。[结果]两种纯水的空白吸光度均较小,满足氨氮测定的空白值要求。F检验表明,两组空白值的方差差异和精密度差异均不显著。统计检验表明,两条标准曲线差异不显著,线性相关性好,不存在系统误差。各种标准量氨氮的标准偏差较小,且变异系数小于5%,满足水环境监测规范(SL219-98)中纳氏试剂分光光度关于氨氮测定精密度与准确度的要求。[结论]该方法经济可行,具有较高的精密度和准确度,减少了实验用水和能耗,对大批量的样品分析具有实际意义。

Research on the Determination of Ammonia Nitrogen with Deionized Water Instead of Non-ammonia Water

[Objective] The study aimed to explore the method of shortening the detection time of water environmental detection and reducing reagent consumption under the precondition of satisfying accuracy and precision requirement.[Method] The deionized water was prepared by 70 ion-exchange water-purifying implement and the ammonia nitrogen was determined with deionized water instead of non-ammonia water.The feasibility of this method was tested through mathematical statistics.[Result] The blank absorbencies of the 2 purified waters were smaller,according with the requirement for blank value in ammonia nitrogen determination.F test showed that the differences on variance and precision between the 2 groups of blank values were not significant.The statistic test showed that the 2 standard curves had no significant difference and systematic error and had good linear correlation.The standard deviations of various ammonia nitrogen at standard quantity were smaller and their variation coefficients were smaller than 5%,satisfying the requirement for precision and accuracy in ammonia nitrogen determination by Nessler's reagent spectrophotometry in the monitoring criterion for water environment(SL219-98).[Conclusion] The method was economic and feasible,had higher precision and accuracy,reduced experimental water consumption and energy consumption,and had actual sense for mass sample analysis.