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.