Method Improvement for Ammonia Nitrogen Determination in Water Quality Based on the Salicylic Acid Spectrophotometry of HJ 536-2009
YU Sheng
YANG Dongliang
SHI Yizhe
ZENG Wenqian
YANG Bin
CHEN Yihu
Abstract：Based on the determination of ammonia nitrogen in water by the salicylic acid spectrophotometric method of HJ 536-2009,the color development temperature and time are optimized.The concept of"drop"in HJ 536-2009 is quantified,and the addition amount of main reagents is optimized.While improving the stability and reproducibility of ammonia nitrogen detection,the accuracy of ammonia nitrogen detection is enhanced.The final optimized conditions are:the color development temperature is 35℃in a water bath,and the color development time is 30 minutes at this temperature.Main reagents:potassium sodium tartrate solution,color developing agent,sodium nitroferricyanide solution and sodium hypochlorite.The addition amounts of the working solutions are 0.30 mL,1.10 mL,0.12 mL and 0.28 mL respectively.In addition,the standard curve of the improved ammonia nitrogen detection method is stable,and the regression coefficient R2 ranges from 0.999 6 to 0.999 9,which is better than the R2 value of HJ 536-2009 under the same conditions.Moreover,the detection accuracy of the improved method is much higher than that of HJ 536-2009.Therefore,the improved laboratory method for ammonia nitrogen detection can replace HJ 536-2009 for detecting ammonia nitrogen in water within a small scope.
Keywords：salicylic acidammonia nitrogenHJ 536-2009method optimization
Publication Date：2025-06-30
Pages：5( 48-52 )