NO3-N的水杨酸比色法快速测定

探讨了水杨酸比色法测定 NO3- N的基本原理与影响因素 ,确定了测定的线性范围 ,并用土壤及水体样品进行了标定。结果表明 ,1水杨酸比色法测定 NO- 3的吸收峰为 4 10～ 4 2 0 nm ,检出极限可达 0 .1mg/L ,比标准的酚二磺酸比色法灵敏 2～ 5倍 ;2水杨酸比色法测定 NO- 3,颜色稳定性强 ,加盖情况下可保存 15 d而无显著变化 ;3改进后的方法适应 p H范围大 (p H>2 ) ,可掩蔽高达 0 .2 m ol/L Cl-及 2 mg/L NO- 2 的干扰。研究认为 ,改进水杨酸比色法测定 NO3- N简便、快速 ,结果准确

Determination of nitrate using a rapid and modifed Salicylate-Spectrophotometric method

Factors such as pH,Cl -,NO 2 affecting the determination of nitrate with salicylate are discussed in this paper,and the linearity is also ascertained.The result of this study shows that:(1) The apex of the absorbance curve is 410-420 nm,even nitrate of 0.1 mol/L can be detected.It is about 2-5 times sensitive than;(2) The stability of the color is high,and color intensity has no striking changes even after 15 days under a plug covered conditions;(3) The critical pH of modified method is over 2,below which color development was strongly inhibited.And it can screening the interference of more that 0.1 mol/L Cl - and 2 mg/L NO - 2.The improved method of determination of nitrate with salicylate is simple,rapid and accurate,and can be used for the analysis of NO - 3 in soils and water.