水杨酸分光光度法测定水中的NO_3^-

Determination on NO_3^- in Water by Spectrophotometry with Salicylic Acid

以水杨酸为显色剂,建立分光光度法测定水中NO3-含量的方法。结果表明,NO3-含量的最佳测定条件为:吸收波长410nm,1.0ml浓硫酸,1.0ml20% NaOH溶液,显色时间20min。此条件下,NO3-含量在0.5～8.0mg/L范围内遵循比尔定律。NO3-的最低检出限为0.1mg/L,加标回收率为98.0%～102.0%。

With salicylic acid as the chromogenic reagent,the determination method on NO 3-content in water by spectrophotometry was established.The results showed that the optimum determination conditions for NO 3-content was absorption wavelength of 410 nm with 1.0 ml concentrated sulfuric acid,1.0 ml 20% NaOH solution and coloration time of 20 min.Under this condition,NO 3-content followed the beer＇s law in 0.5-8.0 mg/L.The lowest detection of NO 3-was 0.1 mg/L with recovery of standard addition of 98.0%-102.0%.