紫外分光光度法测定岩盐中的硝酸盐

Determination of Nitrate in Rock Salt by Ultraviolet Spectrophotometry

沸水溶解岩盐样品,过滤除去水不溶物,紫外分光光度法分别测定滤液在220nm和275nm处的吸光度值,计算出样品中NO3-含量。结果表明,3种不同类型岩盐样品中NO-3的回收率为98.0%—102.0%,相对标准偏差为1.03%—2.92%(RSD,n=5)。与百里酚分光广度法和离子色谱法相比,紫外分光光度法简单快速,准确度、灵敏度、精密度高,适用于岩盐样品中硝酸盐含量的快速检测。

The rock salt sample was dissolved in boiled water and then filtrated to remove the insoluble matter.The amount of nitrate in rock salt was determined by ultraviolet spectrophotometry at 220nm and 275nm.The average recoveries of NO-3 in 3 different salt samples were 98.0%—102.0% with relative standard deviation of 1.03%—2.92%（RSD,n=5）.Compared with thymol spectrophotometry and ion chromatography methods,the ultraviolet spectrophotometry used in the present study was proved to be simple,rapid,sensitive,and accurate,and suitable for rapid detection of nitrate content in rock salt samples.