分光光度法测定海产品中微量镉

Spectrophotometric Determination of Trace Amount of Cadmium in Marine Products

本文在文献［１］基础上，研究了在六次甲基四胺－ＫＮＯ３－ＨＮＯ３存在下，镉与二甲酚橙显色反应的最佳条件。在ｐＨ＝６．２～６．４范围内，镉与二甲酚橙配合物的最大吸收波长λｍａｘ＝５７８．４ｎｍ，摩尔吸光系数为１．６×１０４Ｌｍｏｌ－１ｃｍ－１，镉含量在０．５～６μｇｍＬ－１范围内符合朗伯比耳定律，检测限为０．００７μｇｍＬ－１，回收率在９０％以上，方法简便，灵敏度高，用于样品分析取得满意结果。

The colour reaction of Cd(Ⅱ) on xylend orange in the presence of hexamethylenete tramine KNO 3 HNO 3 has been studied.Cd(Ⅱ) forms the complex at pH=6 2 6 4( λ max =578 4 nm)with an apparent molar absorptivity of 1 6×10 4 L·mol -1 ·cm -1 .Beer′s law is obeyed for Cd(Ⅱ) in the range of 0 5～6 μg·mL -1 .The detection limit is 0 007 μg·mL -1 with the recovery of 90 % 105 %.The method is simple and highly sensitive,and has been applied to the analysis of sample with satisfactory results.