聚合氯化铝絮凝剂中痕量镉测定

Spectrophotometric Determination of Trace Amont of Cadmium in Polyaluminium Chloride

研究了聚合氯化铝絮凝剂中痕量镉的测定新方法并探讨了显色反应机理。新方法是利用分光光度法测定聚合氯化铝中痕量镉。它是在聚乙烯醇 (PVA)存在下 ,镉和碘化钾及罗丹明B进行显色反应。显色反应灵敏度高 ,其最大吸收波长为 6 0 6nm。表观摩尔吸光系数为 3 0 4× 10 5L·mol- 1·cm- 1。桑德尔灵敏度为 3 7× 10 - 4μgCd(Ⅱ ) /cm2 。镉含量在 0～ 0 6 μg/ 10ml范围内服从比尔定律。方法操作简便 ,不需要萃取分离 ,可在水相中直接测定 ,故大大简化了操作手续。将本法用于了聚合氯化铝絮凝剂中痕量镉测定 ,得满意结果。

A sensitive method for determining trace cadmium in Polyaluminium chloride flocculant is proposed.The sensitive method is spectrophotometric method.The highly sensitive colour reaction for determining trace cadmium(Ⅱ) is Cd(Ⅱ) potassium iodide butylrhodaminB in the presence of poly(vingl)alcohol(PVA).The maximun absorbance wavelength is 606?nm.The molar absorptivity is 3.04×10 5 L·mol -1 ·cm -1 .The sandell sensitivity is 3.7×16 -4 μg Cd 2+ /cm 2.The beer law is obeyed for Cd(》) in the rang of 0 0.6/10ml.This method has been applied to determine Cd(Ⅱ) in Polyaluminium chloride flocculant.The determining results are satisfactiory.