乙基罗丹明B和高碘酸钾反应动力学测定痕量铑  

Kinetic Determination of Trace Rhodium Based on the Reaction of Ethylrhodamine B with Potassium Periodate

作　　者：李祖碧[1,2,3] 王加林[1,2,3] 徐其亨 刘云杰[1,2,3] 

机构地区：[1]云南大学成人教育学院 [2]云南大学化学系 [3]昆明贵金属研究所

出　　处：《分析试验室》1999年第2期11-14,共4页Chinese Journal of Analysis Laboratory

摘　　要：研究了一个动力学测定铑的方法。在氯化钠－磷酸溶液和加热下铑催化乙基罗丹明Ｂ褪色，ｌｇ（Ａ０／Ａ）与铑浓度呈线性的范围是０．２～４．０μｇ／２５ｍＬ，检出限为２．２４×１０－１０ｇ／ｍＬ，对２．０μｇ铑标准溶液测定１１次的相对标准偏差为２．１３％。Ｏｓ、Ｒｕ、Ｉｒ对测定有干扰，其他贵金属、有色金属和铁不干扰。本反应对乙基罗丹明Ｂ或铑（Ⅲ）为一级，催化反应的表观活化能为６５．２１ｋＪ／ｍｏｌ。本法已用于某些催化剂和贵金属溶液样品中痕量铑的测定，回收率为９５．６％～１０２．６％，相对标准偏差为１．４８％～２．９５％。A kinetic method for the determination of rhodium was developed.Rhodium was determined by its catalytic effect on the oxidation of ethylrhodamine B by potassium periodate on heating in sodium chloride and phosphoric acid solution with the result of decoloration.The linear relation between log ( A 0/A ) and concentration of Rh(Ⅲ) was found in the range of 0.2～4.0μg/25mL, and the limit of determination was 2.24×10 -10 g/mL.The relative standard deviation obtained from 11 standard solutions containing 2μg/25mL rhodium was 2.13% .Os,Ru and Ir interfere with the spectrophotometric determination,other platinum group metals,nonferrous and iron do not interfere.The reaction is first order in ethylrhodamine B or rhodium,and the apparent activation energy of catalytic reaction was found to be 65.21kJ/mol.The method has been used to determine trace rhodium in some catalyst samples with the recovery of 95.6-102.6%,and relative standard deviations of 1.48～2 95%.

关 键 词：铑 乙基罗丹明B 催化光度法 动力学 测定 

分 类 号：O614.822[理学—无机化学]