分光光度法同时测定铂和钯的新体系  

A New System for Simultaneous Spectrophotometric Determination of Platinum(Ⅳ) and Palladium(Ⅱ)

作　　者：刘根起[1] 张光[1] 周艳梅[1] 王贵方[1] 

机构地区：[1]陕西师范大学化学系,西安710062

出　　处：《分析试验室》1999年第6期23-26,共4页Chinese Journal of Analysis Laboratory

基　　金：陕西省自然科学基金

摘　　要：提出了在酸性溶液中以２－（３，５－二氯－２－吡啶偶氮）－５－二甲氨基苯胺（３，５－ｄｉＣｌ－ＰＡＤＭＡ）作为光度法同时测定铂（Ⅳ）、钯（Ⅱ）的新体系。研究发现，在强酸性介质中，沸水浴加热条件下铂（Ⅳ）方可与试剂定量反应，而钯（Ⅱ）与试剂在室温即可定量反应，在铂（Ⅳ）配合物的最大吸收峰处，二者吸光度具有良好的加和性。基于二者显色反应的温度差异，建立了铂（Ⅳ）、钯（Ⅱ）同时测定的新方法。铂（Ⅳ）、钯（Ⅱ）质量浓度分别在０～０．７５ ｍ ｇ／Ｌ，０～１．２ ｍ ｇ／Ｌ内服从比尔定律。本方法已直接用于合金及催化剂中铂。A new system for simultaneous determination of microamounts of Pt(Ⅳ) and Pd(Ⅱ) with 2 (3,5 diCl PADMA) has been developed.It is based on the different temperatures required for complex formation reactions between the two kinds of metal ions and 3,5 diCl PADMA.Pd reacts quantitatively with the reagent at room temperature,while Pt reacts only in a boiling water bath.At the maximum absorbing peak of Pt 3,5 diCl PADMA complex (633 4nm),the absorption of Pd 3,5 diCl PADMA and Pt 3,5 diCl PADMA complex show very good spectral additive property,though Pd 3,5 diCl PADMA complex's maximum absorption is not at 633 4nm but at 623nm.The apparent molar absorptivities of Pt and Pd complexes are 9 73×10 4 L·mol 1 ·cm 1 and 6 75×10 4 L·mol 1 ·cm 1 respectively at 633 4nm. Good recoveries(96 9%～109%) of Pt and Pd in mixture were obtained.The method has been proved successful for the simultaneous determination of Pt and Pd in alloy and catalyst samples.

关 键 词：分光光度法 同时测定 铂 钯 合金 催化剂 

分 类 号：O614.82[理学—无机化学] O657.32[理学—化学]