对若丹宁偶氮苯甲酸固相萃取光度法测定催化剂中铂  

Solid phase extraction and spectrophotometric determination of platinum in catalysts with p-rhodanineazo benzoic acid

作　　者：黄章杰[1] 刘月英[2] 谢琦莹[2] 

机构地区：[1]昆明理工大学材料与冶金工程学院,云南昆明650093 [2]云南大学化学系,云南昆明650091

出　　处：《冶金分析》2007年第6期32-35,共4页Metallurgical Analysis

基　　金：云南省自然科学基金重点(2005E0003Z);云南省教育厅科学研究基金(5Z0103A)

摘　　要：基于新试剂对若丹宁偶氮苯甲酸(RABA)与铂的显色反应及C_8固相萃取小柱对显色络合物的固相萃取,建立了一种测定痕量铂的新方法。在pH 4.0～6.2的氢氧化钾—邻苯二甲酸氢钾缓冲介质中,十二烷基苯磺酸钠(SDBS)存在下,铂与RABA发生反应形成组成比为1:1的稳定络合物,该络合物可用AccuBond C_8固相萃取小柱富集,用乙醇洗脱后分光光度法测定。在洗脱液介质中,络合物最大吸收波长为520 nm,体系表观摩尔吸光系数ε= 2.49×10~5L·mol^(-1)·cm^(-1),铂(Ⅳ)量在0.1～1.0μg/mL内符合比尔定律。研究了固相萃取条件,讨论了共存离子的干扰及消除。方法用于测定催化剂中铂,测定结果与原子吸收光谱法一致,RSD为1.9%～2.3%(n=7),标准加入回收率为97%～101%。Based on the color reaction of p-rhodanineazo benzoic acid（RABA）with platinum（Ⅳ）and the solid phase extraction of the colored complex with C8 cartridge,a new method for the determination of platinum was developed. In the presence of sodium dodecyl benzenesulfonate （SDBS）and KOH-C6H4（COO）2HK buffer solution（pH 4.0-6.2）medium,RABA reacts with platinum（Ⅳ）to form a stable 1 ： 1 complex. The complex was enriched by AccuBond C8 cartridge and is eluted from the cartridge with ethanol,then the eluant was determined by spectrophotometry. In the ethanol medium, the apparent molar absorptivity of the complex was 2.49×10^5L·mol^-1·cm at 520 nm. Beer＇s law was obeyed in the range of 0.1 - 1.0 μg/mL for platinum. The condition of solid phase extraction was studied. Interference from common ions and its elimination were discussed. The method was applied to determine trace platinum in the catalysts. The results were consistent with those obtained by AAS method,with RSD of 1.9%-2.3%（n=7）and recovery of 97%-101%.

关 键 词：对若丹宁偶氮苯甲酸 铂 固相萃取 分光光度法 

分 类 号：O657.3[理学—分析化学]