Rh（Ⅲ）－TAC－CTMAB体系分光光度法测定Rh的研究

Determination of traces of rhodium with spectrophotometric method in the system of Rh(Ⅲ)-TAC-CTMAB

研究了在阳离子表面活性剂十六烷基三甲基溴化铵（ＣＴＭＡＢ）存在下，用２－（２一噻唑偶氮）－对甲酚（ＴＡＣ），在ｐＨ５．０的ＨＡｃ－ＮａＡｃ缓冲液中分光光度法测定Ｒｈ。Ｒｈ（Ⅲ）与ＴＡＣ的络合比为１：１，表观摩尔吸光系数为ε６８０ｎｍ＝１．２５×１０４Ｌ·ｍｏｌ－１·ｃｍ－１，在１．２～８μｇ／１０ｍＬ范围内符合比尔定律。方法的特征灵敏度为０．０８５μｇ／ｍＬ（１％吸收）。试验了贵金属及常见金属的干扰情况，并研究了干扰消除的方法，ＥＤＴＡ的加入可以消除一定量的Ｃｕ、Ｃｏ、Ｎｉ、Ｚｎ的干扰。对催化剂试样的分析结果令人满意，变异系数均小于３％。

The study of spectrophotometric determination of traces of rhodium with 2-(2-thiazolylazo)-p-cresol(TAC) in the presence of cationic surfactant CTMAB in pH 5.0 HAc-NaAc buffer solution is reported in this paper.Thof rhodium to the reagent is 1: 1. The calibration graph for measurement at 680um is linear in the range of 1. 2～80 μg of rhodium per 10mL,with a molar absorptivity of 1.25×104L·mol-1· cm-1. The effects and the way to reduce the effects of other noble metals and base metals were investigated. The addition of EDTA can reduce the effects of a certain amount of Cu,Co, Ni and Zn. The analytical results of catalyst samples are very well.The relative standard deviation is smaller than 3. 0%.