贵金属高灵敏显色反应的研究——Ⅰ.铂(Ⅱ)-4,5-二溴苯基萤光酮-溴化十六烷基三甲胺-OP体系

Study on Highly Sensitive Color Reactions of Noble Metals Ⅰ.Platinum(Ⅱ)-4,5-Dibromophenylfluorone-Cetyltrimethylammonium Bromide Emulsifier Octyl Phenyl Polyglycol Ether System

本文研究了铂(Ⅱ)-4,5-二溴苯基萤光酮(Br-PF)-溴化十六烷基三甲胺(CTMAB)-OP多元配合物的显色条件及其应用。结果表明,只要将Pt(Ⅳ)预先用K_2C_2O_4还原成Pt(Ⅱ),则在pH3.8～4.5及室温下,Pt(Ⅱ)就可以和Br-PF迅速地形成稳定的极灵敏的配合物,其ε_(540nm)=8.32×10~5L·mol^(-1)·cm^(-1),为铂的增溶光度法中最为灵敏的方法。Pt(Ⅱ)与Br-PF的摩尔比为1:4。铂浓度在0～0.35ppm服从比耳定律。在掩蔽剂存在下可简便地测定催化剂中的微量铂,结果令人满意。

A new hypersensitive color reaction of platinum(Ⅱ) has been studied. Platinum(Ⅳ)was reduced into platinum (Ⅱ) by potassium oxalate solution. Platinum (Ⅱ) reacts with 4, 5dibromophenylfluorone(Br-PF)in the presence of cetyltrimethylammonium bromide and emulsifier polyethyleneglycol octylphenylether to form a multicomponent complex at pH3.8～4.5 and at room temperature. The apparent molar absorptivity and apparent stability constant of the complex are 8.32×10~5L. mol^(-1). cm^(-1) at 540nm and 4. 35×10^(22) respectively. The mcoposition ratio of Pt(Ⅱ) to Br-PF is 1:4. Beer＇s law is obeyed for Pt in the range of 0～0. 35 ppm. Tolerance limits have been shown for 24 foreign ions in the presence of masking agents. The method has been successfully applied to the determination of micro amounts of Pt in the catalyst.