Ma D, Li Y, Ma K, Li J, Chen J, Yan J, Wang Y
Department of Chemistry, Henan Normal University, Major Open Laboratory in Environmental Engineering of Henan Province, Xinxiang, Henan, PR China.
Talanta. 2001 Jan 26;53(5):937-41. doi: 10.1016/s0039-9140(00)00583-x.
The new reagent N-(m-Methylphenyl)-N'-(sodium p-aminobenzenesulfonate)-thiourea (MMPT) was synthesized and its structure was confirmed by elemental analysis, IR, UV and (1)HNMR spectra. The apparent molar absorptivities of usual ions were determined and the chromogenic reaction with microamounts of platinum(IV) was studied in detail. In the medium of an HAc-NaAc buffer solution, MMPT can react with platinum(IV) to form a green soluble complex. The maximum absorbance of the complex is at 754.4 nm (epsilon(754.4)=8.58 x 10(4) L.mol(-1).cm(-1)) and 332.8 nm (epsilon(332.8)=1.14 x 10(5) L.mol(-1).cm(-1)). Beer's law was obeyed for platinum concentrations in the range of 0 approximately 1.28 mg.L(-1); the correlation coefficient was r=0.9995. At 754.4 nm, over 50 ions did not interfere with the reaction. It is one of the simplest and most selective methods available. It was convenient and rapid and has been applied to the direct determination of Pt(IV) in ores and catalysts with satisfactory results.
合成了新型试剂N-(间甲苯基)-N'-(对氨基苯磺酸钠)-硫脲(MMPT)，并通过元素分析、红外光谱、紫外光谱和(1)HNMR光谱对其结构进行了确证。测定了常见离子的表观摩尔吸光系数，并详细研究了其与微量铂(IV)的显色反应。在HAc-NaAc缓冲溶液介质中，MMPT能与铂(IV)反应形成绿色可溶性络合物。该络合物的最大吸收波长为754.4 nm(ε(754.4)=8.58×10(4)L·mol(-1)·cm(-1))和332.8 nm(ε(332.8)=1.14×10(5)L·mol(-1)·cm(-1))。铂浓度在0～1.28 mg·L(-1)范围内符合比尔定律；相关系数r=0.9995。在754.4 nm处，50多种离子不干扰该反应。这是现有最简单、最具选择性的方法之一。该方法简便快速，已用于矿石和催化剂中Pt(IV)的直接测定，结果令人满意。
