钼-水杨基荧光酮-溴化十六烷基三甲基铵显色反应的研究

在0.2-0.8/Ⅳ的盐酸介质中,钼(Ⅵ)与水杨基荧光酮以及溴化十六烷基三甲基铵,可以形成一红色三元络合物。络合物的最大吸收峰位于530纳米,表观摩尔吸光系数ε₅₃₀=1.40×10⁵。钼的浓度为0-8微克/25毫升时,络合物溶液的吸光度遵守比尔定律。三元络合物的组成经测定Mo:SAF:CTMAB=1:2:2。常见金属离子中,除钛与钨(Ⅵ)以外,均不干扰钼的测定。利用本显色反应,曾对多种合金钢中的钼含量进行了测定,取得了较好的效果。

A STUDY ON THE COLOUR REACTION OF MOLYBDENUM WITH SALICYLFLUORONE AND CETYL TRIMETHYL AMMONIUM BROMIDE

A new colour reaction of the molybdenum with salicylfluorone and cetyl trimethyl ammonium bromide has been studied. In a dilute hydrochlpride acid medium (0.2-0.8N) molybdenum can form a red-colour tenary complex with the above-mentioned reagents. The complex exhibits maximum absorption at 530nm, and the value of apparent molar absorption coefficient is found to be 1.40×10⁵. The constituent of the complex is also established as Mo:SAF:CTMAB = 1:2:2 by the methods of isomolar continuous variation and slop ratio, as well as triple diagram.Ahigh sensitive and selective spectrophotometric method is developed for the determination of molybdenum. The Beer's law is obeyed in the range of 0-8μg Mo/25ml. Most metal ions do not interfere with the determination of molybdenum. Oxidized metal ions, such as Fe(III), Cr(VI), V(Y) and Mn(VII), must be reduced with ascorbic acid. The ions of tin (IV) were reduced by sodium hypophosphite in the presence of mercuric ions as catalyst. The ions of zirconium were masked by EDTA. Only the ions of tungsten and titanium interfere seriously. The method is used in the determination of molybdenum in some high alloy steel with satisfactory results.