茜素紫-Mo(Ⅵ)-CTMAB体系分光光度法测定钼尾矿中痕量钼

Spectrophotometry determination of trace molybdenum in gangue by alizarin Violet-Mo(Ⅵ)-CTMAB system

在pH 5.9的磷酸缓冲溶液中,CTMAB存在下,痕量Mo(Ⅵ)与茜素紫作用生成一种新的紫色物质,据此建立了一种测定痕量Mo(Ⅵ)的新分光光度法。该物质的最大吸收波长为375nm,表观摩尔吸光系数ε=1.99×105 L.mol-1.cm-1。在最佳实验条件下,测定Mo(Ⅵ)的线性范围为3.2×1 0-4～6.0mg/L,检出限为1.0×10-4 mg/L。方法用于本地钼尾矿中钼含量的测定,其结果与原子吸收光谱法测定值对照,结果令人满意,测定相对标准偏差为2.3%～2.9%,标准加入回收率为96.0%～106%。

In pH 5.9 phosphate buffer solution, trace Mo（VI） can react with alizarin violet to form a new violet substance, so a new spectrophotometry method for the determination of trace amounts of Mo（VI） was proposed. The maximum absorption wavelength of the new color substance was 375 nm and the apparent molar absorption coefficient was 1.99×10^5L·mol-1·cm-1. Under the optimum conditions, the linear range for the determination of Mo（V[） was 3.2 × 10-4 to 6.0 mg/L with a detection limit of 1.0 × 10-4mg/L. The method was used for the determination of trace amounts of molybdenum in gangue and the results were well agreed with the standard method of atomic absorption spectrometry. The relative standard deviation was 2.3%-2.9% and the recovery rate was 96.0%-106%.