本文研究了在硫酸介质中 ,微量钼 ( )催化加速硫酸肼还原甲苯胺兰褪色及动力学条件 ,建立了催化动力学光度法测定微量钼 ( )的方法。其检出限为 :5.154× 10 -3μg/ m L,测定线性范围 0— 10 μg/ 2 5m L。考察了 2 0多种离子的干扰行为 ,并提出了分离方法。本方法已用于自来水和生物样品中钼 ( )测定 ,相对标准偏差为 :1.6%— 5.4 % ,加标回收率为 :93.6%— 110 % ,结果令人满意 In this paper, the fading and kinetic conditions of reduction of toluidine blue with hydrazine sulfate catalyzed by trace amount of molybdenum (Ⅲ) catalyzed by sulfuric acid were studied in this paper. A catalytic kinetic spectrophotometric method for the determination of trace molybdenum was established. The detection limit was 5.154 × 10 -3 μg / mL and the linear range was 0-10 μg / 25 mL. The interference behavior of more than 20 kinds of ions was investigated, and the separation method was proposed. The method has been applied to the determination of molybdenum in tap water and biological samples with relative standard deviations of 1.6% -5.4% and spiked recoveries of 93.6% -110% with satisfactory results