流动注射-分光光度法测定钴钼催化剂浸渍液中高浓度钼离子

FI-Spectrophotometric Determination of Molybdenum of High Concentration in Maceration Extract of Cobalt-Molybdenum Catalysts

在0.75mol·L-1硫酸溶液中,抗坏血酸可将Mo6+还原为Mo5+,而硫氰酸铵能与生成的Mo5+显色,在波长465nm处有最大吸收峰,据此提出了一种流动注射-分光光度法测定钴钼催化剂浸渍液中超高浓度钼离子含量的方法。钼的质量浓度在3.3～93.3g·L-1范围内与其ΔA呈线性关系,方法的检出限(3s/k)为0.35g·L-1。方法用于钴钼催化剂浸渍液中钼离子含量的测定,测得方法的回收率在95.0%～101%之间,测定值的相对标准偏差(n=11)小于1%。

It was found that in 0.75 mol·L-1 H2SO4 solution,Mo6＋ was reduced to Mo5＋ with ascorbic acid,and a complex between Mo5＋ and NH4SCN was formed with its maximum absorption wavelength at 465 nm.Based on these facts,the determination of Mo6＋ by flow injection（FI）-spectrophotometry was proposed.Linear relationship between values of ΔA and mass concentration of Mo6＋ was kept in the range of 3.3-93.3 g·L-1,with detection limit（3s/k） of the method of 0.35 g·L-1.The proposed method was used in the determination of Mo6＋ in sample of maceration extract of cobalt molybdenum catalysts,and values of recovery found were in the range of 95.0%-101%,with RSD（n=6） less than 1%.