硫氰酸盐光度法测定三氧化钼中钼含量

摘要

研究了硫酸铜作催化剂,硫脲作还原剂,钼与硫氰酸盐的显色反应,并建立了测定工业三氧化钼中钼含量的方法.试样用1 mol氢氧化钠溶解,以硫酸铜硫酸混合溶液酸化后,加入硫脲还原六价钼为五价钼与硫氰酸钾生成橙红色络合物,于波长460 nm处测定溶液吸光度.测定方法的相对标准偏差为0.44％.标样加入量与样品中钼含量相近时,标样回收率达为98.5％ ～ 99.7％.%A spectrophotometric method for determination of molybdenum in molybdenum trioxide with potassium thiocyanate was studied in the present of potassium thiocyanate as a depressant and thiourea as a reductant. Sample was dissolved in sodium hy-droxide(l mol/L). After adding cuprum sulphate and sulfuric acid, Mo(VI) in the solution is reduced to Mo( V ) by thiourea. Mo forms an orange complex with potassium thiocyanate, which can be measured at wavelength of 460 nm. RSD of the method is 0. 44% . When the added amount of standard matter is close to that of sample, the recovery rate of molybdenum is in the range of 98. 5% ～99.7%.