Mo-SCN^--亮绿光度法测定豆类食品中的钼

Spectrophotometric Determination of Molybdenum in Edible Beans with Mo-SCN^--Light Green System

建立测定食品中微量钼的分光光度新方法。在硫酸介质中,钼经盐酸羟胺还原后,与硫氰酸盐、亮绿SF(淡黄)形成三元离子缔合物,该缔合物的最大吸收波长位于488nm,摩尔吸光系数为3.8×104L/(mol.cm)。钼的质量浓度在0.04～1.6μg/mL范围内符合比尔定律,方法检出限为0.011μg/mL。该方法用于豆类食品中微量钼的测定,结果与原子吸收分光光度法测定结果一致。

A new spectrophotometric method for the determination of trace molybdenum in edible beans was developed.After being reduced by hydroxylamine hydrochloride,molybdenum was allowed to react with thiocyanate and light green SF to form a ternary ion associate in the medium of sulphate.The maximum absorption wavelength of the ion associate was 488 nm with a apparent molar absorption coefficient of 3.8 × 104L/（mol.cm）.Beer’s law was obeyed in the molar concentration range of 0.04 to 1.6 μg/mL.The limit of detection of the developed method was 0.011 μg/mL.Consistent results with those obtained by atomic absorption spectrophotometry was obtained for the determination of trace molybdenum in edible beans by this method.