Abstract:

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 × 104 L/(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.

Key words: molybdenum, food, spectrophotometry, light green SF (yellowish)