モリブデン(VI)-インドフェロンキレートの溶媒抽出によるモリブデン(VI)の吸光光度定量

A new method is proposed for the spectrophotometric determination of molybdenum(VI), which is based on the extraction of a molybdenum(VI)-indoferron chelate into chloroform in the presence of 1, 3-diphenylguanidinium (DPG) salt. The combining ratio of molybdenum(VI), indoferron, and DPG in the extracted species was shown to be 1: 2: 1. The extracted species had an absorption maximum at about 555 nm, and the maximum absorbance of the organic phase was obtained when the pH of the aqueous phase was between 1.5 and 2.1. Under the optimum, conditions, Beer's law was obeyed up to 67 μg molybdenum(VI) per 10 ml chloroform. The molar absorption coefficient of the extracted species is about 1×104 cm2 mol-1 at 555 nm. Interfering cations such as iron(III), titanium(IV), and zirconium(IV) can be masked by addition of EDTA.