アルミニウム-クペレートとのイオン交換抽出によるバナジウム(V)の吸光光度定量

抄録

Vanadium(V) was determined by the ion-exchange extraction with aluminum cupferrate in chloroform. Ethanol was added for promoting the extraction of vanadium(V). After (5090) cm³ of a sample solution containing less than 80 μg of vanadium(V) was taken in a separatory funnel, 5 cm³ of 1 mol dm^-3 monochloroacetate buffer solution (pH 2.2) and 10.0 cm³ of 0.005 mol dm^-3 aluminum cupferrate in chloroformethanol (1 + 1) were added. The mixture was shaken for 5 minutes, and the absorbance of chloroform phase was measured at 400 nm against the reagent blank. Under the optimum condition, the relationship, y=0.013 ₀x was obtained between y of the absorbance and x (μg) of the amounts of vanadium(V) in test solution within the range 5≤x≤80. Common cations and anions did not interfere. Iron (III) that interfered the determination could be removed by the extraction with cupferron and chloroform in the presence of hydrogen peroxide as a masking agent for vanadium (V). After hydrogen peroxide was decomposed by adding potassium permanganate, vanadium(V) was determined as described above. About (0.0020.03) % of vanadium in aluminum metals could be determined without separation from the matrices.