Spectrophotometric Determination of Gallium with Victoria Pure Blue BO as Color Reagent

An association complex between Ga(Ⅲ) (in form of GaI-4) and victoria pure blue BO in a phosphate buffer medium of pH 2.4 and in the presence of OP,was formed,having its absorption maximum at 560 nm.The apparent molar absorptivity (ε560) found was 5.53×105L·mol-1·cm-1.Beer′s law was held in the range of 1.3×10-3-7.0×10-2mg·L-1 of gallium(Ⅲ).The proposed method was used in determination of gallium in samples of gangue and coal ash,results obtained were in consistency with those obtained by the standard method (GB/T 8208-1987),with values of RSD′s (n=8) less than 3%.Results of recovery test found were in the range from 97% to 101%.