Spectrophotometric determination of gallium(III) with gallium-dibromohydroxyphenylfluorone-TritonX-100 system

The color reaction of the dibromohydroxyphenylfluorone(DBHPF) with Ga(Ⅲ) in the presence of TritonX-100 was studied.Results show that the reagent reacts with Ga(Ⅲ) to form a stable orange complex with a gallium(Ⅲ)∶DBHPF∶Triton-100 ratio of 1∶2∶2 in the medium of Na2B4O7-HCl buffer solution at pH 9.07.The maximum absorption wavelength and apparent molar absorptivity are at 554 nm and 4.1×105 L·mol-1·cm-1,respectively.Beer's law is obeyed in the range of 0.03-2.2 μg for Ga(Ⅲ) in 10 mL solution.The detection limit is 0.000 1 μg/mL.The method has been applied to the determination of trace Ga(Ⅲ) in pure aluminum and zincilate samples with the relative standard deviation of 1.10%-2.80%(n=6) and the recovery of 103.2%-104.6%.