Study on color reaction of p-carboxylphenylfluorone with alnmininm and its application

A new method was developed for spectrophotometric determination of trace aluminium in magnesium alloy,based on the color reaction of p-carboxylphenylfluorone with aluminium(Ⅲ).In am- monium acetate solution(pH5.7)and in the presence of cationic surfactant CTMAB,aluminium reacts with p-carboxylphenylfluorone sensitively to form a red complex.The complex has a maximum ab- sorption at 573nm,with apparent molar absorptivity of 1.37×10~5L·mol~(-1)·cm~(-1).Beer's law is o- beyed in the range of 0-0.24μg/mL for aluminium.The color reaction system has good selectivity too.Most of metal ions studied can be tolerated in considerable amounts,especially magnesium.Pro- posed method has been applied to direct determination of aluminum in magnesium alloy samples with satisfactory results.