Catalytic kinetic spectrophotometric determination of trace titanium based on titanium(IV)-(DBS-arsenazo)-potassium bromate system

Based on the property that in 0.12 M sulfuric acid medium titanium(IV) catalyzes the discoloring reaction of DBS-arsenazo oxidized by potassium bromate, a new catalytic kinetic spectrophotometric method for the determination of trace titanium (IV) was developed. The linear range of the determination of titanium is 0-2.4 mu g/25 mL. The detection limit of the method is 0.47 ng/mL. The effects of fifty coexisting substances were studied and most of common substances do not interfere with the determination of titanium. The method has good selectivity. The present method was used in the determination of trace amount of titanium in cabbage and potato samples with satisfactory results. The relative standard deviations often replicate determinations of the method are 1.4-1.5 % and the recoveries of standard addition are 97.6-98.0 %, respectively.