Catalytic kinetic spectrophotometric determination of cerium

A new procedure for the determination of cerium was established using the catalytic effect of Ce(IV) on the oxidation of tribromoarsenazo(TB-ASA) by potassium bromate. In 0.080 mol/L sulfuric acid medium, the maximum absorption peak of Ce(IV)-(TB-ASA)- KBrO3 system is at 510 nm. The amount of Ce (IV) and the difference of absorbance (▵) showed a good linear relationship over the range of 5.7×10−8−5.1×10−7 mol/L. The regression equation is ▵=2.3×10−11C(C: mol/L)+0.0196, with a regression coefficient of 0.9914 at the wavelength. The detection limit of the method was 5.1×10−8 mol/L ng/mL. This method was used in the determination of cerium in human blood and chicken liver samples. For the eleventh replicate determinations, its relative standard deviation was 3.04%–3.28%. The recovery of standard addition of the method was 100.7%–104.2 %.