Determination of Iron in Nano-TiO₂ by 1,10-phenanthrolin Spectrophotometry

A determination method of iron content in nano-TiO₂ was presented,in which the sample was dissolved into sulfuric acid and ammonium sulfate,the titania ion was masked by ammonium tartrate.The 1,10-phenanthrolin reacted with Fe²⁺ to form a stable orange-red complex in the medium of CH₃COOH—CH₃COONa(pH 5.5).The absorbance was measured at the wavelength of 510 nm.The apparent molar absorptivity is 4.7×10⁴ and it is obeyed Beer law in the range of 0~100 μg/100 mL for iron concentration.The proposed method is of very good selectivity for determining iron in nanometer titania samples,the relative standard deviation is below 4%,and the recovery is in the range of 94.95%~105.33%.