Spectrophotometric determination of titanium in aluminium alloy with diantipyrylmethane

A method for the determination of titanium in aluminium alloy by diantipyrylmethane (DAPM) spectrophotometry was introduced. The sample was rapidly decomposed by HNO3-HF, and the excessive HF was neutralized by H3BO3. The color reaction occurred in the medium of 1.2 mol/L HCl-1.8 mol/L H2SO4, and the coexisting ions did not interfere in the determination. Beer's law was obeyed in the range of 0.40-10.0 μg/mL for Ti(IV), and the linear regression equation is A = 0.0106 + 0.365 ρ(μg/25 mL), the correlation coefficient is 0.9996. The proposed method was applied to the determination of Ti in aluminium alloy standard samples with the relative standard deviation of 2.5%-5.0%. The results are consistent with the certified values.