Spectrophotometric determination of titanium in plants using 5,5′-thiodisalicylic acid

Titanium (IV) forms a yellow-colored chelate with 5,5′-thiodisalicylic acid, whose sensibility is pD = 6.1 between pH 4 and 6. The stoichiometry of the complex formed is 1:1 at pH 0.5. The system follows Beer's law at pH 4.9 (λ = 385 nm) over the concentration range 0.6–3.2 ppm (ε = 16000 liters · mol⁻¹ · cm⁻¹). The method can be suitably used for determination of titanium in plants.