Determination of Titanium ions in Acid Solutions of Titanium Alloy by Spectrophotometry Method

Before fluorescence detection of Titanium alloy components, acid pickling in HF-HNO₃ solutions is always required in order to remove the superficial oxides of the components. In this paper, a method of measuring the titanium content in the acid solution was established by ultraviolet visible spectrophotometry method, and investigated the effects of pretreatments on the examinations. The results show that the typical absorption peaks of the standard titanium solutions without F element and the usual acid pickling solutions were both at 360 nm, but their linear parameters of titanium content versus absorbance were different apparently. This phenomenon was ascribed to the existence of HF in the acid solutions. In order to eliminate the effects of HF, high-temperature treatment of the solution and adding H₂O₂ to complex Ti ions were conducted,and the absorption peaks of the titanium solutions without F element shifted to 410 nm. The recovery of the method for different acid pickling solutions was 97.78%~104.18% for the Ti element. This method was accurate and simple with satisfactory precision and was suitable for routine quality control analysis.