铬天青S光度法测定纯钛中铝含量

A CAS Spectrophotometric Method of Determining Aluminium in Pure Titanium

研究了铬天青Ｓ光度法用于钛中铝含量为０．１％～１．０％的测定。该法显示，在硫酸——六次甲基四胺缓冲体系中（ｐＨ＝５～６），铝（Ⅲ）与铬天青Ｓ形成紫红色配合物，在波长５５０ｎｍ用分光光度计测得铝含量。研究表明，该法采用无铝纯钛打底制作校正曲线并用过氧化氢、乙二胺四乙酸锌联合掩蔽能够消除钛、铁等的干扰，方法简单，准确性良好，能够较好用于钛及部分钛中铝含量为０．１％～１．０％的测定。

A spectrophotometric method of determining aluminium(01%～10%) in titanium has been studied. It is found that aluminium cations are reacted with chrome azurol S(CAS) to form a purple coordinated complex in the medium of sulfuric acid-hexamine solution (as pH buffer, pH=5～6)Which can be used for the determination of aluminium content. The complex exhibits the maximum absorbance at 550 nm. Aluminium in pure titanium was determined at the wavelength of 550 nm using a spectrophotometer. The results show that Beer′s law is obeyed for 0～50 μg/250 ml, the RSD is ≤32% and the recovery is 100%. Most of the common metal elements in titanium alloys, such as Ti, Ni, Fe, Mn, Zr, Nd, Cu, Sn and V do not interfere in the determination of aluminium after they are masked off by hydrogen peroxide and Zn-EDTA. The method has been applied to the determination of aluminium in the range 010%～100% in pure titanium and some titanium alloys with satisfactory results.