Abstract
A method for the spectrophotometric determination of yttrium or lanthanum in aluminum alloys using the separation of aluminum by oxine extraction has been established.
More than 0.1g of aluminum alloy is dissolved in 3N hydrochloric acid. To remove majority of aluminum and interfering metals such as nickel etc., the solution is treated with acetic acid and oxine, the pH of the solution is adjusted to 4.5 with 20% hexamethylenetetramine and 1N ammonia water, and the metal oxinates are extracted by shaking with 5% solution of oxine in chloroform.
The pH of aqueous solution is adjusted to 6.4 (or 6.6 for lanthanum), and it is treated with 1.8 ml of10% solution of acetylacetone in ethyl alcohol and 2.5ml of 0.05% methylthymol blue solution. The absorbance of the solution is measured at 610 mμ against reference blank.
Relative errors in the determinations of yttrium and lanthanum over the range from 0.05 to 7.0% are both within ±3%.
