Donaldson E M
Analytical Chemistry Section, Mineral Sciences Division, Mines Branch, Department of Energy, Mines and Resources, Ottawa, Canada.
Talanta. 1971 Sep;18(9):905-15. doi: 10.1016/0039-9140(71)80147-9.
A method for determining 0.001-0.10% of aluminium in molybdenum and tungsten metals is described. After sample dissolution, aluminium is separated from the matrix materials by chloroform extraction of its acetylacetone complex, at pH 6.5, from an ammonium acetate-hydrogen peroxide medium, then back-extracted into 12M hydrochloric add. Following separation of most co-extracted elements, except for beryllium and small amounts of chroinium(III) and copper(II), by a combined ammonium pyrrolidincdithiocarbamate-cupfen-on-chlorofonn extraction, aluminium is determined spectrophotometrically with Pyrocatechol Violet at 578 nm. Chromium interferes during colour development but beryllium, in amounts equivalent to the aluminium concentration, does not cause significant error in the results. Interference from copper(II) is eliminated by reduction with ascorbic acid. The proposed method is also applicable to iron, steel, ferrovanadium, and copper-base alloys after preliminary removal of the matrix elements by a mercury cathode separation.
描述了一种测定钼和钨金属中0.001 - 0.10%铝的方法。样品溶解后，在pH 6.5的醋酸铵 - 过氧化氢介质中，通过氯仿萃取其乙酰丙酮络合物将铝与基体材料分离，然后反萃取到12M盐酸中。通过吡咯烷二硫代氨基甲酸铵 - 铜铁试剂 - 氯仿联合萃取分离除铍以及少量铬（III）和铜（II）之外的大多数共萃取元素后，用邻苯二酚紫在578nm处分光光度法测定铝。铬在显色过程中产生干扰，但与铝浓度相当的铍量不会导致结果出现显著误差。用抗坏血酸还原可消除铜（II）的干扰。该方法经汞阴极分离初步去除基体元素后，也适用于铁、钢、钒铁和铜基合金。
