Spectrophotometric determination of cerium subgroup rare earths in nickel-base alloys in the presence of yttrium with p-acetylchlorophosphonazo and mixed surfactants.
Rare earth elements react with p-acetylchlorophosphonazo (CPApA) to form colour complexes. In the presence of emulsifier OP and cetylpyridinium chloride (CPC), the yttrium complex is not formed because of micellar masking, while the cerium subgroup rare earths give more sensitive reactions with CPApA(epsilon(Ce) = 1.16 x 10(5) 1 . mol(-1) . cm(-1)) due to micellar sensitization. Most foreign ions can be tolerated in considerable amounts. The optimum conditions of the complex formation reaction and the composition of the Ce-CPApA complex are described. A simple method is proposed for the determination of cerium subgroup rare earths in nickel-base alloys with satisfactory results.
Hsu
C G
CG
Department of Chemistry, East China Normal University, 3663 Zhong Shan Road N., Shanghai, China.
Li
H
H
Pan
J M
JM