ISSN print edition: 0366-6352
ISSN electronic edition: 1336-9075
Registr. No.: MK SR 9/7
Sulfonephthalein dyes. IV. Methylxylenol blue as a metallochromic indicator for chelatometric microtitrations of rare earth metals
K. Vytřas, M. Malcová, and S. Kotrlý
Department of Analytical Chemistry, Institute of Chemical Technology,
532 10 Pardubice
Abstract: The possibility of using methylxylenol blue as a metallochromic indicator
for the chelatometric determination of Sc3+, La3 + , Ce3+, Sm3+, and Er3 + ions
was examined by the method of photometric and visual comparison microtitration.
The influence of the kind of buffer solution and of pH upon the
steepness of the colour changes of methylxylenol blue was investigated.
Lanthanum, samarium, and erbium can be titrated in the medium of urotropine
or acetate buffer solutions, while for the titration of cerium(III) ions
the acetate buffer solutions are better suited. Scandium is to be titrated in
the medium of dilute nitric acid (pH 2 — 3) or formate buffer solutions. It
is also possible to use methylxylenol blue for consecutive determination
of scandium and lanthanoide in a mixture.
Full paper in Portable Document Format: 295a599.pdf
Chemical Papers 29 (5) 599–605 (1975)