ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Sulfonephthalein dyes. III. Methylxylenol blue as a metallochromic indicator for direct visual chelatometric microtitrations of bivalent metals

K. Vytřas, V. Mach, and S. Kotrlý

Department of Analytical Chemistry, Institute of Chemical Technology, 532 10 Pardubice

Abstract:  Methylxylenol blue proved to be a sensitive metallochromic indicator for chelatometric microdetermination of Pb²⁺, Zn²⁺, Cd²⁺, Hg²⁺, Cu²⁺, Co²⁺, and Mn²⁺ ions in mild acidic media buffered by acetate and urotropine solutions. The influence of p H and of the kind of buffer solution upon the slope of the colour changes of methylxylenol blue was studied via photo­metric microtitrations. Results of the visual comparative titrations using methylxylenol blue were statistically evaluated and compared with the results of other recommended methods. With a few exceptions only the determinations using methylxylenol blue are not laden with systematic errors with regard to the used methods of comparison and may be regarded as very accurate titration methods.

Full paper in Portable Document Format: 291a61.pdf

Chemical Papers 29 (1) 61–67 (1975)