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

Sulfonephthalein dyes. I. Spectrophotometric study of xylenol blue and bromoxylenol blue using colorimetric systems

K. Vytřas

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

Abstract:  Acid-base equilibria of xylenol blue and bromoxylenol blue were studied spectrophotometrically in the visible radiation region. Electronic absorption spectra of both the indicators were measured in the range of their colour transitions and the colour changes were specified by calculating the courses of colour transition curves in chromaticity diagrams CIE—xy, CIE—uv and in a complementary chromaticity diagram Q_xQ_y Colorimetric data were used for calculation of partial dissociation constants of the indicators. Utilizing a uniform colour space CIE—UVW, the sight sensitivity to small colour differences in visual analytical methods was also studied. Advantages of application of tristimulus colorimetric systems in the study of acid-base indicators are discussed

Full paper in Portable Document Format: 282a252.pdf

Chemical Papers 28 (2) 252–261 (1974)