NOTES methanol solution were carried out before and after each set of analyses. Methylene blue was added to improve the color change at the visual end point (8), which was from green to bronze in methanol and from gold to bronze in methyl isobutyl ketone. Titrations could be reproduced to 510.5% in methanol and to ;l=1% in methyl isobutyl ketone. Absorption spectra were obtained on a Beckman DK spectrophotometer. 1. WJ BIERMANN and R. McCoRRELL. Can. J. ...
