Abstract
Phenol is known to color red with xanthydrol in hydrochloric acetic acid solution and a method for the determination of phenol using this reaction was examined. In this method, 1ml. of xanthydrol reagent solution (120mg, of xanthydrol dissolved in glacial acetic acid, 30ml. of hydrochloric acid added, and the whole volume brought to 100ml. with glacial acetic acid) is added to 1ml. of glacial acetic acid solution of phenol (5-60γ/ml.), the mixture is heated on a water bath for 8 minutes, and diluted to 10ml. with glacial acetic acid. Absorbance of this solution is measured at 503mμ, with the blank test using glacial acetic acid in place of the test solution. Acetone may be used to dilute the reaction mixture. The calibration curve is a straight line passing the original point and the coefficient of variation is around 1.0-1.5%. This method of determination can be applied to that of o-cresol, pyrocatechol, and guaiacol by modifying the reaction time and the wave-length of the optical measurement.
