分相滴定指示薬としてのニュートラルレッド

概要

論文の詳細を見る
Neutral red has been used as a pH indicator, and the reagent is extractable into amyl alcohol. In this extraction, it has not been clear which anion is transferred with the neutral red cation isto alcohol. A series of extraction systems with combinations of various anions in the aqueous phase and different organic solvents was therefore examined. It was found that when a small amount of certain anions such as thiocyanate, perchlorate, iodide or bromomercurate (II), was present in the aqueous phase, neutral red cations could be extracted into a specific organic solvent as ion pair. The color intensity of the organic phase was propotional to the amount of the particular anion initially present in the aqueous phase. The main discussion of this paper deals with the neutral red as a two-phase titration indicator ; the results of the color change at the end point are then summarized.
1996-12-10