非水溶液における呈色反応(第2報) : 酢酸エチル溶媒中におけるBromophenol Blueと第三級アミン類との反応について

抄録

Spectral changes due to the bonding of bromophenol blue (I) and tertiary amines in ethyl acetate were examined and a method was established for a concurrent calculation of the two molar extinction coefficients, ε₁ and ε₂. In this method, I is reacted with amines of various concentrations, absorbance of the 1 : 1 and 1 : 2 conjugates present is measured, and the values of ε₁ and ε₂ were obtained as 2.5-2.6×10⁴ and 4-5×10⁴ liter/mole (15-45°), respectively. From these values, equilibrium constant, K₂, was calculated and, it was thereby found that this method offered a simple method for the determination of a minute amount of amines in ethyl acetate.