A modified colorimetric method for the estimation of β-cyclodextrin using phenolphthalein

Abstract

Abstract The binding equilibrium between β-cyclodextrin and phenolphthalein has been used to develop a method for the estimation of β-cyclodextrin in solution. From logarithmic plots of amounts of β-cyclodextrin against absorbance at 554 nm, a relation log X = (log A − log Y)/B was found, which gave an estimate of β-cyclodextrin in the concentration range 0.0045 mg mL−1 (3.96 μm) to 4.7 mg mL−1 (4.14 mm), where X = intercept and B = slope. This method was found to be highly reproducible and reliable.