UV-visible absorbance spectra of purified and unpurified m-cresol purple samples in sodium hydroxide and sodium chloride solutions at pH 12
M-cresol purple is the most widely used pH indicator dye for seawater pH measurements. Impurities in the indicator are known to absorb strongly at one of the wavelengths used in spectrophotometric pH determination and lead to large biases in the pH measurements.  This repository contains data and Matlab scripts to …