Direct solubility determination in optically dense solutions of highly soluble chromophores by the optoacoustic technique: Acidity dependence for Phenol Red
Optoacoustic spectroscopy is applied for direct solubility determination in highly light-absorbing saturated solutions. No dilution or sample preparation is required. The dependence of solubility of Phenol Red on solution acidity in the wide pH range is obtained. Optoacoustic and conventional spectrophotometric measurements provide complementary data.