作者： M.A.Shishkin^a, D.S.Volkov^a, I.M.Pelivanova^b, M.A.Proskurnin^a

^a M.V. Lomonosov Moscow State University, Chemistry Department, Leninskie Hills 1/3, 119991, GSP-1, Moscow, Russia

^b University of Washington, Department of Bioengineering, Seattle, WA, 98195, USA

摘要：The optoacoustic (OA) technique capable for light-absorption measurements in highly concentrated solutions is applied for direct solubility assessment in highly absorbing saturated solutions without any dilution or sample preparation. Maximum solubility of Phenol Red in aqueous solutions at pH>11 is found to be 1.3±0.1g/L. The experimental dependence of solubility of Phenol Red on solution acidity was obtained with optoacoustic and conventional spectrophotometric measurements. The data from both methods show complementary results. The model of the solubility of Phenol Red on solution acidity describing the experimental dependence is proposed, which cannot be attained at pHs above 7 without the OA-technique.