Evaluation of stability constants from multi-wavelength absorbance data: program STAR

• Published in: Analytica chimica acta 1993-04, Vol.276 (2), p.441-454
• Main Authors: Beltrán, J.L., Codony, R., Prat, M.D.
• Format: Article
• Language: English
• Subjects: Absorbance; Chemistry; Computer programs; Exact sciences and technology; General and physical chemistry; General. Nomenclature, chemical documentation, computer chemistry; Stability constants; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry; UV-Visible spectrophotometry
• ISSN: 0003-2670; 1873-4324
• DOI: 10.1016/0003-2670(93)80415-H

The program STAR and STAR/FA were developed for the study of ionic equilibria from spectrophotometric data. Both programs are written in Turbo-Pascal for use on personal computers. STAR is a non-linear regression program for the refinement of complex formation constants of systems that can be described by up to 5 components and 25 species A p B q C r D s H t , where A, B, C and D can be either metal or ligand. The experimental data treated can contain up to 50 absorption spectra, measured at 50 wavelengths. Interaction with the user is provided by menu-driven operation and graphics presentation of data on the computer screen (or plotter). STAR/FA is a complementary program, used for the determination of the number of absorbing species by factor analysis of the absorbance data matrix. It can also be used for the smoothing of the experimental data. Two application examples are given: the interaction of boric acid with 2,3-dihydroxynitrobenzene (from literature data) and the dissociation and complex formation equilibria with Zn(II) ions of 8-hydroxyquinoline-5-sulphonic acid.