A new algorithm for the determination of protolytic constants from spectrophotometric data in multiwavelength mode: Calculations of acidity constants of 4-(2-pyridylazo)resorcinol (PAR) in mixed nonaqueous-water solvents
2006 (English)In: Talanta: The International Journal of Pure and Applied Analytical Chemistry, ISSN 0039-9140, E-ISSN 1873-3573, Vol. 68, no 4, 1201-1214 p.Article in journal (Refereed) Published
A new efficient, simple and versatile algorithm is presented for determination of the protolytic constants from spectrophotmetric data in multiwavelength mode based on the combining of hard and soft modeling. The algorithm was checked by determining the acidity constants of a triprotic acid from theoretical and real absorption-pH data. The real spectral data are obtained from photometric titration of different solutions of 4-(2-pyridylazo)resorcinol (PAR) by a standard base solution under an inert atmosphere. The algorithm starts the minimization process using an user supplied number of components and initial guesses of the unknown parameters and refined in a least squares manner. New algorithm is implemented in the new version of DATAN package (version 3.1). The validity of the obtained results was checked by some well known programs such as DATAN 2.1, SPECFIT/32, SQUAD, a modified version of difference spectra and a A-pH curve method. The comparison of the outputs of the DATAN 3.1 with the other programs reveals that there is a very good agreement between the obtained results and mentioned programs.
Place, publisher, year, edition, pages
2006. Vol. 68, no 4, 1201-1214 p.
acidity constants, DATAN, SQUAD, SPECFIT/32, difference spectra, PAR, water-nonaqueous binary solvents
IdentifiersURN: urn:nbn:se:kth:diva-37522DOI: 10.1016/j.talanta.2005.07.024ISI: 000235124200021ScopusID: 2-s2.0-30644479353OAI: oai:DiVA.org:kth-37522DiVA: diva2:434192