A New Method for the Calculation of Successive Stability Constants

摘要

A computational procedure for solving successive equilibria has been described and applied to a system of simulated data and real experimental results. The procedure apparently is an improvement over more classical methods in that it is able to treat all of the data simultaneously and avoids assumptions involving the number of species present. An additional improvement in the present procedure is that it yields a direct estimate of the standard error associated with the individual molar absorptivities. The spectra of the 'pure' species need not be known in order to obtain useful information. If the spectra of any of the species is known the number of degrees of freedom for the fit is reduced and, in general, this increases the reliability of the results. However, unlike more classical methods, these data need not be available in this approach. One restriction was imposed on the model which was found to decrease the number of false or local minima as well as some which were mathematically comparable to the 'best' solution but physically unreasonable. The restriction simply insured that the calculated molar absorptivity could not fall below a specified limit, usually zero, at any wavelength. (Author)