Components of Program for Analysis of Spectra and Their Testing

The spectral analysis of aqueous solutions of multi-component mixtures is used for identification and distinguishing of individual components in the mixture and subsequent determination of protonation constants and absorptivities of differently protonated particles in the solution in steady state (Meloun and Havel 1985), (Leggett 1985). Apart from that also determined are the distribution diagrams, i.e. concentration proportions of the individual components at different pH values. The spectra are measured with various concentrations of the basic components (one or several polyvalent weak acids or bases) and various pH values within the chosen range of wavelengths. The obtained absorbance response area has to be analyzed by non-linear regression using specialized algorithms. These algorithms have to meet certain requirements concerning the possibility of calculations and the level of outputs. A typical example is the SQUAD(84) program, which was gradually modified and extended, see, e.g., (Meloun et al. 1986), (Meloun et al. 2012).