Chemometric study of kosmotropic and chaotropic ion properties related to Hofmeister effects

다국어 초록 (Multilingual Abstract)

The ion specificity is ubiquitous in biological and colloidal phenomena. In this study, the Hofmeister effects have been observed in binding of univalent cations with the surfactant dimers. Chemometric analysis has also revealed that the ion specificity observed is mainly related to the effect of ions on the water structure, ie, to their kosmotropic and chaotropic properties. These ion properties, generally characteristic of aqueous solutions, are in accordance with the results of the principal component analysis (PCA) and cluster analysis (CA) used for the processing of mass spectrometric data obtained in vacuum, ie, in the medium drastically different then water. Such an application of the chemometric methods has not been presented so far.
The use of chemometric methods for the study of the ion specificity, ie, to study the binding strength of M cations with dimers of anionic surfactant, was proposed. Cluster analysis (CA) and principal component analysis (PCA) were used for mathematical analysis of similarity of the survival curves obtained from MS/MS spectra of [(DS)2M]− complex ions (DS—dodecyl sulfate ions, M = H+, Li+, Na+, K+, Rb+, Cs+, Cu+, Ag+, Tl+, or NH4+). The linear relationship between PC1 and the parameter describing kosmotropic and chaotropic ion properties leads to the conclusion that these ion properties, related to the ion effect on the water structure, have great influence on Hofmeister effects observed in this study.