Details zur Publikation

Referenztyp Zeitschriften
DOI / URL Link
Titel (primär) Salting-out effect in aqueous NaCl solutions: trends with size and polarity of solute molecules
Autor Endo, S.; Pfennigsdorff, A.; Goss, K.-U.;
Journal / Serie Environmental Science & Technology
Erscheinungsjahr 2012
Department AUC;
Band/Volume 46
Heft 3
Sprache englisch;

Salting-out in aqueous NaCl solutions is relevant for the environmental behavior of organic contaminants. In this study, Setschenow (or salting-out) coefficients (Ks [M–1]) for 43 diverse neutral compounds in NaCl solutions were measured using a shared headspace passive dosing method and a negligible depletion solid phase microextraction technique. The results were used to calibrate and evaluate estimation models for Ks. The molar volume of the solute correlated only moderately with Ks (R2 = 0.49, SD = 0.052). The polyparameter linear free energy relationship (pp-LFER) model that uses five compound descriptors resulted in a more accurate fit to our data (R2 = 0.83, SD = 0.031). The pp-LFER analysis revealed that Na+ and Cl in aqueous solutions increase the cavity formation energy cost and the polar interaction energies toward neutral organic solutes. Accordingly, the salting-out effect increases with the size and decreases with the polarity of the solute molecule. COSMO-RS, a quantum mechanics-based fully predictive model, generally overpredicted the experimental Ks, but the predicted values were moderately correlated with the experimental values (R2 = 0.66, SD = 0.042). Literature data (n = 93) were predicted by the calibrated pp-LFER and COSMO-RS models with root mean squared errors of 0.047 and 0.050, respectively. This study offers prediction models to estimate Ks, allowing implementation of the salting-out effect in contaminant fate models, linkage of various partition coefficients (such as air–water, sediment–water, and extraction phase–water partition coefficients) measured for fresh water and seawater, and estimation of enhancement of extraction efficiency in analytical procedures.
ID 12105
dauerhafte UFZ-Verlinkung
Endo, S., Pfennigsdorff, A., Goss, K.-U. (2012):
Salting-out effect in aqueous NaCl solutions: trends with size and polarity of solute molecules
Environ. Sci. Technol. 46 (3), 1496 - 1503