Cooperativity between various types of polar solute–solvent interactions in aqueous media

• Published in: Journal of Chromatography A Vol. 1408; pp. 108 - 117
• Main Authors: Madeira, Pedro P., Bessa, Ana, Loureiro, Joana A., Álvares-Ribeiro, Luís, Rodrigues, Alírio E., Zaslavsky, Boris Y.
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 21.08.2015
• Subjects: Amino Acids - analysis; Aqueous two-phase partitioning; Benzaldehydes - analysis; Benzyl Alcohol - analysis; Coumarins - analysis; Dextrans - chemistry; Energy use; Glucosides - analysis; Hofmeister effect; Linear Models; Mathematical analysis; Partitioning; Partitions; Phenol - analysis; Phenylethyl Alcohol - analysis; Polyethylene Glycols - chemistry; Povidone - chemistry; Regression analysis; Salt additives; Solute–water interactions; Solvation; Solvatochromic comparison method; Solvents; Solvents - chemistry; Water - chemistry; Aqueous two-phase partitioning; Solute–water interactions; Hofmeister effect; Salt additives; Solvatochromic comparison method
• ISSN: 0021-9673; 1873-3778
• DOI: 10.1016/j.chroma.2015.07.002

•Partition coefficients of seven organic compounds are obtained in different ATPS.•The ionic composition of each ATPS was varied.•The solute-specific coefficients for the compounds examined were determined.•The solute specific coefficients change in the solute specific manner.•Cooperativity between various types of interactions is governed by solute structure. Partition coefficients of seven low molecular weight compounds were measured in multiple aqueous two-phase systems (ATPSs) formed by pairs of different polymers. The ionic composition of each ATPS was varied to include 0.01M sodium phosphate buffer (NaPB), pH 7.4 and 0.1M Na2SO4, 0.15M NaCl, and 0.15M NaClO4 all in 0.01M NaPB, pH 7.4. The differences between the solvent features of the coexisting phases in all the ATPSs were estimated from partitioning of a homologous series of dinitrophenylated-amino acids and by the solvatochromic method. The solute-specific coefficients for the compounds examined were determined by the multiple linear regression analysis using the modified linear solvation energy relationship equation. It is established that the solute specific coefficients characterizing different types of the solute–water interactions (dipole–dipole, dipole–ion, and H-bonding) for a given solute change in the presence of different salt additives in the solute specific manner. It is also found that these characteristics are linearly interrelated. It is suggested that there is a cooperativity between various types of solute–water interactions governed by the solute structure.