title: Origin of salt additive effect on solute partitioning in aqueous polyethylene glycol-8000-sodium sulfate two-phase system.
abstract: Partitioning of a homologous series of dinitrophenylted (DNP-) amino acids with aliphatic side chains was examined in aqueous polyethylene glycol (PEG)-8000-sodium sulfate two-phase systems (ATPS) with the additives NaSCN, NaClO4, and NaH2PO4 at concentrations varied from 0.025M up to 0.54M. The differences between the relative hydrophobicities and electrostatic properties of the two phases in all ATPS were estimated. Partitioning of adenine, adenosine mono-, di- and tri-phosphates was also examined in all ATPSs, including those with NaCl additive. Partition coefficients for these compounds and for nonionic organic compounds previously reported [L.A. Ferreira, P. Parpot, J.A. Teixeira, L.M. Mikheeva, B.Y. Zaslavsky, J. Chromatogr. A 1220 (2012) 14.] were analyzed in terms of linear solvent regression relationship. The results obtained suggest that the effects of the salts additives are related to their influence on the water structure.
authors.affiliation: IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: Nuno R
authors.initials: NR
authors.lastname: da Silva
authors.affiliation: IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal; Analiza, Inc., 3615 Superior Ave., Cleveland, OH 44114, USA.
authors.forename: Luisa A
authors.initials: LA
authors.lastname: Ferreira
authors.affiliation: Analiza, Inc., 3615 Superior Ave., Cleveland, OH 44114, USA.
authors.forename: Larissa M
authors.initials: LM
authors.lastname: Mikheeva
authors.affiliation: IBB-Institute for Biotechnology and Bioengineering, Centre of Biological Engineering, Universidade do Minho, Campus de Gualtar, 4710-057 Braga, Portugal.
authors.forename: José A
authors.initials: JA
authors.lastname: Teixeira
authors.affiliation: Analiza, Inc., 3615 Superior Ave., Cleveland, OH 44114, USA. Electronic address: bz@analiza.com.
authors.forename: Boris Y
authors.initials: BY
authors.lastname: Zaslavsky
mesh_terms: D000227:Adenine Nucleotides / Q000302:isolation & purification; D000596:Amino Acids / Q000302:isolation & purification; D057927:Hydrophobic and Hydrophilic Interactions; D010472:Perchlorates / Q000737:chemistry*; D010710:Phosphates / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*; D012965:Sodium Chloride / Q000737:chemistry*; D017670:Sodium Compounds / Q000737:chemistry*; D055672:Static Electricity; D013431:Sulfates / Q000737:chemistry*; D013861:Thiocyanates / Q000737:chemistry*; D014867:Water
chemical_list: D000227:Adenine Nucleotides; D000596:Amino Acids; D010472:Perchlorates; D010710:Phosphates; D017670:Sodium Compounds; D013431:Sulfates; D013861:Thiocyanates; D014867:Water; C012036:sodium sulfate; D011092:Polyethylene Glycols; D012965:Sodium Chloride; C024553:sodium thiocyanate; C031068:sodium perchlorate; C018279:sodium phosphate
keywords: Electrostatic properties; Hofmeister series; Ionic and non-ionic solutes partitioning; PEG–sulfate aqueous two-phase systems; Relative hydrophobicity; Salt additives