Analysis of partitioning of organic compounds and proteins in aqueous polyethylene glycol-sodium sulfate aqueous two-phase systems in terms of solute–solvent interactions

Abstract

Partition behavior of nine small organic compounds and six proteins was examined in poly(ethylene glycol)-8000-sodium sulfate aqueous two-phase systems containing 0.5M osmolyte (sorbitol, sucrose, trehalose, TMAO) and poly(ethylene glycol)-10000-sodium sulfate system, all in 0.01M sodium phosphate buffer, pH 6.8. The differences between the solvent properties of the coexisting phases (solvent dipolarity/polarizability, hydrogen bond donor acidity, and hydrogen bond acceptor basicity) were characterized with solvatochromic dyes using the solvatochromic comparison method. Differences between the electrostatic properties of the phases were determined by analysis of partitioning of sodium salts of dinitrophenylated (DNP-) amino acids with aliphatic alkyl side-chain. It was found out that the partition coefficient of all compounds examined (including proteins) may be described in terms of solute-solvent interactions. The results obtained in the study show that solute-solvent interactions of nonionic organic compounds and proteins in polyethylene glycol-sodium sulfate aqueous two-phase system differ from those in polyethylene glycol-dextran system.

Simultaneous separation, concentration and determination of trace fluoroquinolone antibiotics in environmental samples using a polymer aqueous two‐phase system coupled with HPLC

“…The extraction efficiency and enrichment factor were analyzed at five temperatures (15,20,25,30 enrichment factor. However, the structure of the antibiotics could be destroyed at higher temperatures.…”

“…lower enrichment factor, long handling time and tedious operation). As a green extraction technique, the use of aqueous two‐phase systems (ATPSs) has been widely applied for separation and enrichment of amino acids, nucleic acids, viruses, proteins, natural substances and antibiotics . ATPSs have several advantages, including that they are easily operated and have short handling time, higher enrichment factors and low equipment requirements.…”

Effect of sodium chloride on solute–solvent interactions in aqueous polyethylene glycol–sodium sulfate two-phase systems

“…The purpose of the present work was to explore the effect of NaCl additive on partitioning of different solutes in PEG-Na 2 SO 4 ATPS in terms of solute-solvent interactions. It has been shown [19] previously that the solvatochromic dyes may be used for analysis of the solvent properties of the phases in PEG-sodium sulfate ATPS with NaCl additive in the concentration range from 0 to 0.54 M. We selected the NaCl concentration of 0.215 M, and examined partitioning of eight different organic compounds and six proteins in several PEG-Na 2 SO 4 -0.215 M NaCl ATPSs in the presence of different osmolytes (sorbitol, sucrose, and trimethylamine N-oxide) previously established [19] to affect solvent properties of the phases but not to engage in direct interactions with the solutes being partitioned.…”

“…It has been shown [19] recently that solute partitioning in PEGsodium sulfate ATPS is governed by the solute-solvent interactions in the coexisting phases. Partition coefficient of a solute in an ATPS is defined as the ratio of the solute concentration in the top phase to the solute concentration in the bottom phase and may be described as [19]:…”

“…The differences between the solvent dipolarity/polarizability, * , ˛*, hydrogen-bond donor acidity, ˛, hydrogen-bond acceptor basicity, ˇ, may be quantified with solvatochromic dyes [19]. The difference between the electrostatic properties of the phases may be determined by analysis of the partition coefficients of a homologous series of sodium salts of dinitrophenylated (DNP-) amino acids with aliphatic alkyl side-chains [19,20]. It has been shown that for a given compound (including proteins) the solute-specific coefficients may be determined by multiple linear regression analysis of the partition coefficients of the compound in multiple ATPSs with the same ionic composition.…”