Phase separation in aqueous poly(ethylene glycol)-(NH4)2SO4 systems and some physicochemical properties of the phases

Zaslavsky, Boris Y.; Gulaeva, N. D.; Djafarov, Sahib F.; Масимов, Э. А.; Miheeva, Larisa M.

doi:10.1016/0021-9797(90)90051-o

Cited by 41 publications

(35 citation statements)

References 19 publications

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“…On the other hand, the E parameter varies with the TLL, independently of the salt present in the system. A similar effect was reported in the literature for PEG-(NH 4 ) 2 SO 4 ATPS formed by PEG of different molecular weights [29]: E parameter is independent of the molecular weight while C parameter is affected by it.…”

Section: Resultssupporting

confidence: 74%

“…DG * (CH 2 ) values and parameters C and E, obtained from equations (5) and (6), are presented in table 2. There, it can be seen that both the C and E parameters depend on the system composition [29]. The biphasic systems composed by dihydrogen phosphate salts present the most negative DG * (CH 2 ) values, thus these systems have a larger relative hydrophobicity.…”

Section: Resultsmentioning

confidence: 98%

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Gibbs free energy of transfer of a methylene group on {UCON+(sodium or potassium) phosphate salts} aqueous two-phase systems: Hydrophobicity effects

Silvério

Rodrı́guez

Teixeira

et al. 2010

The Journal of Chemical Thermodynamics

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a b s t r a c tThe Gibbs free energy of transfer of a suitable hydrophobic probe can be regarded as a measure of the relative hydrophobicity of the different phases. The methylene group (CH 2 ) can be considered hydrophobic, and thus be a suitable probe for hydrophobicity. In this work, the partition coefficients of a series of five dinitrophenylated-amino acids were experimentally determined, at 23°C, in three different tie-lines of the biphasic systems: (UCON + K 2 HPO 4 ), (UCON + potassium phosphate buffer, pH 7), (UCON + KH 2 PO 4 ), (UCON + Na 2 HPO 4 ), (UCON + sodium phosphate buffer, pH 7), and (UCON + NaH 2 PO 4 ). The Gibbs free energy of transfer of CH 2 units were calculated from the partition coefficients and used to compare the relative hydrophobicity of the equilibrium phases. The largest relative hydrophobicity was found for the ATPS formed by dihydrogen phosphate salts.

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Section: Resultssupporting

confidence: 74%

Section: Resultsmentioning

confidence: 98%

Gibbs free energy of transfer of a methylene group on {UCON+(sodium or potassium) phosphate salts} aqueous two-phase systems: Hydrophobicity effects

Silvério

Rodrı́guez

Teixeira

et al. 2010

The Journal of Chemical Thermodynamics

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“…Good correlation parameters above R 2 = 0.99 were obtained, which validates the methodology used in this work. When possible, the obtained phase diagrams were confirmed and shown to be in good agreement with the binodal curves already reported in the literature and done in batch scale …”

Section: Resultssupporting

confidence: 88%

High‐throughput screening of aqueous biphasic systems with ionic liquids as additives for extraction and purification of enveloped virus‐like particles

Marchel

Soares

Vormittag

et al. 2019

Engineering Reports

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Due to their unique properties, virus‐like particles (VLPs) have been portrayed as a promising high‐value biopharmaceutical in VLP‐based vaccination and cancer therapy. Nevertheless, due to limited physical and economical capabilities of the current downstream processing of VLPs, their production is still difficult and seen as a major problem that needs to be tackled. In this work, high‐throughput screening on a liquid handling station (LHS) has been implemented for efficient selection of adequate polymer‐salt aqueous biphasic systems (ABS) for extraction and purification of enveloped Hepatitis C virus pseudoparticles (HCVpp). The effect of polyethylene glycol (PEG) molecular weight and salt type (citrate, sulfate, and phosphate) was first evaluated. Furthermore, to optimize extraction parameters, the effect of pH and tie‐line lengths (TLL) was also addressed. For the most promising ABS and extraction conditions, the addition of ten ionic liquids (ILs) as adjuvants was investigated. Insights on the chemical features of ILs that impact HCV‐VLPs partitioning are highlighted. Finally, the potential of studied ABS containing ILs as adjuvants in the extraction and purification of VLPs from cell culture supernatants was addressed. The 100% extraction efficiency of VLPs in the PEG‐rich phase was achieved, and VLP purity was increased compared to the system without IL. In conclusion, these promising results show that ILs can be very effective in modulating the phase properties of polymer‐salt ABS, achieving high HCV‐VLP purification.

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“…A scale of hydrophobicity based on the free energy of transfer of a methylene group between the phases, DG(CH 2 ), proposed by Zaslavsky and coworkers [8,14], has been used to estimate the relative hydrophobicity of several ATPSs [4,[15][16][17][18][19]. ATPSs appear as a practical alternative to the 1-octanol/water biphasic system for the determination of hydrophobicity used in the correlation of drug action in Quantitative Structure-Activity Relationships (QSAR).…”

Section: Introductionmentioning

confidence: 99%

Salt effect on the (polyethylene glycol 8000+sodium sulfate) aqueous two-phase system: Relative hydrophobicity of the equilibrium phases

Ferreira

Teixeira

2011

The Journal of Chemical Thermodynamics

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Salt effect Relative hydrophobicity Gibbs free energy of transfer a b s t r a c tThe relative hydrophobicity of the phases of several {polyethylene glycol (PEG) 8000 + sodium sulfate (Na 2 SO 4 )} aqueous two-phase systems (ATPSs), all containing 0.01 mol Á L À1 sodium phosphate buffer (NaPB, pH 7.4) and increasing concentration of a salt additive, NaCl or KCl, up to 1.0 mol Á L À1 , was measured by the free energy of transfer of a methylene group between the phases, DG(CH 2 ). The DG(CH 2 ) of the systems was determined by partitioning of a homologous series of five sodium salts of dinitrophenylated (DNP) -amino acids with aliphatic side chains in three different tie-lines of each biphasic system. The relative hydrophobicity of the phases ranged from À0.125 to À0.183 kcal Á mol À1 , being the NaCl salt the one to provide the more effective changes. The results show that, within each system, there is a linear relationship between the DG(CH 2 ) and the tie-line length (TLL), and biphasic systems with high salt additive concentration present the most negative DG(CH 2 ) values. Therefore, the feasibility of establishing a relationship between the relative hydrophobicity of the phases in a given TLL and the ionic strength of the salt additive was investigated and a satisfactory correlation was found for each salt.

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Phase separation in aqueous poly(ethylene glycol)-(NH4)2SO4 systems and some physicochemical properties of the phases

Cited by 41 publications

References 19 publications

Gibbs free energy of transfer of a methylene group on {UCON+(sodium or potassium) phosphate salts} aqueous two-phase systems: Hydrophobicity effects

Gibbs free energy of transfer of a methylene group on {UCON+(sodium or potassium) phosphate salts} aqueous two-phase systems: Hydrophobicity effects

High‐throughput screening of aqueous biphasic systems with ionic liquids as additives for extraction and purification of enveloped virus‐like particles

Salt effect on the (polyethylene glycol 8000+sodium sulfate) aqueous two-phase system: Relative hydrophobicity of the equilibrium phases

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