Salts kosmotropic

Addition of kosmotropic salts such as (NH4)2S04 or KH2P04 to the system enhances KP, as the protein is salted out of the bottom phase. 

Figure 15 Plot of the logarithm of the retention volume (log V ) versus the concentration of the displacing salt, ammonium sulfate, in the HP-HIC mode separation at 278 K of the polypeptides and proteins 1, insulin 2, insulin B chain 3, bovine trypsin inhibitor 4, bovine trypsinogen 5, insulin A chain 6, ribonudease A 7, sperm whale myoglobin 8, horse heart cytochrome c. As evident from these plots, the lower molecular weight polypeptide species show smaller changes in retention behavior as the concentration of the kosmotropic salt is varied. (Data from Ref. 207.)...

Thus, sodium citrate, on the basis of its molal surface tension increment and high solubility, would appear to be a good choice as an HIC kosmotropic salt. However, citrate salts are well known for their ability to bind selectively to many proteins at low concentrations, a feature that can be exploited [189-191] in the stabilization of multimeric NAD-dependent enzymes. 

Zafarani-Moattar MX, Hamzehzadeh S (2010) Salting-out effect, preferential exclusion, and phase separation in aqueous solutions of chaotropic water-miscible ionic liquids and kosmotropic salts effects of temperature, anions, and cations. J Chem Eng Data 55 1598-1610... 

Bridges, N.J. Rogers, R.D. (2008). Can kosmotropic salt/chaotropic ionic liquid (salt/salt aqueous biphasic systems) be used to remove pertechnetate from complex salt waste. Separation Science and Technology Vol.43 (No.5) 1083-1090. 

Bridges, N.J., Gutowski, K.E. Rogers, R.D. (2007). Investigation of aqueous biphasic systems formed from solutions of chaotropic salts with kosmotropic salts (salt-salt ABS), Green Chem. Vol. 9 (No.2) 177-183. 

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