A REVERSED MICELLAR SYSTEM USING MIXED SURFACTANTS OF SODIUM BIS (2-ETHYLHEXYL) SULFOSUCCINATE AND DI(2-ETHYLHEXYL) PHOSPHORIC-ACID FOR EXTRACTION OF PROTEINS

Protein extraction, including solubilization of water, in a reversed m icellar solution has been studied using mixed surfactants of sodium bi s(2-ethylhexyl) sulfosuccinate (AOT) and di(2-ethylhexyl) phosphoric a cid (DEHPA) in isooctane. It appears that the mixed micelles could be formed from AOT and charged species of DEHPA molecules in the organic phase, while uncharged DEHPA does not take part in forming the micelle s. The solubilization of water into the mixed micelles depends on pH a nd salt concentration in the aqueous solution as well as composition a nd concentration of surfactants. Hemoglobin having relatively large mo lecular weight could be successfully extracted by the mixed micelles. Furthermore, it was found that the addition of n-hexanol in the micell ar solution is useful for stripping of proteins from the micelles into dilute alkaline solution.