Partition coefficients of flavonols in the poly(ethylene glycol)-K2HPO4-water aqueous two-phase system

The partition coefficients of 3-hydroxyflavone, 7,8-dihydroxyflavone, and q uercetin in the poly(ethylene glycol) 6000 (PEG: Avg. M.W.=7,500) (1) - dip otassium hydrogenphosphate (K2HPO4)(2) - water(3) aqueous two-phase system were determined at 288.15, 298.15 and 308.15 K to obtain information on the effect of the hydroxyl groups of flavonols on their partition coefficients in the aqueous two-phase system. It was found that all target substances p artition-to the top phase in preference to the bottom phase. In addition, t he osmotic virial equation was used to correlate the partition coefficients of the flavonols in this system.