Partitioning of Porphyrin Compounds in An Aqueous Two-phase System of Cationic-anionic Surfactant Mixture

Abstract

A new aqueous two-phase system of cationic-anionic surfactant mixture (ATP-CAS) is proposed for the extractions of porphyrin compounds. ATP-CAS is formed when 0.05mol/l aqueous solutions of dodecyl triethylammonium bromide (C₁₂NE) and sodium dodecyl sulfate (SDS) are mixed with a molar ratio of 1.62:1. The two phases are of mixed surfactant solutions but the concentration in the upper phase is much higher than that of the lower phase. Effects of strong acid, base solutions on the two-phase system are investigated. The results show that negatively charged porphyrins such as meso-tetraphenyl porphine tetrasulfonic acid (TPPS₄) and protoporphyrin (proto) are extracted into the upper phase efficiently while other porphyrins like meso-tetraphenyl porphine (TPP) and tetrakis(4-trimethylammoniophenyl)porphine (T-4(TAP)P) and vitamin B₁₂ distributed in the two phases almost uniformly.