Micellar Liquid Chromatography, The Allocation Mechanism And Its Application In Preliminary Studies

Micellar liquid chromatography (MLC) is a reversed phase liquid chromatography by using a micellar solution as a mobile phase. With the amphipathic properties and the capability to mimic the biomembrane, surfactant with unique structure are often used in the field of drug separation and evaluation of drug membrane-transport. This paper will give the primary studies on the partition mechanisem and application of micellar liquid chromatography.The retention characteristics of solutes in anionic micellar liquid chromatography (AMLC) were investigated in terms of three-phase equilibrium theory, using an anionic surfactant (sodium dodecyl sulfate) solution as mobile phase. Acidic, basic and amphoteric solutes were investigated. The retention of solutes was depended on the assembled interaction of solutes with the micelles in the mobile phase and with the modified stationary phase. When adding organic modifier, the partitioning equilibria between aqueous phase and modified stationary phase, and aqueous phase and micellar phase, were significantly altered, and accordingly retention behavior of solutes was managed by the balance of hydrophobic and electrostatic interaction. Moreover, there were good correlations between lipophilicity from MLC, immobilized artificial membrane (IAM) and n-octanol/buffer, and minimal inhibitory concentration of three microbes for p-hydroxybenzoic ester analogs, suggestive of their inhibitory mechanism associated with membrane affinity.A novel mixed micellar liquid chromatography (MLC), the mobile phase consisting of anionic surfactant sodium dodecyl sulfate (SDS) and nonionic surfactant Brij35, was developed for the simultaneous separation of six matrine-type alkaloids, including matrine, oxymatrine, sophocarpine, oxysophocarpine, sophoridine and oxysophoridine. The factors influencing the separation resolution of the six matrine-type alkaloids were systematically investigated, including the micellar composition and concentration, the type and amount of organic modifier and pH values in the mobile phase. Under the optimal chromatographic separation conditions, the six matrine-type alkaloids could be easily isocratic eluted with the baseline separation within 21 min. Moreover, it was successfully separated the main alkaloids in two Sophora medicinal plants, S. flavescens and S. alopecuroide. The selectivity for carbonyl group and double band decreased with an increased percentage of SDS when mobile phase pH equaled 3 conditions. The results indicated that high selectivity of different kinds of drugs including stereoisomer with...