Preparation And Application Of Some Novel Stationary Phases For High Performance Liquid Chromatography

Incomplete reaction of the silica surface silanols is a problem that continues to plague the area of high performance liquid chromatograph (HPLC), since it may cause severe "effect of silianphilic" when separating polar samples especially basic solutes. So, how to reduce residual silanol activity when making stationary phase for HPLC has become the pop research direction of many chromatographers.In this study, a new bonded-phase with an internal polar functional group-amide (AOBP) was firstly prepared in domestic. Characterization and chromatographic evaluations of the prepared packing were also carried out. The results showed that the stationary phase could be efficiently used for the separation of basic compounds under methanol-water as binary mobile phase. The synthetic method of alkylamide phase was improved. This new method is more simpler and has more reproducible ligand surface concentration in contrast to the conventional two stages reaction.Used p-(3,4-epoxycyclohexyl)ethyltrimethoxy silane as couple regent, reacted with alkylamine, alkylanol, alkylanoic acid then bonded with porous silica, anime-type(ANBP), ether-type(ETBP) and ester-type(ESBP) stationary phase for reversed phase HPLC were firstly prepared , respectively. Characterization and evaluations of the prepared packings were carried out. The influences of organic modifier composition, mobile phase pH and buffer cation concentration on the retention behavior of basic compounds on these novel packings were also studied. A new ligand-exchange stationary phase for the enantioseperation of dl-amino acids was synthesized by treating silica gel with p-(3,4-epoxycyclohexyl)ethyltrimethoxy silane and then bonding L-isoleucine. Some dl-amino acids were separated on the new packing under ligand exchange model.The dependence of retention of basic compounds on temperature on the AOBP, ANBP, ETBP and ESBP columns was investigated. Variation of enthalpy for the transfers of solutes from the mobile phase to the stationary phase wasevaluated. The results further elucidate the separation mechanism of basic analytes on the four new packings.The determination of purine bases in tea, the separation of pyriproxyfen and four basic components in analgesic tablet were studied by use of AOBP, ANBP, ESBP and ETBP as columns, respectively, under methanol/water as mobile phase. The total of purine bases, pyriproxyfen and four basic components in analgesic tablet can be fast determined on those novel columns in contrast to the conventional Kromasil-C8 .The DEAE anion exchanger was prepared by 7 -glycidoxypropyltrimethoxy-siliane was firstly coupled onto porous silica then reacted with diethylaminoethanol under catalyst. The nucleic acids samples were separated on it and the results showed that the DEAE anion exchanger made in our laboratory is expected to take place of the import product to separate nucleic acids efficiently.