Preparation And Evaluation Of Aryl-bonded Silica Gel Stationary Phases For High Performance Liquid Chromatography

Aryl-bonded silica gel stationary phases with conjugated π-electron system is selective chromomatographic separartion materials. They are suitable for the analysis of medicine, pesticide residue, environment pollutants, biochemical samples and chiral compounds because the aryl ligands are able to interact with the analytes based on dipole-dipole and charge-transfer interactions. Aryl and substituting aryl-bonded phases are an attractive subject in the overlapping area of modern chromatography with application sciences, showing great promising prospect for the researches of theory and practice. In this thesis, the preparation, characterization and evaluation of chromatographic performance and retention mechanism of aryl-bonded silica gel stationary phases for high performance liquid chromatography are studied systematically. The major contents are as follows:1. The progress of the study of aryl-bonded silica gel stationary phases in HPLC were reviewed indetail. The main subject focused on the preparation, chromatographic property, rentention mechanism and application of aromatic-bonded silica gel stationary phases for HPLC.The application prospect of the aryl-bonded for HPLC and related techniques in the future is discussed. Above all provide the basis and start point for further research of the subject.2. Three aryl-bonded silica gel stationary phases for high performance liquid chromatography were prepared using coupling reagents by solid-liquid reaction method. They include 3,5-dinitrobenzoyl-bonded silica gel stationary phase (DNB), quinolinyl ether-bonded silica gel stationary phase (QBS) and l,l'-di(2-naphthol) ether-bonded silica gel stationary phase (DNP). Their structures were characterized by elemental analysis, diffuse reflectance infared fourier transform spectroscopy and thermal analysis. The method includes two steps. The coupling reagent was chemically anchored to the silica gel matrix and then aryl ligand was bonded via the opening reaction with the active function groups on the surface of spacer silica gel. The advantage is that redundant reagent can immediately be removed with solvents, which faciliate to the formation of stable ligand bonded layer. Additionally, a calix[8]arene modified ODS (CAODS)with mixed ligands can also be prepared.3. The chromatographic of three new stationary phases were evaluated by using neutal, acidic, basic and polar compounds as probes. Under the same condition, the compared study with traditional ODS was also carried out. The results indicate that excellent linear relationship exist between the log k' of alkylbenzene series and the methylene group number (n). The regress equations were asfollows: DNB, \ogk =0.07568^+0.08288, r=0.9975; QBS, log*-0.09543h-0.3194, r=0.9982; DNP, log￡'=0.1834?-0.3292, r=0.9880. The hydrophobicity order is DNB