Preparation And Application Of Special Capillary Chromatographic Columns For The Separation Of Isomeric Compounds

The isomeric chemicals are widely used in the fields of organic intermediates, pesticides, medicines. Therefore, it is meaningful to study the analytic technique of isomers for manufacturing monitoring and production quality test. The characteristic of isomers lies in the similar structures and analogous boiling points(sometimes the difference is not exceeding 1°C), which makes it inconvenient for the separation and analysis by using common columns. So it is essential to prepare special columns for different isomeric compound systems.In this paper, three β-cyclodextrin(β-CD) derivatives, were prepared and characterized. β-CD derivatives includes permethylated-β-CD, 2,3-di-O-acetyl-6-O -tert-butydimethysilyl-β-CD, 2,3-di-O-benzyl-6-O-tert-butydimethysilyl-β-CD. Per methylated -β-CD (10%,20%,40%), 2,3-di-O-acetyl-6-O-tert-butydimethysilyl-β-CD, 2,3-di-O-benzyl-6-O-tert-butydimethysilyl-β-CD(static method, dynamic method), bentone (SE-54,OV-1), PEG-20M fused silica capillary columns were made by coating in static or dynamic method. Their column properties are discussed. And the polarities of the capillary columns were evaluated by the McReynolds constants. The results show that the polarty of CD derivative columns is moderate.The effects of the different diluents and their proportion are investigated. The results show that film-forming properties, separation properties and the thermally stable properties of the chromatographic columns are better when the proportion of permethylated- β-CD in the stationary phase is 10%~20%. And the chromatographic separation properties are also discussed by the column temperature. The results show that the peak orders are greatly affected by the column temperature.The chromatographic separation properties of isomers, including cresols, xylenols, toluene halide, chlorobenzaldehyde, xylene and dichlorobenzene isomers, are investigated on different columns. The results indicate that cresols and xylenols are separated best in the permethylated -β-CD capillary columns. They are separated...