Preparation And Applications Of Silica-based Stationary Phases For High Performance Liquid Chromatography

High performance liquid chromatography has become a vital analytical separation technique in the area of scientific research,biological medicine,pharmacy,food and so on after years of development and innovation,which was benefit from the progress of column and detection technology.Because of advantages of high mechanical strength,good chemical stability and fast mass transfer,silica-based stationary phase is of great importance in analytical chemistry as the most widely used matrix.However,the application of pure silica column is limited due to strong polarity of silica and the abundant silanols,which was failed in the separation of a great variety of compounds.Therefore,a modification is necessary for silica matrix to obtain the functional packings used for separation of various and complicated compounds.This paper discussed the synthesis process of novel silica-based stationary phases aimed at simplifying the synthetic route,improving the reaction efficiency and increasing range of using on a column.Moreover,end-capping methods and detection methods of new stationary phase were studied in this paper.The details were as follows:1.A simple interpretation about the chemical,physical and surface properties of silica was presented.Follow on that kinds of silica and modification methods were introduced.More importantly,the chromatographic column performances were given as an evaluation of prepared stationary phase.2.A novel polar-embedded and polar-endcapped C18 stationary phase with low activity of residue silanols,high acid and base stability was prepared by one-step method.It demonstrated superior performance in totally aqueous mobile phase compared to tradition C18 column.In addition,separation of carbohydrates under different mobile phases was discussed use the novel packing as hydrophilic interaction chromatography stationary phase.3.Different end-capping columns were synthesized to compare chromatographic performances while using pyridine compounds,amide compounds and benzylamine as eluents under the condition of changed mobile phases.A comparision between the"epoxy end-capping" columns and trimethylchlorosilane end-capping column,no end-capping column was conducted.4.An effective and reliable liquid phase microextraction method was designed for the enrichment of PFOA and PFOS in water.A series of extraction conditions were optimized including the extraction time,pH,ionic strength,concentration of CTAB and so on.The samples were experienced HPLC-ELSD detection after the enrichment process.