Silica-based Packings For Solid Phase Extraction And Their Applications In Pharmaceutical,Food And Environmental Analysis

Because of the complex nature of the sample matrix and the presence of the isomers and degradation products, it is often difficult and challenging to analyse target compounds without sample pre-treatment. Solid phase extraction (SPE) is a novel technology for sample pre-treatment which is simple and convenient, using less organic solvent and easy to automate, therefore it has been widely used in pharmaceutics, food, environmetal and chemistry fields.In this paper, we developed several silica-based SPE packing materials and investigated their applications in pharmaceutical, food, and environmental analysis. The SPE packings with m-aminophenzene boronic acid (m-APBA), strong anion extraction (SAX) and thio-groups were prepared and used to extract and purify the target molecules from complex martrix. Specifically, the m-APBA packing was applied to extract five catecholamine drugs (dopamine, dobutamine, norepinephrine, isoprenalin and epinephrine) from serum for futher biopharamcuitical analysis and the extraction method were optimized to obtain the most suitable the adsorptive and elute conditions, respectively. In the extraction process, the pH plays an important role in adsorption of catecholamines on m-APBA SPE. With a pH 7.8 phosphate buffer solution, the adsorption rates for all five drugs are over 90%. At pH 1.0, adjusting the concentration of sorbitol and NaCl, the recovery of all five drugs can reach the maximal. The thermodynamic and kinetics of adsorption of epinephrine on this packing were investigated, this method was adopted to extract the five drugs from serum sample, the maximal recoveries of spiked epinephrine, dopamine and dobutamine are over 80%; norepinephrine and isoprenalin are over 70%. In food safty field, multi-mode anion extraction (MAX)/SAX SPE cartridges were used to extract three organic arsenics from feed additive, which are roxarsone (ROX), arsanilic acid (ASA) and nitrophenylarsonic acid (NPAA). The methods for sample preparation of organic arsenics from feed and enrichment of them by SPE were established under the guaidance of the United State Environmetal Protection Agency (US EPA) law. It's testified that impurities can be decreased after SPE process using 50% methanol-50% H2O as the extraction solvent,The recoveries of ROX, NPAA and ASA are all higher than 80%. In environmental fields, the thio-group modified packing was applied to collection of heavy methals such as Cu2+ and Pd2+ from solution for futher quantification and determination analysis.SPE technology has been proved to be a promising method for sample preparation and purification since its invention. Nowadays, SPE will be an automate and minim method. It can combine with HPLC-MS, GC-MS and CE-MS, so it can extract target materials easily, fast and sensitively.