Preparation Of New Adsorbent For Solid Phase Extraction And Its Applications In Separation And Enrichment Of Trace Elements

Compared with other elemental dectors, AAS has the characteristics of goodprecision, simple operation and lower cost. However, In the face of complex matrixsamples or analyte of low concentration, it is necessary that some separation andenrichment methods should be involved prior to determination for better sensitivityand selectivity.In recent years, magnetic solid phase extraction (MSPE) technology hasattractted more concern. Compared with tradition solid phase extraction (SPE), MSPEoffers some advantages including its simplicity, shorter extraction time, lowconsumption of organic solvents and ease of automation. And the cost of MSPEprocedure becomes cheaper and more convenient without SPE cartridge and pump.MSPE has been widely applied to the preconcentration of environmental pollutants,drug residues, biological samples and trace metal ions.The combination of AAS and MSPE for the preconcentration of trace elementscould not only reduce the sample matrix interference but also reduce detection limit ofthe analytical method. The aim of this paper is to combine MSPE with AAS detection,and the parameters affecting extraction efficiency were investigated. The adsorptivecapability of magnetic adsorbent was evaluated. And the proposed method wasapplied to the determination of trace elements in real samples. The main contents areas follows:(1) A method for the determination of trace silver in environmental watersamples using polyelectrolyte modified silica gel as solid phase extraction adsorbentand detected by Flame Atomic Absorption Spectrometry (FAAS) was developed. Theeffects of parameters were optimized. And the proposed method was applied to thedetermination of trace silver in tap water, well water and snow water.(2) A new mercapto-modified magnetic material was prepared and used asMSPE adsorbent for the determination of trace mercury in environmental water samples. Several factors affecting extraction efficiency were investigated. A newmethod for the determination of trace mercury by CVAAS after MSPE wasestablished. Analysis performance of the proposed method and the adsorptivecapability of the materials were evaluated. And the proposed method was applied tothe determination of trace mercury in rain water, well water and Wulong gap effluentwater.(3) A new ion imprinted magnetic silica material was prepared by means ofsurface ion imprinting technique and used as MSPE adsorbent for the selectiveextraction of trace silver. A new method for the determination of leaching silver fromantibacterial food packaging materials by FAAS after MSPE was established. Severalfactors affecting extraction efficiency were investigated. The selectivity and analysisperformance of the proposed method were evaluated. And the proposed method wasapplied to the determination of leaching silver from antibacterial food packagingmaterials such as antibacterial water cup, antibacterial lunchbox and plastic wrap.