Study On Determination Of Trace Elements And Elemental Speciation Analysis After Capillary Microextraction

The preliminary separation and preconcentration step are often required prior to elemental analysis in order to overcome the lower concentration of the metal ions and several matrix interferences in real samples. There are a lot of separation and preconcentration techniques, of which capillary microextraction (CME) has become increasingly popular in recent years because it has several major advantages: (1) the fast, simple and direct sample application in very small size without any sample loss; (2) higher preconcentration factor; (3)the use of a minimal amount of toxic organic solvent; (4)lower contamination risk than the traditional procedures; (5) easy automation; (6) low instrumental and running costs. It has been applied widely to separation and preconcentration of metal elements.The aim of this dissertation is to develop the new capillary microextraction adsorents and to evaluate its properties for trace element analysis. Based on these studies, the new techniques of capillary microextraction coupled with electrothermal atomic absorption spectrometry (ETAAS) or capillary electrophoresis (CE) to the separation and preconcentration metal ions. The major contents are described as the following:(1) A simple and sensitive method for the separation of Cr (III) in natural water was developed. The novel method was targeted on extraction of Cr (III) by using a nanometre-scale zirconium phosphate coated capillary tube, and determined by electrothermal atomic absorption spectrometry (ETAAS).(2) A new method of MPTMS coated capillary microextraction (CME) coupling with CE for the determination of trace amounts of MeHg, PhHg and Hg in water sample. The parameters influencing the CME and electrophoresis speciation analysis of three mercury speciation were investigated in detail. The developed method was successfully applied to analysis of MeHg in biological sample.