thesis

Novel strategies and techniques for performing elemental speciation.

Abstract

This thesis reports on the hyphenation of well known individual techniques into novel combinations which allow the creation of new strategies and techniques for performing speciation analysis. Speciation analysis is a relatively new and exciting area of analytical chemistry which gives the analyst a greater understanding of the impact of elemental species on the environment. The use of microcolumns filled with either acidic alumina or sulphydryl cotton to preconcentrate and separate selenium(IV) and selenium(VI) species is reported. The microcolumns were incorporated into flow analysis systems using inductively coupled plasma-mass spectrometry (ICP-MS) for detection of the selenium-82 isotope. With optimised conditions the limits of detection for selenium(VI) using the alumina microcolumn was 8 ng/l while selenium(IV) was separated from selenium(VI) using the sulphydryl cotton microcolumn and gave a detection limit of 15 ng/l. Preliminary results from the combination of gel electrophoresis with laser ablation ICP-MS are reported. This novel combination of the separation technique of gel electrophoresis with the localised solid analysis of laser ablation, gave us the ability to identify and quantify cobalt-protein complexes. The limit of detection for cobalt in the electrophoretic gel was 8 mug/l. The resolution for mapping a crossed immunoelectrophoretic gel was 1 mm. Preliminary studies into the novel combination of electrothermal vaporisation with time-of-flight mass spectrometry are reported. This system gave the ability to perform multielement elemental analysis on small volumes (10 mul) of sample giving detection limits in the mug/l range. Then by changing the instrumental parameters the instrument performed speciation analysis on different chromium complexes and identified the chromium and copper species in a simple standard mixture

    Similar works