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SPECIATION OF ORGANOMETALLIC COMPOUNDS USING MASS SPECTROMETRIC DETECTION

by McKiernan, John William

Abstract (Summary)
Presented in this work are speciation techniques which have been developed for a cupric azo dye, arsenic extracted from fish, and copper and chromium compounds. The organometallic dye Direct Red 83 was subjected to speciation using HPLC coupled with inductively couple plasma mass spectrometry to determine the percentage of copper which is not bound to the dye. This "free copper" made up 13% of the total copper present in the sample. An automated extractor employing accelerated solvent extraction (ASE) has been compared with a traditional sonication method of extraction, for the extraction of arsenicals from fish tissue. Extracted arsenicals were speciated with chromatographic separation and ICP-MS. Both extraction methods produced extraction efficiencies of greater than 71% with RSDs on replicates of less than 5.5%. The chromatographic separation employed a PRP-X100 anion exchange column. The speciation data indicates that the predominate species were arsenobetaine and arsenocholine. Optimization of the automated extraction method indicated that the parameters which had the greatest influence on the recovery of arsenic were sample particle size, dispersion of the sample, and extraction time. Grinding of the sample with a mortar and pestle in a high density glass bead dispersion media produced extraction efficiencies of 88%, 92%, 98%, and 103% for whitefish, shark, tuna, and salmon respectively. Separation methods revealed that in all of the extracts, arsenobetaine (AsB) represented greater than 79% of the arsenic concentration present. Electrospray mass spectrometry (ESMS) has been used to provide both elemental and structural information for chromium (II) acetate, chromium (III) acetylacetonate, and copper (II) acetylacetonate. The electrospray interface, constructed in house, provides control over the ionization conditions, applied potentials and gas curtain flow rates. This enables the operator to tune the conditions to produce elemental spectra, or spectra which contain fragments of the original parent ion. The complex spectra which are found in the fragment studies can be interpreted by calculation of the expected isotope distribution.
Bibliographical Information:

Advisor:

School:University of Cincinnati

School Location:USA - Ohio

Source Type:Master's Thesis

Keywords:elemental speciation organometallic inorganic electrospray arsonic

ISBN:

Date of Publication:01/01/2000

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