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Developments in microwave-induced plasma atomic emission spectroscopy for element-specific chromatographic detection
Abstract
The goal of this work has been to extend the usefulness of the microwave-induced plasma (MIP) as a chromatographic detector through the development of improved instrumentation, and to illustrate the power and versatility of this technique through the development of new applications. A concentric dual flow torch (CDFT) designed for the microwave-induced plasma has been evaluated as an atomic emission detector for gas chromatography and capillary supercritical fluid chromatography. This torch configuration results in a spatially stable plasma, no silicon background, a large solvent capacity (0.5-5.0 mg carbon per second) and extended discharge tube lifetimes. Figures of merit for C, Sn, Se, Mn, B, Cl and Si are presented. Results are presented that illustrate the feasibility of using this torch as an atomic emission detector for capillary supercritical fluid chromatography. Applications have been developed using the CDFT and a commercially available AED system. Speciation of organo-tin compounds in sea water at the part per trillion level has been developed. Extracted alkyltin chlorides were converted to their hydrides inside the injection port by injecting through solid sodiumborohydride. The hydrides formed were then gas chromatographed directly followed by atomic emission detection at the 303 nm emission line of tin. Organo-manganese compounds were selectively detected in gasoline samples and reaction mixtures. Non-linear Mn response was found using the commercial AED system used while the CDFT gave linear response over two orders. Phenylmercuric acetate and phenylmercuric chloride were converted to diphenylmercury inside the injection port of a gas chromatograph by injecting the chlorides through solid sodium. tetraphenylborate. PMA was extracted from several paint samples and quantified after on-line conversion to diphenylmercury. Results compare well with atomic absorption data. A GC-AED method for the determination of isothiazolinones in the blood of premature infants has been developed. Sulfur detection at 181 nm provides high sensitivity and selectivity Injection of whole blood results in detection limits of 100 ppb active ingredients.
Subject Area
Analytical chemistry
Recommended Citation
Dowling, Thomas McVey, "Developments in microwave-induced plasma atomic emission spectroscopy for element-specific chromatographic detection" (1991). Doctoral Dissertations Available from Proquest. AAI9207387.
https://scholarworks.umass.edu/dissertations/AAI9207387