Studies of the analyte-carrier interface in flow injection analysis. Project report, June 1, 1987-December 1, 1989.

摘要

The chemical analysis of species in flowing solution has become popular because it provides a low-cost, rapid way to automate many classical methods. Most of the classical methods used to detect the products of the reaction between analytes and reagents in the carrier are not specific enough to permit direct multicomponent analysis of even relatively simple mixtures, however. Two possible routes to enhancing the specificity of the detector are available: (1) enhance the specificity of detection through a competitive reaction of analytes with a species in the carrier, thereby using the dispersion and diffusion properties of flowing systems to effect a distribution of detectable species across the injected bolus, or (2) use a rapidly scanned detector in concert with mathematical methods for enhancing spectral selectivity. The first method is a competitive kinetic analysis carried out in a flowing medium, with a dispersion-controlled mixing of reactants. The second is a direct multicomponent analysis, applied to a transient sample. The two approaches share some common features, since kinetic and dispersion effects complicate the multicomponent analysis, and because rapid spectral measurement is necessary to map the distribution of reactants and products which is required to evaluate the kinetics of a dispersion-controlled, competitive chemical reaction. The project has as goals the study of rapid multicomponent analysis of transient species in flowing media, the investigation of chemical reactions at interfaces, and the investigation of the effects of competition on the distribution products from an interfacial reaction. Work required to meet these goals includes development of new methods for rapid multicomponent analysis, and the examination of newer methods of detection for interfacial and transient species.