Integrated conductimetric detection:: mass distribution in a dynamic sample zone inside a flow injection manifold

The insights provided by integrated detection (conductimetric) as a novel approach to follow physical dispersion in continuous-flow manifolds are presented. This approach replaces the conventional instantaneous detection and permits to follow the dispersion phenomena, including details of the radial component as the sample plug travels the manifold. Integrated detection permits to look at the radial dispersion in a detailed manner inaccessible to instantaneous detection. The effect of different experimental parameters affecting mass distribution was studied (e.g., flow rate, tube length and diameter, injected sample volume, and reactor type) and their effects on integrated response curves are discussed. A single channel manifold employing aqueous nitric acid as the conducting carrier, and water injected as sample plug, and playing the role of an insulator, provided the physicochemical model for the reported studies. (C) 1999 Elsevier Science B.V. All rights reserved.