Chapter 2 Flow injection techniques

Abstract

Publisher Summary This chapter discusses flow injection (FI) techniques. The success of FI lies in its ability to obtain reproducible transient signals because of reproducible injection volume and speed of injection, as well as reproducible dispersion of the sample into the carrier stream and adequate reproducible mixing with reagents, without significant carryover between samples. FI features versatility, speed of response and miniaturization, which allows virtually any reaction or separation to be carried out on-line and on a micro-scale, with an analytical response available within typically 5–30 s of sample injection. FI has been selected as an alternative to continuous nebulization with ICP-MS and other atomic spectrometric detectors. Dispersion can be increased or decreased, by modifying the FI manifold to satisfy a particular application. Dispersion can be increased or decreased, by modifying the FI manifold to satisfy a particular application. For this reason, dispersion coefficient, D, is typically used to classify FI systems into four general categories. In addition to dispersion, another important parameter is the residence time, T, of the sample in the FI system, since it determines the extent of a chemical reaction.