Sequential injection analysis for electrochemical measurements and process analysis

Abstract

Sequential injection analysis (SIA) is a computer-controlled single-line system that allows most analyses, including multi-reagent types, to be performed with ease. Single standard calibration is possible. This relatively new technique is more suitable for process analyses than conventional flow injection analysis because of its greater simplicity, and it is well suited for laboratory studies of electrodes. Representative example applications of SIA are reviewed for analyses of varying complexity. Electrochemical applications include coulometric titration with automated dilution and potentiometric studies. The matched potential method for assessing relative potentiometric selectivities is reviewed for its unique applicability under analytical conditions; injection techniques provide for rapid assessment. Incorporation of the jet ring cell in a sequential injection manifold provides a powerful means for developing renewable reaction surfaces and sensors. An example of a renewable trace metal colorimetric sensor is presented, based on dithizone adsorbed on renewable C₁₈ particles.