Automatic calibration for on-line process monitoring in continuous-flow systems

Abstract

An automatic procedure for calibration in continuous-flow systems is proposed. A flow gradient unit in the sample channel, controlled via a switching valve, delivers a concentration gradient of the standard so that the standard concentration varies with time after the flow-rate gradient is started. Thus, the signal (absorbance) – concentration relationship can be determined and checked for (recalibration) asfrequently as required. The procedure was applied to a simulated continuous monitoring of hydrazine in waters, as well as to specific water samples that were spiked with hydrazine at different concentrations. © 1995, Taylor & Francis Ltd.