Study on the implementation of flow titrations in sequential injection analysis

Abstract

Several variables that affect flow spectrophotometric titrations in sequential injection analysis (SIA) systems were studied by using titration of a strong acid with a strong base as a model; blue bromothymol was used as an indicator and distilled water was used as a carrier. Both possibilities of performing titrations on SIA systems according to the aspiration sequences (a) titrant B/sample/titrant A and (b) titrant/sample are considered. In case (a) the possibilities regarding the use of different volumes and/or different concentrations of titrant reagents were studied and are discussed. The established methodology allows hydrochloric acid determinations with 0.1 M sodium hydroxide within the range 32–1000 mM by means of logarithmic calibration curves. The analysis rate is of 5 min/sample. © 1999 John Wiley & Sons, Inc. Lab Robotics and Automation 11: 207–216, 1999