Automation of a system for titrimetric measurements. Catalytic thermometric titrations of organic bases

Abstract

A versatile microcomputer-controlled system, TITRO 2, was developed that is suitable for carrying out titrations and recording and processing of titration curves, not only those of sigmoidal type but also segmented, which is not the case with commercial titration systems. The system supports all types of titrations with both volumetric and coulometric addition of the titrant, in addition to the application of a wide range of indication techniques. It also permits subsequent treatment of the obtained titration curves by software smoothing of either the whole curve or its segments, and the determination of the end-point of the smoothed curve. Special attention was paid to the choice of the optimum procedure for the software signal smoothing, and of the end-point determination with segmented titration curves. The software package, written in Turbo Pascal 6.0, allows the export of data to other software packages for statistical treatment. The developed system is very flexible and suitable for use even in modestly equipped research laboratories. It suffices to have a Radiometer ABU 80 burette, a PC (minimum configuration AT 286) and a low-cost interface. The system was tested on examples of the determination of strong, weak and very weak organic bases by catalytic titrations, using acetylation as the indicator reaction. The results obtained were in good agreement with those obtained by the conventional procedure. The system was also employed for some kinetic measurements.