The characterization of a custom-built coulometric Karl Fischer titration apparatus

The instrumentation found in laboratories today is unaffordable for many secondary schools and universities. Although most analytical chemistry curricula at the undergraduate level teach students the principles behind modern instruments, few courses are able to incorporate them into a laboratory setting, thus preventing many science and engineering students from attaining valuable work experience with the equipment they may one day use. This dilemma led our research group to focus on developing inexpensive small-scale instruments. One such device we have produced is a Karl Fischer coulometric titrator. Karl Fischer (KF) titration is a widely used analytical technique for the quantification of water in various substances including laboratory solvents, transformer oils, pharmaceuticals, cosmetics, and food products. This method of titration is carried out within a bipotentiometric cell, where the water content of a sample is quantified based on the number of electrons transferred during titration. Our aim was to develop a low-cost, custom-built KF titration apparatus that facilitates the practical application of KF analysis within standard undergraduate general and analytical chemistry laboratory courses.