Calibration of titration methods

Summary A calibration method is proposed which makes it possible to use titration techniques in the presence of systematic errors, even if these errors depend on the concentrations of the analytes. The approach uses an empirical calibration model which approximates the relationship between apparent (found) and true concentrations of the analytes. Also a calibration of the physical model of the titration process is proposed, as well as a method of determination of the model parameters, which are useful when analytes are determined by fitting the model to experimental data of titration. Both approaches, empirical and based on the physical model, may be applied jointly. The example presented reveals high efficiency of the proposed approach in cases when a deficient physicochemical model of the titration process is used in the determination of an analyte concentration (simulated titration data applied). The calibration proposed may be considered as a generalization of the titrant standardization used in the conventional volumetric analysis. It may be applied to all titration techniques and for all methods of end-point detection and determination of the concentration of analytes. It opens new possibilities for the development of titration methods.Permanent address: Department of Analytical Chemistry, Jagiellonian University, Karasia 3, PL-30-060 Krakow, Poland