Estimation of the role of side reactions in the simulation of complexometric titration

A mathematical model was selected to describe the titration of metal ions with an arbitrary reagent in the presence of masking agents. The model takes into account the stepwise character of the complexation reaction and side reactions of protonation, hydrolysis and masking. The computed titration curves were in good agreement with the data of potentiometric titration. The corresponding program was used to optimize the titration conditions, to select promising titrants (other than complexones), and to predict systematic errors due to the shift of the titration jump in the presence of masking agents. Because of the last-named effect, the results of analysis may be underestimated several times