TITFIT, a comprehensive program for numerical treatment of potentiometric data by using analytical derivatives and automatically optimized subroutines with the Newton-Gauss-Marquardt algorithm.

TITFIT, a computer program written in HP-enhanced BASIC is able to fit potentiometric titration curves with up to 400 points by using the Newton-Gauss-Marquardt technique supplemented by the use of analytical derivatives. The program contains a part which writes an optimized subroutine as needed by the model. The program also has additional facilities such as visual interactive adjustment of parameters and a plotting subroutine for graphical presentation of the final results. Data can be entered either manually through the keyboard or automatically through an RS-232 serial interface. The performance of the program is discussed for the well studied Ni(2+) glycine system; the results are similar to those already published in the literature.