EVALUATION OF EQUILIBRIUM-CONSTANTS FROM POTENTIOMETRIC Z-PH NORMALIZED CURVES USING THE PARTIAL LEAST-SQUARES (PLS) SELF-CALIBRATION METHOD

The Partial Least Squares (PLS) multivariate calibration method accomp anied by the so-called ''self-calibration'' approach enables to evalua te equilibrium data and obtain stability or equilibrium constants. The idea of the PLS self-calibration technique is similar to the so-calle d ''normalized graphs'' method. The calibration matrix is calculated f rom proposed initial parameters applying a method of experimental desi gn. The method is validated on examples of simulated and experimental data and it was proved that it converges quite well. The proposed meth od represents a new approach towards the equilibrium data evaluation. Even though it is demonstrated on examples of potentiometric data, the proposed PLS self-calibration method can be used to evaluate any kind of chemical equilibrium data. A comparison with the ''classical'' app roaches that are used in most of the minimizing programs has been done .