POTENTIOMETRIC NONLINEAR MULTIVARIATE CALIBRATION WITH GENETIC ALGORITHM AND SIMPLEX OPTIMIZATION

In this contribution, a genetic algorithm (GA) and a modified Simplex technique are investigated as a means of developing nonlinear multivar iate calibration models for an array of ion-selective electrodes. The responses of an array of ammonium-, sodium-, potassium-, and calcium-s elective electrodes employed in a now injection analysis system were m odeled over the concentration range of 1 x 10(-4) to 1 x 10(-2) M usin g the GA and simplex techniques to optimize the cell potentials, slope s, and selectivity coefficient parameters of the Nikolskii-Eisenman eq uation for each electrode, Correlations between activities predicted f rom the calibration model and the actual activities of the solutions p resented to the array ranged from 0.98 to 0.88 for the four ions.