2ND-ORDER GLOBALIZATION FOR THE DETERMINATION OF ACTIVATION PARAMETERS IN KINETICS

First order global analysis consists of linking common parameters acro ss series of measurements, e.g., reaction kinetics measured at differe nt wavelengths where the rate constants are the same for all kinetic t races at individual wavelengths. This approach is taken a step further in second order globalisation. A series of measurements is linked tog ether by a new superimposed model which encompasses the individual mea surements. The mathematics for the non-linear least-squares fit of the global parameters is presented. Two modes are possible depending on w hether the linear parameters (absorption spectra) are constant or chan ging across the series. Factor analysis is incorporated for multivaria te measurements. The procedures are exemplified with applications of a ctivation analysis in chemical kinetics. Global analysis of complete t emperature and pressure dependences results directly in the activation parameters of interest, i.e., activation enthalpies, entropies and vo lumes. Due to a significant decrease in the number of parameters to be fitted, the robustness is considerably improved.