Volume 45, Number 1 (January - February 2000)

Key words:  thallium, atomization mechanism, atomic absorption, cubic spline, data processing

Different approaches for data treatment, the orthogonal polynomial  regression and cubic spline function used in the calculation of kinetic parameters in GFAAS, were compared. The determination of activation energy and release order was based on the method proposed in our laboratory. The experimental data for thallium, obtained from probe atomization were utilized in the comparison. The results show that the use of polynomial  regression tends to yield larger values of kinetic order and activation energy as compared to that of cubic spline function, and the kinetic orders determined are less temperature dependent, while the values of the order in the latter case decrease with the increase of temperature. The orders and activation energies for thalium obtained in this experiment are 0.33 ± 0.02 and 83 ± 2 kJ mol^-1, 0.38 ± 0.07 and 88 ± 5 kJ mol^-1 and 0.17 ± 0.04 and 68 ± 4 kJ mol^-1 for 6th-order polynomial, 9th-order polynomial and cubic spline function, respectively.