CALIBRATION IN QUANTITATIVE TLC BASED ON WEIGHTED REGRESSION FUNCTIONS

Abstract

Two methods, one on the basis of relative error in y_i (in that case w_i should be taken as 1/y_i ²) (YWLS) and another on the basis of 1/x_i ² as a weighting factor (XWLS), for the calculation of calibration function are reported and compared with conventional ordinary (OLS) and simple weighted least squares method (WLS). By these procedures the calibration functions for the TLC determination of some triazine herbicides are represented more strongly than by the ordinary least squares method mainly in the cases of heteroscedasticity. Instead of the coefficient of correlation, six coefficients of quality are used to characterize the quality of the calibration functions.

Acknowledgments