Influence of the method of calculation of noise thresholds on wavelength selection in window factor analysis of diode array high-performance liquid chromatography

Abstract

By using a double window and previously described resolvability indices, it is possible to determine which wavelengths in the diode array HPLC of mixtures are most useful for the purpose of resolving chromatograms of mixtures using window factor analysis. It is shown here that the determination of optimum wavelengths depends on the noise threshold. Three approaches to the determination of this threshold are compared. Using a small window more accurately pinpoints the best wavelengths but, because the eigenvalues of small matrices are not representative of a larger population, results in diagnostic wavelengths being missed. The method is illustrated by application to the HPLC of chlorophyll degradation mixtures.