IMPROVEMENT OF SELECTIVITY OF FLAME ATOMIC-ABSORPTION SPECTROMETRY USING FOURIER-TRANSFORMS

Two solutions of the same analyte are propelled towards the nebulizer of the flame spectrometer by two peristaltic pumps running at differen t turning speeds. This produces periodical fluctuations in spectromete r readings,which can be translated to a frequency spectrum by means of Fourier transform. This transformation makes it possible to discrimin ate between the signals from each of the solutions being pumped. Two d ifferent strategies are studied, with the absorbance fluctuations bein g caused by the periodic movement of the rollers or by running the pum ps at periodic turning speeds. The latter approach proved to be the mo st versatile. The system could be extended to the case of several solu tions of the same analyte being simultaneously supplied to the nebuliz er by means of several propelling devices.