Improvement of selectivity of flame atomic absorption spectrometry using Fourier transforms

Abstract

Two solutions of the same analyte are propelled towards the nebulizer of the flame spectrometer by two peristaltic pumps running at different turning speeds. This produces periodical fluctuations in spectrometer readings, which can be translated to a frequency spectrum by means of Fourier transform. This transformation makes it possible to discriminate between the signals from each of the solutions being pumped. Two different strategies are studied, with the absorbance fluctuations being caused by the periodic movement of the rollers or by running the pumps at periodic turning speeds. The latter approach proved to be the most versatile. The system could be extended to the case of several solutions of the same analyte being simultaneously supplied to the nebulizer by means of several propelling devices.