UNAMBIGUOUS CHARACTERIZATION OF A SINGLE TEST SAMPLE BY FLUORESCENCE SPECTROSCOPY AND SOLVENT-EXTRACTION WITHOUT USE OF STANDARDS

We show that a test sample containing several components can be analyz ed unambiguously by a two-dimensional spectroscopic technique, such as fluorescence, if it can be split into two aliquots of unequal compone nt concentrations. Standard spectra are not needed, nor is it necessar y to make assumptions about regions without spectral overlap or about spectral shapes. The requirements are that the spectral response is li near and that the two-dimensional contribution from each component can be factorized into a product of its one-dimensional responses: I(lamb da(1),lambda(2)) = Sigma(i=1)(r)c(i)I(i)(lambda(1))I-i(lambda(2)). In fluorescence spectroscopy this is the normal situation for noninteract ing species. The approach is illustrated on a test sample containing t hree components, which is split into aliquots by solvent extraction. E ven though the components' spectral responses overlap extensively, all spectral features were correctly reproduced in the analysis.