Five- and Six-Component Determinations Using Phase-Resolved Fluorescence Spectroscopy and Synchronous Excitation

Abstract

Multicomponent determinations using phase-resolved fluorescence spectroscopy and synchronous excitation to combine the dimensions of fluorescence lifetime and emission and excitation wavelength are described for five- and six-component systems of spectrally overlapping polycyclic aromatic hydrocarbons. Experimental conditions such as the wavelength intervals scanned, the difference maintained between the emission and excitation monochromators, and the wavelengths and detector phase angles used to generate the data matrices were all generalized rather than optimized for the particular components used in the study. Accuracy was better for the PRFS determinations than for steady-state synchronous excitation determinations using the same number of equations in the data matrix. An average relative error of 0.34% was found for the PRFS determinations of the five-component system, compared with −1.5% obtained for the steady-state determinations, with the use of twenty-four equations. An average relative error of 3.8% was obtained for the PRFS determinations of the six-component system, also with the use of twenty-four equations. The selectivity derived from the fluorescence lifetime dimension in PRFS is therefore shown to be important in multicomponent determinations using generalized conditions for data acquisition and should prove valuable for samples that require both qualitative and quantitative analysis.