Rapid Scanning Constant Energy Synchronous Fluorescence Spectrometry: A Comparison of Flow Cells

Abstract

Rapid scanning constant energy synchronous fluorescence spectrometry (RSCESFS) is evaluated for flow cell design, scan speed, and constant energy interval choice. Analytical figures of merit for several polycyclic aromatic hydrocarbons (PAHs) are given for several experimental conditions, for several flow cells, and for both RSCESFS and conventional (nonscanning) fluorescence spectrometry. With RSCESFS, absolute detection limits as low as 700 fg, linear dynamic ranges as great as five orders of magnitude and the time to record a complete 350 nm spectrum as short as 17 s have been obtained.

Spectral fingerprinting of polycyclic aromatic hydrocarbons in high-volume ambient air samples by constant energy synchronous luminescence spectroscopy

“…The advantages of CESLS for multicomponent analysis are elimination of Rayleigh and Raman solvent scatter interferences and production of simple, reliable, reproducible spectra. These advantages have been discussed previously (29)(30)(31).…”

“…Aliquots of the PAH solutions were used for standard addition and semiquantitation of the PUF extracts. Sources of the PAHs have been listed previously (31). Figure 2.…”

“…analysis (29)(30)(31). CESLS was chosen as a spectral fingerprinting technique because (1) CESLS scanning reduces spectral complexity and minimizes Raman scatter interferences observed in conventional fluorescence scanning and (2) CESLS gives analytical figures of merit for PAHs comparable with those obtained by fluorescence measurements at excitation and emission wavelength maxima (31).…”

“…During CESLS scanning, a constant energy difference is maintained between the two scanning (excitation and emission) monochromators. The constant energy difference is chosen to equal the prominent vibrational loss during an absorption-fluorescence transition (29)(30)(31). For the analysis of polycyclic aromatic hydrocarbons (PAHs) in the gas-and particulate-phase extracts the constant energy difference was chosen to equal the Stokes shift energy of 200 cm'1, or the energy of the predominant -C=Cvibrational mode of 1400 cm'1.…”

Simple synchronous fluorimetric method for determination of benzo[a]pyrene in airborne particulates without a pre-separation procedure

“…This complication can be overcome by using special techniques such as synchronous spectrometry. Constant-energy synchronous luminescence spectrometry (CESLS) [9,10] , one important embranchment, has been successfully applied to BaP identification in PAHs mixture [11][12][13][14] .…”