The detection and determination of polynuclear aromatic hydrocarbons by luminescence spectrometry utilising the Shpol'skii effect at 77 K

Abstract

The luminescence emission spectra of twenty-three polynuclear aromatic hydrocarbons (PAH) have been examined in n-alkane solvents at 77 K. The Shpol'skii effect, in which narrow-band (quasi-linear) emission spectra are obtained under these conditions when a monochromator of adequate resolving power is used, is shown to be readily observed for twelve of the compounds examined in these solvents. Quasi-linear emission spectra have also been obtained in tetrahydrofuran for some of the PAH compounds examined. These emission spectra provide for unambiguous qualitative identification of PAH compounds a t trace concentrations in solution; this effect is demonstrated by identification of the compounds present in an eight-component mixture of PAH compounds.Measurement of the low-temperature quasi-linear luminescence intensity can be applied quantitatively to the determination of these compounds provided that a standard additions procedure is employed in conjunction with the use of an internal standard to ensure sufficient accuracy and precision.

Fluorescence line narrowing spectrometry of polycyclic aromatic hydrocarbons in organic glasses

“…At Figure 34. The general appearance of both the broad band and sharp line spectra agrees quite well with LESS spectra (37). It seems unlikely that the spectrum in Figure 34 is an impurity.…”

“…Kirkbright and DeLima (37) found it necessary to utilize a combined internal standardstandard additions method to achieve quantitation with a working range of more than two decades in concentration, cf., attributes ii and iii.…”

“…Recent analytical Shpolskii methods attempt to minimize irreproducible exclusion of the analyte and aggregate formation, vide infra, by either employing very rapid cooling rates (37) or by depositing the Shpolskii matrix from the vapor phase (30).…”

Analytical application of laser excited Shpol'skii spectroscopy: direct identification and quantitation of polynuclear aromatic compounds

“…6) The use of mixed solvents (159,182) and solvents such as cyclohexane and tetrahydrofuran (182) to expand the scope of application to a broad range of compounds.…”

“…7) The use of internal reference and standard addition techniques to internally compensate for residuse inner filter and enhancement effects (182,184).…”