scholarly journals Absorption and Laser Induced Fluorescence Spectroscopy of Neutral Polycyclic Aromatic Hydrocarbons in Argon matrices

2015 ◽  
Vol 11 (A29A) ◽  
Author(s):  
Salma Bejaoui ◽  
Farid Salama ◽  
Ella Sciamma-O'Brien
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Fluorescence Spectra ◽  
Laser Induced Fluorescence ◽  
Broad Emission Band ◽  
Band Emission ◽  
Polycyclic Aromatic ◽  
Argon Matrices ◽  
Extended Red Emission ◽  
Solid Argon

Polycyclic aromatic hydrocarbons (PAHs) are considered as plausible carriers for the extended red emission (ERE), a photoluminescent process associated with a wide variety of interstellar environments, as well as for broad emission band features seen in cometary spectra. We report the absorption spectra of phenanthrene, anthracene, fluoranthene, pentacene, pyrene, chrysene and triphenylene isolated at 10 K in solid argon matrices together with laser induced fluorescence (LIF) spectra at 355 nm of matrix-isolated anthracene and fluoranthene. LIF spectra are compared with the UV/blue fluorescence spectra of the Red Rectangle Nebula (RR). The LIF spectra measured in solid Ar matrices have been shifted to the predicted position of the PAH band emission in the gas phase for comparison with the astronomical observations (Fig. 1).

Site-Selection Fluorescence Spectrometry of Polycyclic Aromatic Hydrocarbons in Vapor-Deposited Argon Matrices

1988 ◽  
Vol 42 (6) ◽  
pp. 1079-1083 ◽  
Author(s):  
Brian F. Macdonald ◽  
John L. Hammons ◽  
Randy R. Gore ◽  
Jon R. Maple ◽  
E. L. Wehry
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Site Selection ◽  
Fluorescence Spectra ◽  
Laser Excitation ◽  
Broad Band ◽  
Excitation Wavelength ◽  
Fluorometric Detection ◽  
Polycyclic Aromatic ◽  
Argon Matrices

The use of tunable laser excitation to effect significant sharpening in the inhomogeneously-broadened fluorescence spectra of polycyclic aromatic hydrocarbons (PAHs) isolated in argon matrices at 15 K is reported. The broad-band-excited fluorescence spectra of most PAHs in solid argon exhibit complex multiplet structures assumed due to the location of individual PAH molecules in different types of discrete “sites” in the polycrystalline matrix. Under laser excitation, the fluorescence spectra of PAHs are strongly dependent on excitation wavelength. For most PAHs, there exists an “optimum” excitation wavelength, at which a “single-site” fluorescence spectrum comprising one intense feature having a bandwidth of SO cm−1 or less is obtained. The excitation and emission wavelengths for site-selection fluorescence of eleven PAHs matrix isolated in argon are tabulated, and the trade-offs implicit in choice of optimum excitation wavelengths for site-selection fluorometric detection of PAHs in multicomponent samples are addressed. Quantitative results for five constituents of a sixteen-component standard reference material exhibit excellent agreement with certified values.

POLYCYCLIC AROMATIC HYDROCARBONS IN OYSTERS (CRASSOSTREA VIRGINICA) FROM GEORGIA COASTAL WATERS, ANALYZED BY HIGH-PRESSURE LIQUID CHROMATOGRAPHY

1981 ◽  
Vol 1981 (1) ◽  
pp. 341-345 ◽  
Author(s):  
Richard F. Lee ◽  
Dorothy Lehsau ◽  
Michael Madden ◽  
William Marsh
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Liquid Chromatography ◽  
Aromatic Hydrocarbons ◽  
Coastal Waters ◽  
Fluorescence Spectra ◽  
Reverse Phase ◽  
Reverse Phase Liquid Chromatography ◽  
Polycyclic Aromatic ◽  
Phase Liquid ◽  
Kings Bay

ABSTRACT A number of polycyclic aromatic hydrocarbons (PAH) were detected in oysters from sites in coastal Georgia with analysis by reverse-phase liquid chromatography with fluorescence detection. Compounds were identified by collection of peaks and comparison of excitation and emission fluorescence spectra with authentic standards. Major PAH in the oysters from the ports of Savannah and Brunswick included methylfluorene, anthracene, 2,3-benzofluorene, methylpyrene, 2,3-benzanthracene, benzo(b) fluoranthene, benzo(k)fluoranthene, and benzo(a)pyrene. Concentrations of most PAH were low in oysters from Skidaway River, which is part of the intracoastal waterway, and Kings Bay submarine base. The concentration of benzo(a)pyrene, a well known carcinogen, was 0.5 micrograms per kilogram in Brunswick and Savannah but was not detected (less than 0.01 micrograms per kilogram) in Skidaway River and Kings Bay.

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