scholarly journals Study of Photoionization of Solids—Resonance Ionization

1985 ◽  
Vol 5 (5) ◽  
pp. 297-307 ◽  
Author(s):  
F. Verdun ◽  
J. F. Muller ◽  
G. Krier

Multiphoton ionization (MPI) mechanism in the solid state being still controversial we coupled a tunable laser to the LAMMA 500 microprobe to reinvestigate, using different UV irradiations, the ionization of some organic and organometallic solid compounds. Two polycyclic aromatic hydrocarbons (PAH) anthracene and pyrene and metallic derivatives of copper and cadmium were tested. Preliminary results are consistent with thermal desorption of neutral molecules as the first step followed by photoionization in the vapor phase.Thus the ionization mechanisms described for gases or vapors, and in particular some REMPI or RIS processes appear to apply to our experimental conditions.

1973 ◽  
Vol 26 (1) ◽  
pp. 221 ◽  
Author(s):  
JL Garnett ◽  
KJ Nicol ◽  
A Rainis

Experimental conditions are reported for resolving the hyperfine splitting of e.p.r. spectra obtained from the interaction of polycyclic aromatic hydrocarbons with platinum oxide. By contrast with earlier interpretations where only a singlet was obtained even with perylene, the present results indicate that the adsorbed species are radical cations.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Yuxiang Ma ◽  
Longkai Shi ◽  
Yulan Liu ◽  
Qiyu Lu

The influence of technological operations during oil refining process on polycyclic aromatic hydrocarbons (PAHs) in neutralized, bleached, and deodorized oils was investigated on the basis of laboratory-scale study. Under the best experimental conditions, benzo[a]pyrene decreased by 85.1%, 99.7%, and 40.8% in neutralized, bleached, and deodorized oils, respectively. Total of 16 analytes decreased by 55.7%, 87.5%, and 47.7%, respectively. Bleaching with activated charcoal was the most efficient procedure to reduce PAHs in crude oil. Neutralization had a modest influence on sixteen analytes; however, deodorization was only responsible for a slight decrease in the light PAHs and heavy PAHs contents. Data obtained in this study suggest that the use of activated carbon during oil refining process is highly recommended; moreover, these results provide a useful guidance for oil refining plant to reduce security risk and ensure the quality of the vegetable oil products.


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