The Effect of Oxygen on the Fluorescence Quenching of Polycyclic Aromatic Hydrocarbons in Two- Component Mixtures of CCl4 with Cyclohexane, Benzene and Acetonitrile

1991 ◽  
Vol 46 (8) ◽  
pp. 707-709 ◽  
Author(s):  
Andrzej Chojnowski ◽  
Wieslaw M. Wiczk ◽  
Tadeusz Latowski

AbstractFluorescence quenching of anthracene and perylene has been studied in deoxygenated and nondeoxygenated two-component mixtures of CCl4 with cyclohexane, benzene and acetonitrile. It was indicate that the dissolved oxygen only reduces the fluorescence lifetimes of the hydrocarbons, thus suppressing the efficiency of quenching

1987 ◽  
Vol 42 (11) ◽  
pp. 1290-1295 ◽  
Author(s):  
Wiesław M. Wiczk ◽  
Tadeusz Latowski

Fluorescence quenching of aromatic hydrocarbons in a large concentration range of the quencher has been studied in a variety of two-component mixtures of tetrachloromethane with other solvents. In aliphatic solvents the process could be described by the Stern-Volmer equation, whereas in the remaining mixtures the fluorescence quenching curves showed a parabolic behaviour which has been explained in terms of specific interactions between the components of the mixtures.


1986 ◽  
Vol 41 (5) ◽  
pp. 761-766 ◽  
Author(s):  
Wiesław M. Wiczk ◽  
Tadeusz Latowski

Fluorescence quenching of anthracene has been studied in two-component mixtures of CCl4 with cyclohexane, benzene, p-xylene and mesitylene. Non-typical quenching curves have been found in mixtures containing benzene and its derivatives.


1975 ◽  
Vol 30 (10) ◽  
pp. 1311-1314 ◽  
Author(s):  
H. Dreeskamp ◽  
E. Koch ◽  
M. Zander

Abstract Fluorescence quenching of 22 polycyclic aromatic hydrocarbons by nitromethane in toluene and acetonitrile solutions has been studied. Contrary to Sawicki’s observations that the fluorescence of hydrocarbons with the fluoranthene skeleton is not quenched that of 11.12-and 3.4-benzofluor-anthene and fluoranthene itself is quenched. These compounds have a high energy of the fluorescence transition. The fluorescence quenching of the compounds investigated follows a dynamic quenching mechanism. The bimolecular rate constant of fluorescence quenching increases exponentially with the energy of the fluorescing state of alternant hydrocarbons.


1991 ◽  
Vol 23 (1-3) ◽  
pp. 427-436 ◽  
Author(s):  
Y. Shimizu ◽  
H. M. Liljestrand

A fluorescence quenching method was used to determine the sorption of polycyclic aromatic hydrocarbons (PAHs) onto natural solids in batch experiments. This method is based upon the observation that PAHs fluoresce in aqueous solution but not when associated with natural solids. It avoids problems of incomplete solid-liquid separation. As natural solids, eleven different USEPA soils and sediments were used. Anthracene and 2-aminoanthracene, which are respectively non-ionic and ionic PAHs, were chosen as sorbates. The fractional decrease in fluorescence intensity as a function of added natural solid concentration is referred to as Stem-Volmer plots. The plots were linear for all natural solids investigated. The conditional sorption coefficients (Ksc) at pH 6 through 8 and I=0.1 M were obtained as the slopes of the plots. While the Ksc values of anthracene were independent of pH, the values of 2-aminoanthracene decreased with increasing pH. The Ksc values of anthracene correlated well with the organic carbon content of natural solids. However, the values of 2-aminoanthracene did not depend on the content of organic carbon in natural solids. For 2-aminoanthracene, inorganic matrices of the natural solids may contribute to the sorption.


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