scholarly journals Experimental evidence of incomplete fluorescence quenching of pyrene bound to humic substances: implications for Koc measurements

2016 ◽  
Vol 15 (7) ◽  
pp. 889-895 ◽  
Author(s):  
E. A. Shirshin ◽  
G. S. Budylin ◽  
N. Yu. Grechischeva ◽  
V. V. Fadeev ◽  
I. V. Perminova
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Fluorescence Quenching ◽  
Experimental Evidence ◽  
Humic Substances ◽  
Aromatic Hydrocarbons ◽  
Partition Coefficients ◽  
Quantitative Assessment ◽  
Organic Materials ◽  
Polycyclic Aromatic

Fluorescence quenching (FQ) is extensively used for quantitative assessment of partition coefficients (KOC) of polycyclic aromatic hydrocarbons (PAHs) to natural organic materials – humic substances (HS).

scholarly journals Dimers of polycyclic aromatic hydrocarbons: the missing pieces in the soot formation process

2019 ◽  
Vol 21 (16) ◽  
pp. 8282-8294 ◽  
Author(s):  
X. Mercier ◽  
O. Carrivain ◽  
C. Irimiea ◽  
A. Faccinetto ◽  
E. Therssen
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Experimental Evidence ◽  
Aromatic Hydrocarbons ◽  
Diffusion Flame ◽  
Formation Process ◽  
Soot Formation ◽  
Laminar Diffusion Flame ◽  
Laminar Diffusion ◽  
Polycyclic Aromatic

Experimental evidence supporting the existence of PAH dimers in the proximity of the soot nucleation region of a methane laminar diffusion flame.

Partitioning of unsubstituted Polycyclic Aromatic Hydrocarbons between surface sediments and the water column in the Brisbane River Estuary

1990 ◽  
Vol 41 (4) ◽  
pp. 443 ◽  
Author(s):  
SI Kayal ◽  
DW Connell
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Water Column ◽  
Aromatic Hydrocarbons ◽  
Partition Coefficients ◽  
Laboratory Experiments ◽  
River Estuary ◽  
Chemical Properties ◽  
Linear Relationships ◽  
Physico Chemical ◽  
Polycyclic Aromatic

In all, 23 sediment samples and 8 water column samples from the Brisbane River estuary, Queensland, Australia, were analysed for polycyclic aromatic hydrocarbons (PAHs) in order to assess the field partitioning behaviour of these hydrocarbons. Twelve PAHs, ranging in molecular weight from naphthalene to benzo[a]pyrene, were identified and quantified. Their partition coefficients, indexed to sediment organic carbon and lipid content, were calculated after filtering to remove particulates and making a calculated adjustment for colloids, or organic matter, in the water phase. In logarithmic form, the partition coefficients were related to the physico-chemical properties of the compounds (Kow, Sw, RRT) by relationships having a parabolic shape rather than being linear. However, compounds with log Kow values of less than 5.5 gave linear relationships comparable to, but distinctly different from, those obtained from laboratory experiments. It is suggested that field conditions have distinctive differences from laboratory experiments that do not allow the direct translation of laboratory-based relationships to the natural aquatic environment.

On the Fluorescence Quenching of Polycyclic Aromatic Hydrocarbons by Nitromethane

1975 ◽  
Vol 30 (10) ◽  
pp. 1311-1314 ◽  
Author(s):  
H. Dreeskamp ◽  
E. Koch ◽  
M. Zander
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Fluorescence Quenching ◽  
Rate Constant ◽  
Aromatic Hydrocarbons ◽  
High Energy ◽  
Dynamic Quenching ◽  
Quenching Mechanism ◽  
Polycyclic Aromatic ◽  
Acetonitrile Solutions ◽  
Alternant Hydrocarbons

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.

scholarly journals Estimation of n-octanol/water partition coefficients of polycyclic aromatic hydrocarbons by quantum chemical descriptors

2008 ◽  
Vol 6 (2) ◽  
pp. 310-318 ◽  
Author(s):  
Gui-Ning Lu ◽  
Xue-Qin Tao ◽  
Zhi Dang ◽  
Xiao-Yun Yi ◽  
Chen Yang
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Quantum Chemical ◽  
Partition Coefficients ◽  
Density Functional ◽  
Optimal Model ◽  
Quantum Chemical Descriptors ◽  
Polycyclic Aromatic ◽  
Pls Analysis ◽  
Chemical Descriptors

AbstractQuantitative structure-property relationship (QSPR) modeling is a powerful approach for predicting environmental behavior of organic pollutants with their structure descriptors. This study reports an optimal QSPR model for estimating logarithmic n-octanol/water partition coefficients (log K OW) of polycyclic aromatic hydrocarbons (PAHs). Quantum chemical descriptors computed with density functional theory at B3LYP/6-31G(d) level and partial least squares (PLS) analysis with optimizing procedure were used for generating QSPR models for log K OW of PAHs. The squared correlation coefficient (R 2) of the optimal model was 0.990, and the results of crossvalidation test (Q 2cum=0.976) showed this optimal model had high fitting precision and good predictability. The log K OW values predicted by the optimal model are very close to those observed. The PLS analysis indicated that PAHs with larger electronic spatial extent and lower total energy values tend to be more hydrophobic and lipophilic.

Sign in / Sign up

Export Citation Format

Share Document