Photophysics of polycyclic aromatic hydrocarbons adsorbed on silica gel surfaces. 1. Fluorescence lifetime distribution analysis: an ill-conditioned problem

1993 ◽  
Vol 97 (22) ◽  
pp. 5980-5986 ◽  
Author(s):  
Yuan S. Liu ◽  
William R. Ware
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Silica Gel ◽  
Fluorescence Lifetime ◽  
Aromatic Hydrocarbons ◽  
Lifetime Distribution ◽  
Distribution Analysis ◽  
Fluorescence Lifetime Distribution ◽  
Polycyclic Aromatic

Photophysics of polycyclic aromatic hydrocarbons adsorbed on silica gel surfaces. 2. Lifetime distribution and symmetry

1993 ◽  
Vol 97 (22) ◽  
pp. 5987-5994 ◽  
Author(s):  
Yuan S. Liu ◽  
Paul de Mayo ◽  
William R. Ware
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Silica Gel ◽  
Aromatic Hydrocarbons ◽  
Lifetime Distribution ◽  
Polycyclic Aromatic

Liquid Chromatographic Determination of Polycyclic Aromatic Hydrocarbons in Fish and Shellfish

1985 ◽  
Vol 68 (5) ◽  
pp. 945-949
Author(s):  
Keigo Takatsuki ◽  
Shigeru Suzuki ◽  
Nobutoshi Sato ◽  
Isamu Ushizawa
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Silica Gel ◽  
Aromatic Hydrocarbons ◽  
Ethyl Ether ◽  
Analytical Method ◽  
Alkaline Digestion ◽  
Polycyclic Aromatic ◽  
Liquid Chromatographic ◽  
Fish And Shellfish

Abstract A simple and accurate analytical method for determination of polycyclic aromatic hydrocarbons (PAHs) in fish and shellfish is presented, which is considered to be useful for routine analyses and for screening purposes. The procedure involves alkaline digestion, extraction with n-hexane, silica gel column chromatography, and liquid chromatographic (LC) determination with fluorometric detection. During development of the analytical method for determination of PAHs, it was found that benzo[a]pyrene, a representative PAH, was decomposed easily by the analytical procedure, and this tendency was investigated for the experimental conditions used. Benzo[a]pyrene was decomposed by the coexistence of alkaline conditions, light, and oxygen; by peroxides in aged ethyl ether; and by oxygen when adsorbed on silica gel. Thus, to obtain good recoveries and precise analytical results, these decomposition conditions must be avoided. The following precautions are recommended: protection from light through all analytical steps; addition of Na2S to alkaline digestion mixture as an antioxidant; complete removal of peroxides from ethyl ether just before use; quick column chromatography on silica gel; and prevention of air from contact with adsorbent. When this simple method was applied to fish and shellfish samples, very good recoveries of PAHs from fortified fish samples were obtained, and no serious interferences were observed in fish and shellfish extracts

Concentration and Estimation of 14 Polycyclic Aromatic Hydrocarbons at Low Levels in High-Protein Foods, Oils, and Fats

1972 ◽  
Vol 55 (3) ◽  
pp. 631-635
Author(s):  
Gernot Grimmer ◽  
Armin Hildebrandt
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Aluminum Oxide ◽  
Silica Gel ◽  
Aromatic Hydrocarbons ◽  
Fats And Oils ◽  
Effective Concentration ◽  
Group I ◽  
Polycyclic Aromatic ◽  
Low Levels ◽  
Aluminum Oxide Column

Abstract Fourteen polycyclic hydrocarbons in (I) meat, poultry, fish, and yeast, and (II) fats and oils have been isolated and determined. To separate group I homogeneously, 2N methanolic KOH is used. In the first step of concentration (methanol-water-cyclohexane partition (4 + 1 + 5)), a 200 g sample is reduced to 0.2 g of polycyclic fraction without any emulsions. The same effective concentration is found for group II without a saponification step by partition in N,N-dimethylformamide-water-cyelohexane (9 + 1 + 10). Further very effective concentration (100:1) of polycyclics results from filtration on Sephadex LH 20 (solvent:sopropanol). After further cleanup by filtration on silica gel (Woelm, 15% water), phenanthrene, anthracene, pyrene, fluoranthene, chrysene, benzo(a)anthracene, benzo(a)pyrene, benzo-(e)pyrene, benzo(k)fluoranthene, perylene, anthanthrene, benzo(g,h,i)perylene, dibenz(a,h)-anthracene, and coronene are separated on an aluminum oxide column (Woelm, 5.4% water) or equivalent. Recoveries ranged from 75 to 92% for all polycyclics down to the 2 ppb level.

Depth-Dependent Heterogeneity in Membranes by Fluorescence Lifetime Distribution Analysis

2012 ◽  
Vol 3 (18) ◽  
pp. 2676-2681 ◽  
Author(s):  
Sourav Haldar ◽  
Mamata Kombrabail ◽  
G. Krishnamoorthy ◽  
Amitabha Chattopadhyay
Keyword(s):  
Fluorescence Lifetime ◽  
Lifetime Distribution ◽  
Distribution Analysis ◽  
Fluorescence Lifetime Distribution

scholarly journals IDENTIFICATION OF SOME CARCINOGENIC POLYCYCLIC AROMATIC HYDROCARBONS IN BANGLADESHI VEHICLES EXHAUST TAR BY GAS CHROMATOGRAPHY-MASS SPECTROPHOTOMETER

2010 ◽  
Vol 8 (3) ◽  
pp. 353-355 ◽  
Author(s):  
M. Amzad Hossain ◽  
S. M. Salehuddin
Keyword(s):  
Gas Chromatography ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Glass Fiber ◽  
Silica Gel ◽  
Aromatic Hydrocarbons ◽  
Solvent Mixture ◽  
Sodium Sulphate ◽  
Glass Fiber Filter ◽  
Polycyclic Aromatic

A more sensitive GC-MS method has been established for the determination of some carcinogenic polycyclic aromatic hydrocarbons (PAHs) in vehicles exhaust tar samples. The tar samples were extracted using dichloromethane (DMC): n-hexane solvent mixture. A multi-layer clean-up (silica gel/sodium sulphate) column was used, followed by glass fiber filter (GFF) paper. The method was successfully applied to determine a number of PAHs present in exhaust tar sample of different vehicles of the Atomic Energy Centre, Dhaka, Bangladesh.   Keywords: Carcinogenic polycyclic aromatic hydrocarbons, vehicles tar samples, identification, GC-MS/MS

A Short Method of Testing Petroleum Waxes for the Presence of Polycyclic Aromatic Hydrocarbons

1963 ◽  
Vol 46 (4) ◽  
pp. 725-731 ◽  
Author(s):  
William Lijinsky ◽  
Irving Domsky ◽  
Chitta R Raha
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Silica Gel ◽  
Aromatic Hydrocarbons ◽  
Maximum Absorbance ◽  
Polycyclic Aromatic ◽  
Short Method

Abstract A method for determining the possible presence of carcinogenic polycyclic aromatic hydrocarbons in petroleum waxes is based o n the maximum absorbance within four wavelength ranges of an extract prepared by chromatography. The procedure involves chromatography on silica gel and partition of the adsorbate between cyclohexane and nitromethane, followed, if necessary, by a second chromatography on silica gel impregnated with nitromethane.

Effects of adsorbed water and hydrocarbon reactivity on the nitration of polycyclic aromatic hydrocarbons adsorbed on silica gel and Fe2O3 particles with NO2

2020 ◽  
Vol 236 ◽  
pp. 117641
Author(s):  
Kiyoshi Hasegawa ◽  
Takuya Takanami ◽  
Tomoko Kawai ◽  
Shigehiro Kagaya
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Silica Gel ◽  
Aromatic Hydrocarbons ◽  
Adsorbed Water ◽  
Polycyclic Aromatic
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