Ligand-exchange chromatographic separation of polycyclic aromatic hydrocarbons and polycyclic aromatic sulfur heterocycles on a chelating silica gel loaded with palladium (II) or silver (I) cations

1997 ◽  
Vol 359 (7-8) ◽  
pp. 538-541 ◽  
Author(s):  
U. Pyell ◽  
S. Schober ◽  
G. Stork
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Silica Gel ◽  
Aromatic Hydrocarbons ◽  
Chromatographic Separation ◽  
Ligand Exchange ◽  
Polycyclic Aromatic Sulfur Heterocycles ◽  
Polycyclic Aromatic ◽  
Sulfur Heterocycles

Polycyclic Aromatic Hydrocarbons and Polycyclic Aromatic Sulfur Heterocycles: Examination of Molecular Structure-Fluorescence Probe Character Correlations

1990 ◽  
Vol 44 (6) ◽  
pp. 951-957 ◽  
Author(s):  
William E. Acree ◽  
Sheryl A. Tucker ◽  
Lisa E. Cretella ◽  
Anita I. Zvaigzne ◽  
Kenneth W. Street ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Polycyclic Aromatic Hydrocarbons ◽  
Aromatic Hydrocarbons ◽  
Fluorescence Probe ◽  
Polycyclic Aromatic Sulfur Heterocycles ◽  
Polycyclic Aromatic ◽  
Sulfur Heterocycles ◽  
Character Correlations

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.

Ligand exchange reactions between ferrocene and 9,10-dimethylanthracene

1978 ◽  
Vol 56 (13) ◽  
pp. 1782-1787 ◽  
Author(s):  
Ronald G. Sutherland ◽  
W. Jack Pannekoek ◽  
Choi Chuck Lee
Keyword(s):  
Polycyclic Aromatic Hydrocarbons ◽  
Exchange Reaction ◽  
Aromatic Hydrocarbons ◽  
Ligand Exchange ◽  
Ring System ◽  
Exchange Reactions ◽  
Ligand Exchange Reaction ◽  
Polycyclic Aromatic

The reaction of 9,10-dimethylanthracene (8) with ferrocene (FcH) in the presence of AlCl3–Al in decalin gave the stereospecifically hydrogenated product, η6-cis-(endo-9,10-dihydro)-9,10-dimethylanthracene-η5-cyclopentadienyliron cation (10a), the hydrogenation at C-9,10 being cis and endo or on the same side as the cyclopentadienyliron (CpFe) moiety. When cis-9,10-dihydro-9,10-dimethylanthracene, generated from 10a by photolysis or pyrolytic sublimation, was used as the arene in the ligand exchange reaction, complexing with the CpFe group could occur from either side of the ring system, giving rise to a mixture of 10a and the η6-cis-(exo-9,10-dihydro)-9,10-dimethylanthracene-η5-cyclopentadienyliron cation (10b). The η6-cis-9,10-dihydro-9,10-dimethylanthracene-trans-bis-η5-cyclopentadienyliron dication, with the two CpFe groups trans, was also prepared either from a stepwise ligand exchange using 10a or directly from reaction of 8 using an excess of FcH. A mechanism is proposed for the hydrogenation that has been found to accompany ligand exchange reactions between polycyclic arenes and FcH and possible applications are pointed out for the synthesis of partially hydrogenated polycyclic aromatic hydrocarbons.

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
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