Mb. Smirnov et Eb. Frolov, A complete analysis of a crude oil C-2-carbazole fraction by H-1 NMR spectroscopy, ORG GEOCHEM, 29(5-7), 1998, pp. 1091-1099
A new approach for a complete analysis of petroleum C-2 carbazoles has been
developed. C-2 carbazole subfraction isolated from crude oil using liquid
chromatography on silica gel and preparative reverse-phase HPLC, was invest
igated by proton nuclear magnetic resonance spectroscopy and gas chromatogr
aphy. As an example, the analysis of C-2 carbazoles from the Van-Yagansk oi
l (Upper Jurassic, West Siberia province) is reported. The isolated subfrac
tion included all C-2 carbazoles and also a part of some of the least retai
nable C-3 carbazoles. Dimethylcarbazoles have been determined in the C-2 su
bfraction as the predominant type of isomers. Ethyl-, i-propyl-. methylethy
l- and n-propylcarbazoles were determined in low abundances. Distribution o
f 1-, 2- and 3- (jointly), 4-ethylcarbazoles was determined. All the dimeth
ylcarbazoles were determined in the oil, with the content of 4,5-dimethylca
rbazole being negligible. (C) 1998 Elsevier Science Ltd. All rights reserve
d.