Carbazoles, phenazines and dibenzofuran in petroleum products; methods of isolation, separation and determination

Alkylindoles, -carbazoles and -phenazines were isolated from a petroleum distillate by adsorption on activated aluminum oxide and desorption with methanol. After removal of methanol and dilution with benzene, the concentrate was extracted with 72% perchloric acid to obtain the alkylindoles and alkylcarbazoles as soluble perchlorates. These compound types were then isolated from the acidic layer by addition of water and extraction with benzene. A concentrate of the benzene extract was separated by gas chromatography into alkylindoles and 6 different carbazoles, the latter being characterized by ultraviolet and mass spectrometric techniques. The carbazoles were determined photometrically with 2-bromo-2-nitroindandione-1,3 reagent and by gas chromatography. Phenazine and several alkylphenazines were isolated from the nitrogen compound concentrate as solid perchlorates, liberated by alkali treatment of their perchlorates, and separated by gas chromatography ; ultraviolet and mass spectra were used for their identification. Dibenzofuran was identified in the residual concetrate after the acid extraction. Les auteurs proposent une méthode pour isoler les carbazole phénazine et dibenzofuranne dans un distillat de pétrole. par adsorption sur alumine activée et désorption au moyen de méthanol. Une méthode est également décrite pour leur séparation, leur identification et leur dosage, en utilisant la chromatographie en phase gazeuse, ainsi que les techniques par spectrométrie de masse et dans l'ultra-violet. Die Isolierung, Trennung und Bestimmung von Carbazolen, Phenazinen und Dibenzofuran in p'etroleumprodukten kann durch Adsorption an aktiviertem Aluminiumoxyd und Desorption mit Methanol erfolgen. Zur Trennung und Bestimmung werden Gaschromatographie, Messungen im Ultraviolett und Massenspektrometric angewandt. Phenazine werden als Perchlorate isoliert und mit den erwähnten Methoden getrennt und bestimmt.