Polar bonded-phase sorbents for high performance liquid chromatographic separations of polycyclic aromatic hydrocarbons

Automated liquid chromatographic compound class group-type separation of crude oils and bitumens using chemically bonded silica-NH2

“…A large number of sorbent evaluations for the chemical class separation of the neutral fraction obtained from liquid fossil fuels have been reported (7)(8)(9)(10)(11)(12)(13)(14). Most of these evaluations have involved detailed studies of molecular structure and substituent effects on the retention characteristics of aromatic hydrocarbons.…”

“…Most of these evaluations have involved detailed studies of molecular structure and substituent effects on the retention characteristics of aromatic hydrocarbons. Although chemically bonded silica-NH2 (8)(9)(10), silica-R(NH2)2 (7-10), (2,4-dinitroanilinopropyl)silica (silica-DNAP) (7,11), and alumina (12)(13)(14)(15) have been shown to be superior for aromatic ring-number separations, the direct separation of total crude oils or related materials is not possible on these substrates. Preliminary sample preparation is required to prevent irreversible adsorption and/or precipitation of the polar components onto the sorbents.…”

“…Although the schemes for the separations are quite varied, they typically involve separations of oils according to functionality (i.e., acids, bases, and neutrals) followed by chemical group-type (compound-class) fractionation (j-6). High-performance liquid chromatographic (HPLC) chemical group-type separation of the neutral fraction in petroleums and related materials has received considerable attention (7)(8)(9)(10)(11)(12)(13)(14)(15). Most of this attention has been focused on detailed studies of molecular structure and substituent effects on the retention characteristics of aromatic hydrocarbons on various sorbents.…”

“…Most of this attention has been focused on detailed studies of molecular structure and substituent effects on the retention characteristics of aromatic hydrocarbons on various sorbents. Of the sorbents studied, chemically bonded silica-NH2 (8)(9)(10), silica-R(NH2)2 (7)(8)(9)(10), (2,4-dinitroanilinopropyl)silica (silica-DNAP) (7,11), and alumina (12)(13)(14)(15) have been considered superior for aromatic ring-number separations in that molecular structure and substituent effects which perturb class separations are minimized. Although these studies have provided important data, publications on the application of these sorbents and others to the rapid, automated, routine separations of total crude oils have been few.…”

Novel extraction of tar sands by sonication with the aid of in-situ surfactants

“…; Sadeghi, K. M.; Kuo, J. F.; Jang, L.-K.; Yen, T. F. U.S. Patent 4,765,885, August 23, 1988. (7) Sadeghi, M.-A. ; Sadeghi, K. M.; Kuo, J. F.; Jang, L.-K.; Yen, T. F. U.S. Patent 4,891,131, January 2, 1990.…”