Atypische Gel-Chromatographie im System Sephadex—Isopropanol

Determination of oxygenated polycyclic aromatic hydrocarbons in airborne particulate matter by capillary gas chromatography and gas chromatography/mass spectrometry

“…Therefore, a further separation step with the chromatographic system Sephadex LH-20/2-propanol was necessary. This system not only facilitates the separation of aliphatic from aromatic compounds but elutes the aromatic substances in an order of increasing ring number (27,28). The solvent of the moderately polar fraction obtained in the first separation step was closely reduced to dryness by rotary evaporation.…”

Multimode separation of polycyclic aromatic compounds by size exclusion chromatography with poly(divinylbenzene)

“…Since increased electron density was implicated as a causative factor in the nonsize retention of planar PAC, an attempt was made to correlate their elution volumes with molecular parameters that reflect electron density. These parameters included the following: energies of highest occupied molecular orbitals, polarographic reduction potentials, UV band energies, and several reactivity indicators (38); resonance energy (15,23); total number of electrons (13); number of bonding electrons (9, 13); ionization potential (13); and number of -bonding carbon atoms (9).…”

“…Also, a pronounced nonsize effect often observed with pericondensed PAC has proved useful for the characterization of petroleum crudes (20,21). Furthermore, with the Sephadex gels, chromatographic conditions have often been altered to exaggerate a specific nonsize effect such as adsorption or hydrogen bonding to obtain a desired separation (22)(23)(24).…”

Handbook of Air Pollution Analysis

“…The utilization of the diffusion battery for the determination of the chemical composition of size-differentiated aerosols has become attractive in recent years, in consequence of the realization that an important fraction of atmospheric sulphates, nitrates [183] and lead [184] may exist as particles smaller than 0.3 flm, where cascade impactors are inefficient.…”

“…More recent clean-up procedures have involved the use of alumina column chromatography followed by gel permeation chromatography with Sephadex LH-20 [184] which has the advantage of increased sample capacity, improved separation from interfaces and reproducibility.…”