High-performance liquid chromatography fractionation using a silver-modified column followed by two-dimensional comprehensive gas chromatography for detailed group-type characterization of oils and oil pollutions.
Successful remediation of oil-contaminated soils relies on a sound preceding characterization of the oil chemical composition and physicochemical properties. Comprehensive two-dimensional gas chromatography with flame ionization detection (GCxGC/FID) is known to be very suitable for the analysis of complex samples such as petroleum hydrocarbons. However, in spite of the high-separation power offered by GCxGC, it fails to completely separate certain hydrocarbon groups in petroleum hydrocarbon mixtures. This hampers a detailed chemical composition assessment which can lead to wrong conclusions on the behaviour of the oil in soil systems, e.g. biological degradability and water solubility. This paper describes a high-performance liquid chromatography (HPLC) system with a silver-modified column as a prefractionation step to GCxGC to improve chemical identification. With HPLC, the petroleum hydrocarbons were baseline separated into a saturated fraction (including alkanes and cycloalkanes) and an unsaturated fraction (including alkenes, aromatic hydrocarbons and heterocyclic components). Each fraction eluted in a small time window limiting the dilution caused by HPLC. The two fractions were collected and quantitatively analyzed with GCxGC/FID. Cold splitless injection of 4 microl was adopted to compensate the dilution caused by the prefractionation step. With oil-spiked soil samples, a good reproducibility was obtained (RSD=3.5%; n=7) and the recovery was satisfactory (87.7%).
Mao
Debin
D
Flemish Institute for Technological Research (VITO), Boeretang 200, Mol, Belgium.
Van De Weghe
Hendrik
H
Diels
Ludo
L
De Brucker
Nicole
N
Lookman
Richard
R
Vanermen
Guido
G
D002849:Chromatography, Gas / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006838:Hydrocarbons / Q000032:analysis* / Q000302:isolation & purification; D010578:Petroleum / Q000032:analysis*; D012989:Soil Pollutants / Q000032:analysis* / Q000302:isolation & purification
D006838:Hydrocarbons; D010578:Petroleum; D012989:Soil Pollutants