Hydrocarbon Oil Index in Water, Soil and Sludge

Ingrid Hayenga

AnalytiX Volume 7 Article 3


Kits and test sets for the chromatographic determination of hydrocarbon content

The special mineral oil standard mixture type A and B, which is used as a stock solution for calibration, is produced gravimetrically from the certified reference material BAM-K010 supplied by the Federal Institute for Materials Research and Testing BAM. The exact content, including the expanded uncertainty and the expiry date, appears on the label. This certified standard solution is supplied in CERTAN® capillary bottles which ensure a perfect seal and guarantee a constant analyte concentration.

For the determination of mineral oil content in various matrixes (water, soil, sludge) three different DIN/EN standards exist. Each one specifies a method for the determination of the hydrocarbon oil index by means of extraction in n-heptane followed by analysis by gas chromatography (GC).

The hydrocarbon oil index is the sum of the concentrations of long-chain and branched aliphatic, alicyclic, aromatic and alkyl-substituted aromatic hydrocarbons present in the sample that are extractable with a hydrocarbon solvent with boiling point above 36 °C, are not adsorbed on Florisil and have GC retention times between n-decane (C10) and n-tetracontane (C40).

We offer two Mineral Oil kits and three Florisil® suitability test sets that contain special dual layer Florisil®/Na2SO4 SPE tubes and all reagents and standards used in the above-mentioned ISO/DIN/EN standards.

The kits allow users to extract and analyze fifteen water samples in duplicate (kit 68172), twenty-two soil samples (kit 56681), twenty solid waste samples or eight liquid waste samples (kit 56681).

The Florisil® suitability test sets were developed for the analysis of ten (set 52462), nineteen (set 07958) or twenty-four Florisil® (set 50397) samples.

Table 1.Test kits and suitability test sets

Florisil® is a registered trademark of the U.S. Silica Company
CERTAN® is a registered trademark of LGC Promochem