EN ISO 16703 pdf download Soil quality — Determination of content of hydrocarbon in the range C to C by gas chromatography
3Terms and definitions
For the purposes of this document, the following terms and definitions apply.
(by gas chromatography) sum of compounds extractable with acetone/n-heptane (2+1) that do not adsorb ona Florisil1) column and can be chromatographed on a non-polar capillary column with retention times betweenthose of n-decane (C1oH22) and n-tetracontane (C4oH82).
NOTE Substances that comply with this definition are mainly long-chain or branched aliphatic，alicyclic,lowerpolycyclic- or alkyl-substituted aromatic hydrocarbons.
Non-polar and weakly polar compounds (e.g. halogenated hydrocarbons) and high contents of polarcompounds may interfere with the determination.
A known amount of the homogenized soil sample is extracted by mechanical shaking or sonication withacetone/n-heptane. The organic layer is separated and washed twice with water. Polar compounds areremoved by adsorption on Florisil. An aliquot of the purified extract is analysed by capillary gaschromatography with flame ionization detection.The total peak area in the range delimited by the standardsn-decane and n-tetracontane is measured,and the amount of hydrocarbons in the sample is quantifiedagainst an external standard consisting of equal amounts of two different types of mineral oil.
Instead of heptane,another non-polar solvent (e.g. petroleum ether, cyclohexane, n-hexane) may be used,however its suitability for the extraction of hydrocarbons from soil shall be proven.
NOTE lf lower detection limits are required, petroleum ether can be used as extraction solvent in combination withlarge-volume injection or concentration of the final extract.
ln general, all reagents shall be reagent grade and suitable for their specific purposes.6.1Acetone,(CH3)zco.
6.3 Florisil1) for preparation of clean-up column, particle size 150 um to 250 um (60 mesh to 100 mesh).heated for at least 16 h at 140 °C and stored in a desiccator over a molecular sieve.
NOTE Commercially available cartidges containing 2 g of Florisil and 2 g of sodium sulfate are also applicable.6.4Anhydrous sodium sulfate(Na,So4), heated for at least 2 h at 550 °℃.