DIN Standards Committee Water Practice
DIN EN ISO 15009
Soil quality - Gas chromatographic determination of the content of volatile aromatic hydrocarbons, naphthalene and volatile halogenated hydrocarbons - Purge-and-trap method with thermal desorption (ISO 15009:2012); German version EN ISO 15009:2013
Bodenbeschaffenheit - Gaschromatographische Bestimmung des Anteils an flüchtigen aromatischen Kohlenwasserstoffen, Naphthalin und flüchtigen Halogenkohlenwasserstoffen - Purge-und-Trap-Anreicherung mit thermischer Desorption (ISO 15009:2012); Deutsche Fassung EN ISO 15009:2013
Overview
This International Standard specifies a method for quantitative gas-chromatographic determination of volatile aromatic hydrocarbons, naphthalene and volatile halogenated hydrocarbons in soil. This International Standard is applicable to all types of soil. (In the case of unsaturated peaty soils, absorption of the extraction solution can occur.) Test samples are taken from an untreated field moist soil sample. To prevent losses of the volatiles, samples are taken as undisturbed as possible in the field with a tube corer or by adding methanol immediately in the field. The test sample is extracted with methanol. After centrifugation, if necessary, part of the methanol extract is brought into a purge vessel filled with water. The volatile compounds are purged with nitrogen or helium and adsorbed on a suitable adsorbing agent. The adsorbed compounds are desorbed thermally and by means of a carrier gas flow, whether or not via a cold trap, brought into a gas chromatograph. The various compounds are separated by using a capillary column with an immobile phase of low polarity. Volatile organic compounds are detected with appropriate detectors such as: mass spectrometric detector (MS), flame ionization detector (FID), electron capture detector (ECD), photo ionization detector (PID) or electrolytic conductivity detector (ELCD). Identification and quantification takes place by comparison of retention times and peak heights (or peak areas) towards internal standard added with the corresponding variables of an external standard solution. The efficiency of the procedure depends on the composition of the soil that is investigated. The described procedure does not take into account incomplete extraction caused by structure and composition of the soil sample. When using non-specific detectors such as FID and ECD, the confirmation of the identity of the detected compounds and their concentrations should be done by repeating the gas chromatographic analysis using a column of different polarity. When using gas chromatography-mass spectrometry (GC-MS), the identity confirmation and the quantification can be done in a single run. The lower limit of quantification is dependent on the equipment used and the quality of the methanol grade used for the extraction of the soil sample. Under the conditions specified in this International Standard the following limits of quantification apply (expressed on basis of dry matter): a) Typical limit of quantification when using GC-FID: for volatile aromatic hydrocarbons: 0,1 mg/kg b) Typical limit of quantification when using GC-ECD: for volatile halogenated hydrocarbons: 0,01 mg/kg Lower limits of quantification for some compounds can be achieved by using mass spectrometry (MS) with selected ion detection. The committee responsible for this standard is NA 119-01-02-02 UA "Chemische und physikalische Verfahren" ("Chemical and physical processes") of NA 119-01-02 AA "Abfall- und Bodenuntersuchung" ("Examination of waste and soil") at the Water Practice Standards Committee (NAW) at DIN.
