ISO 16558-1:2015 specifies a method for the quantitative determination of the total extractable volatile, the volatile aliphatic, and aromatic fractions of petroleum hydrocarbon content in field moist soil samples by gas chromatography with mass spectrometric detection. The aromatic fractions are determined by the sum of individual aromatic compounds.
The sum of the volatile aliphatic (C5 to C10) and aromatic (C6 to C10) fractions can be referred to as "volatile oil".
The results of the test carried out can be used for risk assessment studies related to contaminations with petroleum hydrocarbons.
ISO 16558-1:2015 provides a method applicable to petroleum hydrocarbon contents from about 5 mg/kg soil expressed as dry matter for the whole aliphatic fraction C5 to C10 and about 5 mg/kg soil expressed as dry matter for the aromatic fraction in the boiling range of C6 to C10.
With this method, all hydrocarbons with a boiling range of 36 °C to 184 °C, n-alkanes between C5H12 to C10H22, isoalkanes, cycloalkanes, BTEX, and di- and tri-alkyl benzenes compounds are determined as total volatile petroleum hydrocarbons C5 to C10. In addition, volatile aliphatic and aromatic fractions are specified.
For the determination of semi-volatile aliphatic and aromatic fractions of petroleum hydrocarbons in soil samples, see ISO/TS 16558-2.
NOTE The sub-fractions proposed in this part of ISO 16558 have shown to be suitable for risk assessment studies. However, other sub-fractions between C5H12 to C10H22 can be determined in conformity with this part of ISO 16558.
On the basis of the peak pattern of the gas chromatogram and of the boiling points of the individual n-alkanes listed in Annex A, the approximate boiling range of the mineral oil and some qualitative information on the composition of the contamination can be achieved.