The limit of detection depends on the determinants, the equipment used, the quality of chemicals used for the extraction of the sample, and the clean-up of the extract. Typically, a lower limit of application of 0,01 mg/kg (expressed as dry matter) can be ensured for each individual PAH.
Sludge, soil, and treated biowaste can differ in properties and also in the expected contamination levels of PAH and presence of interfering substances. These differences make it impossible to describe one general procedure. ISO 13859:2014 contains decision tables based on the properties of the sample and the extraction and clean-up procedure to be used. Two general lines are followed, an agitation procedure (shaking) or use of Soxhlet/pressurized liquid extraction.