Total hydrocarbons were determined by infrared spectrophotometry
following UNE 77307, polycyclic aromatic hydrocarbons (PAHs)
by gas chromatography (ISO 18287), polychlorinated biphenyls
(PCBs) and organochlorine insecticides by gas chromatography (ISO
10382) and phenols by gas chromatography (EPA Method 8401, Soil
Quality).