Assessing the transfer of pentachlorophenol through soil columns using 13[C]isotope

The transfer of organic pollutants was studied through soil columns using 13[C]-labelled pentachlorophenol (PCP) as a model compound. The organic carbon content and the 13[C]/12[C] ratio were measured in two soil sections, 0–3 cm and 3–6 cm, and in percolated water using an Elemental Analyser coupled with a Magnetic Mass Sector. The mass balance of carbon was evaluated and the amount of PCP was calculated in each compartment of the soil–water systems. The results show that more than 80% of the PCP-derived 13[C] remained in the upper layer of the soil column. Approximately 20% was transferred to the lower soil layer, and less than 1% was found in the water leachates. The 13[C]-labelled tracers may thus be used as an alternative to radioactive compounds to follow the fate of organic pollutants in soil and water under field conditions.