MONITORING EVAPORATION OF POLYCHLORINATED-BIPHENYLS (PCB) IN LONG-TERM DEGRADATION EXPERIMENTS

The physical loss of polychlorinated biphenyls (PCB) due to evaporation causes frequently false positive results in biodegradation experiments often lasting weeks or months. Therefore, determination of the PCB concentration in both liquid and gaseous phases is unavoidable for a correct appraisal of the biodegradation results. For this purpose the original proposal by Fava et al. (1991) has been modified with the aim to select a proper sorbent: (1) minimum amount of which would be needed for complete sorption of evaporated PCB, in order to provide for appropriate aeration of the liquid medium; (2) from which sorbed PCB could be eluted by n-hexane, in order to use the eluate directly for gas-chromatographic analysis.