Methodische Aspekte zur Datierung von Grundwasser mittels FCKW F11, F12 und F113

With the aim to reliably using anthropogenic chlorofluorocarbons in tracing groundwater transport we have studied the dynamical and geochemical behaviour of the two main CFC species CFC-12 (CCl 2 F 2 ) and CFC-11 (CCl 3 F) in the main natural systems of interest. Basic data for the atmosphere, the unsaturated soil zone, groundwater and surface water have been collected. The CFC's are being measured routinely with a home-made gas chromatograph in the range between 8 pmol/l for water (solution equilibrium with the atmosphere) and down to 1/800 of this. So far, about ten thousand measurements have been made, one tenth of these are on water samples.