Chlorofluorocarbons and noble gas measured on water bottle samples during POLARSTERN cruise ANT-XXIV/3

During the cruise a total of 1620 samples on 97 CTD/water bottle stations were collected for chlorofluorocarbons (CFC-11 and CFC-12); 32 stations were occupied along the Greenwich Meridian section, 37 stations along the Weddell Sea section, and 28 stations across the Drake Passage. The water samples from the CTD/rosette system were collected into 100 ml glass ampoules and sealed off after a CFC free headspace of pure nitrogen had been applied. The CFC samples will be analysed in the CFC-laboratory at the IUP in Bremen. The determination of CFC concentration will be accomplished by purge and trap sample pre-treatment followed by gas chromatographic (GC) separation on a capillary column and electron capture detection (ECD). The amount of CFC degassing into the headspace will be accounted for during the measurement procedure in the lab. The system will be calibrated by analyzing several different volumes of a known standard gas. Additionally the blank of the system is analyzed regularly. […]