Preservation of atmospheric dimethyl sulphide samples on Tenax in sea-to-air flux measurements

The low concentration of dimethyl sulphide (DMS) in the atmosphere makes it necessary to concentrate the gas before gas-chromatographic analysis. One of the preferred methods has been to use a cold Tenax adsorbent in this concentration step. DMS concentration onto Tenax-TA traps is shown to be sensitive to temperature and to humidity. Implementation of cooling and concentration devices for the measurement of DMS over the air–sea interface is difficult since these measurements are typically made in exposed conditions where temperature control can be problematic. Instead of concentrating DMS in traps, collecting bulk air in Tedlar bags allows storage for at least one week without loss of DMS. This approach allows the concentration and analysis to be postponed until return to the laboratory where analytical conditions can be much better controlled—improving precision and accuracy in DMS measurement needed for gas flux estimation.