USE OF NICKEL-TUBE PYROLYSIS FOR HYDROGEN-ISOTOPE ANALYSIS OF WATER AND OTHER COMPOUNDS

Addition of a simple evacuated collection device to nickel-tube pyroly sis bombs permits collection of the hydrogen gas produced during decom position of water and other substances containing hydrogen. Tests usin g water samples spanning a broad range of H-2/H-1 ratios show that the method can be readily calibrated to yield precision comparable to tha t of the widely used zinc-reduction method. Preliminary results from p yrolysis of polyethylene foil, insect chitin, wood cellulose, peptide, and biotite mica (bound water) suggest that this modification of the nickel pyrolysis technique may have broad application, especially wher e both oxygen- and hydrogen-isotope compositions of the material are o f interest. (C) 1997 Elsevier Science B.V.