EVALUATING HYDROGEN ISOTOPIC COMPOSITIONS USING HYDROGEN COLLECTED FROM NICKEL PYROLYSIS

摘要

Recent modifications to a nickel pyrolysis technique have enhanced the efficiency of δ~(18)O analyses on micro-water and organic samples [1]. The hydrogen that diffuses through the nickel lattice during pyrolysis also provides the oppoortunity to evaluate the hydrogen isotopic compositions of these types of samples [2]. To test the reliability of the δ~2H values obtained from the modified nickel pyrolysis technique, hydrogen was collected from waters pyrolysed in nickel bombs, then analysed for δ~2H.Pyrolysis bombs containing graphite (10 mg) were placed in an inert environment [1]. Water samples (10 μL) encompassing a range of isotopic compositions were injected into the bombs, which were then sealed. The bombs were then inserted into a quartz tube, which was subsequently evacuated. The encapsulated bombs were heated (at 1050°C) for different periods of time, during which hydrogen diffusing through the nickel lattice was retained in the quartz tube. Results of the analyses are shown in Fig. 1.