Determination of Deute riu m in Wafer and Organic Compounds SIR: Deuterium in water or in organic compounds is usually determined by the method described by Graff and Rittenberg (2) or a modification (1). The sample of water, or water obtained by the combustion of an organic sample. is reduced to hydrogen by the aid of heated zinc. The resulting gaseous hydrogen is subjected to mass spectrcmetric analysis. There are two difficulties with the practical application of the method: The memory effect of the apparatus and the isotope fractionation caused by the partial reduction often interfere with the measurement. The author improved the method by changing the apparatus completely to avoid the memory effect and by adding platinum as catalyst to facilitate the reduction.
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