peaks due to the parent mdecules were left, i e . , until the CHs+ peak from CH4 had been eliminated. The results obtained using this method of analysis on a mixture of CH4 and CDb are given in Table I. Table I1 shows a typical set of results obtained for the analysis of a mixbre containing four of the methanes. The precision with which the values couId be measured has been indicated. TABLE I AYATVSIS OF CH4-CD4 MIYTIJRE Compound
CII, CHU,, c D1
Analysis at l o w electron voltage, +‘ 5