A deuterium-labeling study on the reproduction of hydronium ions in the PTR-MS detection of ethanol

作者：Inomata Satoshi^*; Tanimoto Hiroshi

来源：International Journal of Mass Spectrometry, 2009, 285(1-2): 95-99.

DOI：10.1016/j.ijms.2009.05.001

• PTR-MS
• H(3)O( ) ethanol reaction
• Ethanol
• Deuterium-labeling study
• Alcohol

The reactions of hydronium ions (H(3)O( )) with ethanol (C(2)H(5)OH) and deuterium-labeled ethanols (CD(3)CH(2)OH and CH(3)CD(2)OH) were investigated by means of proton transfer reaction mass spectrometry (PTR-MS). Besides the protonation reaction of H(3)O( ) with C(2)H(5)OH, three fragmentation processes yielding C(2)H(5)( ), CH(2)OH( ), and H(3)O( ) ions were previously implied. In this paper, we report the branching ratios for those four channels at six different field strengths (E/N ratios) of the drift tube. The contribution of the channel that reproduces hydronium ions (H(3)O( )) was determined by detecting H(2)DO( ) ions at m/z 20 produced in reactions of H(3)O( ) with deuterium-labeled ethanols (CD(3)CH(2)OH and CH(3)CD(2)OH). The reproduction of H(3)O( ) ions was found to be significant between 108 and 162Td of the E/N ratio, however, it did not quantitatively account for the low detection sensitivity of ethanol by PTR-MS, suggesting the presence of unidentified reaction channel(s). The unidentified reaction channel(s) might be the H(3)O( )-reproducing channel itself, because the contribution from this channel would be underestimated in this experiment due to loss process(es) such as an H/D exchange between H(2)DO( ) and H(2)O.

• 出版日期2009-8-1