Bulletin of the Korean Chemical Society

  • 제18권6호
  • /
  • Pages.573-578
  • /
  • 1997
  • /
  • 0253-2964(pISSN)
  • /
  • 1229-5949(eISSN)
대한화학회 (Korean Chemical Society)
권호 표지
DOI QR코드

DOI QR Code

Characterization of Ion Fragmentations of Fatty Acids

  • 발행 : 1997.06.20
PDF 다운로드
⟨ 이전 논문 다음 논문 ⟩

초록

Ion fragmentations of fatty acids such as stearic acid, palmitic acid, myristic acid, and lauric acid were studied using mass spectrometry and semiempirical calculations. The mass spectra of fatty acids showed the distributions of CH₃(CH₂)$_n^+$ and $[(CH_2)_nCO_2H]^+$ fragment ions. The relative ion abundance distributions of $[(CH_2)_nCO_2H]^+$ showed the local maxima at n=6, 10, and 14. The local maximum phenomena were also found in the mass spectra of methyl stearate but not in those of normal alcohols. These local maxima could be explained not by heats of reaction for fragmentation but by the cyclic structures of the molecular ions. The AM1 semiempirical calculations for fatty acids clearly show that the linear structures are more favorable than the cyclic ones for neutral molecules while the cyclic structures are more favorable than the linear ones for ionic molecules. The distances between carboxyl group and methylene of the cylic structures of ionized fatty acids were calculated. The methylene carbons with n=6, 10, and 14 were closer to the carboxyl group than adjacent ones.

키워드

참고문헌

  1. J. Am. Chem. Soc. v.99 Lossing, F. P.
  2. Int. J. Mass Spectrom. Ion Phys. v.25 Botter R.
  3. Org. Mass Spectrom. v.27 Liou, C.-C.;Eichmann, E. S.;Brodbelt, J. S.
  4. Org. Mass Spectrom. v.26 Ahmed, M. S.;Hudson, C. E.;Giam, C. S.;McAdoo, D. J.
  5. Anal. Chem. v.54 Keough, T.
  6. Org. Mass Spectrom. v.23 Wysocki, V. H.;Bier, M. E.;Cooks, R. G.
  7. preparation Choi, S.-S.;So, H.-Y.
  8. Mass Spectrom. Rev. v.7 Bouchoux, G.
  9. J. Chromatogr. v.388 Goto, J.;Watanabe, K.;Miura, H.;Nambara, T.;Iida, T.
  10. Biochemical Applications of Mass Spectrometry Oldham, G.;Stenhagen, E.;G. R. Waller(ed.)
  11. J. Phys. Chem. Ref. Data v.13 Lias, S. G.;Liebman, J. F.;Levin, R. D.
  12. J. Am. Chem. Soc. v.107 Dewar, M. J. S.;Zoebisch, E. F.;Henly, E. F.;Stewart, J. J.
  13. J. Am. Soc. Mass Spectrom. v.4 Eichmann, E. S.;Brodbelt, J. S.
  14. J. Am. Soc. Mass Spectrom. v.4 Eichmann, E. S.;Brodbelt, J. S.
  15. Org. Mass Spectrom. v.18 Burgers, P. C.;Holmes, J. L.;Lossing, F. P.;Povel, F. R.;Terlouw, J. K.