In:
Proceedings of the National Academy of Sciences, Proceedings of the National Academy of Sciences, Vol. 94, No. 4 ( 1997-02-18), p. 1049-1053
Abstract:
Intramolecular carbon isotope distributions reflect details of the
origin of organic compounds and may record the status of complex
systems, such as environmental or physiological states. A strategy is reported here for high-precision determination of 13 C/ 12 C ratios at specific positions in
organic compounds separated from complex mixtures. Free radical fragmentation of methyl palmitate, a test compound, is induced by an
open tube furnace. Two series of peaks corresponding to bond breaking from each end of the molecule are analyzed by isotope ratio mass
spectrometry and yield precisions of SD(δ- 13 C) 〈 0.4‰.
Isotope labeling in the carboxyl, terminal, and methyl positions demonstrates the absence of rearrangement during activation and
fragmentation. Negligible isotopic fractionation was observed as degree of fragmentation was adjusted by changing pyrolysis temperature.
[1- 13 C]methyl palmitate with overall δ- 13 C = 4.06‰, yielded values of +457‰ for the
carboxyl position, in agreement with expectations from the dilution, and an average of −27.95‰ for the rest of the molecule,
corresponding to −27.46‰ for the olefin series. These data demonstrate the feasibility of automated high-precision
position-specific analysis of carbon for molecules contained in complex mixtures.
Type of Medium:
Online Resource
ISSN:
0027-8424
,
1091-6490
DOI:
10.1073/pnas.94.4.1049
Language:
English
Publisher:
Proceedings of the National Academy of Sciences
Publication Date:
1997
detail.hit.zdb_id:
209104-5
detail.hit.zdb_id:
1461794-8
SSG:
11
SSG:
12
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