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Gas chromatography—stable isotope ratio analysis at natural abundance levels
Author(s) -
Barrie A.,
Bricout J.,
Koziet J.
Publication year - 1984
Publication title -
biomedical mass spectrometry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.475
H-Index - 121
eISSN - 1096-9888
pISSN - 0306-042X
DOI - 10.1002/bms.1200111106
Subject(s) - chemistry , isotope , mass spectrometry , natural abundance , gas chromatography , tracer , isotope ratio mass spectrometry , analytical chemistry (journal) , abundance (ecology) , chromatography , combustion , stable isotope ratio , isotope analysis , capillary gas chromatography , accuracy and precision , sensitivity (control systems) , nuclear physics , ecology , physics , statistics , mathematics , organic chemistry , electronic engineering , fishery , engineering , biology
In recent years stable isotopes have begun to replace radioisotopes as tracers in metabolic studies. However, these are relatively expensive in the enrichments and quantities required by either conventional gas chromatography/mass spectrometry (GC/MS) or stable isotope ratio analysis (SIRA), the former having good sensitivity but low precision and the latter low sensitivity with more than adequate precision. We describe here a technique for 13 C which achieves an appropriate balance between precision and sensitivity for such studies. A combustion interface is placed between the output from a capillary gas chromatograph and a dual collector SIRA mass spectrometer. Compounds eluting from the gas chromatograph are converted into discrete pulses of CO 2 gas and intensities of 13 CO 2 and 12 CO 2 are measured simultaneously. Typically, 13 C relative abundances can be obtained from 0.8 nmol of a C 10 compound (8 nmol CO 2 ) with a precision (1SD) of better than 1‰ (0.0011 at.% 13 C). This permits a reduction by at least a factor of 10 in the quantity of tracer required compared with conventional methods.