ISSN:
0306-042X
Keywords:
Chemistry
;
Analytical Chemistry and Spectroscopy
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
Notes:
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 13C 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 CO2 gas and intensities of 13CO2 and 12CO2 are measured simultaneously. Typically, 13C relative abundances can be obtained from 0.8 nmol of a C10 compound (8 nmol CO2) with a precision (1SD) of better than 1‰ (0.0011 at.%13C). This permits a reduction by at least a factor of 10 in the quantity of tracer required compared with conventional methods.
Additional Material:
3 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/bms.1200111106
