Continuous-flow isotope ratio mass spectrometry using the chemical reaction interface with either gas or liquid chromatographic introduction.
A novel method of sample introduction into an isotope ratio mass spectrometer (IRMS) is described. The technique uses the chemical reaction interface (CRI) to convert samples coming from a gas chromatograph (GC) or high-performance liquid chromatograph (HPLC) into CO2 using a microwave-induced helium plasma. Optimization parameters for both GC/CRI/IRMS and HPLC/CRI/IRMS are described. In both modes of operation, it was possible to obtain 13CO2/12CO2 ratios with standard deviations less than 1%. Investigation of HPLC/CRI/IRMS performance at low and high concentrations (0.5-10 micrograms) resulted in no significant deviations of the isotope ratios. The ability to differentiate samples of different biological origins was illustrated using chlorophyll a from spinach and algae, where a large difference was observed but good precision was maintained (SD < 0.60%).
Teffera
Y
Y
Department of Pharmacology, George Washington University Medical Center, Washington, D.C. 20037, USA.
Kusmierz
J J
JJ
Abramson
F P
FP
D002849:Chromatography, Gas / Q000295:instrumentation*; D002853:Chromatography, Liquid / Q000295:instrumentation*; D013058:Mass Spectrometry / Q000295:instrumentation*