SEARCH Articles Figures Tables Chromatography GC mass spectrometry Chromatography isotope ratio mass spectrometry GC - Gas chromatography GC-IRMS Gas chromatography isotope ratio mass Gas chromatography isotope ratio mass spectrometry Gas chromatography, IRMS Gas chromatography, isotope Gas chromatography-isotope ratio Gas chromatography/mass spectrometry Gas mass spectrometry IRMS Isotope ratio mass spectrometry Isotope ratios Isotope spectrometry Isotopes masses Isotopic mass spectrometry Isotopic masses MASS RATIO Mass spectrometry GC-IRMS Mass spectrometry isotopes Mass spectrometry, isotope ratio (IRMS