A robust method for direct calibration of isotope ratios in gases against liquid/solid reference materials, including a laboratory comparison for δ13 C-CH4.
Peter SperlichHeiko MoossenHeike GeilmannSarah J BuryJulie C S BrownRowena C MossGordon W BrailsfordWilli A BrandPublished in: Rapid communications in mass spectrometry : RCM (2022)