title: The Role of Naturally Occurring Stable Isotopes in Mass Spectrometry, Part III: Small Gas Molecule Calculations.
abstract: In the third instalment of this tutorial, the authors explain the determination of the isotopic composition of a sample from a mass spectrometric measurement, and the methods of calculation as well as the units used. This tutorial outlines the practices in common usage, so that researchers new to this field can obtain a good understanding of the fundamentals involved.
authors.affiliation: Medical Research Council Human Nutrition Research, Cambridge, UK.
authors.forename: Les
authors.initials: L
authors.lastname: Bluck
authors.forename: Dietrich A
authors.initials: DA
authors.lastname: Volmer