气相色谱-燃烧-同位素比值质谱法测定单体氨基酸的碳稳定同位素组成

Abstract：A combined gas chromatography combustion—isotope ratio mass spectrometry method(GC—C IRM S)for stable carbon isotope analysis of amino acids is presented．Un— like hydrocarbons amino acids require derivatization prior to GC—C—IRM S analysis．Repli— cate carbon isotope analyses of trifluoroacetyl isopropyl ester derivatives of 1 7 amino acids by IRM S revealed that the derivatization process is reproducible． Due to a reproducible isotopic fractionation an empirical correction factor for each individual amino acid iS derived separately for derivatives and the original 。C value of the underivatized amino acid is cal— CUlated．