abstract |
[Problem] n The present invention relates to a method for determining the origin of glutamic acid in a sample and, in a broader sense, relates to a method for determining the origin of an amino acid. n [Solution] n As a result of the completion of the present invention, it becomes possible to measure the stable isotope ratio of an amino acid, with a considerably higher accuracy than that of conventional methods, by measuring the δ13C of the amino acid by EA-IRMS and measuring the δ15N by GC-IRMS. In addition, the present invention makes it possible to determine the origin of an amino acid by comparing the stable isotope ratio of the amino acid whose origin is unclear with the stable isotope ratio of an amino acid whose origin is clear. |