Kinumi, T., Goto, M., Eyama, S., Kato, M., Kasama, T. and Takatsu, A. (2012) Development of SI-Traceable C-Pep- tide Certified Reference Material NMIJ CRM 6901-a Using Isotope-Dilution Mass Spectrometry-Based Amino Acid Analyses. Analytical and Bioanalytical Chemistry, 404, 13-21.