Analytic validation of a gas chromatography-mass spectrometry method for quantification of six amino acids in canine serum samples. Academic Article uri icon


  • OBJECTIVE: To analytically validate a gas concentration of chromatography-mass spectrometry (GC-MS) method for measurement of 6 amino acids in canine serum samples and to assess the stability of each amino acid after sample storage. SAMPLES: Surplus serum from 80 canine samples submitted to the Gastrointestinal Laboratory at Texas A&M University and serum samples from 12 healthy dogs. PROCEDURES: GC-MS was validated to determine precision, reproducibility, limit of detection, and percentage recovery of known added concentrations of 6 amino acids in surplus serum samples. Amino acid concentrations in serum samples from healthy dogs were measured before (baseline) and after storage in various conditions. RESULTS: Intra- and interassay coefficients of variation (10 replicates involving 12 pooled serum samples) were 13.4% and 16.6% for glycine, 9.3% and 12.4% for glutamic acid, 5.1% and 6.3% for methionine, 14.0% and 15.1% for tryptophan, 6.2% and 11.0% for tyrosine, and 7.4% and 12.4% for lysine, respectively. Observed-to-expected concentration ratios in dilutional parallelism tests (6 replicates involving 6 pooled serum samples) were 79.5% to 111.5% for glycine, 80.9% to 123.0% for glutamic acid, 77.8% to 111.0% for methionine, 85.2% to 98.0% for tryptophan, 79.4% to 115.0% for tyrosine, and 79.4% to 110.0% for lysine. No amino acid concentration changed significantly from baseline after serum sample storage at -80C for 7 days. CONCLUSIONS AND CLINICAL RELEVANCE: GC-MS measurement of concentration of 6 amino acids in canine serum samples yielded precise, accurate, and reproducible results. Sample storage at -80C for 1 week had no effect on GC-MS results.

published proceedings

  • Am J Vet Res

altmetric score

  • 2.45

author list (cited authors)

  • Lopes, R., Grtzner, N., Berghoff, N., Lidbury, J. A., Suchodolski, J. S., & Steiner, J. M.

citation count

  • 3

complete list of authors

  • Lopes, Rosana||Grützner, Niels||Berghoff, Nora||Lidbury, Jonathan A||Suchodolski, Jan S||Steiner, Jörg M

publication date

  • December 2015