Determination of Free Amino Acid Concentrations in Bovine Plasma Using High‐Pressure Liquid Chromatography With Electrospray Ionization Mass Spectrometry Detection

The use of a stable isotope labeled version of each amino acid analyte as internal standard added to plasma samples at the beginning of the procedure corrected for any losses, instrument variability, and chemistry of derivatization. Use of this method to quantify bovine plasma amino acids will allow better understanding of physiological processes underlying nutritional interventions in dairy production systems and may be more broadly applicable to ruminant and other animal production systems.