This test method involves chemically modifying amino acids after hydrolysis to form stable, UV- or fluorescence-detectable derivatives. This enhances detection sensitivity and allows efficient separation using reversed-phase UPLC columns. Samples undergo acid hydrolysis to release free amino acids, which are then reacted with a derivatizing reagent (e.g., AccQ•Tag™) to form stable derivatives. These derivatized amino acids are separated on a reversed-phase UPLC column and detected using UV detectors. Quantification is achieved by comparing to calibration standards. This test method quantifies alanine, arginine, aspartic acid, glutamic acid, glycine, histadine, hydroxyproline, isoleucine, leucine, lysine, phenylalanine, proline, serine, threonine, tyrosine, and valine.