This was followed by derivatization, drying, and dilution
with sample diluents. The amino acids derivative samples were
analyzed using high performance liquid chromatography (HPLC)
(1260 Infinity, Agilent Technologies, Malaysia) and compared
against the standard amino acids which were analyzed prior to
these. The peak area of each amino acid in the chromatogram was
calculated and compared with that of the standard and reported as
number of residue per thousand amino acids content.