^a Asparagine (asn) is largely converted to aspartate during derivatization [a small fraction will also undergo dehydration at the amide position, producing HFBI-beta-cyanoalanine, which chromatographs just before gamma-aminobutyrate (gaba)].
^b Gutamine (gln) is largely converted to glutamate during derivatization.
^c Gutamine (gln) is partially converted to pyroglutamate (pglu) during derivatization as a result of loss of the amide group and cyclization of the molecule.