high performance liquid chromatography with coulometric electrochemical detection has been used to achieve simultaneous determination of norepinephrine , epinephrine , 5-hydroxytryptophan , normetanephrine , dopamine , metanephrine , 3,4-dihydroxyphenylacetic acid , n-acetyldopamine , tyramine , tryptophan , 5-hydroxyindoleacetic acid , 5-hydroxytryptamine , n-acetyl-5-hydroxytryptamine , homovanillic acid , tyrosine , p-octopamine , n-acetyl-p-octopamine , and p-synephrine .
C0000578
5-hydroxytryptophan
C0041249
tryptophan