Sensitive determination of deuterated and non-deuterated tryptophan, tryptamine and serotonin by combined capillary gas chromatography and negative ion chemical ionization mass spectrometry

Abstract

Sensitive methods for the determination of deuterated and non-deuterated tryptophan, tryptamine and serotonin by combined capillary gas chromatography and negative ion chemical ionization mass spectrometry were developed. [3,3- 2H 2]- l-Tryptophan, which was used as a tracer, was synthesized for studies of their in vivo metabolism. Tryptophan was converted into its trifluoroacetylmethyl derivative after prepurification with an AG 50W-X2 cation-exchange column. Tryptamine and serotonin were extracted with 20% butanol in diethyl ether and derivatized with trifluoroacetic anhydride. These derivatives were separated and determined by selected ion monitoring. In these determinations, [2′,3,3,4′,5′,6′,7′- 2H 7]- d,l-tryptophan, [α,α,β,β- 2H 4]tryptamine and [α,α,β,β- 2H 4]serotonin were used as internal standards.