Binary fluorous alkylation of biogenic primary amines with perfluorinated aldehyde followed by fluorous liquid chromatography-tandem mass spectrometry analysis.

We have developed a novel method for the determination of biogenic amines (dopamine, norepinephrine, 3-methoxytyramine, normetanephrine, serotonin, tyramine, tryptamine, 5-methoxytryptamine, and histamine) utilizing liquid chromatography with electrospray ionization tandem mass spectrometry (LC–ESI-MS/MS) combined with a separation-oriented derivatization technique. Using this approach, primary amino groups in the target amines were selectively dialkylated with a perfluorinated aldehyde reagent (2H,2H,3H,3H-perfluoroundecan-1-al) through reductive amination. The derivatives were directly injected onto an LC column containing perfluoroalkyl-modified stationary phase and were separated via gradient elution using a water/methanol/trifluoroacetic acid mixture and trifluoroethanol with formic acid as mobile phases. Matrix-induced signal suppression effects were eliminated because the binary fluorous-labeled amines were strongly retained on the fluorous-phase LC column, whereas the nonfluorous derivatives, incl...