Estimation of picomole quantities of piperidine in tissues

Piperidine is a putative neurotransmitter. Its sensitive determination is one of the prerequisites for the evaluation of its assumed physiological role. For its derivatization 5-di-n-butylaminonaphthalene-1-sulphonyl chloride, a new reagent which improves methods applying 5-dimethylaminonaphthalene-1-sulphonyl chloride, is used. Reaction of the perchloric acid tissue extract with this reagent, thin-layer chromatographic separation of the fluorescent derivatives and mass spectrometric evaluation of the di-n-butylaminonaphthalenesulphonyl piperidine spot by a version of the integrated ion current technique allows the determination of piperidine in tissues in picomole quantities. Standard deviation of the determinations of 2 to 16 pmol of piperidine added to 50 mg of brain tissue was ±8%. The method was applied to the analysis of different tissues. Brain concentrations of piperidine in different species were found to be lower by a factor up to 100 in comparison with published data.