Analysis of melatonin in human plasma by gas chromatography negative chemical ionization mass spectrometry

Alfred J. Lewy, S. P. Markey

Research output: Contribution to journalArticle

194 Scopus citations


Three techniques have been used to measure human plasma melatonin: bioassay, radioimmunoassay, and gas chromatography-mass spectrometry (GCMS). GC-MS is theoretically capable of the greatest specificity, but in general suffers from insufficient sensitivity. Negative chemical ionization, a new technique, provides a 150-fold increase in GC-MS sensitivity for electron-capturing compounds. Negative chemical ionization GC-MS permits routine measurement in human plasma of melatonin at a concentration as low as 1 picogram per milliliter.

Original languageEnglish (US)
Pages (from-to)741-743
Number of pages3
Issue number4357
StatePublished - Jan 1 1978


ASJC Scopus subject areas

  • General

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