Identification of Compounds in Commercial Kava Extracts by Gas Chromatography with Electron Ionization High-Resolution Mass Spectrometry

ABSTRACT

This paper discusses the identification of kava lactones and related compounds by gas chromatography (GC) and quadrupole time-of-flight mass spectrometry (QTOFMS) with an electron ionization source. Three herbal preparations from different sources were analyzed by both GC-low-resolution MS and GC-high-resolution MS. The exact mass measurements generated with a research QTOFMS with mass accuracies in the low ppm range were combined with the isotope abundance ratios to confirm the presence of kava lactones and to identify additional compounds present in the Kava extracts. Although the availability of standards is of upmost importance to unequivocally confirm compound identities, the combination of accurate mass (< 3 ppm average mass accuracy), isotope abundance ratios, high resolution (>10,000) and literature information on the approximate composition of the herbal extracts provides a powerful analytical tool to help identify organic compounds in herbal extracts.