Investigation of Pyrrolizidine Alkaloids and Their N-Oxides in Commercial Comfrey-Containing Products and Botanical Materials by Liquid Chromatography Electrospray Ionization Mass Spectrometry.

Examines a method for the extraction and identification of pyrrolizidine alkaloids (PA) and their N-oxides in botanical materials and commercial comfrey-containing products, using liquid chromatography electrospray ionization mass spectrometry. Optimization of the extraction procedure and the chromatographic conditions; Application of the method to the analysis of herbal remedies; Measurable quantities of PA in products that were labeled to contain comfrey.