Constituents of Cannabis sativa L. XVIII--Electron voltage selected ion monitoring study of cannabinoids.

Cannabis sativa L. contains more than 420 different constituents. Sixty-one of these constituents are cannabinoids. The electron voltage selected ion monitoring technique was used in the study of this unique group on natural compounds. Mass spectra of each compound were recorded at various eV settings (5.5-21 eV). The electron voltage selected ion recordings were obtained by plotting the relative intensities of characteristic fragment ions against electron voltage. The method was proven useful in the structure analysis of cannabinoids since it requires only minute quantities of sample. It was possible to recognize homologs and to differentiate positional and double bond isomers as well as cannabinoids with the same molecular weight.