Mass Spectrometry of Domoic Acid, a Marine Neurotoxin t

Domoic acid is a naturally occurring amino acid, formerly available in iimited amounts as a natural product of some algae of the family Rhodomelaceae. As the result of a recent incidence of toxicity in cultured blue mussels (Mytiius eaulis) from a highly localized region of Atlantic Canada, useful amounts of thi substance are likely to become available in the near future. Domoic acid is an important substance for fundamental studies in neurobiology as it possesses the highest afinity amongst known substances for the kainate receptors of the central nervous system. The present work describes fast atom bombardment (FAB) mas spectra of domoic acid, and of some of its isomers present in minor quantities in contaminated mussel extracts. These FAB spectra are subject to interferences from beam-induced reduction reactions associated with matrices such as glycerol, but not with others such as 3-nitrobenzyl alcohol. Tandem mass spectrometry of the MH+ ions from these compounds is also reported. As a more feasible approach to quantitative analysis at trace levels, formation of the volatile tert-butyldimethylsilyl derivatives has been investigated and shown to be highly promising.