title: Characterization of the oxidation products of paralytic shellfish poisoning toxins by liquid chromatography/mass spectrometry.
abstract: Periodate oxidation of the toxins responsible for paralytic shellfish poisoning (PSP) yields fluorescent products that are useful for trace analysis by reversed-phase liquid chromatography. Some toxins are oxidized to the same product, while others are transformed to a mixture of products; in all cases, the products are too unstable to be isolated preparatively. A mobile phase containing heptafluorobutyric acid as an ion-pair agent was developed to improve compatibility with liquid chromatography/mass spectrometry (LC/MS) analysis. Several LC/MS techniques were investigated: chemical ionization with the moving belt interface, atmospheric-pressure chemical ionization, thermospray, continuous-flow fast-atom bombardment, and ion-spray. Only LC/ion-spray MS was able to provide spectra of the oxidized products. The products were characterized as purines resulting from: (a) breakage of the C4-C12 bond and aromatization of the remaining rings (loss of 4 hydrogens); (b) partial elimination of a carbamoyl or N-sulfocarbamoyl side-chain (this is promoted by the presence of an N-1-hydroxy group); and (c) partial hydrolysis of an N-sulfocarbamoyl side-chain to a carbamoyl group.
authors.affiliation: Institute for Marine Biosciences, National Research Council of Canada, Halifax, Nova Scotia.
authors.forename: M A
authors.initials: MA
authors.lastname: Quilliam
authors.forename: M
authors.initials: M
authors.lastname: Janecek
authors.forename: J F
authors.initials: JF
authors.lastname: Lawrence
mesh_terms: D008401:Gas Chromatography-Mass Spectrometry; D008387:Marine Toxins; D010084:Oxidation-Reduction
chemical_list: D008387:Marine Toxins