title: The first identification of the rare cyanobacterial toxin, homoanatoxin-a, in Ireland.
abstract: The first identification of the rare cyanobacterial neurotoxin, homoanatoxin-a, in Ireland is reported. A sensitive fluorimetric liquid chromatographic (LC) method was applied to the analysis of homoanatoxin-a in the low microg/l range. The analysis of the anatoxins in water samples required weak cation exchange solid phase extraction, fluorimetric derivatisation with 4-fluoro-7-nitro-2,1,3-benzoxadiazole (NBD-F), and isocratic reversed-phase LC. Confirmation of toxin identity was made using LC with electrospray mass spectrometry (MS) of the NBD-derivatised homoanatoxin-a as well as LC-MS/MS of the free toxin. Application of the fluorimetric LC protocol to examine cyanotoxins in 20 Irish lakes resulted in the detection of homoanatoxin-a at four locations, Lough Sillan (24 microg/l), Inniscarra Reservoir (34 microg/l), Lough Key (12 microg/l), Caragh Lake (1.4 microg/l). An improved procedure for the isolation of homoanatoxin-a from cyanobacteria was also developed and confirmation of homoanatoxin-a was achieved by chromatographic and mass spectral comparison with authentic toxin isolated from a laboratory clone culture of Planktothrix (formerly Oscillatoria) formosa.
authors.affiliation: PROTEOBIO, Department of Chemistry, Mass Spectrometry Centre for Proteomics and Biotoxin Research, Cork Institute of Technology, Cork, Bishopstown, Ireland.
authors.forename: Ambrose
authors.initials: A
authors.lastname: Furey
authors.forename: Janet
authors.initials: J
authors.lastname: Crowley
authors.forename: Aine Ni
authors.initials: AN
authors.lastname: Shuilleabhain
authors.forename: Olav M
authors.initials: OM
authors.lastname: Skulberg
authors.forename: Kevin J
authors.initials: KJ
authors.lastname: James
mesh_terms: D019086:Bridged Bicyclo Compounds, Heterocyclic / Q000302:isolation & purification*; D002853:Chromatography, Liquid / Q000379:methods; D005618:Fresh Water / Q000737:chemistry; D007494:Ireland; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods
chemical_list: D019086:Bridged Bicyclo Compounds, Heterocyclic; C073221:homoanatoxin