Furey Ambrose, Crowley Janet, Shuilleabhain Aine Ni, Skulberg Olav M, James Kevin J
PROTEOBIO, Department of Chemistry, Mass Spectrometry Centre for Proteomics and Biotoxin Research, Cork Institute of Technology, Cork, Bishopstown, Ireland.
Toxicon. 2003 Mar 1;41(3):297-303. doi: 10.1016/s0041-0101(02)00291-x.
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.
