Increasing reports of blooms of the blue-green alga Cylindrospermopsis raciborskii (C. raciborskii), which contains the hepatotoxic alkaloid cylindrospermopsin (CYN), have led to public health concerns in Australia.
The toxicology of CYN appears complex and is still being elucidated.
We have utilized the combination of sensitivity and specificity afforded by coupling high performance liquid chromatography (HPLC) to a tandem mass spectrometer (MS/MS) to produce an assay which is suitable for monitoring low CYN concentrations in water samples.
Intact algal cells in the water sample are lysed by a freeze-thaw cycle.
After filtration (0.45 mum filter), 110 muL is injected.
The HPLC uses an Altima C18 (250 x 4.6 mm, 5 mum) column at 40°C. Chromatography utilizes a linear gradient from 1 to 60% methanol over 5 min, with a final isocratic stage holding at 60% methanol for 1 min.
The mobile phase is buffered to 5 mM with ammonium acetate.
The transition from the M+H ion (416 m/z) to the 194 m/z fragment is monitored.
Linearity of this assay is 1-600 mug/L [peak area=304 x CYN (mug/L) - 569 ; r2=1.000 (n=7) ]. Using a single point standard curve, total coefficients of variation were 26.4,10.5,12.6, and 10.7% at 0.78,5.2,104, and 1040 mug/L. This assay is utilized in conjunction with algal cell counts and mouse bioassays to monitor water bodies for public health purposes.
The rationale used in employing these methods is discussed.
Mots-clés Pascal : Bloom, Chromatographie HPLC, Spectrométrie masse tandem, Concentration chimique, Alcaloïde, Queensland, Australie, Océanie, Eau potable, Toxicologie, Cyanobacteria, Bactérie, Toxine, Cylindrospermopsis raciborskii, Cylindrospermopsine
Mots-clés Pascal anglais : Bloom, HPLC chromatography, Mass spectrometry MS/MS, Chemical concentration, Alkaloid, Queensland, Australia, Oceania, Drinking water, Toxicology, Cyanobacteria, Bacteria, Toxin
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 99-0328471
Code Inist : 002A05B10. Création : 16/11/1999.