Use of HPLC-MS/MS to monitor cylindrospermopsin, a blue-green algal toxin,for public health purposes

Increasing reports of blooms of the blue-green alga Cylindrospermopsis raci borskii (C. raciborskii), which contains the hepatotoxic alkaloid cylindros permopsin (CYN), have led to public health concerns in Australia. The toxic ology of CYN appears complex and is still being elucidated. We have utilize d 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 concentrat ions in water samples. Intact algal cells in the water sample are lysed by a freeze-thaw cycle. After filtration (0.45 mu m filter), 110 mu L is injec ted. The HPLC uses an Altima C18 (250 x 4.6 mm, 5 mu m) column at 40 degree s 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 mit) to the 194 mit fragment is monitored, Linearity of this assay is 1-600 mu g/L [peak area=304xCYN (mu g/L) - 569; r(2) = 1.000 (n = 7)]. Using a single point standard curve, total coefficients of varia tion were 26.4, 10.5, 12.6, and 10.7% at 0.78, 5.2, 104, and 1040 mu g/L. T his assay is utilized in conjunction with algal cell counts and mouse bioas says to monitor water bodies for public health purposes. The rationale used in employing these methods is discussed. (C) 1999 by John Wiley & Sons, In c.