Determination of the Hepatotoxin Cylindrospermopsin Produced by

the Cyanobacterium Cylindrospermopsis Raciborskii

Report No WSAA 123

July 1997

 

SYNOPSIS

 

This project was carried out with 3 aims:

 

·         To isolate sufficient cylindrospermopsin from bloom/cultured material to use as a chemical standard in an analytical method

 

·         To develop a method for the determination of cylindrospermopsin in cyanobacterial material and water

 

·         To carry out some preliminary investigations of the behaviour of cylindrospermopsin in water treatment processes

 

Toxic Cylindrospermopsis raciborskii was successfully cultured. However attempts to isolate the pure toxin using semi-preparative HPLC by monitoring toxicity of collected fractions with the mouse bioassay were unsuccessful. Once an analytical standard of cylindrospermopsin was obtained, it was relatively easy to identify the fraction containing this toxin. Had time been available, the isolation of sufficient material for use as an analytical standard and in investigations of its behaviour during water treatment should have been possible using semi-preparative HPLC. Using cytotoxicity testing for determining the presence of cylindrospermopsin was also unsuccessful.

 

Liquid chromatography/mass spectometry (LC/MS) employing direct interface of the HPLC injector to the mass spectrometer and selective ion recording (SIR) was capable of determining the presence of cylindrospermopsin in cultures. The results suggested that this toxin should be able to be monitored by conventional thermospray LC/MS.

 

Experiments aimed at determining whether cylindrospermopsin was removed by processes used for water disinfection, eg, chlorine and UV radiation, were relatively unsuccessful. There was some indication that treatment with chlorine removed some toxin. Further water treatment studies should be carried out as a matter of urgency due to the recent blooms of toxic C. raciborskii in Australian reservoirs.

 

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