Screening for cyanobacterial toxins in bloom and strain samples by thin layer chromatography

Two thin layer chromatographic (TLC) procedures were evaluated for the capacity screening of cyanobacterial peptide hepatotoxins and anatoxin-a in laboratory-cultured strain samples and in natural bloom samples. Seventy-five samples previously investigated with the reference methods, the chief of which was mouse bioassay, were analyzed blindly by TLC. Forty-three of the samples were hepatotoxic according to the reference methods, and 39 of them were found to contain peptide hepatotoxins by TLC coupled to u.v.-densitometry. Seven samples contained anatoxin-a according to the reference methods, and five of these were found to contain anatoxin-a by TLC, using derivatization with Fast Black K salt. Four of the samples which were neurotoxic by mouse bioassay also contained hepatotoxins by TLC. Twenty-four samples were nontoxic according to the reference methods, and in 23 of these no toxins were found by TLC either.