ANALYSIS OF PARALYTIC SHELLFISH POISONING TOXINS BY AUTOMATED PRECOLUMN OXIDATION AND MICROCOLUMN LIQUID-CHROMATOGRAPHY WITH FLUORESCENCE DETECTION

Periodate oxidation of the toxins responsible for paralytic shellfish poisoning (PSP) yields fluorescent purines suitable for trace analysis by reversed-phase LC. Mobile phases containing perfluorinated acids, such as heptafluorobutyric acid, as ion-pair agents were found to prov ide high capacity factors for the oxidized products. Gradient elution on a microbore column with large volume injections and fluorescence de tection permitted the detection of femtomole quantities of PSP toxins. A fully automated pre-column oxidation procedure was developed for an LC autosampler system in order to improve precision and allow unatten ded analyses. The complete method was applied successfully to various samples, including shellfish and toxic phytoplankton.