DEVELOPMENT OF A MANGANESE-DIOXIDE SOLID-PHASE REACTOR FOR OXIDATION OF TOXINS ASSOCIATED WITH PARALYTIC SHELLFISH POISONING

Using manganese dioxide as a solid-phase oxidant, a post-column HPLC r eactor for paralytic shellfish poison toxins was constructed and evalu ated. Operating parameters such as reaction temperature and pH, flow-r ate, reactor column size, and MnO2 particle size were studied. Based o n a 3:1 signal-to-noise ratio, the limits of detection for the non-hyd roxylated toxins were in the sub-nanogram range, while the hydroxylate d toxins were ten times less detectable. The limit of detection for sa xitoxin was about 0.1 ng per injection. The repeatability of replicate injections was less than or equal to 10% (relative standard deviation ). The system was used to analyze extracts of shellfish and plankton, yielding results that were in agreement with those obtained by establi shed analytical methods. Extracts of shellfish contaminated at the reg ulatory limit of 0.8 mu g/g were successfully analyzed.