Date of Award


Degree Type


Degree Name

Master of Science in Food Science and Nutrition


Food Science, Technology, Nutrition and Dietetics

First Advisor

Henry Dymsza


Paralytic shellfish frequently fatal malady contaminated shellfish poisoning (PSP) is a serious, frequently fatal malady resulting from the ingestion of contaminated shellfish. Filter feeding bivalves, including clams and mussels, become toxic after ingesting toxic dinoflagellate algae of the genus Gonvaulax.

Due thousands to strict guidelines on shellfish bed closures, thousands of dollars depend on an analyst’s precision in measurement of the toxins on shellfish bed closures on an analyst's precision in measurement of the toxin. Measurement has traditionally been by means of a mouse bioassay. Since no proficiency test existed, the purpose of this work was to develop one.

Accordingly, after testing a number of substrates, including class and mussels, a proficiency test specimen was formulated by the use of saxitoxin in a mashed potato matrix. These samples containing 200 and 500ug/100g saxitoxin dihydrochloride were sent to 16 state and Canadian laboratories for analysis in duplicate. The results revealed that within laboratory variance was less than between laboratory variance. The source of the errors was poor dilution technique by some laboratories. Estimates were found to be inflated due to initial overestimation of toxicity. Making solutions more toxic produced one of several "correct" dilutions that produced death times in the 5-7 minute range. It was also found that when using saxitoxin, circadian rhythm of the mice has no effect on their response.

The simplicity of the mashed potato matrix makes it a suitable matrix for collaborative studies. Periodic use of this test specimen will help insure correct analysis and maximum utilization of shellfish resources.



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