Saxitoxins, produced by species of harmful algal blooms (HABs), cause paralytic shellfish poisoning (PSP) when contaminatedseafood is consumed. For nearly 50 years the U. S. Food and Drug Administration (FDA) has provided a saxitoxin dihydrochloride standard to state shellfish laboratories and others who monitor seafood safety, andhas distributed it as a National Institutes of Standards and Technology (NIST) Reference Material (RM) since 2010.

NIST Reference Material® 8642 FDA Saxitoxin Dihydrochloride Solution is provided as ten individually packaged borosilicate glass ampoules each containing approximately 1.2 mL of a 20 % ethanol/water solution containing 5 mmol/L hydrochloric acid with a reference value of 103 ± 4 µg/g Saxitoxin Dihydrochloride. With this material out of stock, a Renewal Reference Material is under preparation. Photo Credit NOAA

NIST Reference Material® 8642 FDA Saxitoxin Dihydrochloride Solution (RM 8642) is extensively purified saxitoxin, whose demand has exceeded its supply. To address this demand, NOAA scientists with the National Centers for Coastal Ocean Science conducted activity analysis of a newly produced FDA Saxitoxin Dihydrochloride Solution and documented that the material met all performance criteria with no detectable differences compared toNIST RM 8642. These data allow the newly prepared material pass a critical decision gate to production and distribution as a reference material.

Saxitoxin dihydrochloride is used to calibrate the receptor assay (AOAC International Official Method 2011.27) and the mouse bioassay (AOAC International Official Method 959.08), the long-standing regulatory method for quantifying PSP toxins in shellfish. Availability of reference materials and standardized detection methods for shellfish toxins is essential to ensuring comparability of results within and between testing facilities and prevent trade barriers to shellfish harvested in the United States.

For more information, contact Maggie.Broadwater@noaa.gov.