1 Matrix Extensions for the NSSP LC-MS/MS Diarrhetic Shellfish Poison method 2 Abstract 3 4 The Washington State Public Health Laboratories (WAPHL) Biotoxin Laboratory tests more than 5 2000 samples per year from the shores of the state for Diarrhetic Shellfish Poison (DSP), 6 specifically, dinophysis toxins, a trio of lipophilic toxins produced by the Dinophysis genus of 7 dinoflagellates. DSP toxins are known to cause gastrointestinal issues in humans who consume 8 elevated levels of the toxins. The toxins that result in DSP poisoning are difficult to quantify 9 reliably due to matrix suppressions and enhancements from the various substances within 10 shellfish matrices. 11 12 Washington State is currently using a modified European Union LC-MS/MS method that is 13 generalized for the analysis of many types of lipophilic toxins. In 2017, the U.S. Food and Drug 14 Administration developed a method for DSP testing that has a greater sensitivity and specificity 15 than the EU method and this method has now been adopted into the National Shellfish 16 Sanitation Program (NSSP) for the testing of clams. It is the only DSP method fully accepted 17 into the NSSP for monitoring shellfish for diarrhetic shellfish poisoning toxins and is validated for 18 a single matrix. This method is currently approved for full regulatory testing of clams but is 19 limited to screening only of mussels and other species. The WAPHL seeks funding to perform 20 matrix extension projects for mussels and a variety of other shellfish species that are deemed to 21 be important for public health. All shellfish species that are being monitored for DSP toxins 22 under the NSSP need to be confirmed as a valid matrix prior to performing regulatory testing 23 using this method. We are planning to collaborate with the method developer, Dr. Jonathan 24 Deeds at the FDA for this project. This proposed project will follow Discipline D Special Projects, 25 Track 3: Method Development and Method Validation. Completion of this project and future 26 applications for project funding will allow laboratories nationwide to perform DSP testing that is 27 approved for regulatory use on a wide variety of shellfish species.
