PROJECT SUMMARY The overall goal of this special project is to conduct a preliminary, exploratory investigation of the feasibility of developing a new method for arsenic (As) speciation in seafood based on a simple extraction procedure with separation and detection using LC-ICP-MS. The proposed project will leverage the current expertise and capabilities at the Wadsworth Center, where a simple LC-ICP-MS method has already been developed, and which could be validated for use across the FERN network by multiple laboratories. Specific objectives will include exploring the feasibility of combining As(III) and As(V) by oxidizing the former to the latter, to produce a single inorganic As species (iAs). Other objectives will include deciding how many different As species should be captured in the proposed method, while recognizing calibration standards exist only for limited number of As species. A key objective will be to produce a suitable candidate reference material based on a seafood product matrix that can be homogenized, and distributed to multiple laboratories for the first interlaboratory study. Other objectives will include a single laboratory validation of the proposed method, and the design of the first interlaboratory round robin to gather baseline data on network capabilities