Characterization of the NIST shellfish Standard Reference Material 4358

A new shellfish Standard Reference Material 4358 was developed by the National Institute of Standards and Technology through an international interlaboratory comparison that involved twelve laboratories-participants from nine countries. The results from the participants were statistically evaluated, and the most robust certified values were based on the median of laboratories' reported means and the uncertainties derived using the bootstrap method. Massic activity certified values were established for fourteen radionuclides, five activity ratios, and informational massic activity values for eight more radionuclides and two activity ratios. (author)