Description and results of the NIST/NOAA 2005 interlaboratory comparison exercise for trace elements in marine mammals

The National Institute of Standards and Technology's (NIST) National Marine Analytical Quality Assurance Program (NMAQAP) is dedicated to improving the quality of analytical measurements of trace elements, organic contaminants and emerging compounds of concern in marine and environmental systems, through various quality assurance mechanisms, including analytical method development and value assignment, quality assurance materials production, cryogenic marine specimen archival and the coordination of interlaboratory comparison exercises. This report focusses on the description and results of the 2005 Interlaboratory Comparison Exercise for Trace Elements in Marine Mammals. This program is co-sponsored by the National Oceanic and Atmospheric Administration, National Marine Fisheries Service, Office of Protected Resources, specifically, the Marine Mammal Health and Stranding Response Program. Two quality control materials derived from fresh-frozen marine mammal livers were produced and characterised at the NIST and were then distributed to over 30 laboratories. A maximum likelihood solution model was used to assign consensus data that served as a benchmark for comparison, and a series of group metrics were generated to assist the laboratories with the interpretation of performance and analytical assessment.