Interlaboratory comparison studies are directed toward the measurement of 24 fatty acids in selected serum and plasma matrices. Frozen or freeze-dried serum or plasma samples together with control materials are sent to laboratories for analysis. Results are then returned to NIST for data evaluation and tabulation. Value-assignment of the samples is based on the median of all the laboratory results, with confirmation based on measurement at NIST using one or more different methods. Consultation and troubleshooting regarding methods of analysis are also provided.
An example figure from the first report illustrating alpha-linolenic acid levels in four study materials is shown below.