Interlaboratory comparison studies were 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 were sent to laboratories for analysis. Results were then returned to NIST for data evaluation and tabulation. Value-assignment of the samples was 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 were also provided. A report of exercise results was sent to participants that summarized the results from each comparability study.
The National Institute of Standards and Technology (NIST) and the National Institutes of Health (NIH) Office of Dietary Supplements (ODS) established a Fatty Acids in Human Serum and Plasma Quality Assurance Program (FAQAP). The FAQAP concluded in 2017, and parts of the FAQAP community will now be served through the HAMQAP.
A report for the first exercise has been published, NISTIR 7953: Interlaboratory Analytical Comparison Study of Total Fatty Acid Concentrations in Human Serum: Results for Exercise 01: QA12FASER01.
An example figure from the first report illustrating alpha-linolenic acid levels in four study materials is shown below.
RELATED STANDARD REFERENCE MATERIALS
We recommend that laboratories use Standard Reference Materials (SRMs) such as SRM 1950 Metabolites in Human Plasma to validate methodology and to value-assign in-house control materials. SRMs for fatty acids in human serum and plasma may be purchased from the Standard Reference Materials Program at NIST (301-975-2200; fax: 301-948-3730; or e-mail: firstname.lastname@example.org).