The Micronutrients Measurement Quality Assurance Program, coordinated by the Chemical Sciences Division, supports measurement technology for selected fat- and water-soluble vitamins and carotenoids in human serum. This program was initiated in 1984 by the National Cancer Institute Division of Cancer Prevention and Control to ensure the long-term reliability of the measurements made while studying the possible cancer chemoprevention roles of these compounds. From an initial core of 10 NCI-grantee laboratories, the program currently involves 34 fee-paying laboratories. This program provides participants with measurement comparability assessment through use of interlaboratory comparison studies, Standard Reference Materials and control materials, and methods development and validation.
NIST Micronutrients Measurement Quality Assurance (QA) Program supports the long-term (months to years) reliability of selected fat- or water-soluble vitamin measurements in human serum and plasma. Results from the comparison studies help participants to make accurate clinical and health-care decisions as well as to maintain and improve their measurement comparability. Laboratories use the program to demonstrate their compliance with federally regulated requirements [Clinical Laboratory Improvement Act (CLIA)], which extend to all laboratories performing diagnostic testing.
Additional Technical Details:
Serum-based samples with assigned values for target analytes (e.g., retinol, tocopherols, and beta--carotene and performance-evaluation standards are distributed by NIST to participants for analysis. NIST staff provide participants with technical feedback concerning their measurement performance and suggestions for methods development and refinement. A certificate of participation in the QA program is issued at the end of each calendar year.
The Micronutrients Measurement QA Program at NIST has administered over 90 interlaboratory comparison exercises for the measurement of selected fat- and water-soluble vitamins in human serum and plasma. The comparability of laboratory measurements for target analytes has improved substantially over time. This has been achieved through the development and promulgation of robust measurement technologies, identification and production of suitable reference materials, isolation and identification of measurement system biases, and support and encouragement of long-term within-laboratory measurement quality control efforts. The average estimated coefficient of variation for retinol and α-tocopherol has been approximately 5% for the past seven years and about 10% for β-carotene for that same period of time.
For program information, including how to join, click here.
Start Date:October 1, 1984
Lead Organizational Unit:mml
Related Programs and Projects:
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Brown Thomas, J., Sharpless, K.E., eds., Methods for Analysis of Cancer Chemopreventive Agents in Human Serum, NIST Special Publication 874, U. S. Gov't Printing Office, Washington, DC, 128 pages, (1995).
Sharpless, K.E., Duewer, D.L., Population Distributions and Intralaboratory Variance for Fat-Soluble Vitamin-Related Compounds in Human Serum, Anal. Chem., 67: 4416-4422 (1995).
Brown Thomas, J., Kline, M.C., Schiller, S.B., Ellerbe, P.M., Sniegoski, L.T., Duewer, D.L., Sharpless, K.E., Certification of Fat-Soluble Vitamins, Carotenoids, and Cholesterol in Human Serum: Standard Reference Material 968b, Fresenius' J. Anal. Chem., 356:1-9 (1996).
Margolis, S.A.; Duewer, D.L., Measurement of Ascorbic Acid in Human Plasma and Serum: Intralaboratory Repeatability, Interlaboratory Repeatability, Interlaboratory Reproducibility, and Stability in Lyophilized Plasma and Metaphosphoric Acid Preserved Plasma and Serum, Clin. Chem., 42: 1257-1262 (1996).
Duewer, D.L., Brown Thomas, J., Kline, M.C., MacCrehan, W.A., Schaffer, R., Sharpless, K.E., May, W.E., NIST/NCI Micronutrients Measurement Quality Assurance Program: Measurement Reproducibility, Repeatability, Stability, and Relative Accuracy for Fat-Soluble Vitamin-Related Compounds in Human Sera, Anal. Chem., 69: 1406-1413 (1997).
Margolis, S.A., Schapira, R.M., Liquid Chromatographic Measurement of L-Ascorbic Acid and D-Ascorbic Acid in Biological Samples, J. Chromatogr. B, 690: 25-33 (1997).
Sharpless, K.S., Brown Thomas, J., Turley, C.P., Brewster, M.A., “Vitamin A,” In: LaboratoryMedicine: A Scientific and Managerial Infobase, Version 2.6, A.J. Pesce and L.A. Kaplan, (eds.) Pesce Kaplan Publisher, Cincinnati, OH, CD-Rom (1997).
Sharpless, K.S., Brown Thomas, J., Turley, C.P., Brewster, M.A., “Vitamin E,” In: Laboratory Medicine: A Scientific and Managerial Infobase, Version 2.6, A.J. Pesce and L.A. Kaplan, (eds.) Pesce Kaplan Publisher, Cincinnati, OH, CD-Rom (1997).
Brown Thomas, J., Kline, M.C., Duewer, D.L., Sharpless, K.E, The Stability of Retinol, α-Tocopherol, Trans-Lycopene, and Trans- β-Carotene in Liquid-frozen and Lyophilized Serum in Human Serum, Clin. Chim. Acta, 276:75-87 (1998).
Duewer, D. L., Kline, M.C., Sharpless, K.E., Brown Thomas, J.M., Gary, K.T., Sowell, A.L., Micronutrients Measurement Quality Assurance Program: Helping Participants Use Inter-laboratory Comparison Exercise Results to Improve their Long-term Measurement Performance, Anal. Chem., 71: 1870 -1878 (1999).
Duewer. D.L., Kline, M.C., Sharpless, K.E., Brown Thomas, J., Stacewicz-Sapuntzakis, M., Sowell, A.L., NIST Micronutrients Measurement Quality Assurance Program: Characterizing Individual Participant Measurement Performance Over Time, Anal. Chem., 72: 3611- 3619 (2000).
Duewer. D.L., Kline, M.C., Sharpless, K.E., Brown Thomas, J., NIST Micronutrients Measurement Quality Assurance Program: Characterizing the Measurement Community’s Performance Over Time, Anal. Chem., 72: 4163-4170 (2000).
Brown Thomas, J., Kline, M.C., Gill, L.M., Yen, J.H., Duewer, D.L., Sniegoski, L.T., Sharpless, K.E., Preparation and Value Assignment of Constituents in Standard Reference Material 968c: Fat-Soluble Vitamins, Carotenoids, and Cholesterol in Human Serum, Clin. Chim. Acta, 305:141 -155 (2001).