NIST Micronutrients Measurement Quality Assurance Program: Performance History of the Fat-Soluble Vitamin-Related Studies

Summary

Publication Title: NIST Micronutrients Measurement Quality Assurance Program: Performance History of the Fat-Soluble Vitamin-Related Studies

Series Title: NIST Interagency or Internal Reports

Personal Author: Duewer, David L.

Publication Number: NIST IR; NIST interagency report; NIST internal report; 7880-50

Date Issued: 2022

Subject: Carotenoids
Ubiquinones
Vitamin A
Vitamin E
Apparent precision
Concordance
Human serum
Interlaboratory measurement reproducibility functions
Liquid-frozen samples
Lyophilized samples
Micronutrients Measurement Quality Assurance Program (MMQAP)
SRM 968
Robust scale estimators

Government Author: Commerce Department, National Institute of Standards and Technology (NIST) .

Category: Executive Agency Publications

SuDoc Class Number: C 13.

Abstract: From 1984 to 2017, the National Institute of Standards and Technology (NIST) Micronutrients Measurement Quality Assurance Program (MMQAP) coordinated 79 Round Robin (RR) interlaboratory studies designed to improve measurement comparability among laboratories measuring fat soluble vitamins and carotenoids in human serum and plasma. There were 22 participants in the initial study; participation increased to 58 in 1997 and then declined in stages to 29 by 2017. A total of 138 academic, commercial, governmental, or non-governmental organizations actively participated in at least one RR; two laboratories participated in 77 of the 79 RRs. A total of 350 human serum or plasma samples were distributed in the RRs, typically three to five per RR. One hundred thirty one (131) of these samples were unique materials. While the initial RRs focused on just retinol (vitamin A), ? tocopherol (vitamin E), and ? carotene (provitamin A) over the life of the program 57 vitamin related measurands were reported at least once. Fifteen (15) measurands were reported sufficiently often to enable analysis of measurement performance over time: total retinol, retinyl palmitate, ? tocopherol, ? plus ? tocopherol, total ? carotene, trans ? carotene, total cis ? carotene, total ? carotene, total lycopene, trans lycopene, total ? cryptoxanthin, total lutein, total zeaxanthin, total lutein plus zeaxanthin, and coenzyme Q10. In addition to documenting the number and nature of the MMQAP's participants, measurands, materials, and reported measurements, this report explores the evolution of among-participant concordance and within-participant apparent precision as functions of calendar date documents and the relationships among results reported for materials delivered to participants both as liquid-frozen and lyophilized samples.