NISTIR 7880-16 

NIST Micronutrients Measurement 

Quality Assurance Program 

Summer 2004 

Comparability Studies 

Results for Round Robin LVI 

Fat-Soluble Vitamins and Carotenoids in Human Serum 

and Round Robin 21 Ascorbic Acid in Human Serum 

David L. Duewer 

Jeanice B. Thomas 

 

 

 

 

NISTIR 7880-16
 

NIST Micronutrients Measurement 

Quality Assurance Program 

Summer 2004 

Comparability Studies 

Results for Round Robin LVI 

Fat-Soluble Vitamins and Carotenoids in Human Serum 

and Round Robin 21 Ascorbic Acid in Human Serum 

David L. Duewer 

Jeanice B. Thomas 

Chemical Sciences Division 

Materials Measurement Laboratory 

June 2013 

 U.S. Department of Commerce 

Cameron F. Kerry, Acting Secretary 

 National Institute of Standards and Technology 

 Patrick D. Gallagher, Under Secretary of Commerce for Standards and Technology and Director 
(This page intentionally blank) 

ii
 
 

 

Abstract 

The National Institute of Standards and Technology coordinates the Micronutrients Measurement 

Quality Assurance Program (MMQAP) for laboratories that measure fat- and water-soluble vitamins 

and carotenoids in human serum and plasma. This report describes the design of and results for the 

Summer 2004 MMQAP measurement comparability improvement studies: 1) Round Robin LVI FatSoluble Vitamins and Carotenoids in Human Serum and 2) Round Robin 21 Total Ascorbic Acid in 

Human Serum. The materials for both studies were shipped to participants in May 2004; 

participants were requested to provide their measurement results by September 13, 2004. 

Keywords 

Human Serum
 

Retinol, α-Tocopherol, γ-Tocopherol, Total and Trans-β-Carotene
 

Total Ascorbic Acid
 

iii 
 

 

 

 

 

 

 

Table of Contents 

Abstract............................................................................................................................................... iii
 

Keywords ............................................................................................................................................ iii
 

Table of Contents ............................................................................................................................... iv
 

Introduction......................................................................................................................................... 1
 

Round Robin LVI: Fat-Soluble Vitamins and Carotenoids in Human Serum ............................ 1
 

Round Robin 21: Vitamin C in Human Serum............................................................................... 2
 

References ............................................................................................................................................ 3
 

Appendix A. Shipping Package Inserts for RR56........................................................................ A1
 

Appendix B. Final Report for RR56 ..............................................................................................B1
 

Appendix C. “All-Lab Report” for RR56 ......................................................................................C1
 

Appendix D. Representative “Individualized Report” for RR56 ............................................... D1
 

Appendix E. Shipping Package Inserts for RR21 ......................................................................... E1
 

Appendix F. Final Report for RR21............................................................................................... F1
 

Appendix G. “All-Lab Report” for RR21..................................................................................... G1
 

Appendix H. Representative “Individualized Report” for RR21............................................... H1
 

iv 
 

Introduction 

Beginning in 1988, the National Institute of Standards and Technology (NIST) has coordinated the 

Micronutrients Measurement Quality Assurance Program (MMQAP) for laboratories that measure 

fat- and water-soluble vitamins and carotenoids in human serum and plasma. The MMQAP 

provides participants with measurement comparability assessment through use of interlaboratory 

studies, Standard Reference Materials (SRMs) and control materials, and methods development and 

validation. Serum-based samples with assigned values for the target analytes (retinol, alphatocopherol, gamma/beta-tocopherol, trans- and total beta-carotene, and total ascorbic acid) and 

performance-evaluation standards are distributed by NIST to laboratories for analysis. 

Participants use the methodology of their choice to determine analyte content in the control and 

study materials. Participants provide their data to NIST, where it is compiled and evaluated for 

trueness relative to the NIST value, within-laboratory precision, and concordance within the 

participant community. NIST provides the participants with a technical summary report concerning 

their performance for each exercise and suggestions for methods development and refinement. 

Participants who have concerns regarding their laboratory’s performance are encouraged to consult 

with the MMQAP coordinators. 

All MMQAP interlaboratory studies consist of individual units of batch-prepared samples that are 

distributed to each participant. For historical reasons these studies are referred to as “Round 

Robins”. The MMQAP program and the nature of its studies are described elsewhere. [1,2] 

Round Robin LVI: Fat-Soluble Vitamins and Carotenoids in Human Serum 

Participants in the MMQAP Fat-Soluble Vitamins and Carotenoids in Human Serum Round Robin 

LVI comparability study (hereafter referred to as RR56) received two lyophilized and three liquidfrozen human serum test samples for analysis. Unless multiple vials were previously requested, 

participants received one vial of each serum. These sera were shipped on dry ice to participants in 

May 2004. The communication materials included in the sample shipment are provided in 

Appendix A. 

Participants are requested to report values for all fat-soluble vitamin-related analytes that are of 

interest to their organizations. Not all participants report values for the target analytes, and many 

participants report values for non-target analytes. 

The final report delivered to every participant in RR56 consists of three documents: 

•	 A cover letter for the current study, a brief description of the other two documents, and a 

discussion of our analysis of the overall results that may be of broad interest. This cover 

letter is reproduced as Appendix B. 

•	 The “All-Lab Report” that lists all of the reported measurement results, a number of 

consensus statistics for analytes reported by more than one participant, and the mean median 

and pooled SD from any prior distributions of the serum. This report also provides a 

numerical “score card” for each participant’s measurement comparability for the more 

commonly reported analytes. This report is reproduced as Appendix C. 

1
 
 

 

 

•	 An “Individualized Report” that graphically analyzes each participant’s results for all 

analytes reported by at least five participants. This report also provides a graphical summary 

of their measurement comparability. The graphical tools used in this report are described in 

detail elsewhere [3]. An example “Individualized Report” is reproduced as Appendix D. 

Round Robin 21: Vitamin C in Human Serum 

Participants in the MMQAP Vitamin C in Human Serum Round Robin 21 comparability study 

(hereafter referred to as RR21) received four frozen serum test samples, two frozen control sera, and 

a solid ascorbic acid control material for analysis. Unless multiple vials were previously requested, 

participants received one vial of each material. These sample materials were shipped on dry ice to 

participants in May 2004. The communication materials included in the sample shipment are 

provided in Appendix E. 

The test and control serum materials were prepared by adding equal volumes of 10 % 

metaphosphoric acid (MPA) to human serum that had been spiked with ascorbic acid. While these 

samples contain some dehydroascorbic acid, its content is variable. Therefore, the participants 

report only total ascorbic acid (TAA, ascorbic acid plus dehydroascorbic acid). Participants are also 

encouraged to prepare calibration solutions from the supplied solid control to enable calibrating their 

serum measurements to the same reference standard. 

The final report delivered to every participant in RR21 consists of three documents: 

•	 A cover letter for the current study, a brief description of the other two documents, and a 

discussion of our analysis of overall results that may be of broad interest. This cover letter is 

reproduced as Appendix F. 

•	 The “All-Lab Report” that summarizes all of the reported measurement results and provides 

several consensus statistics. This report is reproduced as Appendix G. 

•	 An “Individualized Report” that graphically analyzes each participant’s results for TAA, 

including a graphical summary of their measurement comparability. The graphical tools 

used in this report are described in detail elsewhere [3]. An example “Individualized Report” 

is reproduced as Appendix H. 

2
 
 

References 

1 Duewer DL, Brown Thomas J, Kline MC, MacCrehan WA, Schaffer R, Sharpless KE, May WE, 

Crowell JA. NIST/NCI Micronutrients Measurement Quality Assurance Program: Measurement 

Repeatabilities and Reproducibilities for Fat-Soluble Vitamin-Related Compounds in Human 

Sera. Anal Chem 1997;69(7):1406-1413. 

2 Margolis SA, Duewer DL. Measurement Of Ascorbic Acid in Human Plasma and Serum: 

Stability, Intralaboratory Repeatability, and Interlaboratory Reproducibility. Clin Chem 

1996;42(8):1257-1262. 

3 Duewer DL, Kline MC, Sharpless KE, Brown Thomas J, Gary KT, Sowell AL. Micronutrients 

Measurement Quality Assurance Program: Helping Participants Use Interlaboratory Comparison 

Exercise Results to Improve Their Long-Term Measurement Performance. Anal Chem 

1999;71(9):1870-1878. 

3
 
Appendix A. Shipping Package Inserts for RR56 

The following three items were included in each package shipped to an RR56 participant: 

• Cover letter 

• Datasheet 

• Packing List and Shipment Receipt Confirmation Form 

The cover letter and datasheet were enclosed in a sealed waterproof bag along with the 

samples themselves. The packing list was placed at the top of the shipping box, between 

the cardboard covering and the foam insulation. 

A1
May 12, 2004 

Dear Colleague: 

UNITED STATES DEPARTMENT OF c:pMMEllCE Nationlll lllllCieuCe at ............ and Teahnolagy 

Gaithersburg, Maryland 2089&CXXl1 

Enclosed are the samples (Sera 304 - 308) for the second fat-soluble vitamins and carotenoids in serum 

round robin study (Round Robin L VI) for the 2004 NIST Micronutrients Measurement Quality Assurance 

Program. You will find one vial of each of three liquid-froz.en and two lyophilized serum samples for 

analysis along with a fonn for reporting your results. When reporting your results, please submit one 

value for each analyte for a given serum sample. If a value is obtained below your limit of quantification, 

please indicate this result on the form by using NQ (Not Quantified). Results are due to NIST by 

September 13, 2004. Results received more than two weeks after the due date will not be included in the 

summary report for this round robin study. The feedback report concerning the study will be provided 

around mid-October. 

Lyophilized samples should be reconstituted with 1.0 mL of HPLC-grade water or equivalent. We 

recommend that dissolution be facilitated with 3 to 5 min agitation in an ultrasonic bath or at least 30 min 

at room temperature with intermittent swirling. (CAUTION: Vigorous shaking will cause foaming and 

possibly interfere with accurate measurement. The rubber stopper contains phthalate esters that may 

leach into the sample upon intermittent cont.act of the liquid sample with the stopper. These esters absorb 

strongly in the UV region and elute near retinol in most LC systems creating analytical problems.) 

Pipette a known volume of serum from the vial for analysis. The final volume of the reconstituted sample 

is greater than 1.0 mL. Water should not be added to the liquid-frozen samples 306, 307, and 308. 

For consistency, we request that laboratories use the following absorptivities (E 1% cm): retinol, 1843 at 

325 nm (ethanol); retinyl palmitate, 975 at 325 nm (ethanol); u-tocopherol, 75.8 at 292 nm (ethanol); y- . 

tocopherol, 91.4 at 298 nm (ethanol); ex-carotene, 2800 at 444 nm (hexane); P-caiotene, 2560 at 450 nm 

(ethanol), 2592 at 452 nm (hexane); lycopene, 3450 at 472 nm (hexane). 

Please mail or fax your results for Round Robin L VI to: 

Micronutrients Measurement Quality Assurance Program 

NIST · 

100 Bureau Drive Stop 8392 

Gaithersburg, MD 20899-8392 

Fax: (301) 977-0685 

If you have questions or co ents regarding this study, please call me at (301) 975-3120; e-mail me at 

jbthomas@nist.gov; or 111A.un.c111o. queries to the above address. 

I' 

u 

l ce Brown Thomas 

Res ch Chemist 

· ytical Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosures 

A2

NISI 
 

 

 

Participant #: ________ Date: _____________ 

Round Robin LVI 

NIST Micronutrients Measurement Quality Assurance Program 

Analyte 304 305 306 307 308 Units* 

total retinol 

trans-retinol 

didehydroretinol 

retinyl palmitate 

α-tocopherol 

γ/β-tocopherol 

δ-tocopherol 

total β-carotene 

trans-β-carotene 

total cis-β-carotene 

total α-carotene 

total lycopene 

trans-lycopene 

total β-cryptoxanthin 

total α-cryptoxanthin 

total lutein 

total zeaxanthin 

total lutein&zeaxanthin

 total Coenzyme Q10 

ubiquinol (QH2) 

ubiquinone (Qox) 

phylloquinone (K1) 

25-hydroxyvitamin D 

Other analytes? 

* we prefer μg/mL 

Were sera {306,307,308} frozen when received? Yes | No 

Comments: 

Mail: M2QAP 

NIST, Stop 8392 Please return results before Fax: 301-977-0685 

Gaithersburg, MD 20899-8392 13-Sep-2004 Email: David.Duewer@NIST.gov 

A3
 

 

 

 

Participant #: ________ Date: _____________ 

Fat-Soluble Vitamins Round Robin LVI 

NIST Micronutrients Measurement Quality Assurance Program 

Packing List and Shipment Receipt Confirmation Form 

This box contains (we hope) one vial each of the following five FSV M2QAP sera: 

Serum Form Reconstitute? 

#304 Lyophilized Yes (1 ml H2O) 

#305 Lyophilized Yes (1 ml H2O) 

#306 Liquid frozen No 

#307 Liquid frozen No 

#308 Liquid frozen No 

Please 1) Open the pack immediately 

2) Check that it contains one vial each of the above samples 

3) Check if sera {306, 307, 308} arrived frozen 

4) Store the samples at -20  ̊C or below until analysis 

5) Complete the following information 

6) Fax the completed form to us at 301-977-0685 

(or email requested information to david.duewer@nist.gov) 

1) Date this shipment arrived: ___________________________ 

2) Are all five vials intact? Yes | No 

If "No", which one(s) were damaged? 

3) Was there any dry-ice left in cooler? Yes | No 

4) Did sera {306, 307, 308} arrive frozen? Yes | No 

5) At what temperature are you storing the samples? _______  ̊C 

6) When do you anticipate analyzing these samples? ________________________ 

Your prompt return of this information is appreciated. 

The M2QAP Gang 

Mail: M2QAP 

NIST, Stop 8392 Fax: 301-977-0685 

Gaithersburg, MD 20899-8392 Email: David.Duewer@NIST.gov 

A4
 

 

Appendix B. Final Report for RR56 

The following two pages are the final report as provided to all participants: 

•	 Cover letter. 

•	 An information sheet that: 

o	 describes the contents of the “All-Lab” report, 

o	 describes the content of the “Individualized” report, 

o	 describes the nature of the test samples and details their previous distributions, 

if any, and 

o	 summarizes aspects of the study that we believe may be of interest to the 

participants. 

B1
~=--

November 3, 2004 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standards and Technology 

Gaithersburg, Maryland 20899-

Enclosed is the summary report of the results for round robin LVI (RR56) of the 2004 NIST 

Micronutrients Measurement Quality Assurance Program (M2

QAP) for the fat-soluble vitamins and 

carotenoids in human serum. Included in this report are: (1) a summary of data and measurement 

comparability scores for all laboratories, (2) a detailed graphical analysis of your results; and (3) a 

graphical summary of your measurement comparabilities relative to the NIST assigned values. The 

NIST-assigned values are equally weighted means of the medians from this interlaboratory comparison 

exercise and the means from the analyses performed by NIST . . Data for evaluating laboratory performance in RR 56 are provided in the comparability summary (Score 

Card) on page 5 of the All Lab Report. Laboratory comparability is summarized as follows: results rated 

1 to 3 are within 1 to 3 standard deviation(s) of the assigned value, respectively; those rated 4 are >3 

standard deviations from the assigned value. 

-' 

If you have concerns regarding your laboratory's performance, we suggest that you obtain and analyze a 

unit of SRM 968c, Fat-Soluble Vitamins, Carotenoids, and Cholesterol in Human Serum. If your 

measured values do not agree with the certified values, we· suggest that you contact us for consultation. 

Samples for the first 2005 QA interlaboratory exercises will be shipped starting the week of November 

8. We will send you a reminder via e-mail or fax a week prior to shipment. It is critical that you 

carefully inspect all samples upon arrival and that you promptly corifirm to us that they have arrived. We 

will replace samples (lost or damaged in shipment or mis-packaged by us) only for participants who 

report the· problem. within one calendar week after the pac~age arrives. 

If you have any questions regarding this report, please contact Dave Duewer at david.duewer@nist.gov 

or me atjbthomas@nist.gov tel: 301/975-3120, or fax: 301/977-0685. 

ice Brown Thomas 

e earch Chemist 

alytical Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosures 

B2

NISI 
 

The NIST M2QAP Round Robin LIV (RR56) report consists of: 

Page “All Lab” Report 

1-3 A listing of all results and statistics for analytes reported by at least two laboratories. 

4a A list of results for the analytes reported by only one laboratory. 

4b A legend for the above two lists. 

5 The text version of the “Comparability Summary” (or “Score Card”). 

Page “Individualized” Report 

1 Your values, the number of labs reporting values, and our assigned values. 

2 to “Four Plot” summaries of your current and past measurement performance, one page for 

n each analyte you report that is also reported by at least 8 other participants. 

n+1 The “target” plot version of your “Comparability Summary” scores. 

Samples. The five sera below were distributed in RR56. 

Serum Description Prior Distributions 

304 Lyophilized blended serum with native carotenoid #248 RR44 (9/98), #258 RR46 (6/99), 

levels, augmented with trans-retinol and γ/β- #263 RR47 (5/00), #280 RR51 (3/02) 

tocopherol; SRM 968c Level I. 

305 Lyophilized, native, single donor serum prepared in #266 RR48 (9/00), #277 RR50 (0/01) 

1999. The same material was used for #308. #282 RR51 (3/02), #295 RR54 (9/03) 

306 The same fresh-frozen blended serum as #307, #285 RR52 (9/02), #297 RR54 (9/03)
 

augmented with ≈0.3 μg/mL trans-retinol. It was
 

prepared in 2002. 

307 The same fresh-frozen blended serum as #306, #286 RR52 (9/02), #298 RR54 (9/03)
 

augmented with ≈0.3 μg/mL 13-cis-retinol. It was
 

prepared in 2002. 

308 Fresh-frozen, native, single donor serum prepared in #271 RR49 (3/01), #275 RR50 (9/01) 

1999. The same material was used for #305. #279 RR51 (3/02), #296 RR54 (9/03) 

Results 

1)	 Sera Stability. There was no significant change in the median level nor increase in the variability of 

any measurand in any of the sera. 

2)	 Matrix (Lyophilized vs. Fresh-Frozen) Differences. Sera 305 and 306 were prepared from the same 

serum pool. Since we suggest that you reconstitute our lyophilized samples with 1.0 mL water rather 

than to a total volume of 1.0 mL, the measurand levels in Serum 305 should be ≈ 95% of those in 

Serum 306. The observed average ratio ± SD over all measurands with 10 or more quantitative 

measurements is 0.937 ± 0.018. If any of your Sera 305/308 ratios are much different than 0.95, you 

should look at your measurement system for those measurands. If your ratios are consistently much 

different from 0.95, you should review how you reconstitute lyophilized materials. 

B3
 

 

Appendix C. “All-Lab Report” for RR56 

The following six pages are the “All-Lab Report” as provided to all participants, with two 

exceptions: 

• the participant identifiers (Lab) have been altered. 

• the order in which the participant results are listed has been altered. 

The data summary in the “All-Lab Report” has been altered to ensure confidentiality of 

identification codes assigned to laboratories. The only attributed results are those 

reported by NIST. The NIST results are not used in the assessment of the consensus 

summary results of the study. 

C1
 

Round Robin LVI Laboratory Results 

All Values in μg/mL 

Total Retinol trans-Retinol Retinyl Palmitate α-Tocopherol γ/β-Tocopherol 

Lab 304 305 306 307 308 

C2

FSV-BA 0.841 0.467 0.653 0.571 0.502 

FSV-BB 0.851 0.438 0.625 0.607 0.458 

FSV-BC 0.812 0.433 0.619 0.609 0.467 

FSV-BD 0.869 0.428 0.605 0.590 0.453 

FSV-BE 0.930 0.450 0.630 0.640 0.490 

FSV-BF 0.870 0.440 0.610 0.490 0.460 

FSV-BG 0.825 0.420 0.603 0.600 0.453 

FSV-BH 0.810 0.436 0.646 0.423 0.441 

FSV-BI 0.914 0.496 0.672 0.642 0.507 

FSV-BJ 0.847 0.435 0.613 0.602 0.454 

FSV-BK 0.845 0.442 0.585 0.579 0.489 

FSV-BL 1.000 0.600 0.720 0.660 0.540 

FSV-BM 0.852 0.511 0.657 0.643 0.528 

FSV-BN 0.806 0.405 0.613 0.589 0.423 

FSV-BO 0.934 0.398 0.622 0.593 0.438 

FSV-BP 0.917 0.448 0.723 0.687 0.555 

FSV-BQ 0.895 0.519 0.662 0.596 0.525 

FSV-BR ≥0.830 ≥0.450 ≥0.630 - ≥0.470

FSV-BS 0.783 0.329 0.446 0.410 0.384 

FSV-BT 0.887 0.468 0.606 0.560 0.458 

FSV-BU 0.850 0.433 0.619 0.590 0.461 

FSV-BV 1.010 0.497 0.634 0.439 0.490 

FSV-BW 0.950 0.480 0.660 0.660 0.490 

FSV-BX 0.864 0.444 0.639 0.629 0.471 

FSV-CB 0.710 0.384 0.507 0.480 0.369 

FSV-CC 0.810 0.410 0.570 0.540 0.450 

FSV-CD 0.877 0.439 0.644 0.627 0.454 

FSV-CE 0.738 0.392 0.480 0.450 0.390 

FSV-CF 0.875 0.453 0.629 0.620 0.469 

FSV-CG 0.922 0.442 0.609 0.584 0.462 

FSV-CI 0.844 0.453 0.669 0.487 0.476 

FSV-CS 0.777 0.397 0.569 0.540 0.411 

FSV-CT 

FSV-CW ≥1.088 ≥0.552 ≥0.835 - ≥0.643

FSV-CZ 0.860 0.450 0.680 0.580 0.480 

FSV-DA 0.850 0.452 0.725 0.636 0.479 

FSV-DD 1.497 0.780 1.081 1.031 0.765 

FSV-DF 0.853 0.425 0.659 0.616 0.457 

FSV-DI 0.950 0.432 0.680 0.590 0.466 

FSV-DW 0.880 0.490 0.670 0.650 0.480 

FSV-ET 0.850 0.440 0.620 0.590 0.380 

304 305 306 307 308 

0.830 0.450 0.630 0.410 0.470 

0.790 0.400 0.570 0.380 0.450 

1.088 0.552 0.835 0.825 0.643 

0.850 0.452 0.725 0.372 0.479 

304 305 306 307 308 

0.036 0.057 0.021 0.021 0.053 

0.029 0.053 0.014 0.011 0.059 

0.039 0.051 0.025 0.023 0.056 

0.030 0.057 0.020 0.018 0.057 

nq nq nq nq nq 

0.026 0.039 0.011 0.010 0.041 

0.054 0.080 0.024 0.019 0.082 

0.026 0.065 0.022 0.020 0.080 

0.036 0.048 0.017 0.021 0.047 

0.024 0.039 0.013 0.011 0.044 

0.024 0.053 0.012 

0.022 0.039 0.011 

0.015 0.056 

0.008 0.040 

304 305 306 307 308 

6.85 6.46 2.70 2.72 6.97 

7.65 7.03 3.08 2.99 7.45 

7.80 7.20 2.70 2.60 7.80 

7.80 6.60 2.80 2.90 7.10 

7.00 6.30 2.50 2.60 6.30 

7.47 6.62 2.89 2.93 7.26 

7.53 7.02 2.85 2.78 7.26 

6.44 6.21 2.51 2.53 6.43 

7.28 6.80 2.68 2.67 7.02 

6.82 5.42 2.64 2.48 5.65 

6.03 5.60 3.01 3.01 6.89 

6.90 6.30 2.80 3.00 6.70 

7.00 5.33 2.28 2.53 6.23 

6.63 5.69 2.58 2.54 6.16 

7.35 6.58 2.88 2.80 6.90 

7.60 6.20 3.00 3.00 7.60 

7.77 6.76 2.77 2.60 6.97 

4.87 4.67 1.49 2.45 3.76 

7.02 5.93 3.20 3.24 6.90 

7.84 6.92 3.24 3.30 7.17 

8.90 7.29 2.77 2.78 7.44 

8.00 7.24 3.02 3.03 7.41 

7.71 6.82 2.99 2.92 7.18 

7.28 6.46 2.96 2.83 7.09 

7.04 6.31 2.70 2.71 7.03 

6.96 6.25 2.48 2.38 6.42 

7.41 6.84 3.06 2.64 7.46 

7.20 6.90 3.20 3.10 6.90 

6.39 5.93 2.43 2.49 6.56 

5.86 5.37 2.05 2.10 5.43 

9.58 8.53 2.59 2.48 6.89 

8.90 7.60 2.60 2.80 8.10 

7.60 6.90 3.20 2.90 7.20 

7.51 6.81 2.82 3.31 7.28 

7.88 7.01 2.96 2.91 7.28 

7.32 6.64 2.73 2.68 6.33 

7.00 6.40 2.60 2.50 6.90 

304 305 306 307 

3.80 1.90 0.73 0.73 

3.42 1.71 0.68 0.63 

4.00 1.80 0.70 0.70 

3.70 1.80 0.70 0.70 

3.65 1.77 0.76 0.75 

3.55 1.84 0.72 0.73 

4.05 1.96 0.73 0.70 

3.63 1.49 0.52 0.68 

2.57 0.88 0.09 0.31 

3.27 1.59 0.69 0.72 

3.96 2.01 0.67 0.71 

4.81 2.10 0.74 0.76 

4.70 2.22 0.86 0.86 

3.83 1.81 0.73 0.72 

3.54 1.72 0.65 0.60 

3.56 1.74 0.69 0.70 

3.09 1.50 0.53 0.55 

4.11 1.92 0.69 0.63 

4.70 2.10 0.80 0.80 

3.94 1.87 0.70 0.82 

3.84 1.77 0.68 0.67 

3.60 1.70 0.70 0.60 

N 38 38 38 38 38 4 4 4 4 4 11 11 11 11 11 37 37 37 37 37 22 22 22 22 

Min 0.710 0.329 0.446 0.410 0.369 0.790 0.400 0.570 0.372 0.450 0.022 0.039 0.011 0.008 0.040 4.87 4.67 1.49 2.10 3.76 2.57 0.88 0.09 0.31 

Median 0.857 0.441 0.630 0.592 0.464 0.840 0.451 0.677 0.395 0.474 0.029 0.053 0.017 0.018 0.056 7.32 6.60 2.77 2.78 6.97 3.75 1.80 0.70 0.70 

Max 1.497 0.780 1.081 1.031 0.765 1.088 0.552 0.835 0.825 0.643 0.054 0.080 0.025 0.023 0.082 9.58 8.53 3.24 3.31 8.10 4.81 2.22 0.86 0.86 

SD 0.050 0.026 0.039 0.049 0.027 0.008 0.010 0.007 0.007 0.009 0.56 0.51 0.29 0.29 0.52 0.32 0.15 0.04 0.07 

CV 6 6 6 8 6 0 0 0 0 0 29 19 40 39 17 8 8 10 10 7 9 8 5 9 

Npast 43 39 36 37 37 9 9 8 7 9 14 13 9 9 12 47 44 37 37 42 26 25 22 22 

Medianpast 0.858 0.446 0.624 0.590 0.467 0.839 0.437 0.608 0.389 0.451 0.035 0.052 0.016 0.016 0.054 7.53 6.76 2.92 2.90 7.14 3.850 1.847 0.746 0.752 

SDpast 0.057 0.041 0.052 0.049 0.043 0.047 0.037 0.030 0.044 0.033 0.012 0.011 0.006 0.004 0.013 0.68 0.58 0.24 0.27 0.57 0.342 0.126 0.090 0.073 

NIST 0.848 0.451 0.619 0.601 0.447 7.66 6.86 2.64 2.78 7.13 3.91 1.85 0.71 0.72 

NNIST 3 3 3 3 3 3 3 3 3 3 3 3 3 3 

Srep 0.031 0.016 0.042 0.066 0.041 0.18 0.23 0.13 0.13 0.61 0.05 0.04 0.05 0.02 

Shet 0.021 0.016 0.010 0.037 0.013 0.01 0.13 0.06 0.10 0.10 0.07 0.01 0.01 0.02 

SNIST 0.037 0.022 0.043 0.076 0.043 0.18 0.26 0.15 0.16 0.62 0.09 0.04 0.05 0.03 

NAV 0.852 0.446 0.624 0.592 0.456 0.840 0.451 0.677 0.395 0.474 0.029 0.053 0.017 0.018 0.056 7.49 6.73 2.71 2.78 7.05 3.83 1.82 0.70 0.71 

NAU 0.067 0.036 0.051 0.076 0.045 0.013 0.017 0.011 0.011 0.017 0.65 0.59 0.41 0.40 0.63 0.36 0.19 0.09 0.09 

All Lab Report 
 

Round Robin LVI Laboratory Results
 

All Values in μg/mL
 

C3

Total β-Carotene trans-β-Carotene Total cis-β-Carotene Total α-Carotene 

Lab
 304 305 306 307 308 304 305 306 307 308
 

0.150 0.301 0.045 0.045 0.340
 

0.169 0.323 0.044 0.051 0.366
 

0.143 0.292 0.040 0.040 0.291
 

0.299 0.043
 

0.179 0.307 0.061 0.056 0.342
 

0.149 0.252 0.052 0.048 0.293
 

0.154 0.292 0.049 0.049 0.324
 

0.138 0.266 0.042 0.043 0.296
 

0.168 0.319 0.050 0.046 0.334
 

0.226 0.409 0.057 0.058 0.490
 

0.161 0.327 0.051 0.061 0.357
 

304 305 306 307 308
 304 305 306 307 308
 

FSV-BA
 0.160 0.319 0.045 0.047 0.360 0.011 0.018 0.002 0.002 0.019 0.015 0.028 0.003 0.004 0.030
 

FSV-BB
 0.179 0.347 0.044 0.051 0.390 0.010 0.024 nd 0.000 0.025 0.012 0.030 0.003 0.004 0.033
 

FSV-BC
 

FSV-BD
 

FSV-BE
 0.172 0.321 0.042 0.045 0.340
 

FSV-BF
 0.130 0.290 0.039 0.050 0.295 0.016 0.029 0.008 0.011 0.026
 

FSV-BG
 0.160 0.366 0.055 0.055 0.379 0.019 0.026 0.008 0.009 0.031
 

FSV-BH
 0.155 0.319 0.040 0.040 0.315 0.012 0.027 nq nq 0.024 0.009 0.020 nq nq 0.020
 

FSV-BI
 0.197 0.409 0.057 0.056 0.429 0.016 0.033 0.004 0.004 0.036
 

FSV-BJ
 0.191 0.381 0.033 0.032 0.389 0.016 0.030 nq nq 0.035
 

FSV-BK
 

FSV-BL
 

FSV-BM
 

FSV-BN
 0.325 0.047 0.021 0.023
 

FSV-BO
 0.183 0.359 0.052 0.041 0.422 0.010 0.019 nq nq 0.031
 

FSV-BP
 0.198 0.354 0.078 0.061 0.388 0.027 0.024 0.027 0.017 0.025
 

FSV-BQ
 

FSV-BR
 

FSV-BS
 ≥0.179 ≥0.307 ≥0.061 ≥0.056 ≥0.342 0.031 0.047 0.025 0.024 0.042
 

FSV-BT
 0.168 0.277 0.057 0.053 0.323 0.014 0.019 0.004 0.004 0.022 0.017 0.024 0.008 0.007 0.029
 

FSV-BU
 0.154 0.305 0.038 0.041 0.323 0.015 0.027 0.007 0.007 0.028
 

FSV-BV
 0.212 0.352 0.050 0.051 0.364 0.013 0.019 0.003 0.003 0.021
 

FSV-BW
 0.188 0.349 0.052 0.049 0.364 0.012 0.028 nq nq 0.024
 

FSV-BX
 ≥0.154 ≥0.292 ≥0.049 ≥0.049 ≥0.324 0.020 0.030 0.008 0.008 0.032
 

FSV-CB
 0.115 0.322 0.047 0.049 0.344 0.006 0.015 0.002 0.003 0.022
 

FSV-CC
 

FSV-CD
 0.162 0.273 0.044 0.041 0.312 0.021 0.036 nd nd 0.045
 

FSV-CE
 0.163 0.326 0.055 0.040 0.358
 

FSV-CF
 

FSV-CG
 0.150 0.289 0.044 0.045 0.319 0.012 0.023 0.005 0.005 0.023 0.017 0.033 0.004 0.004 0.037
 

FSV-CI
 0.172 0.305 0.066 0.065 0.318 0.034 0.041 <0.016 <0.016 0.046
 

FSV-CS
 0.187 0.355 0.053 0.052 0.372 0.020 0.036 0.003 0.006 0.038 0.014 0.030 0.005 0.005 0.031
 

FSV-CT
 0.192 0.358 0.037 0.047 0.412
 

FSV-CW
 ≥0.226 ≥0.409 ≥0.057 ≥0.058 ≥0.490 0.021 0.035 0.009 0.006 0.043
 

FSV-CZ
 0.176 0.328 0.070 0.072 0.352
 

FSV-DA
 0.180 0.353 0.056 0.067 0.383 0.019 0.026 0.004 0.007 0.026 0.014 0.030 0.006 0.006 0.032
 

FSV-DD
 

FSV-DF
 

FSV-DI
 0.174 0.343 0.045 0.044 0.346
 

FSV-DW
 0.110 0.220 0.050 0.050 0.220 0.013 0.024 0.006 0.007 0.024
 

FSV-ET
 0.180 0.360 0.050 0.050 0.380 

N 26 27 27 26 26 10 11 11 10 10 7 8 5 6 7 23 24 17 17 23 2

Min 0.110 0.220 0.033 0.032 0.220 0.138 0.252 0.040 0.040 0.291 0.010 0.018 0.002 0.000 0.019 0.006 0.015 0.002 0.003 0.020 0.17

Median 0.173 0.328 0.050 0.050 0.359 0.157 0.301 0.049 0.049 0.337 0.012 0.023 0.004 0.004 0.024 0.016 0.029 0.006 0.006 0.031 0.29

Max 0.212 0.409 0.078 0.072 0.429 0.226 0.409 0.061 0.061 0.490 0.020 0.036 0.005 0.007 0.038 0.034 0.047 0.027 0.024 0.046 0.41

SD 0.020 0.031 0.008 0.006 0.044 0.015 0.021 0.006 0.007 0.037 0.004 0.004 0.001 0.002 0.002 0.005 0.005 0.003 0.003 0.007 0.04

CV 11 10 16 13 12 9 7 12 15 11 31 18 26 58 9 31 18 49 42 24 1

304 

0.29

0.33

0.28

0.26

0.29

0.26

0.36

0.35

0.39

0.37

0.30

0.29

0.41

0.35

0.17

0.29

0.29

0.32

0.36

0.33

0.29

0.19

Npast 31 30 27 27 30 15 14 12 12 14 9 9 6 6 9 27 26 16 15 25 2

Medianpast 0.173 0.323 0.051 0.050 0.348 0.161 0.297 0.048 0.048 0.319 0.014 0.023 0.003 0.004 0.023 0.016 0.029 0.006 0.005 0.030 0.30

SDpast 0.022 0.047 0.007 0.007 0.038 0.018 0.028 0.006 0.004 0.023 0.007 0.008 0.002 0.002 0.006 0.004 0.007 0.003 0.002 0.007 0.05

NIST ≥0.155 ≥0.308 ≥0.050 ≥0.054 ≥0.306 0.155 0.308 0.050 0.054 0.306 nq 0.034 nq nq 0.025
 

NNIST 3 3 3 3 3 3 3 3 3 3 3 3
 

Srep 0.008 0.017 0.003 0.002 0.016 0.008 0.017 0.003 0.002 0.016 0.003 0.003
 

Shet 0.002 0.012 0.005 0.001 0.011 0.002 0.012 0.005 0.001 0.011 0.001 0.002
 

SNIST 0.008 0.021 0.006 0.002 0.020 0.008 0.021 0.006 0.002 0.020 0.003 0.003
 

NAV 0.164 0.319 0.050 0.052 0.333 0.156 0.306 0.049 0.051 0.322 0.012 0.023 0.004 0.004 0.024 0.016 0.031 0.006 0.006 0.028 0.29

NAU 0.030 0.049 0.011 0.011 0.063 0.018 0.033 0.009 0.010 0.043 0.004 0.008 0.003 0.003 0.008 0.006 0.010 0.003 0.003 0.011 0.06

All Lab Report 
 

Round Robin LVI Laboratory Results 

All Values in μg/mL 

trans-Lycopene Total β-Cryptoxanthin Total α-Cryptoxanthin Total Lutein 

Lab 304 305 306 307 308 

C4

FSV-BA 0.154 0.177 0.095 0.094 0.200 

FSV-BB 0.144 0.160 0.087 0.084 0.172 

FSV-BC 

FSV-BD 

FSV-BE 

FSV-BF 

FSV-BG 0.144 0.194 0.111 0.108 0.209 

FSV-BH 

FSV-BI 

FSV-BJ 

FSV-BK 

FSV-BL 

FSV-BM 

FSV-BN 0.168 0.096 

FSV-BO 

FSV-BP 

FSV-BQ 

FSV-BR 

FSV-BS 

FSV-BT 0.148 0.138 0.096 0.095 0.162 

FSV-BU 

FSV-BV 

FSV-BW 

FSV-BX 0.122 0.157 0.088 0.087 0.176 

FSV-CB 

FSV-CC 

FSV-CD 

FSV-CE 

FSV-CF 

FSV-CG 0.166 0.182 0.099 0.100 0.202 

FSV-CI 

FSV-CS 

FSV-CT 

FSV-CW 0.100 0.097 0.060 0.064 0.114 

FSV-CZ 

FSV-DA 0.174 0.197 0.108 0.130 0.217 

FSV-DD 

FSV-DF 

FSV-DI 

FSV-DW 

FSV-ET 

304 305 306 307 308 

0.078 0.059 0.020 0.020 0.070 

0.069 0.049 0.019 0.018 0.053 

0.063 0.043 0.014 0.015 0.044 

0.080 0.050 0.018 0.019 0.047 

0.074 0.051 0.020 0.018 0.053 

0.087 0.066 0.020 0.020 0.066 

0.083 0.055 0.017 0.018 0.059 

0.049 0.013 

0.059 0.037 0.012 0.009 0.047 

0.068 0.048 0.018 0.026 0.044 

0.088 0.066 0.033 0.031 0.065 

0.064 0.047 0.018 0.018 0.047 

0.072 0.047 0.019 0.019 0.053 

0.056 0.030 0.008 0.008 0.032 

0.066 0.039 0.016 0.020 0.046 

0.069 0.046 0.017 0.018 0.052 

0.084 0.056 0.025 0.024 0.060 

0.072 0.051 0.023 0.022 0.058 

0.088 0.067 0.026 0.026 0.074 

0.070 0.051 0.019 0.019 0.053 

0.077 0.049 0.013 0.016 0.059 

0.097 0.070 0.030 0.031 0.077 

0.077 0.058 0.020 0.025 0.062 

0.069 0.052 0.021 0.022 0.050 

304 305 306 307 308 

0.023 0.029 0.012 0.012 0.035 

0.018 0.022 0.010 0.010 0.024 

0.018 0.005 

0.026 0.029 0.014 0.014 0.032 

0.021 0.024 0.011 0.011 0.025 

0.020 0.025 0.011 0.014 0.026 

304 305 306 307 308 

0.057 0.097 0.053 0.049 0.099 

0.058 0.091 0.045 0.051 0.097 

0.043 0.073 0.038 0.038 0.079 

0.048 0.077 0.041 0.040 0.081 

0.063 0.087 0.043 0.044 0.089 

0.061 0.031 0.070 0.105 

0.050 0.075 0.044 0.036 0.086 

0.068 0.083 0.041 0.040 0.078 

0.053 0.084 0.043 0.046 0.092 

0.051 0.057 0.033 0.048 0.075 

0.055 0.074 0.042 0.036 0.078 

0.054 0.084 0.047 0.045 0.091 

0.052 0.078 0.047 0.048 0.086 

0.068 0.100 0.059 0.060 0.116 

0.055 0.088 0.046 0.055 0.094 

0.067 0.089 0.048 0.048 0.093 

0.043 0.070 0.044 0.044 0.067 

304 3

0.034 0

0.020 0

0.034 0

0.030 0

0

0.026 0

0.031 0

0.031 0

0.038 0

0.041 0

0.024 0

0.030 0

0.046 0

0.039 0

0.041 0

N 8 9 9 8 8 23 24 24 23 23 5 6 6 5 5 16 17 17 17 17 14 

Min 0.100 0.097 0.060 0.064 0.114 0.056 0.030 0.008 0.008 0.032 0.018 0.018 0.005 0.010 0.024 0.043 0.057 0.031 0.036 0.067 0.020 0

Median 0.146 0.168 0.096 0.094 0.188 0.072 0.051 0.019 0.019 0.053 0.021 0.024 0.011 0.012 0.026 0.054 0.083 0.044 0.046 0.089 0.032 0

Max 0.174 0.197 0.111 0.130 0.217 0.097 0.070 0.033 0.031 0.077 0.026 0.029 0.014 0.014 0.035 0.068 0.100 0.059 0.070 0.116 0.046 0

SD 0.014 0.019 0.008 0.012 0.025 0.010 0.007 0.003 0.004 0.011 0.003 0.004 0.001 0.002 0.005 0.006 0.010 0.004 0.006 0.011 0.006 0

CV 9 11 8 12 14 14 14 14 21 20 13 16 11 16 19 11 12 9 14 13 19 

Npast 13 11 10 10 11 27 26 23 23 25 5 5 5 4 6 17 16 16 16 16 15 

Medianpast 0.161 0.169 0.098 0.098 0.186 0.073 0.051 0.019 0.018 0.054 0.021 0.024 0.011 0.010 0.025 0.055 0.084 0.045 0.044 0.089 0.032 0

SDpast 0.029 0.033 0.011 0.009 0.040 0.013 0.009 0.004 0.004 0.009 0.005 0.004 0.003 0.003 0.005 0.014 0.013 0.012 0.013 0.018 0.010 0

NIST 0.073 0.054 0.026 0.024 0.049 0.056 0.091 0.046 0.049 0.088 0.019 0

NNIST 3 3 2 3 3 3 3 3 3 3 3 

Srep 0.003 0.005 0.002 0.000 0.005 0.003 0.008 0.003 0.002 0.007 0.001 0

Shet 0.002 0.002 0.002 0.001 0.006 0.003 0.003 0.005 0.003 0.001 0.000 0

SNIST 0.004 0.005 0.003 0.001 0.008 0.004 0.008 0.006 0.004 0.007 0.001 0

NAV 0.146 0.168 0.096 0.094 0.188 0.073 0.052 0.023 0.022 0.051 0.021 0.024 0.011 0.012 0.026 0.055 0.087 0.045 0.047 0.089 0.026 0

NAU 0.026 0.030 0.017 0.016 0.033 0.017 0.013 0.007 0.006 0.013 0.003 0.004 0.001 0.002 0.005 0.011 0.017 0.010 0.010 0.017 0.013 0

All Lab Report 
 

Round Robin LVI Laboratory Results
 

All Values in μg/mL
 

Total Lutein&Zeaxanthin Coenzyme Q10 Phylloquinone (K1) x1000 

Lab 304 305 306 307 616 

C5

FSV-BA 0.083 0.121 0.067 0.062 0.140 

FSV-BB 0.099 0.142 0.077 0.073 0.147 

FSV-BC 

FSV-BD 

FSV-BE 

FSV-BF 0.079 0.102 0.058 0.057 0.112 

FSV-BG 0.065 0.101 0.054 0.057 0.103 

FSV-BH 0.077 0.104 0.055 0.055 0.113 

FSV-BI 0.078 0.106 0.063 0.058 0.111 

FSV-BJ 

FSV-BK 

FSV-BL 

FSV-BM 

FSV-BN 0.076 0.042 0.082 0.122 

FSV-BO 0.0757 0.0950 0.0580 0.0489 0.1030 

FSV-BP 0.115 0.134 0.082 0.075 0.123 

FSV-BQ 

FSV-BR 

FSV-BS 0.107 0.162 0.089 0.091 0.198 

FSV-BT 0.102 0.109 0.058 0.056 0.106 

FSV-BU 0.082 0.098 0.054 0.055 0.104 

FSV-BV 0.116 0.109 0.058 0.059 0.116 

FSV-BW 0.074 0.092 0.049 0.051 0.108 

FSV-BX 0.084 0.113 0.061 0.064 0.122 

FSV-CB 0.089 0.076 0.046 0.069 0.096 

FSV-CC
 

FSV-CD
 0.096 0.104 0.062 0.058 0.105 

FSV-CE 

FSV-CF 

FSV-CG 0.110 0.128 0.075 0.076 0.142 

FSV-CI 0.096 0.104 0.063 0.054 0.110 

0.077 0.110 0.062 0.058 0.118 FSV-CS 

FSV-CT 0.082 0.100 0.058 0.069 0.115 

FSV-CW 0.114 0.143 0.089 0.091 0.164 

FSV-CZ
 

FSV-DA
 0.094 0.122 0.068 0.080 0.130 

FSV-DD 

FSV-DF 

FSV-DI 

FSV-DW 0.084 0.095 0.068 0.069 0.098 

FSV-ET 

304 305 306 307 308 

0.501 0.651 0.320 0.355 0.746 

0.634 0.769 0.459 0.395 0.726 

0.970 1.110 0.660 0.660 1.230 

0.500 0.800 0.300 0.400 0.900 

0.680 0.700 0.590 0.530 0.930 

0.688 0.806 0.476 0.458 0.810 

304 305 306 307 308 

0.84 0.51 0.19 0.18 0.49 

0.82 0.39 0.15 0.17 0.45 

0.72 0.45 0.16 0.18 0.37 

N 23 24 24 24 24 6 6 6 6 6 3 3 3 3 3 

Min 0.065 0.076 0.042 0.049 0.096 0.500 0.651 0.300 0.355 0.726 0.72 0.39 0.15 0.17 0.37 

Median 0.084 0.105 0.061 0.061 0.114 0.657 0.785 0.468 0.429 0.855 0.82 0.45 0.16 0.18 0.45 

Max 0.116 0.162 0.089 0.091 0.198 0.970 1.110 0.660 0.660 1.230 0.84 0.51 0.19 0.18 0.49 

SD 0.016 0.016 0.008 0.012 0.014 0.113 0.065 0.153 0.086 0.119 

CV 19 15 13 20 12 17 8 33 20 14 

Npast 26 25 22 22 23 6 6 7 7 5 0 0 0 0 0 

Medianpast 0.094 0.114 0.065 0.063 0.120 0.617 0.831 0.470 0.475 0.895 

SDpast 0.018 0.015 0.015 0.013 0.020 0.329 0.219 0.062 0.072 0.195 

NIST 0.075 0.112 ≥0.046 0.068 0.105 

NNIST 3 3 3 3
 

Srep 0.002 0.006 0.002 0.009
 

Shet 0.002 0.002 0.003 0.002
 

SNIST 0.003 0.006 0.004 0.009
 

NAV 0.080 0.109 0.061 0.064 0.109 0.657 0.785 0.468 0.429 0.855 0.820 0.450 0.160 0.180 0.450 

NAU 0.018 0.022 0.013 0.014 0.025 0.113 0.065 0.153 0.086 0.119 

All Lab Report 
 

 

 

 

 

Round Robin LVI Laboratory Results
 

All Results in μg/mL
 

Analytes Reported By One Laboratory 

Term 

N 

Min 

Median 

Max 

SD 

CV 

Npast 

Medianpast 

SDpast 

NIST 

NNIST 

Srep 

Shet 

SNIST 

NAV 

NAU 

-

nd 

nq 

<x 

≥x

Analyte Code 304 305 306 307 308 

25-hydroxyvitamin D FSV-BN 0.0830 0.0590 0.0700 0.0730 0.0630 

Phytoene FSV-DA 0.017 0.026 0.010 0.010 0.027 

Phytofluene FSV-DA 0.042 0.048 0.027 0.032 0.053 

Retinyl stearate FSV-DA 0.007 0.012 0.004 0.004 0.014 

trans-Lutein FSV-DA 0.048 0.077 0.041 0.049 0.083 

Ubiquinol FSV-BW 0.800 1.000 0.500 0.500 0.940 

Ubiquinone FSV-BW 0.170 0.110 0.160 0.160 0.290 

Legend 

Definition

 Number of (non-NIST) quantitative values reported for this analyte

 Minimum (non-NIST) quantitative value reported

 Median (non-NIST) quantitative value reported 

 Maximum (non-NIST) quantitative value reported

 Standard deviation for (non-NIST) results: 0.741*(3rd Quartile - 1st Quartile)

 Coefficient of Variation for (non-NIST) results: 100*SD/Median

 Mean of N(s) from past RR(s)

 Mean of Median(s) from past RR(s)

 Pooled SD from past RR(s)
 

 Mean of all analyses (vials x duplicates) reported by a NIST analyst

 Number of total vials analyzed in duplicate by NIST analysts

 W ithin-vial pooled standard deviation

 Among-vial pooled standard deviation 

2

)

0.5 Total standard deviation for NIST analyses: (Srep 2

 + Shet 

 NIST Assigned Value

 = (Median + MeanNIST)/2 for analytes reported by NIST analyst(s)

 = Median for analytes reported by ≥ 10 labs but not NIST

2

)

0.5 NIST Assigned Uncertainty: (S2

 + Sbtw 

 S is the maximum of (0.05*NAV, SD, SNIST, eSD) and Sbtw is the standard

 deviation between Medianpart and MeanNIST. The expected long-term SD, eSD,

 is defined in: Duewer, et al. Anal Chem 1997;69(7):1406-1413.

 Not analyzed

 Not detected (i.e., no detectable peak for analyte)

 Detected but not quantitatively determined

 Concentration at or below the limit of quantification, x

 Concentration greater than or equal to x

All Lab Report Page 5 / 6 

C6
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Round Robin LVI Laboratory Results 

Comparability Summary 

Lab 

FSV-BA 

FSV-BB 

FSV-BC 

FSV-BD 

FSV-BE 

FSV-BF 

FSV-BG 

FSV-BH 

FSV-BI 

FSV-BJ 

FSV-BK 

FSV-BL 

FSV-BM 

FSV-BN 

FSV-BO 

FSV-BP 

FSV-BQ 

FSV-BR 

FSV-BS 

FSV-BT 

FSV-BU 

FSV-BV 

FSV-BW 

FSV-BX 

FSV-CB 

FSV-CC 

FSV-CD 

FSV-CE 

FSV-CF 

FSV-CG 

FSV-CI 

FSV-CS 

FSV-CT 

FSV-CW 

FSV-CZ 

FSV-DA 

FSV-DD 

FSV-DF 

FSV-DI 

FSV-DW 

FSV-ET 

NISTa 

n 

% 1 

% 2 

% 3 

% 4 

TR aT g/bT bC tbC aC TLy TbX TLu TZ L&Z 

1 1 1 1 1 1 1 1 1 1 1 

1 1 1 1 1 1 1 1 1 1 1 

1 

1 1 1 

1 1 1 1 

1 1 1 2 1 1 1 1 

1 1 1 1 1 1 1 1 1 2 

2 1 1 1 2 1 1 

2 1 1 2 1 1 1 1 1 1 

1 1 1 2 1 1 1 1 1 1 

1 2 

3 2 1 

2 1 

1 2 2 1 1 1 1 1 1 1 

1 2 1 1 1 2 2 

2 1 2 4 2 1 2 2 2 

2 1 3 

1 1 1 1 

3 4 4 1 4 1 2 1 1 1 

1 1 1 1 1 1 1 1 1 1 1 

1 1 1 1 1 1 1 

2 2 2 1 1 1 2 

1 1 3 1 1 1 1 2 

1 1 1 1 1 1 

2 1 1 2 2 1 1 

1 1 1 

1 1 1 1 1 1 1 1 1 1 

3 1 1 1 

1 1 

1 2 1 1 1 1 1 2 1 

1 3 2 2 3 

2 3 1 1 1 1 1 1 1 1 1 

1 1 1 1 1 1 

2 2 3 1 2 

1 1 2 

1 1 1 1 1 1 1 1 1 1 1 

4 

1 1 

1 1 1 1 1 2 2 2 

1 1 2 1 2 1 

1 1 1 1 

1 1 1 1 1 1 1 1 1 

39 38 23 27 12 24 23 25 18 16 25 

TR aT g/bT bC tbC aC TLy TbX TLu TZ L&Z 

69 74 74 74 92 79 87 80 89 88 76 

21 18 17 26 0 8 13 20 11 13 20 

8 5 4 0 8 4 0 0 0 0 4 

3 3 4 0 0 8 0 0 0 0 0 

Label 

Lab 

TR 

aT

g/bT 

bC 

tbC 

aC 

TLy 

TbX 

TLu 

TZ 

L&Z 

n 

% 1 

% 2 

% 3 

% 4 

Definition 

Participant code 

Total Retinol 

α-Tocopherol 

γ/β-Tocopherol 

Total β-Carotene 

trans-β-Carotene 

Total α-Carotene 

Total Lycopene 

Total β-Cryptoxanthin 

Total Lutein 

Total Zeaxanthin 

Total Lutein & Zeaxanthin 

number of participants providing quantitative data 

Percent of CS = 1 (within 1 SD of medians) 

Percent of CS = 2 (within 2 SD of medians) 

Percent of CS = 3 (within 3 SD of medians) 

Percent of CS = 4 (3 or more SD from medians) 

“Comparability Score” 

The Comparability Score (CS) of summarizes your measurement 

performance for a given measurand, relative to the consensus 

medians. CS is the average distance, in standard deviation units, 

that your measurement performance characteristics are from the 

consensus performance. CS is calculated when the number of 

quantitative values you reported for a measurand, Nyou, is at least 

two and the measurand has been reported by 10 or more 

participants. 

CS = MIN(4, INT(1 + C2 + AP 2 )) 

N yo u You − Median C = Concordanc e = i i ∑ Ny ou NAU i i 

N you  You i − Median i 

2 

AP = Apparent Precision = ∑  (Ny ou − 1)   NAU i  i  

NAU = NIST Assigned Uncertainty, our estimate of the overall 

measurement standard deviation for each sample. The 

estimate includes serum heterogeneity, analytical 

repeatability, and among-participant reproducibility variance 

components. 

For further details, please see: Duewer DL, Kline MC, Sharpless 

KE, Brown Thomas J, Gary KT. Micronutrients Measurement 

Quality Assurance Program: Helping participants use 

interlaboratory comparison exercise results to improve their longterm measurement performance. Anal Chem 1999;71(9):1870-8. 

All Lab Report Page 6 / 6 

C7
 

Appendix D. Representative “Individualized Report” for RR56 

Each participant in RR56 received an “Individualized Report” reflecting their reported 

results. Each report included a detailed analysis for analytes that were assayed by at least 

five participants. The following analytes met this criterion in RR56: 

• Total Retinol 

• Retinyl Palmitate 

• α-Tocopherol 

• γ/β-Tocopherol 

• δ-Tocopherol 

• Total β-Carotene 

• trans-β-Carotene 

• Total cis-β-Carotene 

• Total α-Carotene 

• Total Lycopene 

• trans-Lycopene 

• Total β-Cryptoxanthin 

• Total α-Cryptoxanthin 

• Total Lutein 

• Total Zeaxanthin 

• Total Lutein & Zeaxanthin 

• Coenzyme Q10 

The following 15 pages are the “Individualized Report” for the analytes evaluated by 

participant FSV-BA. 

D1
 

 Set 1 of 42 

Individualized Round Robin LVI Report: FSV-BA 

Summary 

Serum 304 Serum 305 Serum 306 Serum 307 

D2

Analyte You NAV n You NAV n You NAV n You NAV n 

Total Retinol 0.841 0.852 38 0.467 0.446 38 0.653 0.624 38 0.571 0.592 38 

Retinyl Palmitate 0.04 0.03 11 0.1 0.1 11 0.0 0.0 11 0.02 0.02 11 

α-Tocopherol 6.85 7.49 37 6.46 6.73 37 2.70 2.71 37 2.72 2.78 37 

γ/β-Tocopherol 3.801 3.831 22 1.900 1.823 22 0.733 0.703 22 0.728 0.709 22 

δ-Tocopherol 0.110 0.130 7 0.100 0.100 7 0.032 0.038 7 0.035 0.039 7 

Total β-Carotene 0.160 0.164 26 0.319 0.319 27 0.045 0.050 27 0.047 0.052 26 

trans-β-Carotene 0.150 0.156 10 0.301 0.306 11 0.045 0.049 11 0.045 0.051 10 

Total cis-β-Carotene 0.011 0.012 7 0.018 0.023 8 0.002 0.004 5 0.002 0.004 6 

Total α-Carotene 0.015 0.016 23 0.028 0.031 24 0.003 0.006 17 0.004 0.006 17 

Total Lycopene 0.294 0.299 22 0.333 0.337 23 0.183 0.185 23 0.180 0.192 22 

trans-Lycopene 0.154 0.146 8 0.177 0.168 9 0.095 0.096 9 0.094 0.094 8 

Total β-Cryptoxanthin 0.078 0.073 23 0.059 0.052 24 0.020 0.023 24 0.020 0.022 23 

Total α-Cryptoxanthin 0.023 0.021 5 0.029 0.024 6 0.012 0.011 6 0.012 0.012 5 

Total Lutein&Zeaxanthin 0.083 0.080 23 0.121 0.109 24 0.067 0.061 24 0.062 0.064 24 

You : Your reported values for the listed analytes (micrograms/milliliter) 

NAV : NIST Assigned Values, here equal to this RR's median 

n : Number of non-NIST laboratories reporting quantitative values for this analyte in this serum 

Please check our records against your records. Send corrections and/or updates to... 

Micronutrients Measurement Quality Assurance Program 

National Institute of Standards and Technology 

100 Bureau Drive Stop 8392 

Gaithersburg, MD 20899-8392 USA Email: d

Individualized Report 
 

 Set 1 of 42

Individualized RR LVI Report: FSV-BA 

Total Retinol 

Apparent Precision, SD [Analyte], μg/mL

248258263280304266277282295305271275279296308285297306286298307 

Your [Analyte], μg/mL

Median [Analyte], μg/mL 

Apparent Precision, SD 

Long-term Precision, SD Concordance, SD 

3rd Quartile (75%) 

You, this RR You, ≥x, this RR NIST, this RR 

Median (50%) 

You, past RRs You, ≥x, past RRs Others, this RR 1st Quartile (25%) 

For details of the construction and interpretation of these plots, see:
 

Duewer, Kline, Sharpless, Brown Thomas, Gary, Sowell. Anal Chem 1999;71(9):1870-8.
 

Serum History Comments 

#304 Lyophilized: #248(44), #258(46), #263(47), #280(51) Augmented, multi-source (SRM 968c Level I) 

#305 Lyophilized: #266(48), #277(50), #282(51), #295(54) Same pool as #308, native 

#306 Fresh-frozen: #285(52), #297(54) Same pool as #307, trans-Retinol augmented 

#307 Fresh-frozen: #286(52), #298(54) Same pool as #306, cis-Retinol augmented 

#308 Fresh-frozen: #271(49), #275(50), #279(51), #296(54) Same pool as #305, native 

 Individualized Report Page 2 / 15 

D3
 

 Set 1 of 42

Individualized RR LVI Report: FSV-BA 

Retinyl Palmitate 

Apparent Precision, SD [Analyte], μg/mL

248258263280304266277282295305271275279296308285297306286298307 

Your [Analyte], μg/mL

Median [Analyte], μg/mL 

Apparent Precision, SD 

Long-term Precision, SD Concordance, SD 

3rd Quartile (75%) 

You, this RR You, ≥x, this RR NIST, this RR 

Median (50%) 

You, past RRs You, ≥x, past RRs Others, this RR 1st Quartile (25%) 

For details of the construction and interpretation of these plots, see:
 

Duewer, Kline, Sharpless, Brown Thomas, Gary, Sowell. Anal Chem 1999;71(9):1870-8.
 

Serum History Comments 

#304 Lyophilized: #248(44), #258(46), #263(47), #280(51) Augmented, multi-source (SRM 968c Level I) 

#305 Lyophilized: #266(48), #277(50), #282(51), #295(54) Same pool as #308, native 

#306 Fresh-frozen: #285(52), #297(54) Same pool as #307, trans-Retinol augmented 

#307 Fresh-frozen: #286(52), #298(54) Same pool as #306, cis-Retinol augmented 

#308 Fresh-frozen: #271(49), #275(50), #279(51), #296(54) Same pool as #305, native 

 Individualized Report Page 3 / 15 

D4
 

 Set 1 of 42

Individualized RR LVI Report: FSV-BA 

α-Tocopherol 

Apparent Precision, SD [Analyte], μg/mL

Your [Analyte], μg/mL

248258263280304266277282295305271275279296308285297306286298307

Median [Analyte], μg/mL 

Long-term Precision, SD 

Apparent Precision, SD 

Concordance, SD 

3rd Quartile (75%) 

You, this RR You, ≥x, this RR NIST, this RR 

Median (50%) 

You, past RRs You, ≥x, past RRs Others, this RR 1st Quartile (25%) 

For details of the construction and interpretation of these plots, see:
 

Duewer, Kline, Sharpless, Brown Thomas, Gary, Sowell. Anal Chem 1999;71(9):1870-8.
 

Serum History Comments 

#304 Lyophilized: #248(44), #258(46), #263(47), #280(51) Augmented, multi-source (SRM 968c Level I) 

#305 Lyophilized: #266(48), #277(50), #282(51), #295(54) Same pool as #308, native 

#306 Fresh-frozen: #285(52), #297(54) Same pool as #307, trans-Retinol augmented 

#307 Fresh-frozen: #286(52), #298(54) Same pool as #306, cis-Retinol augmented 

#308 Fresh-frozen: #271(49), #275(50), #279(51), #296(54) Same pool as #305, native 

 Individualized Report Page 4 / 15 

D5
 

 Set 1 of 42

Individualized RR LVI Report: FSV-BA 

γ/β-Tocopherol 

Apparent Precision, SD [Analyte], μg/mL

248258263280304266277282295305271275279296308285297306286298307 

Your [Analyte], μg/mL

Median [Analyte], μg/mL 

Apparent Precision, SD 

Long-term Precision, SD Concordance, SD 

3rd Quartile (75%) 

You, this RR You, ≥x, this RR NIST, this RR 

Median (50%) 

You, past RRs You, ≥x, past RRs Others, this RR 1st Quartile (25%) 

For details of the construction and interpretation of these plots, see:
 

Duewer, Kline, Sharpless, Brown Thomas, Gary, Sowell. Anal Chem 1999;71(9):1870-8.
 

Serum History Comments 

#304 Lyophilized: #248(44), #258(46), #263(47), #280(51) Augmented, multi-source (SRM 968c Level I) 

#305 Lyophilized: #266(48), #277(50), #282(51), #295(54) Same pool as #308, native 

#306 Fresh-frozen: #285(52), #297(54) Same pool as #307, trans-Retinol augmented 

#307 Fresh-frozen: #286(52), #298(54) Same pool as #306, cis-Retinol augmented 

#308 Fresh-frozen: #271(49), #275(50), #279(51), #296(54) Same pool as #305, native 

 Individualized Report Page 5 / 15 

D6
 

 Set 1 of 42

Individualized RR LVI Report: FSV-BA 

δ-Tocopherol 

Apparent Precision, SD [Analyte], μg/mL

Your [Analyte], μg/mL

248258263280304266277282295305271275279296308285297306286298307

Median [Analyte], μg/mL 

Concordance, SD 

Apparent Precision, SD 

Long-term Precision, SD 

3rd Quartile (75%) 

You, this RR You, ≥x, this RR NIST, this RR 

Median (50%) 

You, past RRs You, ≥x, past RRs Others, this RR 1st Quartile (25%) 

For details of the construction and interpretation of these plots, see:
 

Duewer, Kline, Sharpless, Brown Thomas, Gary, Sowell. Anal Chem 1999;71(9):1870-8.
 

Serum History Comments 

#304 Lyophilized: #248(44), #258(46), #263(47), #280(51) Augmented, multi-source (SRM 968c Level I) 

#305 Lyophilized: #266(48), #277(50), #282(51), #295(54) Same pool as #308, native 

#306 Fresh-frozen: #285(52), #297(54) Same pool as #307, trans-Retinol augmented 

#307 Fresh-frozen: #286(52), #298(54) Same pool as #306, cis-Retinol augmented 

#308 Fresh-frozen: #271(49), #275(50), #279(51), #296(54) Same pool as #305, native 

 Individualized Report Page 6 / 15 

D7
 

 Set 1 of 42

Individualized RR LVI Report: FSV-BA 

Total β-Carotene 

Apparent Precision, SD [Analyte], μg/mL

Your [Analyte], μg/mL

248258263280304266277282295305271275279296308285297306286298307

Median [Analyte], μg/mL 

Long-term Precision, SD 

Apparent Precision, SD 

Concordance, SD 

3rd Quartile (75%) 

You, this RR You, ≥x, this RR NIST, this RR 

Median (50%) 

You, past RRs You, ≥x, past RRs Others, this RR 1st Quartile (25%) 

For details of the construction and interpretation of these plots, see:
 

Duewer, Kline, Sharpless, Brown Thomas, Gary, Sowell. Anal Chem 1999;71(9):1870-8.
 

Serum History Comments 

#304 Lyophilized: #248(44), #258(46), #263(47), #280(51) Augmented, multi-source (SRM 968c Level I) 

#305 Lyophilized: #266(48), #277(50), #282(51), #295(54) Same pool as #308, native 

#306 Fresh-frozen: #285(52), #297(54) Same pool as #307, trans-Retinol augmented 

#307 Fresh-frozen: #286(52), #298(54) Same pool as #306, cis-Retinol augmented 

#308 Fresh-frozen: #271(49), #275(50), #279(51), #296(54) Same pool as #305, native 

 Individualized Report Page 7 / 15 

D8
 

 Set 1 of 42

Individualized RR LVI Report: FSV-BA 

trans-β-Carotene 

Apparent Precision, SD [Analyte], μg/mL

Your [Analyte], μg/mL

248258263280304266277282295305271275279296308285297306286298307

Median [Analyte], μg/mL 

Long-term Precision, SD 

Apparent Precision, SD 

Concordance, SD 

3rd Quartile (75%) 

You, this RR You, ≥x, this RR NIST, this RR 

Median (50%) 

You, past RRs You, ≥x, past RRs Others, this RR 1st Quartile (25%) 

For details of the construction and interpretation of these plots, see:
 

Duewer, Kline, Sharpless, Brown Thomas, Gary, Sowell. Anal Chem 1999;71(9):1870-8.
 

Serum History Comments 

#304 Lyophilized: #248(44), #258(46), #263(47), #280(51) Augmented, multi-source (SRM 968c Level I) 

#305 Lyophilized: #266(48), #277(50), #282(51), #295(54) Same pool as #308, native 

#306 Fresh-frozen: #285(52), #297(54) Same pool as #307, trans-Retinol augmented 

#307 Fresh-frozen: #286(52), #298(54) Same pool as #306, cis-Retinol augmented 

#308 Fresh-frozen: #271(49), #275(50), #279(51), #296(54) Same pool as #305, native 

 Individualized Report Page 8 / 15 

D9
 

 Set 1 of 42

Individualized RR LVI Report: FSV-BA 

Total cis-β-Carotene 

248258263280304266277282295305271275279296308 285297306286298307

Apparent Precision, SD [Analyte], μg/mL

Your [Analyte], μg/mL

Median [Analyte], μg/mL 

Concordance, SD 

Apparent Precision, SD 

Long-term Precision, SD 

3rd Quartile (75%) 

You, this RR You, ≥x, this RR NIST, this RR 

Median (50%) 

You, past RRs You, ≥x, past RRs Others, this RR 1st Quartile (25%) 

For details of the construction and interpretation of these plots, see:
 

Duewer, Kline, Sharpless, Brown Thomas, Gary, Sowell. Anal Chem 1999;71(9):1870-8.
 

Serum History Comments 

#304 Lyophilized: #248(44), #258(46), #263(47), #280(51) Augmented, multi-source (SRM 968c Level I) 

#305 Lyophilized: #266(48), #277(50), #282(51), #295(54) Same pool as #308, native 

#306 Fresh-frozen: #285(52), #297(54) Same pool as #307, trans-Retinol augmented 

#307 Fresh-frozen: #286(52), #298(54) Same pool as #306, cis-Retinol augmented 

#308 Fresh-frozen: #271(49), #275(50), #279(51), #296(54) Same pool as #305, native 

 Individualized Report Page 9 / 15 

D10
 

 Set 1 of 42

Individualized RR LVI Report: FSV-BA 

Total α-Carotene 

Apparent Precision, SD [Analyte], μg/mL

Your [Analyte], μg/mL

248258263280304266277282295305271275279296308285297306286298307

Median [Analyte], μg/mL 

Long-term Precision, SD 

Apparent Precision, SD 

Concordance, SD 

3rd Quartile (75%) 

You, this RR You, ≥x, this RR NIST, this RR 

Median (50%) 

You, past RRs You, ≥x, past RRs Others, this RR 1st Quartile (25%) 

For details of the construction and interpretation of these plots, see:
 

Duewer, Kline, Sharpless, Brown Thomas, Gary, Sowell. Anal Chem 1999;71(9):1870-8.
 

Serum History Comments 

#304 Lyophilized: #248(44), #258(46), #263(47), #280(51) Augmented, multi-source (SRM 968c Level I) 

#305 Lyophilized: #266(48), #277(50), #282(51), #295(54) Same pool as #308, native 

#306 Fresh-frozen: #285(52), #297(54) Same pool as #307, trans-Retinol augmented 

#307 Fresh-frozen: #286(52), #298(54) Same pool as #306, cis-Retinol augmented 

#308 Fresh-frozen: #271(49), #275(50), #279(51), #296(54) Same pool as #305, native 

 Individualized Report Page 10 / 15 

D11
 

 Set 1 of 42

Individualized RR LVI Report: FSV-BA 

Total Lycopene 

Apparent Precision, SD [Analyte], μg/mL

Your [Analyte], μg/mL

248258263280304266277282295305271275279296308285297306286298307

Median [Analyte], μg/mL 

Concordance, SD 

Apparent Precision, SD 

Long-term Precision, SD 

3rd Quartile (75%) 

You, this RR You, ≥x, this RR NIST, this RR 

Median (50%) 

You, past RRs You, ≥x, past RRs Others, this RR 1st Quartile (25%) 

For details of the construction and interpretation of these plots, see:
 

Duewer, Kline, Sharpless, Brown Thomas, Gary, Sowell. Anal Chem 1999;71(9):1870-8.
 

Serum History Comments 

#304 Lyophilized: #248(44), #258(46), #263(47), #280(51) Augmented, multi-source (SRM 968c Level I) 

#305 Lyophilized: #266(48), #277(50), #282(51), #295(54) Same pool as #308, native 

#306 Fresh-frozen: #285(52), #297(54) Same pool as #307, trans-Retinol augmented 

#307 Fresh-frozen: #286(52), #298(54) Same pool as #306, cis-Retinol augmented 

#308 Fresh-frozen: #271(49), #275(50), #279(51), #296(54) Same pool as #305, native 

 Individualized Report Page 11 / 15 

D12
 

 Set 1 of 42

Individualized RR LVI Report: FSV-BA 

trans-Lycopene 

Apparent Precision, SD [Analyte], μg/mL

248258263280304266277282295305271275279296308285297306286298307 

Your [Analyte], μg/mL

Median [Analyte], μg/mL 

Apparent Precision, SD 

Long-term Precision, SD Concordance, SD 

3rd Quartile (75%) 

You, this RR You, ≥x, this RR NIST, this RR 

Median (50%) 

You, past RRs You, ≥x, past RRs Others, this RR 1st Quartile (25%) 

For details of the construction and interpretation of these plots, see:
 

Duewer, Kline, Sharpless, Brown Thomas, Gary, Sowell. Anal Chem 1999;71(9):1870-8.
 

Serum History Comments 

#304 Lyophilized: #248(44), #258(46), #263(47), #280(51) Augmented, multi-source (SRM 968c Level I) 

#305 Lyophilized: #266(48), #277(50), #282(51), #295(54) Same pool as #308, native 

#306 Fresh-frozen: #285(52), #297(54) Same pool as #307, trans-Retinol augmented 

#307 Fresh-frozen: #286(52), #298(54) Same pool as #306, cis-Retinol augmented 

#308 Fresh-frozen: #271(49), #275(50), #279(51), #296(54) Same pool as #305, native 

 Individualized Report Page 12 / 15 

D13
 

 Set 1 of 42

Individualized RR LVI Report: FSV-BA 

Total β-Cryptoxanthin 

Apparent Precision, SD [Analyte], μg/mL

Your [Analyte], μg/mL

248258263280304266277282295305271275279296308285297306286298307

Median [Analyte], μg/mL 

Long-term Precision, SD 

Apparent Precision, SD 

Concordance, SD 

3rd Quartile (75%) 

You, this RR You, ≥x, this RR NIST, this RR 

Median (50%) 

You, past RRs You, ≥x, past RRs Others, this RR 1st Quartile (25%) 

For details of the construction and interpretation of these plots, see:
 

Duewer, Kline, Sharpless, Brown Thomas, Gary, Sowell. Anal Chem 1999;71(9):1870-8.
 

Serum History Comments 

#304 Lyophilized: #248(44), #258(46), #263(47), #280(51) Augmented, multi-source (SRM 968c Level I) 

#305 Lyophilized: #266(48), #277(50), #282(51), #295(54) Same pool as #308, native 

#306 Fresh-frozen: #285(52), #297(54) Same pool as #307, trans-Retinol augmented 

#307 Fresh-frozen: #286(52), #298(54) Same pool as #306, cis-Retinol augmented 

#308 Fresh-frozen: #271(49), #275(50), #279(51), #296(54) Same pool as #305, native 

 Individualized Report Page 13 / 15 

D14
 

 Set 1 of 42

Individualized RR LVI Report: FSV-BA 

Total Lutein&Zeaxanthin 

Apparent Precision, SD [Analyte], μg/mL

Your [Analyte], μg/mL

248258263280304266277282295305271275279296308285297306286298307

Median [Analyte], μg/mL 

Long-term Precision, SD 

Apparent Precision, SD 

Concordance, SD 

3rd Quartile (75%) 

You, this RR You, ≥x, this RR NIST, this RR 

Median (50%) 

You, past RRs You, ≥x, past RRs Others, this RR 1st Quartile (25%) 

For details of the construction and interpretation of these plots, see:
 

Duewer, Kline, Sharpless, Brown Thomas, Gary, Sowell. Anal Chem 1999;71(9):1870-8.
 

Serum History Comments 

#304 Lyophilized: #248(44), #258(46), #263(47), #280(51) Augmented, multi-source (SRM 968c Level I) 

#305 Lyophilized: #266(48), #277(50), #282(51), #295(54) Same pool as #308, native 

#306 Fresh-frozen: #285(52), #297(54) Same pool as #307, trans-Retinol augmented 

#307 Fresh-frozen: #286(52), #298(54) Same pool as #306, cis-Retinol augmented 

#308 Fresh-frozen: #271(49), #275(50), #279(51), #296(54) Same pool as #305, native 

 Individualized Report Page 14 / 15 

D15
Set 1 of 42 

Individualized Round Robin LVI Report: FSV-BA
 

Graphical Comparability Summary
 

Total Retinol α-Tocopherol Total β-Carotene 

D16

Retinyl Palmitate γ/β-Tocopherol trans-β-Carotene To

Total Lycopene δ-Tocopherol Total cis-β-Carotene Total L

trans-Lycopene Total β-Cryptoxanthin Total α-Carotene Co

Individualized Report 
 

 

Appendix E. Shipping Package Inserts for RR21 

The following five items were included in each package shipped to an RR21 participant: 

•	 Cover letter 

•	 Protocol for Preparation and Analysis of the Ascorbic Acid Solid Control
 

Material
 

•	 Preparation and Validation of Ascorbic Acid Solid Control Material Datasheet 

•	 Analysis of Control Materials and Test Samples Datasheet 

•	 Packing List and Shipment Receipt Confirmation Form 

The cover letter, preparation protocol, and the two datasheets were enclosed in a sealed 

waterproof bag along with the samples themselves. The packing list was placed at the 

top of the shipping box, between the cardboard covering and the foam insulation. 

E1
May 12, 2004 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

National Institute af Standards and Technalagy 

Gaithersburg, Maryland 20899-CXXl1 

The samples within this package constitute Vitamin C Round Robin 21 (RR21) of the 2004 Micronutrients 

Measurement Quality Assurance Program. 

R!Ul consists of four vials of frozen serum test samples (#11, #24, #41, and #55), one vial of ascorbic acid 

solid control material (Control), and two vials of froien serum control materials (Control # 1 and Control #2). 

Please follow the attached protocols when you prepare and analyze these samples. If you cannot prepare the 

solid control solutions gravimetrically, please prepare equivalent solutions volumetrically and report the exact 

volumes used. (Routine 0.5 g gravimetric measurements are generally 10-fold more acctirate than routine 0.5 

mL volumetric measurements.) ' 

' 

The two serum control materials are a new component of the M2QAP for Vitamin C. Please use these 

materials to validate the performance of your measurement system before you analyze the test samples. The 

target value for Control #1 is 8.5 ±0.5 μmol/L sa.rμple; the target value for Control #2 is 28.1 ±1.0 μmol/L 

sample. 

Please be aware that sample contact with any oxidant-contaminated surface (vials, glassware, etc.) may degrade 

your measurement system's performance (SA Margolis and E Park, "Stability of Ascorbic Acid in Solutions in 

Autosampler Vials", Clinical Chemistry 2001, 47(8), 1463-1464). You should suspect such degradation if you 

observe un~sually large variation in replicate ,analyses. 

The report for RR20 was mailed during the week of May 3. If you find your results for RR20 unsatisfactory, 

we recommend that you obtain Standard Reference Material (SRM) 970 Ascorbic Acid in Serum to 

validate your methodology and value assign in-house control materials. This SRM may be purchased from the 

Standard Materials Reference Program at NIST (Tel: 301-975-6776, Fax: 301-948-3730, or e-mail: 

srminfo@nist.gov ). 

If you have any questions or concerns about the Vitamin C Micronutrients Measurement Quality Assurance 

Program please contact me at tel: 301-975-3120, fax: 301-977-0685, or e-mail: jbthomas@nist.gov . . 

We ask that you return your results for the RR 21 samples before September 13, 2004. We would appreciate 

receiving your results as soon as they become available. Please use the attached form. Your results will be 

kept confidential. 

ice Brown Thomas 

earch Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosures 

E2

NISI 
 

 

 

 

 

Micronutrient Measurement Quality Assurance Program for
 

Vitamin C
 

Please Read Through Completely BEFORE Analyzing Samples 

Protocol for Preparation and Analysis of the Ascorbic Acid Solid Control Material 

The ascorbic acid solid control material (in the amber vial) should be prepared and used in the 

following manner: 

1)	 Prepare at least 500 mL of 5% mass fraction metaphosphoric acid (MPA) in distilled water. This 

solution will be referred to as the “Diluent” below. 

2)	 Weigh 0.20 to 0.22 g of the ascorbic acid solid control material to 0.0001 g (if possible), dissolve 

it in the Diluent in a 100 mL volumetric flask, and dilute with the Diluent to the 100 mL mark. 

Weigh the amount of Diluent added to 0.1 g. Record the weights. The resulting material will be 

referred to as the “Stock Solution” below. 

3)	 Prepare three dilute solutions of the Stock Solution as follows: 

Dilute Solution 1: Weigh 0.500 mL of the Stock Solution to 0.0001 g into a 100 mL volumetric 

flask; dilute with Diluent to the 100 mL mark. Record the weight. 

Dilute Solution 2: Weigh 0.250 mL of the Stock Solution to 0.0001 g into a 100 mL volumetric 

flask; dilute with Diluent to the 100 mL mark. Record the weight. 

Dilute Solution 3: Weigh 0.125 mL of the Stock Solution to 0.0001 g into a 100 mL volumetric 

flask; dilute with Diluent to the 100 mL mark. Record the weight. 

4)	 Calculate and record the total ascorbic acid concentrations, [TAA], in these Dilute Solutions. 

If you follow the above gravimetric preparation directions, the [TAA] in μmol/L is calculated: 

(g Stock Solution in Dilute Solution 	 ) (⋅ g AA in Stock Solution )⋅(56785 mol/g μ ⋅ L) [TAA] DS = (g AA in Stock Solution ) + (g Diluent in Stock Solution)

For example, if you prepared the Stock Solution with 0.2000 g of solid ascorbic acid and 103.0 g 

of Diluent, then 0.5 mL of the Stock Solution should weigh (0.2+103)/200 = 0.52 g and 

[TAA] DS1 = (0.52 g)(0.2 g)∙(56785 μmol/g·L)/(0.2 + 103 g) = 57.2 μmol/L. Likewise, 0.25 mL 

of the Stock Solution should weigh 0.26 g and [TAA] DS2 = 28.4 μmol/L and 0.125 mL should 

weigh 0.13 g and [TAA] DS3 = 14.2 μmol/L. 

5)	 Measure the ultraviolet absorbance spectrum of Dilute Solution 1 against the Diluent as the blank 

using paired 1 cm path length cuvettes. Record the absorbance at 242, 243, 244, and 245 nm. 

Record the maximum absorbance (Amax ) within this region. Record the wavelength (λmax ) at 

which this maximum occurs. 

The extinction coefficient (E1%) of ascorbic acid at λmax (using a cell with a 1 cm path length) of 

Dilute Solution #1 can be calculated: 

E3
 

 

 

 

 

 

1% dL (A max )⋅	 ((g AA in Stock Solution ) + (g Diluent in Stock Solution )) E ( ) = g ⋅ cm (g Stock Solution in Dilute Solution 1)⋅(g AA in Stock Solution)

If your spectrophotometer is properly calibrated, λmax should be between 243 and 244 nm and 

E1% should be 550 ± 30 dL/g·cm. If they are not, you should calibrate the wavelength and/or 

absorbance axes of your spectrophotometer and repeat the measurements. 

6)	 Measure and record the concentration of total ascorbic acid in all three dilute solutions and in the 

5% MPA Diluent in duplicate using exactly the same method that you will use for the serum 

control materials and test samples, including any enzymatic treatment. We recommend that you 

analyze these solutions in the following order: Diluent, Dilute Solution 1, Dilute Solution 2, 

Dilute Solution 3, Dilute Solution 3, Dilute Solution 2, Dilute Solution 1, Diluent. 

a)	 Compare the values of the duplicate measurements. Are you satisfied that your measurement 

precision is adequate? 

b)	 Compare the measured with the calculated [TAA] values. This is most conveniently done by 

plotting the measured values on the y-axis of a scatterplot against the calculated values on the 

x-axis. The line through the four {calculated, measured} data pairs should go through the 

origin with a slope of 1.0. Are you satisfied with the agreement between the measured and 

calculated values? 

Do not analyze the serum control materials or test samples until you are satisfied that your 

system is performing properly! 

7) Once you have confirmed that your system is properly calibrated, analyze the serum control 

materials (see protocol below). The target values for these materials are: 

Control #1: 8.5 ±0.5 μmol/L of sample 

Control #2: 28.1 ±1.0 μmol/L of sample. 

If your measured values are not close to these target values, please review your sample 

preparation procedure and whether you followed exactly the same measurement protocol the 

solutions prepared from the solid control material as you used for these serum controls. If the 

protocols differ, please repeat from Step 6 using the proper protocol. If the proper protocol was 

used, your measurement system may not be suitable for MPA-preserved samples. Please contact 

us: 301-975-3120 or Jeanice.BrownThomas@NIST.gov. 

Do not analyze the test samples until you are satisfied that your system is performing properly 

and is suitable for the analysis of MPA-preserved serum! 

Protocol for Analysis of the Serum Control Materials and Test Samples 

The serum control materials and test samples are in sealed ampoules. They were prepared by adding 

equal volumes of 10% MPA to spiked human serum. We have checked the samples for stability and 

homogeneity. Only the total ascorbic acid is stable. While these samples contain some 

dehydroascorbic acid, its content is variable. Therefore, only total ascorbic acid should be reported. 

The serum control materials and test samples should be defrosted by warming at 20 °C for not more 

than 10 min otherwise some irreversible degradation may occur. 

Each serum test sample contains between 0.0 and 80.0 μmol of total ascorbic acid/L of solution. The 

total ascorbic acid in each ampoule should be measured in duplicate. Please report your results in 

μmol/(L of the sample solution) rather than μmol/(L of serum NIST used to prepare the sample). 

E4
Participant #: Date: 

Vitamin C Round Robin 21 

NIST Micronutrient Measurement Quality Assurance Program 

Preparation and Validation of Ascorbic Acid Solid Control Material 

STOCK SOLUTION 

Mass of ascorbic acid in the Stock Solution ..................................................__________ g 

Mass of 5% MPA Diluent added to the 100 mL volumetric flask .................__________ g 

DILUTE SOLUTION 1 

Mass of added stock solution (0.5 mL) ..........................................................__________ g 

Mass of 5% MPA Diluent added to the 100 mL volumetric flask.................__________ g 

Absorbance of Dilute Solution 1 at 242 nm...................................................__________ AU
 

Absorbance of Dilute Solution 1 at 243 nm...................................................__________ AU
 

Absorbance of Dilute Solution 1 at 244 nm...................................................__________ AU
 

Absorbance of Dilute Solution 1 at 245 nm...................................................__________ AU
 

Absorbance of Dilute Solution absorbance maximum ..................................__________ AU
 

Wavelength of maximum absorbance............................................................__________ nm
 

Calculated E1% ...............................................................................................__________ dL/g·cm
 

Calculated [TAA] DS1 .....................................................................................__________ μmol/L
	

DILUTE SOLUTION 2 

Mass of added stock solution (0.25 mL) ........................................................__________ g 

Mass of 5% MPA Diluent added to the 100 mL volumetric flask .................__________ g 

Calculated [TAA] DS2 .....................................................................................__________ μmol/L
	

DILUTE SOLUTION 3 

Mass of added stock solution (0.125 mL) ......................................................__________ g 

Mass of 5% MPA Diluent added to the 100 mL volumetric flask .................__________ g 

Calculated [TAA] DS3 .....................................................................................__________ μmol/L
	

Please return before September 13, 2004 to: 

MMQAP Fax: 301-977-0685 

100 Bureau Drive, Stop 8392 Email: david.duewer@nist.gov 

Gaithersburg, MD 20899-8392 

E5
 

 

 

 

 

 

 

 

 

 

 

Participant #: Date: 

Vitamin C Round Robin 21 

NIST Micronutrient Measurement Quality Assurance Program
 

Analysis of Control Materials and Test Samples
 

Sample Replicate 1 Replicate 2 Units
 

Dilute Solution 1 μmol/L of Dilute Solution 

Dilute Solution 2 μmol/L of Dilute Solution 

Dilute Solution 3 μmol/L of Dilute Solution 

5% MPA Diluent μmol/L of Diluent 

μmol/L of Sample Serum Control #1 Target: 8.5 ±0.5 μmol/L 

μmol/L of Sample Serum Control #2 Target: 28.1 ±1.0 μmol/L 

Serum Test Sample #11 μmol/L of Sample 

Serum Test Sample #24 μmol/L of Sample 

Serum Test Sample #41 μmol/L of Sample 

Serum Test Sample #55 μmol/L of Sample 

Were samples frozen upon receipt? Yes | No 

Analysis method: HPLC-EC | HPLC-Fluor DAB | HPLC-OPD | HPLC-UV | AO-OPD | Other
 

If “Other”, please describe:
 

COMMENTS: 

Please return before September 13, 2004 to: 

MMQAP Fax: 301-977-0685 

100 Bureau Drive, Stop 8392 Email: david.duewer@nist.gov 

Gaithersburg, MD 20899-8392 

E6
 

 

 

 

Participant #: ________ Date: _____________ 

Vitamin C Round Robin 21
 

NIST Micronutrients Measurement Quality Assurance Program
 

Packing List and Shipment Receipt Confirmation Form
 

This box contains one vial each of the following seven VitC M2QAP samples: 

Sample Form 

VitC #11 Liquid frozen (1:1 serum:10% MPA) 

VitC #24 Liquid frozen (1:1 serum:10% MPA) 

VitC #41 Liquid frozen (1:1 serum:10% MPA) 

VitC #55 Liquid frozen (1:1 serum:10% MPA) 

Control #1 Liquid frozen (1:1 serum:10% MPA) 

Control #2 Liquid frozen (1:1 serum:10% MPA) 

Control Solid AA 

Please 1) Open the pack immediately 

2) Check that it contains one vial each of the above samples 

3) Check if the samples arrived frozen 

4) Store the samples at -20  ̊C or below until analysis 

5) Complete the following information 

6) Fax the completed form to us at 301-977-0685 

(or email requested information to david.duewer@nist.gov) 

1) Date this shipment arrived: ___________________________ 

2) Are all of the vials intact? Yes | No 

If "No", which one(s) were damaged? 

3) Was there any dry-ice left in cooler? Yes | No 

4) Did the samples arrive frozen? Yes | No 

5) At what temperature are you storing the samples? _______  ̊C 

6) When do you anticipate analyzing these samples? ________________________ 

Your prompt return of this information is appreciated. 

The M2QAP Gang 

Mail: M2QAP 

NIST, Stop 8392 Fax: 301-977-0685 

Gaithersburg, MD 20899-8392 Email: David.Duewer@NIST.gov 

E7
 

 

Appendix F. Final Report for RR21 

The following two pages are the final report as provided to all participants: 

•	 Cover letter. 

•	 An information sheet that: 

o	 describes the contents of the “All-Lab” report, 

o	 describes the content of the “Individualized” report, 

o	 describes the nature of the test samples and details their previous distributions, 

if any, and 

o	 summarizes aspects of the study that we believe may be of interest to the 

participants. 

F1
November 2, 2004 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standard& and Technology 

Gaithersburg, Maryland 20899-0)()1 

Enclosed is the summary report of the results for Round Robin 21 (RR2 l) for the measurement 

of total ascorbic acid (T AA, ascorbic acid plus dehydroascorbic acid) in human serum. Included 

in this report are: a summary of data for all laboratories and a summary of individual laboratory 

performance and interlaboratory ac~uracy and repeatability. As in previous reports, the estimated 

standard deviations (eSD) for the measurements are defined as 0.74x interquartile range and the 

esti.mate coefficients of variation ( eCV) are defined as 1 OOx eSD/median. 

RR 21 consisted of four test samples (#11, #24, #41, and #55), two serum control materials, and 

one solid control material for preparation of T AA control solutions. Details regarding the 

samples can be found in the enclosed report. 

If you have concerns regarding your laboratory's performance, we suggest that you obtain and 

analyze a unit of Standard Reference Material (SRM) 970, Vitamin C in Frozen Human Serum. 

SRM 970 can be purchased from the NIST SRM Program at phone: 301-975-6776; 

fax: 301-948-3730. If your measured values do not agree with the certified values, we suggest 

that you contact us for consultation. 

Samples for the first vitamin C round robin study (RR 22) for the 2005 Vitamin C in Serum QA Program 

will be shipped starting the week of November 8. If you have questions or concerns regarding this 

report, please contact David Duewer at 301-975-3935; e-mail: david.duewer@nist.gov or me at 

301-975-3120; e-mail: jbthomas~st.gov; or fax: 301-977-0685. 

~,'\I I 

I I f 

·, f' J ...-) /0 0)11 (l/) (L ) 11 U(_ 

/I 

ice Brown Thomas 

Research Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosures 

N•Si 

F2
The NIST M2

QAP Vitamin C Round Robin 21 (RR21) report consists of 

Page “Individualized” Report 

1 Summarizes your reported values for the nominal 55 mmol/L solution you prepared from the 

ascorbic acid solid control sample, the two serum control samples, and the four serum test 

samples. 

2 Graphical summary of your RR 21 sample measurements. 

Page “All Lab” Report 

1 A tabulation of results and summary statistics for Total Ascorbic Acid [TAA] in the RR21 

samples and control/calibration solutions. 

Serum-based Samples. Two serum controls and four unknowns were distributed in RR21. 

CS1 SRM 970 level 1, ampouled in mid-1998. 

CS2 SRM 970 level 2, ampouled in mid-1998. 

S21:1 Serum 11, stripped serum used in the preparation of the augmented sera for this study; 

ampouled in late 2001, previously distributed in RR19 (Sep-03). 

S21:2 Serum 24, augmented serum ampouled in late 2001, previously distributed in 

RR17 (Sep-02) and RR19 (Sep-03). 

S21:3 Serum 41, augmented serum ampouled in late 2001, previously distributed in
 

RR18 (Mar-03) and RR19 (Sep-03). 

S21:4 Serum 55, augmented serum ampouled in late 2001, previously distributed in 

RR 16 (Mar-02), RR17 (Sep-02) and RR20 (Mar-04). 

Results. 

1)	 All participants who prepared the four control/calibration solutions (the three “Dilute Solutions” and 

the 5% MPA “Diluent”) did so correctly. The criteria used to evaluate this success are: the density of 

the 5% MPA (≈1.03 g/mL), the observed wavelength maximum of “Dilute Solution #1”(≈244 nm), 

the observed absorbance at that maximum (≈0.55 OD), the calculated E1% #1”(≈550 dL/g·cm). 

2)	 Judging from the calibration parameters calculated for the control/calibration solutions (intercepts 

close to 0.0 and slopes close to 1.0), the measurement systems for most participants are well 

calibrated, although the slopes for two participants are 15% to 20% lower than expected. 

3)	 One participant reported values for the controls that were well outside the target range and one 

participant did not report values for the controls. If the measured values for the control samples are 

not close to the targets, even if your measured and calculated values for the calibration solutions 

agree, there is a problem with your measurement system. 

4)	 Please note that we have recertified the SRM 970 materials. The recertified values for total ascorbic 

acid are as follows: 

Level I – 8.41 μmol/L, ≈95% confidence range of 7.75 μmol/L to 9.07 μmol/L. 

Level II – 28.05 μmol/L, ≈95% confidence range of 27.56 μmol/L to 28.54 μmol/L. 

F3
 

Appendix G. “All-Lab Report” for RR21 

The following single page is the “All-Lab Report” as provided to all participants, with 

two exceptions: 

• the participant identifiers (Lab) have been altered. 

• the order in which the participant results are listed has been altered. 

The data summary in the “All-Lab Report” has been altered to ensure confidentiality of 

identification codes assigned to laboratories. The only attributed results are those 

reported by NIST. The NIST results are not used in the assessment of the consensus 

summary results of the study. 

G1
Micronutrients Measurement Quality Assurance Program for Total Ascorbic Acid 

"Round Robin" 21 - September 2004 

Control / Calibration Samples MPA Dilute Solution 1 Samples 

G2

Density 

Lab Date Dil:1 Dil:2 Dil:3 Dil:1 Dil:2 Dil:3 MPA Inter Slope R2 SEE g/mL λmax Amax E1% CS#1 CS#2 S21:1 S21:2 S21:3 S21:4 CS#

VC-MA 13/09/04 56.1 28.3 13.9 55.5 27.9 13.6 0.0 -0.09 0.99 1.000 0.1 1.031 244. 0.5551 562.2 8.0 26.7 <0.68 8.7 33.0 47.0 8

VC-MB 14/07/04 57.5 28.6 8.9 55.5 25.8 8.0 0.0 -0.60 0.96 0.999 1.0 1.032 245. 0.5534 546.5 7.5 27.7 <5.2 9.6 35.9 50.1 8

VC-MC 07/09/04 57.2 28.6 13.7 57.9 30.0 15.0 0.0 0.64 1.01 0.999 0.8 1.031 243. 0.5386 534.8 8.3 34.7 nq 9.1 33.7 53.3 7

VC-MG 13/09/04 57.6 28.9 14.6 56.5 27.3 13.2 0.0 -0.62 0.99 0.999 0.7 1.030 243. 0.5550 547.2 7.8 28.5 nq 9.3 36.8 52.0 8

VC-MH 09/06/04 61.6 30.8 14.9 61.9 30.6 14.5 0.1 -0.21 1.00 1.000 0.3 1.030 243.8 0.6125 564.2 8.4 28.3 0.3 8.5 33.5 46.1 8

VC-MI 10/09/04 57.5 28.9 14.3 48.7 22.4 14.6 1.47 0.81 0.986 3.0 1.028 8.7 25.7 3.7 10.0 26.9 36.3 8

VC-MK 09/09/04 61.7 30.7 15.2 53.1 24.5 14.0 0.5 0.27 0.85 0.997 1.4 1.033 244. 0.6089 560.7 12.6 34.4 4.3 13.6 38.5 51.6 14

VC-MR 13/09/04 57.5 28.6 14.2 58.1 29.8 14.7 0.0 0.28 1.01 1.000 0.5 1.031 245. 0.5650 557.7 8.7 27.4 0.4 10.2 33.5 47.7 8

VC-MT 08/09/04 56.9 27.9 13.4 57.3 27.5 13.4 0.0 -0.15 1.01 1.000 0.4 1.031 243. 0.5580 557.3 8.7 28.3 0.3 8.3 27.4 42.6 8

VC-MY 13/09/04 0.1 6.8 74.5 123.8 

NIST 24/10/03 59.1 29.2 14.0 58.7 32.1 13.6 0.0 0.47 1.00 0.996 2.0 1.024 243. 0.5723 549.7 8.9 28.8 1.2 10.1 34.0 44.4 8

9 9 9 9 9 9 8 9 8 8 8 9 9 6 10 10 10 

58.2 29.0 13.7 56.0 27.3 13.4 0.1 1.031 243.9 0.5683 553.8 8.7 29.1 1.5 9.4 37.4 55.0 9

2.0 1.0 1.9 3.6 2.7 2.1 0.2 0.001 0.8 0.0272 10.1 1.5 3.2 1.9 1.8 13.5 24.7 2

56.1 27.87 8.9 48.7 22.41 8.0 0.0 1.028 243.0 0.5386 534.8 7.5 25.7 0.1 6.8 26.9 36.3 7

57.2 28.58 13.7 55.5 25.80 13.4 0.0 1.030 243.0 0.5546 547.0 8.0 27.4 0.3 8.6 33.1 46.3 8

57.5 28.64 14.2 56.5 27.45 14.0 0.0 1.031 243.9 0.5566 557.5 8.4 28.3 0.4 9.2 33.6 48.9 8

57.6 28.91 14.6 57.9 29.75 14.6 0.0 1.031 244.3 0.5760 561.1 8.7 28.5 2.8 9.9 36.6 51.9 8

61.7 30.80 15.2 61.9 30.62 15.0 0.5 1.033 245.0 0.6125 564.2 12.6 34.7 4.3 13.6 74.5 123.8 14

0.5 0.4 0.7 2.0 3.4 1.0 0.0 0.001 1.3 0.0086 8.5 0.5 1.4 0.2 1.1 4.1 4.3 0

1 1 5 4 12 7 0.12 0.55 2 2 6 5 12 12 9 

MADe eSD 

CV CV 

Median Median 

%75 %75 

Max Max 

Min Min 

%25 %25 

N N 

Average Average 

SD SD 

Gravimetric, μmol/L Measured, μmol/L Calibration Parameters Spectrophotometry Measured, μmol/L 

All Lab Report 
Appendix H. Representative “Individualized Report” for RR21 

Each participant in RR21 received an “Individualized Report” reflecting their reported 

results. The following two pages are the “Individualized Report” for participant 

“VC-MA”. 

H1
 

Set 1 of 11 

Vitamin C "Round Robin" 21 Report: Participant VC-MA
 

Date RR Method 

11/18/02 16 HPLC-EC 

12/12/02 17 HPLC-EC 

03/20/03 18 HPLC-EC 

11/13/03 19 HPLC-EC 

02/23/04 20 HPLC-EC 

09/13/04 21 HPLC-EC 

Date RR Sample 

11/13/03 19 S19:1 

09/13/04 21 S21:1 

12/12/02 17 S17:1 

11/13/03 19 S19:2 

09/13/04 21 S21:2 

03/20/03 18 S18:2 

11/13/03 19 S19:3 

09/13/04 21 S21:3 

11/18/02 16 S16:3 

12/12/02 17 S17:3 

02/23/04 20 S20:2 

09/13/04 21 S21:4 

MPA Dilute Solution 1 Control/Calibration Solutions 

Density Spectrophotometry Ymeas = Inter + Slope* Xgrav 

N Mean SDrepeat SDreprod 

0 

3 9.1 0.3 0.4 

3 34.8 0.4 1.6 

4 48.5 1.8 1.8 

g/mL 

1.032 

1.026 

1.026 

1.026 

1.031 

1.030 

λmax Amax E1% 

242.0 0.575 576.5 

242.0 0.552 551.0 

244.0 0.509 563.1 

243.0 0.584 561.9 

243.0 0.552 560.7 

244.0 0.555 562.2 

Inter Slope R2 SEE 

-0.4 1.07 0.999 0.90 

-0.3 1.06 1.000 0.49 

-0.1 1.02 1.000 0.18 

1.1 1.03 0.998 1.24 

-0.4 1.05 1.000 0.65 

-0.1 0.99 1.000 0.10 

Mean 1.028 243.0 0.55 562.6 

SD 0.003 0.9 0.03 8.2 

CV 0.26 0.37 4.7 1.4 

[TAA] mmol/Lsample 

Rep1 Rep2 Fadj Mean SDdup 

na na 1.0 

na na 1.0 

9.9 9.1 1.0 9.5 0.6 

9.2 9.1 1.0 9.2 0.1 

8.8 8.7 1.0 8.7 0.1 

35.1 36.0 1.0 35.6 0.6 

35.9 35.8 1.0 35.9 0.1 

33.2 32.9 1.0 33.0 0.2 

49.9 44.9 1.0 47.4 3.5 

49.7 49.1 1.0 49.4 0.4 

50.6 50.0 1.0 50.3 0.4 

47.1 47.0 1.0 47.0 0.0 

Please check our records against your records. Send corrections and/or updates to... 

Micronutrients Measurement Quality Assurance Program 

National Institute of Standards and Technology 

100 Bureau Drive Stop 8392 Fax: (301) 977-0685 

Gaithersburg, MD 20899-8392 USA Email: david.duewer@nist.gov 

Individualized Report Page 1/2 

H2
 

 

 

Set 1 of 11 

Vitamin C "Round Robin" 21 Report: Participant VC-MA 

Total Ascorbic Acid 

[Total Ascorbic Acid], μmol/L 

Your [Total Ascorbic Acid], μmol/L

RR19

S21:1

RR17RR19

S21:2

RR18RR19

S21:3

RR16RR17RR20

S21:4 

Median [Total Ascorbic Acid], μmol/L 

Apparent Precision, SD 

Concordance, SD 

3rd Quartile (75%) You, RR 21
 NIST, RR 21 Median (50%) You, RR 16-20
 Others, RR 21 1st Quartile (25%) 

For details of the construction and interpretation of these plots, see: 

Duewer, Kline, Sharpless, Brown Thomas, Gary, Sowell. Anal Chem 1999;71(9):1870-8. 

Sample Comments
 

S21:1 Serum 11, previously distributed in RR 19
 

S21:2 Serum 24, previously distributed in RRs 17 and 19
 

S21:3 Serum 41, previously distributed in RRs 18 and 19
 

S21:4 Serum 55, previously distributed in RRs 16, 17, and 20
 

Individualized Report Page 2/2 

H3