NISTIR 7880-21 

NIST Micronutrients Measurement 

Quality Assurance Program 

Winter 2002 

Comparability Studies 

Results for Round Robin LI 

Fat-Soluble Vitamins and Carotenoids in Human Serum 

and Round Robin 16 Ascorbic Acid in Human Serum 

David L. Duewer 

Sam A. Margolis (Retired) 

Katherine E. Sharpless 

Jeanice B. Thomas 

 

 

 

 

NISTIR 7880-21
 

NIST Micronutrients Measurement 

Quality Assurance Program 

Winter 2002 

Comparability Studies 

Results for Round Robin LI 

Fat-Soluble Vitamins and Carotenoids in Human Serum 

and Round Robin 16 Ascorbic Acid in Human Serum 

David L. Duewer 

Sam A. Margolis (Retired) 

Katherine E. Sharpless 

Jeanice B. Thomas 

Chemical Sciences Division 

Materials Measurement Laboratory 

-XQH 2013 

U.S. Department of Commerce 

&DPHURQ).HUU\ 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 

Winter 2002 MMQAP measurement comparability improvement studies: 1) Round Robin LI FatSoluble Vitamins and Carotenoids in Human Serum and 2) Round Robin 16 Total Ascorbic Acid in 

Human Serum. The materials for both studies were shipped to participants in January 2002; 

participants were requested to provide their measurement results by April 8, 2002. 

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 LI: Fat-Soluble Vitamins and Carotenoids in Human Serum............................... 1
 

Round Robin 16: Vitamin C in Human Serum............................................................................... 2
 

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

Appendix A. Shipping Package Inserts for RR51........................................................................ A1
 

Appendix B. Final Report for RR51 ..............................................................................................B1
 

Appendix C. “All-Lab Report” for RR51 ......................................................................................C1
 

Appendix D. Representative “Individualized Report” for RR51 ............................................... D1
 

Appendix E. Shipping Package Inserts for RR16 ......................................................................... E1
 

Appendix F. Final Report for RR16............................................................................................... F1
 

Appendix G. “All-Lab Report” for RR16..................................................................................... G1
 

Appendix H. Representative “Individualized Report” for RR16............................................... 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 LI: Fat-Soluble Vitamins and Carotenoids in Human Serum 

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

LI comparability study (hereafter referred to as RR51) received four lyophilized and one 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 

January 2002. 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 RR51 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 16: Vitamin C in Human Serum 

Participants in the MMQAP Vitamin C in Human Serum Round Robin 16 comparability study 

(hereafter referred to as RR16) received three frozen serum test samples 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 January 

2002. The communication materials included in the sample shipment are provided in Appendix E. 

The test 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 RR16 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 RR51 

The following three items were included in each package shipped to an RR51 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
~-:..:;;i;:i::::-:;:~L::-~~ '° 

-..................... ~--

0 

0 "' 

0 

NIST CENTENNIALC 

January 24, 2002 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standards and Technology 

Gaithersburg, Maryland 20899-

Happy New Year! Enclosed is the set of samples for the first quality assurance round robin exercise 

(Round Robin LI) for 2002. You will find one vial of each of four lyophilized and one liquid-frozen 

serum samples for analysis along with a form for reporting your results. When reporting your results, 

please submit one value for each analyte for a given serum sample. If an obtained value is below your 

limit of quantitation, please indicate this result on the form by using NQ (Not Quantified). Results are 

due to NIST by April 8, 2002. 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-May. 

Lyophilized samples should be reconstituted with 1.0 mL ofHPLC-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 contact 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 sample 279. 

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); cx-tocopherol, 75.8 at 292 nm (ethanol); ytocopherol, 91.4 at 298 nm (ethanol); ex-carotene, 2800 at 444 nm (hexane); P-carotene, 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 LI to: 

Micronutrients Measurement Quality Assurance Program 

NIST 

100 Bureau Drive Stop 8392 

Gaithersburg, MD 20899-8392 

Fax: (301) 977-0685 

To improve the efficiency of our program for next year, the intent-to-participate forms for the 2003 

QA Program will be mailed in May 2002. Please return all forms by September 1, 2002. Laboratories 

will be invoiced for the 2003 program at the end of September 2002. Samples for the first fat-soluble 

vitamins/carotenoids and vitamin C in serum round robins will be shipped during the first week of 

November 2002. Please call me at (301) 975-3120; e-mail me atjbthomas@nist.gov; or mail/fax queries 1: :::.v• ·~~cpan;;-orcommenB 

Je ce Brown Thomas 

R se ch Chemist 

·cal Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosures NISI 

A2
 

 

 

Participant #: ________ Date: _____________ 

Round Robin LI 

NIST Micronutrients Measurement Quality Assurance Program 

Analyte 279 280 281 282 283 Units* 

total retinol 

trans-retinol 

retinyl palmitate 

α-tocopherol 

γ/β-tocopherol 

δ-tocopherol 

total β-carotene 

trans-β-carotene 

total cis-β-carotene 

total α-carotene 

trans-α-carotene 

total lycopene 

trans-lycopene 

total β-cryptoxanthin 

total α-cryptoxanthin 

total lutein 

total zeaxanthin 

total lutein&zeaxanthin 

ubiquinone-10 (Q10) 

phylloquinone (K1) 

25-hydroxyvitamin D 

Other analytes? 

* we prefer μg/mL 

Was serum 279 frozen when received? Yes | No 

Comments: 

Mail: M2QAP 

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

Gaithersburg, MD 20899-8392 8-Apr-2002 Email: David.Duewer@NIST.gov 

A3
 

 

 

 

Participant #: ________ Date: _____________ 

Fat-Soluble Vitamins Round Robin LI
 

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? 

#279 

#280 

#281 

#282 

#283 

Liquid frozen 

Lyophilized 

Lyophilized 

Lyophilized 

Lyophilized 

No 

Yes (1 ml H2O) 

Yes (1 ml H2O) 

Yes (1 ml H2O) 

Yes (1 ml H2O) 

Please 1) Open the pack immediately 

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

3) Check if serum #279 arrived frozen 

4) Store the samples upright 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 serum #279 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 will help control M2QAP expenses. 

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 RR51 

The following three 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
May 21, 2002 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standards and Technology 

Gaithersburg, Maryland 20899-0001 

Enclosed is the summary report of the results for Round Robin LI (RR 51) for fat-soluble vitamins and 

carotenoids. Included in this report are: a summary of data for all laboratories; the measurement 

comparability summary for evaluating laboratory performance; lyophilized vs. fresh-frozen commutability 

data, a summary of individual laboratory performance and inter laboratory accuracy and precision; and a 

summary of the NIST assigned value (NA V) vs. your laboratory value for the analytes that you measured. As 

in previous reports, 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 51 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. 

Intent-to-participate forms for the 2003 QA program will be mailed in about two weeks. This form will 

provide us with formal notification of your intent to participate in the program for the upcoming year. The 

program will consist of two round robin studies for the fat-soluble vitamins and carotenoids and one study for 

vitamin C in serum. To participate in the fat-soluble vitamins and carotenoids in serum studies, the 

participation fee is $1600 for U.S. laboratories and $2000 for non-U.S. laboratories. To participate in the 

vitamin C in serum study, the participation fee is $800 for U.S. laboratories and $1000 for non-U.S. 

laboratories. We ask that you return the fonn to us by no later than September 1, 2002. 

Shipping has become more diffic~lt post September 11, 2001. It is important that you carefully inspect all 

samples on arrival and that you promptly confirm that they have arrived and that they have remained frozen. 

While we can (and do) determine the date of receipt (and the signature of the signee) of shipments when we 

don't receive direct confirmation, this costs us significant time and effort. We will now replace lost or 

damaged samples only for participants who have promptly reported the difficulty. 

Samples for the next round robin (RR52) will be distributed during the week of June 10, 2002. We will send 

you a reminder via e-mail or fax a week prior to shipment. Please notify us, preferably before the week of 

June 10, if you have special shipping instructions. 

If you have any questions regarding this report, please contact David Duewer at 301/975-3935; e-mail: 

david.duewer@nist.gov, r me at 3 1 975-3120; e-mail: jbthomas@nist.gov; fax: 301/977-0685. 

ice Brown Thomas 

search Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

cc: L.C. Sander 

S.A. Wise NISI 

B2
 

The NIST M2QAP Round Robin LI (RR51) report consists of: 

Page 

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 10 other participants. 

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

Page “All Lab” Report 

1-3 

4a 

4b 

5 

Samples.

Serum 

279 

280 

281 

282 

283 

“Individualized” Report 

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

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

A legend for the above two lists.
 

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

 The five sera below were distributed in RR51.
 

Description 

Liquid-frozen native serum; partner to 

lyophilized serum 282. 

Lyophilized blended serum with native 

carotenoid levels, augmented with retinol and 

γ-tocopherol; SRM 968c level-I. 

Lyophilized native serum apparently 

augmented with 13-cis- enriched “retinol”. 

Lyophilized native serum; partner to liquidfrozen serum 279. 

Lyophilized native serum augmented with 

retinyl palmitate. 

Prior Distributions 

#271 in RR49 (3/01), #275 in RR50 (9/01) 

#248 in RR44 (9/98), #258 in RR46 (6/99), 

#263 in RR47 (5/00) 

#293 in RR30 (3/94), #254 in RR45 (3/99), 

#255 in RR46 (6/99), #269 in RR49 (3/01) 

#266 in RR48 (9/00), #277 in RR50 (9/01) 

#181 in RR28 (6/93), #222 in RR37 (6/96), 

#243 in RR43 (6/98) 

Observations 

1)	 As in earlier distributions of these materials, several participants noted the presence an “insoluble 

stringy clot” in Serum 279 and/or 282. These solids do not appear to influence measurement 

performance. 

2)	 Sera Stability. There has been no significant change in the median level or in the variability of any 

measurand in any of the five sera. The oldest serum distributed in RR 51 was produced in early 

1993. All of these materials have been continuously stored –80 °C. 

3)	 Total versus trans-retinol. Serum 281 has an unusually high level of cis-retinol, roughly 20% of the 

total retinol. The following is the relevant section of one of Kathy Sharpless’s recent 

chromatograms, using a BakerbondTM C18 column and method “B” described in the SRM 968c 

Certificate of Analysis (http://srmcatalog.nist.gov/srmcatalog/certificates/968c.pdf). Based upon the 

retention time of exemplar compounds, the leading peak appears to be entirely 13-cis-retinol. 

B3
We strongly urge all of you who report “retinol” to carefully evaluate the relevant sections of your 

chromatograms for serum #281. If you report trans-retinol and did not resolve the cis-retinol peak 

reasonably well, you should either confirm that your system is capable of identifying the transisomer in the presence of known 13-cis or you should consider reporting “total retinol.” If you report 

“total retinol” and at least partially resolve the 13-cis peak but did not include its area, you should 

modify your integration parameters or consider reporting “trans-retinol.” 

We have prepared a series of sera with known high levels of 13-cis-retinol for future distribution. At 

least one of them will be distributed in the next round robin (RR 52). 

4)	 Ubiquinone (Coenzyme Q10). While too few participants routinely report “ubiquinone” to enable 

regular feedback on measurement performance, there are enough historical data for the sera 

distributed in RR 51 to address several issues. The following Figure presents all available participant 

data for all of the distributions of the sera and summarizes the expected distributions as box-plots. 

Each symbol type represents values reported by a particular participant. 

0.1 

1 

Ubiquinone Q10, 

μg/mL 

271275279266277282248258263280254255269281222243283 

Serum 

Are participants reporting the same measurand? Probably not. Coenzyme Q10 (CoQ10) is the sum 

of reduced (ubiquinol, QH2) and oxidized forms (ubiquinone, Qox). There appear to be fairly 

consistent among-participants biases which may in part arise from differing definitions of what’s 

being measured. Starting with RR 52, the Report form will list all three forms. 

Are the “Ubiquinone” measurands stable in the M2

QAP sera? Probably. The best evidence is 

provided by the {liquid frozen (271, 275, 279), lyophilized (266, 277, 282)} pairs: for most 

participants, the levels in these two materials have been nearly equal. Additionally, the values 

reported by about half of the participants reporting this measurand appear pretty consistent over time. 

B4
 

 

Appendix C. “All-Lab Report” for RR51 

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 LI Laboratory Results 

All Results in μg/mL 

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

C2

Lab 279 280 281 282 283 279 280 281 282 283 279 280 281 282 283 279 280 281 282 283 279 280 281 282 283 27

FSV-BA 0.470 0.858 1.132 0.452 0.494 0.060 0.040 0.063 0.057 0.106 7.15 7.39 27.36 6.77 7.21 1.96 3.89 6.16 1.87 2.36 

FSV-BB 0.434 0.831 1.070 0.419 0.447 0.056 0.029 0.030 0.052 0.085 7.20 7.87 27.11 7.03 7.44 1.81 3.64 5.64 1.73 2.16 

FSV-BD 0.511 0.871 0.983 0.469 0.506 6.50 6.40 23.60 5.50 6.20 

FSV-BE 0.510 0.980 1.220 0.410 0.530 7.40 8.00 27.40 6.30 7.40 2.10 4.30 6.70 1.60 2.50 

FSV-BF 0.430 0.810 1.000 0.440 0.450 7.00 7.40 26.80 6.70 6.90 1.80 3.70 5.60 1.80 2.20 

FSV-BG 0.458 0.897 1.153 0.443 0.558 0.063 0.029 0.032 0.058 0.087 6.95 7.82 28.51 6.77 7.46 1.90 4.24 6.59 1.93 2.67 

FSV-BH 0.450 0.807 0.923 0.480 0.434 7.25 7.79 27.53 6.86 7.25 2.09 4.15 6.58 1.99 2.51 nd 

FSV-BI 0.496 0.894 1.140 0.460 0.480 nd nd nd nd 0.122 7.34 7.58 28.04 6.77 6.63 2.11 4.12 6.43 1.87 2.17 

FSV-BJ 0.432 0.827 1.046 0.414 0.437 0.035 nq nq 0.049 0.147 7.52 7.91 29.16 6.85 7.29 2.04 4.41 6.96 1.88 2.51 

FSV-BK 0.444 0.893 1.144 0.423 0.474 6.80 7.46 27.26 6.53 6.84 

FSV-BL 0.520 0.860 0.860 0.490 0.460 8.01 9.04 27.61 7.28 7.54 

FSV-BM 0.469 0.848 1.089 0.475 0.488 7.20 7.99 29.20 7.20 8.50 

FSV-BN 0.462 0.866 1.028 0.416 0.479 0.038 0.024 0.008 0.039 0.059 6.05 6.74 23.32 5.47 6.14 1.50 3.08 4.45 1.30 1.75 0.0

FSV-BNa 0.433 0.840 1.019 0.428 0.477 0.034 0.026 0.014 0.040 0.080 5.70 6.78 24.00 5.96 6.18 1.47 3.11 4.75 1.42 1.74 nd 

FSV-BO 0.415 0.773 0.776 0.478 0.390 6.40 7.70 28.60 6.40 7.60 

FSV-BP 0.460 0.838 1.114 0.464 0.506 6.56 7.56 28.10 7.61 7.12 

FSV-BQ 0.509 0.929 1.235 0.486 0.506 7.30 7.90 28.50 7.10 7.40 

FSV-BR >0.466 >0.878 >1.020 >0.449 >0.493 0.466 0.878 1.020 0.449 0.493 6.80 7.55 27.83 6.73 7.47 

FSV-BS 

FSV-BT 0.457 0.894 1.068 0.455 0.500 0.044 0.018 0.017 0.050 0.102 5.61 6.22 22.31 5.54 6.07 1.28 2.77 4.73 1.43 1.61 0.7

FSV-BU 0.436 0.774 0.968 0.426 0.502 6.48 7.46 24.53 7.04 7.98 1.79 3.43 5.57 1.64 2.31 

FSV-BV 0.487 0.880 1.078 0.465 0.532 7.28 7.71 26.93 7.16 7.64 1.85 3.78 6.05 1.77 2.20 

FSV-BW 0.507 0.905 0.853 0.443 0.475 0.066 0.035 0.030 0.059 0.115 7.71 7.80 30.64 6.87 7.48 2.11 4.00 6.94 1.88 2.29 

FSV-BX >0.450 >0.835 >0.942 >0.438 >0.490 0.450 0.835 0.942 0.438 0.490 6.78 7.38 24.13 6.68 7.21 1.85 3.86 5.76 1.82 2.36 

FSV-CB 0.417 0.770 0.916 0.387 0.431 7.03 7.11 24.36 6.35 6.47 

FSV-CC >0.450 >0.840 >0.950 >0.440 >0.480 0.450 0.840 0.950 0.440 0.480 7.32 7.78 26.95 6.55 7.24 

FSV-CD 0.496 0.920 1.218 0.484 0.516 0.052 0.031 0.010 0.038 0.100 7.62 7.84 30.27 7.43 7.57 2.08 4.10 6.38 2.14 2.68 

FSV-CE 0.461 0.856 1.003 0.429 0.491 6.61 7.31 25.84 6.39 6.77 

FSV-CF 0.547 0.911 1.148 0.506 0.527 7.90 8.10 29.00 7.30 7.80 

FSV-CG 0.498 0.879 1.113 0.506 0.516 6.66 6.43 24.50 6.09 6.42 2.15 3.81 6.02 1.91 2.33 0.1

FSV-CI 0.460 0.790 0.740 0.420 0.440 0.060 0.040 0.030 0.050 0.110 7.20 7.10 32.40 6.40 7.20 2.00 3.80 7.00 1.70 2.30 

FSV-CL 0.354 0.618 0.808 0.328 0.364 8.71 8.37 29.53 7.53 8.17 2.10 3.63 6.37 1.74 2.33 

FSV-CP 7.59 8.15 27.38 6.73 6.63 2.16 4.08 5.63 2.17 2.23 

FSV-CR 0.490 0.890 1.030 0.440 0.520 8.30 8.50 30.10 6.70 7.90 

FSV-CV 0.530 0.910 0.920 0.460 0.430 0.068 0.082 0.050 0.110 0.140 7.99 8.22 23.14 7.46 7.37 2.07 3.99 5.97 1.76 2.08 0.1

FSV-CW >0.390 >0.779 >0.940 >0.382 >0.388 0.390 0.779 0.940 0.382 0.388 0.046 0.022 0.011 0.045 0.098 7.38 7.93 28.73 7.14 7.39 1.97 4.00 6.23 1.89 2.36 0.1

FSV-CZ 0.450 0.940 1.180 0.498 0.510 5.80 7.30 18.20 6.30 6.60 

FSV-DD >0.477 >0.700 >0.782 >0.401 >0.447 0.477 0.700 0.782 0.401 0.447 

FSV-DF 0.427 0.819 1.113 0.414 0.446 

FSV-DI >0.394 >0.808 >0.838 >0.343 >0.369 0.394 0.808 0.838 0.343 0.369 0.039 0.019 0.007 0.031 0.062 7.55 8.20 27.00 7.35 7.51 1.85 3.87 6.21 1.78 2.17 0.1

FSV-DQ 8.29 8.68 25.85 7.88 8.18 2.21 3.14 7.06 2.08 1.93 

FSV-DR 0.470 0.840 1.070 0.420 0.470 7.15 7.09 25.26 6.47 6.88 

FSV-DU 0.460 0.900 1.150 0.410 0.480 6.52 8.10 25.38 6.60 6.97 

FSV-DW 0.726 1.408 1.847 0.748 0.816 6.96 7.75 27.65 7.04 7.29 

FSV-EQ 0.553 0.956 1.254 0.516 0.557 8.40 7.80 30.10 7.10 7.90 

FSV-ET 0.380 0.720 0.850 0.370 0.370 6.30 6.80 22.50 6.10 6.50 1.60 3.10 4.70 1.40 1.80 

FSV-FB 0.510 0.890 1.300 0.510 0.580 0.510 0.890 1.300 0.510 0.580 7.09 7.97 30.29 7.53 7.68 

N 38 38 38 38 38 7 7 7 7 7 13 12 12 13 14 44 44 44 44 44 25 25 25 25 25 

Min 0.354 0.618 0.740 0.328 0.364 0.390 0.700 0.782 0.343 0.369 0.034 0.018 0.007 0.031 0.059 5.61 6.22 18.20 5.47 6.07 1.28 2.77 4.45 1.30 1.61 0.0

Median 0.462 0.869 1.070 0.447 0.484 0.450 0.835 0.942 0.438 0.480 0.052 0.029 0.024 0.050 0.101 7.18 7.77 27.37 6.77 7.29 1.97 3.86 6.16 1.80 2.29 0.1

Max 0.726 1.408 1.847 0.748 0.816 0.510 0.890 1.300 0.510 0.580 0.068 0.082 0.063 0.110 0.147 8.71 9.04 32.40 7.88 8.50 2.21 4.41 7.06 2.17 2.68 0.7

SD 0.050 0.053 0.130 0.044 0.050 0.037 0.049 0.071 0.040 0.055 0.016 0.009 0.015 0.012 0.021 0.65 0.45 2.64 0.55 0.54 0.21 0.33 0.70 0.14 0.15 0.0

CV 11 6 12 10 10 8 6 8 9 11 31 32 63 25 21 9 6 10 8 7 11 9 11 8 6 

Npast 38 44 45 42 46 9 10 9 9 0 13 14 11 14 12 45 48 46 49 44 25 26 26 27 23 

Medianpast 0.470 0.855 1.050 0.448 0.477 0.451 0.842 1.022 0.437 0.055 0.037 0.037 0.052 0.114 7.10 7.46 27.05 6.76 7.05 1.98 3.85 6.07 1.85 2.31 0.1

SDpast 0.042 0.058 0.104 0.045 0.051 0.031 0.046 0.098 0.035 0.014 0.012 0.035 0.011 0.028 0.61 0.74 2.26 0.66 0.57 0.14 0.35 0.53 0.13 0.28 0.0

NISTa 

NISTb 

NNIST 4 4 3 4 2 4 4 3 4 2 4 4 4 4 2 4 4 4 4 2 

Mean 0.479 0.868 0.992 0.478 0.482 0.479 0.852 0.795 0.476 0.469 7.23 7.27 26.94 7.06 6.99 2.00 3.72 6.03 1.96 2.43 0.1

0.481 0.858 1.065 0.499 0.474 0.481 0.858 0.838 0.499 0.474 

0.477 0.878 0.919 0.458 0.490 0.477 0.847 0.752 0.453 0.464 

7.20 7.25 26.64 7.29 7.19 2.13 3.86 6.40 2.13 2.62 

7.26 7.30 27.24 6.82 6.80 1.86 3.58 5.66 1.80 2.23 0.1

Srep 0.006 0.020 0.038 0.010 0.013 0.006 0.019 0.028 0.008 0.013 0.26 0.12 0.81 0.24 0.30 0.10 0.24 0.11 0.10 0.08 0.0

Shet 0.008 0.009 0.008 0.007 0.008 0.010 0.009 0.007 0.23 0.08 1.26 0.17 0.13 0.08 0.10 0.13 0.0

Sanl 0.003 0.014 0.103 0.029 0.011 0.003 0.008 0.061 0.032 0.007 0.04 0.03 0.43 0.33 0.28 0.19 0.20 0.52 0.23 0.28 

SNIST 0.010 0.026 0.110 0.031 0.017 0.010 0.022 0.068 0.034 0.015 0.35 0.15 1.56 0.45 0.41 0.25 0.32 0.54 0.28 0.29 0.0

NAV 

NAU 

0.470 0.868 1.031 0.463 0.483 

0.051 0.068 0.141 0.049 0.050 

0.465 0.843 0.869 0.457 0.475 

0.042 0.066 0.127 0.048 0.056 

0.052 0.029 0.024 0.050 0.101 

0.021 0.018 0.017 0.020 0.029 

7.20 7.52 27.16 6.91 7.14 

0.66 0.72 2.66 0.61 0.64 

1.98 3.79 6.10 1.88 2.36 

0.25 0.37 0.71 0.31 0.30 

0.1

0.0

All Lab Report 
Round Robin LI Laboratory Results 

All Results in μg/mL 

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

C3

Lab 279 280 281 282 283 279 280 281 282 283 279 280 281 282 283 279 280 281 282 283 279 

FSV-BA 0.335 0.161 0.327 0.312 0.072 0.317 0.151 0.301 0.293 0.068 0.018 0.010 0.026 0.018 0.004 0.028 0.013 0.010 0.026 0.011
 

FSV-BB
 0.329 0.163 0.335 0.314 0.066 0.310 0.153 0.306 0.295 0.062 0.018 0.011 0.029 0.020 0.004 0.033 0.017 0.015 0.031 0.011
 

FSV-BD
 

FSV-BE
 0.410 0.210 0.420 0.380 0.080
 

FSV-BF
 0.402 0.171 0.395 0.367 0.066 0.035 0.019 0.015 0.031 0.010
 

FSV-BG
 0.335 0.186 0.359 0.349 0.066 0.030 0.021 0.021 0.032 0.016
 

FSV-BH
 0.380 0.204 0.400 0.361 0.075 0.353 0.184 0.358 0.332 0.075 0.027 0.020 0.042 0.029 nd 0.038 0.018 0.014 0.033 0.016
 

FSV-BI
 0.401 0.201 0.400 0.364 0.075 0.034 0.018 0.011 0.032 0.012
 

FSV-BJ
 0.383 0.192 0.410 0.343 0.065 0.039 0.020 0.018 0.035 0.013
 

FSV-BK
 

FSV-BL
 

FSV-BM
 

FSV-BN
 0.354 0.174 0.365 0.327 0.069 0.329 0.169 0.327 0.303 0.068 0.025 0.005 0.038 0.024 0.001 0.030 0.013 0.008 0.028 0.010 

FSV-BNa 0.333 0.186 0.383 0.352 0.069 0.318 0.165 0.328 0.320 0.066 0.015 0.021 0.055 0.032 0.003 0.028 0.012 0.007 0.028 0.009
 

FSV-BO
 0.347 0.167 0.366 0.329 0.075 0.032 0.026 0.022 0.031 0.013
 

FSV-BP
 0.338 0.166 0.370 0.352 0.156 0.033 0.017 nd 0.032 nd
 

FSV-BQ
 

FSV-BR
 

FSV-BS
 >0.305 >0.143 >0.303 >0.293 >0.050 0.305 0.143 0.303 0.293 0.050 >0.018 >0.002 nq >0.016 >0.006 0.018 0

FSV-BT 0.260 0.117 0.253 0.246 0.061 0.239 0.105 0.225 0.225 0.054 0.021 0.012 0.028 0.021 0.008 0.023 0.012 0.011 0.020 0.014
 

FSV-BU
 0.364 0.173 0.357 0.336 0.078 0.027 0.015 0.012 0.027 0.014
 

FSV-BV
 0.351 0.189 0.373 0.323 0.075 0.026 0.014 0.010 0.024 0.011 

FSV-BW 0.354 0.168 0.371 0.305 0.072 0.023 0.009 nd 0.025 nd
 

FSV-BX
 >0.315 >0.162 >0.326 >0.316 >0.075 0.315 0.162 0.326 0.316 0.075 0.033 0.019 0.018 0.032 0.022
 

FSV-CB
 0.337 0.153 0.324 0.303 0.070 0.024 0.010 0.008 0.022 0.010
 

FSV-CC
 

FSV-CD
 0.266 0.153 0.354 0.268 0.056 0.032 0.016 0.013 0.035 0.013
 

FSV-CE
 0.331 0.167 0.327 0.303 0.067 

FSV-CF 

FSV-CG 0.333 0.161 0.349 0.301 0.074 0.307 0.142 0.303 0.275 0.065 0.026 0.019 0.046 0.026 0.008 0.030 0.015 0.014 0.028 0.015
 

FSV-CI
 >0.309 >0.182 >0.503 >0.327 >0.078 0.309 0.182 0.503 0.327 0.078 0.041 0.036 0.071 0.050 0.028
 

FSV-CL
 0.263 0.149 0.311 0.252 0.060 0.024 0.013 0.010 0.019 0.009
 

FSV-CP
 

FSV-CR
 

FSV-CV
 0.390 0.170 0.410 0.300 0.070 0.010 0.019 0.037 0.007 0.031 

FSV-CW 0.332 0.177 0.349 0.337 0.070 0.314 0.163 0.316 0.313 0.065 0.018 0.014 0.033 0.024 0.005 >0.028 >0.016 >0.015 >0.032 >0.013 0.028 0

FSV-CZ 0.290 0.190 0.300 0.300 0.120 

FSV-DD 

FSV-DF 

FSV-DI >0.266 >0.139 >0.284 >0.254 >0.025 0.266 0.139 0.284 0.254 0.025 

FSV-DQ 0.462 0.197 0.413 0.382 0.101 0.083 0.031 0.054 0.028 0.018
 

FSV-DR
 0.380 0.170 0.330 0.330 0.130 

FSV-DU >0.320 >0.170 >0.340 >0.290 >0.054 0.320 0.170 0.340 0.290 0.054 

FSV-DW 0.251 0.100 0.209 0.164 0.043 0.231 0.089 0.178 0.154 0.037 0.020 0.011 0.031 0.010 0.005 

FSV-EQ 0.309 0.147 0.290 0.272 0.059 0.023 0.009 0.008 0.020 0.007
 

FSV-ET
 0.330 0.160 0.330 0.310 0.070
 

FSV-FB
 0.344 0.181 0.357 0.334 0.060 0.307 0.153 0.309 0.294 0.060 0.037 0.028 0.048 0.040 nd 0.026 0.013 0.006 0.021 0.008 

N 

Min 

Median 

Max 

SD 

CV 

Npast 

Medianpast 

SDpast 

NISTa 

NISTb 

NNIST 

Mean 

Srep 

Shet 

Sanl 

SNIST 

30 

0.251 

0.338 

0.462 

0.034 

10 

32 

0.351 

0.040 

4 

0.384 

0.014 

0.013 

0.011 

0.022 

30 

0.100 

0.170 

0.210 

0.019 

11 

31 

0.174 

0.023 

4 

0.177 

0.016 

0.004 

0.006 

0.017 

30 

0.209 

0.357 

0.420 

0.039 

11 

34 

0.368 

0.043 

4 

0.393 

0.016 

0.008 

0.006 

0.019 

30 

0.164 

0.325 

0.382 

0.034 

11 

32 

0.319 

0.056 

4 

0.380 

0.014 

0.015 

0.011 

0.023 

30 

0.043 

0.070 

0.156 

0.007 

10 

31 

0.079 

0.016 

2 

0.074 

0.005 

0.005 

0.007 

15 

0.231 

0.310 

0.353 

0.016 

5 

14 

0.315 

0.028 

2 

0.365 

0.005 

0.006 

0.008 

15 

0.089 

0.153 

0.184 

0.018 

12 

15 

0.164 

0.017 

2 

0.171 

0.008 

0.003 

0.009 

15 

0.178 

0.309 

0.503 

0.019 

6 

14 

0.322 

0.040 

2 

0.348 

0.003 

0.000 

0.003 

15 

0.154 

0.294 

0.332 

0.024 

8 

15 

0.294 

0.032 

2 

0.344 

0.008 

0.009 

0.012 

15 

0.025 

0.065 

0.078 

0.011 

16 

10 

0.076 

0.009 

1 

0.070 

0.001 

10 

0.015 

0.021 

0.037 

0.006 

27 

10 

0.024 

0.006 

10 

0.005 

0.013 

0.028 

0.007 

53 

9 

0.015 

0.007 

10 

0.026 

0.036 

0.055 

0.011 

32 

10 

0.036 

0.022 

10 

0.010 

0.024 

0.040 

0.006 

26 

10 

0.023 

0.009 

8 

0.001 

0.004 

0.008 

0.002 

39 

7 

0.006 

0.004 

25 

0.010 

0.030 

0.083 

0.005 

18 

26 

0.030 

0.009 

2 

0.029 

0.001 

0.004 

0.004 

25 

0.009 

0.016 

0.036 

0.004 

28 

27 

0.016 

0.004 

2 

0.013 

0.003 

0.002 

0.003 

23 

0.006 

0.013 

0.071 

0.006 

45 

25 

0.013 

0.005 

2 

0.012 

0.004 

0.000 

0.004 

25 

0.007 

0.028 

0.050 

0.006 

20 

28 

0.030 

0.008 

2 

0.030 

0.001 

0.002 

0.002 

23 

0.007 

0.013 

0.031 

0.004 

30 

20 

0.016 

0.005 

1 

0.009 

0.000 

2 

0.018 

0.023 

0.028 

0 

2 

0.027 

0.001 

0.001 

0.001 

0

0

0

0

0

0

0

0.376 0.172 0.389 0.388 0.078 

0.393 0.181 0.397 0.373 0.070 0.365 0.171 0.348 0.344 0.070 0.028 0.010 0.049 0.029 nd 0.029 0.013 0.012 0.030 0.009 0.027 0

NAV 

NAU 

0.361 0.173 0.375 0.353 0.072 0.338 0.164 0.330 0.319 0.068 0.021 0.013 0.036 0.024 0.030 0.015 0.013 0.029 0.011 

0.059 0.027 0.057 0.061 0.014 0.050 0.020 0.042 0.047 0.011 0.007 0.007 0.013 0.008 0.010 0.006 0.006 0.009 0.006 

All Lab Report 
Round Robin LI Laboratory Results 

All Results in μg/mL 

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

C4

Lab 279 280 281 282 283 279 280 281 282 283 279 280 281 282 283 279 280 281 282 283 279 280 281 282 283 

FSV-BA 0.190 0.159 0.244 0.175 0.271 0.063 0.080 0.044 0.059 0.064
 

FSV-BB
 0.323 0.295 0.437 0.305 0.429 0.164 0.137 0.207 0.152 0.223 0.051 0.068 0.037 0.049 0.052 0.023 0.018 0.015 0.022 0.024 0.094 0.054 0.063 0.090 0.079

FSV-BD
 

FSV-BE
 

FSV-BF
 0.397 0.344 0.562 0.370 0.559 0.051 0.068 0.037 0.044 0.040 

FSV-BG 0.350 0.334 0.557 0.309 0.447 0.178 0.181 0.293 0.174 0.254 0.066 0.095 0.049 0.063 0.078 0.098 0.066 0.086 0.101 0.099

FSV-BH
 0.377 0.341 0.526 0.347 0.477 0.074 0.104 0.060 0.070 0.088 0.083 0.045 0.051 0.078 0.065

FSV-BI
 0.319 0.278 0.447 0.290 0.400 0.059 0.080 0.037 0.053 0.051 0.110 0.069 0.071 0.103 0.091

FSV-BJ
 0.399 0.392 0.638 0.373 0.539 0.046 0.071 0.037 0.044 0.045 0.101 0.076 0.072 0.088 0.080

FSV-BK
 

FSV-BL
 

FSV-BM
 

FSV-BN
 0.345 0.308 0.481 0.304 0.514 0.197 0.178 0.257 0.168 0.290 0.042 0.062 0.014 0.030 0.032 0.016 nd nd nd nd 0.083 0.056 0.054 0.078 0.062 

FSV-BNa 0.304 0.302 0.485 0.318 0.512 0.171 0.171 0.260 0.186 0.285 0.035 0.063 0.015 0.035 0.037 nd nd nd nd nd 0.091 0.057 0.049 0.078 0.072

FSV-BO
 0.336 0.251 0.463 0.266 0.482 0.053 0.065 0.037 0.048 0.050 0.076 0.037 0.046 0.074 0.058

FSV-BP
 0.386 0.322 0.438 0.476 0.514 0.052 0.073 0.046 0.059 0.063 

FSV-BQ 

FSV-BR 

FSV-BS 0.266 0.240 0.304 0.253 0.295 0.039 0.047 0.035 0.035 0.040 0.048 0.036 0.052 0.063 0.062

FSV-BT
 0.310 0.245 0.418 0.292 0.425 0.146 0.114 0.196 0.134 0.195 0.064 0.092 0.056 0.067 0.080 0.034 0.029 0.024 0.028 0.037 0.098 0.087 0.069 0.095 0.094

FSV-BU
 0.317 0.264 0.427 0.288 0.457 0.047 0.066 0.032 0.042 0.051
 

FSV-BV
 0.390 0.373 0.555 0.358 0.542 0.043 0.065 0.030 0.039 0.043 

FSV-BW 0.341 0.310 0.531 0.317 0.508
 

FSV-BX
 0.142 0.129 0.219 0.157 0.251 0.053 0.068 0.036 0.048 0.054 0.088 0.054 0.058 0.089 0.083

FSV-CB
 0.301 0.239 0.392 0.271 0.401 0.051 0.069 0.036 0.047 0.053 0.092 0.052 0.066 0.084 0.089

FSV-CC
 

FSV-CD
 0.287 0.277 0.510 0.287 0.336 0.050 0.058 0.039 0.047 0.055 

FSV-CE 

FSV-CF 

FSV-CG 0.382 0.327 0.537 0.347 0.522 0.212 0.174 0.284 0.190 0.291 0.050 0.059 0.037 0.045 0.052 0.112 0.082 0.079 0.099 0.099

FSV-CI
 0.075 0.046 0.062 0.062 0.063

FSV-CL
 0.343 0.297 0.508 0.303 0.465 0.057 0.071 0.034 0.047 0.051 0.028 0.017 0.013 0.024 0.026 

FSV-CP 

FSV-CR 

FSV-CV 0.310 0.290 0.520 0.310 0.460 

FSV-CW 0.337 0.314 0.464 0.340 0.468 0.157 0.141 0.206 0.153 0.217 0.053 0.070 0.042 0.049 0.054 0.022 0.017 0.015 0.020 0.020 >0.074 >0.048 >0.048 >0.071 >0.058 

FSV-CZ 

FSV-DD 

FSV-DF 

FSV-DI 0.240 0.221 0.358 0.232 0.304 0.137 0.110 0.117 0.139 0.120 

FSV-DQ 0.387 0.454 0.288 0.570 0.786 0.051 0.076 0.040 0.048 0.053 0.094 0.047 0.064 0.085 0.089

FSV-DR
 

FSV-DU
 

FSV-DW 0.136 0.101 0.161 0.104 0.151 0.065 0.087 0.061 0.046 0.078 0.079 0.058 0.074 0.074 0.075

FSV-EQ
 0.324 0.291 0.449 0.294 0.442 0.054 0.074 0.048 0.050 0.059
 

FSV-ET
 

FSV-FB
 0.289 0.259 0.422 0.281 0.407 0.251 0.226 0.367 0.244 0.362 0.047 0.065 0.031 0.045 0.047 0.086 0.060 0.060 0.082 0.071 

N 

Min 

Median 

Max 

SD 

CV 

Npast 

Medianpast 

SDpast 

NISTa 

NISTb 

NNIST 

Mean 

Srep 

Shet 

Sanl 

SNIST 

NAV 

NAU 

23 23 23 

0.287 0.239 0.288 

0.337 0.302 0.481 

0.399 0.454 0.638 

0.049	 0.040 0.067 

15 13 14 

27 26 28 

0.351 0.311 0.504 

0.044 0.055 0.102 

0.403	 0.347 0.569 

2 2 2 

0.403 0.347 0.569 

0.012 0.024 0.015 

0.000 0.019 0.009 

0.012 0.031 0.017 

23 

0.266 

0.309 

0.570 

0.042 

14 

28 

0.326 

0.053 

0.379 

2 

0.379 

0.004 

0.024 

0.024 

23 

0.336 

0.468 

0.786 

0.058 

12 

23 

0.447 

0.100 

0.532 

1 

0.532 

0.031 

13 

0.136 

0.178 

0.266 

0.041 

23 

12 

0.187 

0.045 

13 

0.101 

0.171 

0.240 

0.033 

19 

12 

0.158 

0.027 

13 

0.161 

0.257 

0.367 

0.064 

25 

13 

0.253 

0.058 

13 

0.104 

0.174 

0.253 

0.027 

16 

12 

0.163 

0.038 

13 

0.151 

0.271 

0.362 

0.051 

19 

8 

0.302 

0.071 

25 

0.035 

0.051 

0.074 

0.007 

14 

25 

0.056 

0.009 

25 

0.047 

0.069 

0.104 

0.008 

12 

27 

0.075 

0.014 

25 

0.014 

0.037 

0.061 

0.007 

18 

25 

0.043 

0.009 

25 

0.030 

0.047 

0.070 

0.004 

9 

27 

0.053 

0.011 

25 

0.032 

0.052 

0.088 

0.009 

17 

19 

0.066 

0.016 

5 

0.016 

0.023 

0.034 

0.004 

19 

5 

0.026 

0.005 

4 

0.017 

0.017 

0.029 

5 

0.022 

0.006 

4 

0.013 

0.015 

0.024 

5 

0.019 

0.010 

4 

0.020 

0.023 

0.028 

6 

0.025 

0.005 

4 

0.020 

0.025 

0.037 

7 

0.035 

0.007 

18 

0.048 

0.092 

0.137 

0.011 

12 

15 

0.089 

0.021 

18 

0.036 

0.057 

0.110 

0.015 

26 

16 

0.055 

0.014 

18 

0.046 

0.063 

0.117 

0.012 

20 

16 

0.063 

0.025 

18 

0.062 

0.085 

0.139 

0.012 

14 

15 

0.085 

0.013 

18 

0.058 

0.079 

0.120 

0.018 

22 

12 

0.077 

0.016 

0.062 0.077 nq 0.068 0.061 0.105 0.064 0.075 0.107 0.080 

0.060 0.064 0.039 0.056 0.056 0.029 0.028 0.020 0.035 nd >0.085 >0.042 >0.067 >0.084 >0.070 

4 

0.061 

0.005 

0.009 

0.001 

0.011 

4 2 4 2 1 1 1 1 

0.071 0.039 0.062 0.058 0.029 0.028 0.020 0.035 

0.007 0.003 0.003 0.003 0.000 0.003 0.002 

0.003 0.001 0.001 

0.010 0.009 0.003 

0.012 0.003 0.009 0.005 

4 

0.095 

0.005 

0.007 

0.014 

0.016 

4 

0.054 

0.008 

0.006 

0.017 

0.019 

4 

0.071 

0.005 

0.003 

0.006 

0.008 

4 

0.096 

0.004 

0.005 

0.016 

0.017 

3 

0.058 

0.004 

0.035 

0.032 

0.048 

0.370 0.325 0.525 0.344 0.500 

0.088 0.076 0.118 0.086 0.108 

0.174 0.165 0.251 0.171 0.262 

0.035 0.033 0.059 0.030 0.051 

0.056 0.070 0.038 0.055 0.056 

0.014 0.016 0.009 0.016 0.013 

0.026 0.094 0.055 0.067 0.090 0.069 

0.018 0.019 0.014 0.019 0.050 

All Lab Report	 
Round Robin LI Laboratory Results 

All Results in μg/mL 

Total Zeaxanthin Total Lutein&Zeaxanthin Coenzyme Q10 Phylloquinone (K1) 

C5

Lab 279 280 281 282 283 279 280 281 282 283 279 280 281 282 283 279 280 281 282 

FSV-BA 0.117 0.084 0.077 0.112 0.099
 

FSV-BB
 0.037 0.040 0.045 0.036 0.048 0.131 0.094 0.108 0.126 0.127 

FSV-BD
 

FSV-BE
 0.530 0.800 0.410 0.520 

FSV-BF 0.123 0.086 0.093 0.118 0.115
 

FSV-BG
 0.020 0.017 0.013 0.018 0.018 0.110 0.075 0.094 0.110 0.111
 

FSV-BH
 0.034 0.038 0.029 0.031 0.039 0.117 0.083 0.080 0.109 0.104
 

FSV-BI
 0.036 0.036 0.032 0.034 0.035 0.146 0.105 0.103 0.137 0.126 

FSV-BJ 0.748 0.587 0.883 0.635 0.743
 

FSV-BK
 

FSV-BL
 

FSV-BM
 

FSV-BN
 0.017 0.016 0.013 0.011 0.015 0.100 0.072 0.067 0.090 0.077 

FSV-BNa 0.017 0.022 0.017 0.018 0.016 0.108 0.079 0.065 0.097 0.088
 

FSV-BO
 0.027 0.060 0.055 0.027 0.039 0.103 0.097 0.101 0.101 0.097
 

FSV-BP
 0.109 0.098 0.089 0.112 0.108
 

FSV-BQ
 

FSV-BR
 

FSV-BS
 0.020 0.020 0.022 0.020 0.024 0.068 0.056 0.074 0.083 0.086 

FSV-BT 0.030 0.040 0.026 0.030 0.033 0.129 0.127 0.095 0.125 0.127
 

FSV-BU
 0.138 0.113 0.099 0.133 0.142
 

FSV-BV
 0.122 0.098 0.085 0.115 0.108 

FSV-BW 

FSV-BX 0.028 0.032 0.023 0.025 0.030 0.115 0.086 0.081 0.114 0.113 

FSV-CB 0.027 0.034 0.026 0.025 0.032 0.120 0.086 0.092 0.109 0.121 

FSV-CC 

FSV-CD 0.122 0.094 0.088 0.108 0.100
 

FSV-CE
 

FSV-CF
 

FSV-CG
 0.021 0.022 0.015 0.018 0.020 0.133 0.104 0.094 0.117 0.119
 

FSV-CI
 0.028 0.030 0.031 0.018 0.027 0.103 0.076 0.093 0.080 0.090 0.180 0.320 0.170 0.180 

FSV-CL 0.098 0.079 0.074 0.090 0.091
 

FSV-CP
 

FSV-CR
 

FSV-CV
 0.160 0.102 0.101 0.150 0.120 1.280 1.030 1.290 1.200 1.040 

FSV-CW 0.031 0.036 0.028 0.030 0.034 >0.105 >0.084 >0.076 >0.101 >0.092 0.870 0.720 0.900 0.830 0.830
 

FSV-CZ
 0.970 1.200 1.200 1.000 0.940
 

FSV-DD
 

FSV-DF
 

FSV-DI 0.398 0.495 0.868 0.515 0.626 0.590 0.670 0.480 0.410 

FSV-DQ 0.027 0.029 0.030 0.024 0.028 0.121 0.076 0.094 0.109 0.117 

FSV-DR 

FSV-DU 

FSV-DW 0.041 0.048 0.055 0.036 0.059 0.119 0.105 0.128 0.110 0.134 

FSV-EQ 0.198 0.200 0.120 0.177 0.190
 

FSV-ET
 

FSV-FB
 0.023 0.028 0.022 0.023 0.029 0.109 0.098 0.082 0.105 0.100 

NISTa 

NISTb >0.032 >0.034 >0.042 >0.036 >0.041 >0.117 >0.075 >0.108 >0.121 >0.111 

N 17 17 17 17 17 25 25 25 25 25 5 5 5 5 5 3 3 3 3 

Min 0.017 0.016 0.013 0.011 0.015 0.068 0.056 0.065 0.080 0.077 0.398 0.495 0.868 0.515 0.626 0.180 0.320 0.170 0.180 

Median 0.027 0.032 0.026 0.025 0.030 0.119 0.094 0.093 0.110 0.111 0.870 0.720 0.900 0.830 0.830 0.530 0.670 0.410 0.410 

Max 0.041 0.060 0.055 0.036 0.059 0.198 0.200 0.128 0.177 0.190 1.280 1.200 1.290 1.200 1.040 0.590 0.800 0.480 0.520 

SD 0.008 0.012 0.007 0.009 0.008 0.015 0.017 0.013 0.010 0.016 0.165 0.329 0.235 0.271 0.146 

CV 28 38 25 35 27 12 18 14 9 14 19 46 26 33 18 

Npast 14 15 12 14 14 23 26 22 26 17 6 0 8 10 0 0 0 0 0 

Medianpast 0.025 0.032 0.025 0.025 0.035 0.120 0.094 0.087 0.118 0.112 0.912 0.855 0.858 

SDpast 0.006 0.009 0.007 0.006 0.013 0.025 0.018 0.019 0.018 0.034 0.234 0.089 0.241 

NNIST 2 2 2 2 2 2 2 2 2 2 

Mean 0.032 0.034 0.042 0.036 0.020 0.117 0.075 0.108 0.121 0.055
 

Srep 0.002 0.008 0.002 0.001 0.001 0.009 0.017 0.004 0.003 0.007
 

Shet 0.007 0.003 0.000 0.002 0.029 0.014 0.011 0.004 0.002 0.078
 

Sanl
 

SNIST 0.007 0.009 0.002 0.002 0.029 0.017 0.020 0.006 0.004 0.079 

NAV 

NAU 

0.030 0.033 0.035 0.031 0.026 0.118 0.085 0.101 0.116 0.084 

0.008 0.009 0.013 0.012 0.030 0.025 0.024 0.022 0.024 0.088 

All Lab Report 
 

 

 

 

 

Round Robin LI Laboratory Results
 

All Results in μg/mL
 

Analytes Reported By One Laboratory
 

Term 

N 

Min 

Medianpart 

Max 

SD 

CV 

Npast 

Medianpast 

SDpast 

NNIST 

MeanNIST 

Srep 

Shet 

Sanl 

SNIST 

NAV 

NAU 

nd 

nq 

<x 

italics

Analyte Code 279 280 281 282 283 

trans-β-Cryptoxanthin NISTb 0.051 0.061 0.033 0.050 0.073 

trans-Zeaxanthin NISTb 0.032 0.034 0.042 0.036 0.043 

Phytofluene FSV-CL 0.027 0.028 0.042 0.029 0.041 

Phytoene FSV-CL 0.051 0.052 0.060 0.051 0.048 

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)
 

 Number of vials analyzed in duplicate by NIST analyst(s)

 Mean of the NIST-analyzed vial means

 W ithin-vial pooled standard deviation

 Among-vial pooled standard deviation

 Between NIST analyst standard deviation 

2

)

0.5 Total standard deviation for NIST analyses: (Srep 2

 + Shet 2 + Sanl 

 NIST Assigned Value

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

 = Medianpart 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 detected (i.e., no detectable peak for analyte)

 Detected but not quantitatively determined

 Concentration at or below the limit of quantification, x

 Not explictly reported but calculated by NIST from reported values

All Lab Report Page 5 / 6 

C6
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Lab 

FSV-BA 

FSV-BB 

FSV-BD 

FSV-BE 

FSV-BF 

FSV-BG 

FSV-BH 

FSV-BI 

FSV-BJ 

FSV-BK 

FSV-BL 

FSV-BM 

FSV-BN 

FSV-BNa 

FSV-BO 

FSV-BP 

FSV-BQ 

FSV-BR 

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-CL 

FSV-CP 

Round Robin LI Laboratory Results 

Comparability Summary 

TR tR RP aT g/bT bC tbC aC TLy tLy TbX TLu TZ L&Z Label Definition
 

1 2 1 1 1 1 1 1 1 1 1 1
 Lab Participant code
 

1 1 1 1 1 1 1 1 1 1 1 2 1
 TR Total Retinol
 

1 2
 tR trans-Retinol
 

2 1 1 2 1
 RP Retinyl palmitate
 

1 1 1 1 1 1 1
 aT α-Tocopherol
 

1 1 1 1 1 1 1 1 2 1
 g/bT γ/β-Tocopherol
 

1 1 1 1 2 1 1 3 1 2 1
 bC Total β-Carotene
 

1 1 1 1 1 1 1 1 1 1
 tbC trans-β-Carotene
 

1 2 1 1 1 1 1 1 1 1 1
 aC Total α-Carotene
 

1 1
 TLy Total Lycopene
 

2 2 1
 tLy trans-Lycopene
 

1 2
 TbX Total β-Cryptoxanthin
 

1 1 2 2 1 1 1 1 1 2 2
 TLu Total Lutein
 

1 1 2 2 1 1 1 1 1 2
 TZ Total Zeaxanthin
 

2 1 1 2 1 1 1
 L&Z Total Lutein&Zeaxanthin
 

1 1 4 1 2 1 1 1 1
 

1 1 1
 n number of participants providing quantitative data 

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

1 1 3 3 2 2 1 1 2 2 1 2 1
 % 2 Percent of CS = 2 (within 2 SD of medians)
 

1 1 1 1 1 1 1 1 2 1
 % 3 Percent of CS = 3 (within 3 SD of medians)
 

1 1 1 1 1 1 1 1 1 1
 % 4 Percent of CS = 4 (3 or more SD from medians) 







− 





 

1 1 1 1 1 1 1 

1 1 1 1 1 1 1 

2 1 1 1 1 1 2 1 1 “Comparability Score”
 

1 1
 The Comparability Score (CS) summarizes your measurement 

1 1 1 1 1 1 1 1 performance for a given analyte relative to the consensus 

medians in this study. CS is the average distance (in units of 1 1 1 1 standard deviation) of your measurement performance 2 1 1 characteristics from the consensus performance. CS is 

1 2 1 1 1 1 1 1 1 1 calculated when the number of quantitative values you reported, 

Nyou, is at least two and at least six participants reported 2 1 2 1 3 4 quantitative values for the analyte. 3	 2 1 1 1 1 1 

1 1 We define CS as follows: 

MINIMUM 4,INTEGER 1 

you Youi Median i 

NAU i 





 FSV-CR 1	 2 



 

2 2 CS = + C + AP

FSV-CV 2 3 2 1 1 3 1 

∑ 

= 

N 

i 1 

FSV-CW 2 1 1 1 1 1 1 1 1 1 1 1 

FSV-CZ 1	 2 2 1 1 1 C = Concordance = 

FSV-DD 2 N 2 

Nyou 

FSV-DF 1 

FSV-DR 

FSV-DU 

FSV-DW 

FSV-EQ 

FSV-ET 

FSV-FB 

NISTa 

NISTb 

n 

% 1 

% 2 

% 3 

% 4 

FSV-DI 2 1 1 1 2 2 1 2 1 

FSV-DQ 2 2 2 4 3 1 3 

1 1 3 

1 1 1 3 

4 1 3 3 2 2 1 

2 2 1 1 1 1 1 1 1 

2 2 2 1 

2 2 1 1 1 1 1 2 1 

1 1 1 1 1 1 1 

1 1 1 1 1 1 1 1 1 

40 9 13 46 27 32 15 26 24 12 26 18 16 24 

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

70 56 77 67 81 78 67 85 92 67 77 89 69 92 

25 44 15 30 15 13 20 4 4 33 19 6 31 4 

3 0 8 2 4 6 13 4 4 0 4 6 0 4 

3 0 0 0 0 3 0 8 0 0 0 0 0 0 

i 1 

you 



 



 ∑ 

= 

N 

Youi 

NAU 

− 

AP = Apparent Precision = 

i 

 



 

1 

Median 

i 

− 

NAU = NIST Assigned Uncertainty 

you 

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 long-term measurement 

performance. Anal Chem 1999;71(9):1870-8. 

All Lab Report	 Page 6 / 6 

C7
 

Appendix D. Representative “Individualized Report” for RR51 

Each participant in RR51 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 RR51: 

• Total Retinol 

• trans-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 Lutein 

• Total Zeaxanthin 

• Total Lutein & Zeaxanthin 

• Coenzyme Q10 

The following 12 pages are the “Individualized Report” for the analytes evaluated by 

participant FSV-BA. 

D1
 

 Set 1 of 49

Individualized Round Robin LI Report: FSV-BA 

Summary 

Serum 279 Serum 280 Serum 281 Serum 282 

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

Total Retinol 0.470 0.470 38 0.858 0.868 38 1.132 1.031 38 0.452 0.463 38 

Retinyl Palmitate 0.06 0.05 13 0.0 0.0 12 0.1 0.0 12 0.06 0.05 13 

α-Tocopherol 7.15 7.20 44 7.39 7.52 44 27.36 27.16 44 6.77 6.91 44 

γ/β-Tocopherol 1.964 1.983 25 3.885 3.789 25 6.161 6.097 25 1.869 1.882 25 

Total β-Carotene 0.335 0.361 30 0.161 0.173 30 0.327 0.375 30 0.312 0.353 30 

trans-β-Carotene 0.317 0.337 15 0.151 0.162 15 0.301 0.328 15 0.293 0.319 15 

Total cis-β-Carotene 0.018 0.021 10 0.010 0.013 10 0.026 0.036 10 0.018 0.024 10 

Total α-Carotene 0.028 0.030 25 0.013 0.015 25 0.010 0.013 23 0.026 0.029 25 

trans-Lycopene 0.190 0.178 13 0.159 0.171 13 0.244 0.257 13 0.175 0.174 13 

Total β-Cryptoxanthin 0.063 0.056 25 0.080 0.070 25 0.044 0.038 25 0.059 0.055 25 

Total Lutein&Zeaxanthin 0.117 0.118 25 0.084 0.085 25 0.077 0.101 25 0.112 0.116 25 

D2

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

NAV : NIST Assigned Values, equal to (NIST's average-of-averages + this RR's median) / 2 

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: 

 Individualized Report 
 

 Set 1 of 49

Individualized RR LI Report: FSV-BA 

Total Retinol 

Apparent Precision, SD 

[Analyte], μg/mL 

193254255269281181222243283248258263280266277282271275279

Your [Analyte], μg/mL

Median [Analyte], μg/mL 

Apparent Precision, SD 

Long-term Precision, SD 

Median (50%) 

Concordance, SD 

3rd Quartile (75%) You, this RR You, >x, this RR NIST, this RR 

1st Quartile (25%) 

You, >x, past RRs You, past RRs Others, this RR 

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 

#279 #271 RR49, #275 RR50 Fresh frozen pair of #282 

#280 #248 RR44, #258 RR46, #263 RR47 SRM 968c Lv I 

#281 #193 RR30, #254 RR45, #255 RR46, #269 RR49 ~30% of retinol as 13-cis isomer 

#282 #266 RR48, #277 RR50 Lyophilized pair of #279 

#283 #181 RR28, #222 RR37, #243 RR43 

 Individualized Report Page 2 / 12 

D3
 

 Set 1 of 49

Individualized RR LI Report: FSV-BA 

Retinyl Palmitate 

Apparent Precision, SD 

[Analyte], μg/mL 

193254255269281181222243283248258263280266277282271275279

Your [Analyte], μg/mL

Median [Analyte], μg/mL 

Apparent Precision, SD 

Long-term Precision, SD 

Median (50%) 

Concordance, SD 

3rd Quartile (75%) You, this RR You, >x, this RR NIST, this RR 

1st Quartile (25%) 

You, >x, past RRs You, past RRs Others, this RR 

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 

#279 #271 RR49, #275 RR50 Fresh frozen pair of #282 

#280 #248 RR44, #258 RR46, #263 RR47 SRM 968c Lv I 

#281 #193 RR30, #254 RR45, #255 RR46, #269 RR49 ~30% of retinol as 13-cis isomer 

#282 #266 RR48, #277 RR50 Lyophilized pair of #279 

#283 #181 RR28, #222 RR37, #243 RR43 

 Individualized Report Page 3 / 12 

D4
 

 Set 1 of 49

Individualized RR LI Report: FSV-BA 

α-Tocopherol 

Apparent Precision, SD 

[Analyte], μg/mL 

193254255269281181222243283248258263280266277282271275279

Your [Analyte], μg/mL

Median [Analyte], μg/mL 

Apparent Precision, SD 

Long-term Precision, SD 

Median (50%) 

Concordance, SD 

3rd Quartile (75%) You, this RR You, >x, this RR NIST, this RR 

1st Quartile (25%) 

You, >x, past RRs You, past RRs Others, this RR 

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 

#279 #271 RR49, #275 RR50 Fresh frozen pair of #282 

#280 #248 RR44, #258 RR46, #263 RR47 SRM 968c Lv I 

#281 #193 RR30, #254 RR45, #255 RR46, #269 RR49 ~30% of retinol as 13-cis isomer 

#282 #266 RR48, #277 RR50 Lyophilized pair of #279 

#283 #181 RR28, #222 RR37, #243 RR43 

 Individualized Report Page 4 / 12 

D5
 

 Set 1 of 49

Individualized RR LI Report: FSV-BA 

γ/β-Tocopherol 

Apparent Precision, SD 

[Analyte], μg/mL 

193254255269281181222243283248258263280266277282271275279

Your [Analyte], μg/mL

Median [Analyte], μg/mL 

Apparent Precision, SD 

Long-term Precision, SD 

Median (50%) 

Concordance, SD 

3rd Quartile (75%) You, this RR You, >x, this RR NIST, this RR 

1st Quartile (25%) 

You, >x, past RRs You, past RRs Others, this RR 

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 

#279 #271 RR49, #275 RR50 Fresh frozen pair of #282 

#280 #248 RR44, #258 RR46, #263 RR47 SRM 968c Lv I 

#281 #193 RR30, #254 RR45, #255 RR46, #269 RR49 ~30% of retinol as 13-cis isomer 

#282 #266 RR48, #277 RR50 Lyophilized pair of #279 

#283 #181 RR28, #222 RR37, #243 RR43 

 Individualized Report Page 5 / 12 

D6
 

 Set 1 of 49

Individualized RR LI Report: FSV-BA 

Total β-Carotene 

Apparent Precision, SD 

[Analyte], μg/mL 

193254255269281181222243283248258263280266277282271275279

Your [Analyte], μg/mL

Median [Analyte], μg/mL 

Apparent Precision, SD 

Long-term Precision, SD 

Median (50%) 

Concordance, SD 

3rd Quartile (75%) You, this RR You, >x, this RR NIST, this RR 

1st Quartile (25%) 

You, >x, past RRs You, past RRs Others, this RR 

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 

#279 #271 RR49, #275 RR50 Fresh frozen pair of #282 

#280 #248 RR44, #258 RR46, #263 RR47 SRM 968c Lv I 

#281 #193 RR30, #254 RR45, #255 RR46, #269 RR49 ~30% of retinol as 13-cis isomer 

#282 #266 RR48, #277 RR50 Lyophilized pair of #279 

#283 #181 RR28, #222 RR37, #243 RR43 

 Individualized Report Page 6 / 12 

D7
 

 Set 1 of 49

Individualized RR LI Report: FSV-BA 

trans-β-Carotene 

Apparent Precision, SD 

[Analyte], μg/mL 

193254255269281181222243283248258263280266277282271275279

Your [Analyte], μg/mL

Median [Analyte], μg/mL 

Apparent Precision, SD 

Long-term Precision, SD 

Median (50%) 

Concordance, SD 

3rd Quartile (75%) You, this RR You, >x, this RR NIST, this RR 

1st Quartile (25%) 

You, >x, past RRs You, past RRs Others, this RR 

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 

#279 #271 RR49, #275 RR50 Fresh frozen pair of #282 

#280 #248 RR44, #258 RR46, #263 RR47 SRM 968c Lv I 

#281 #193 RR30, #254 RR45, #255 RR46, #269 RR49 ~30% of retinol as 13-cis isomer 

#282 #266 RR48, #277 RR50 Lyophilized pair of #279 

#283 #181 RR28, #222 RR37, #243 RR43 

 Individualized Report Page 7 / 12 

D8
 

 Set 1 of 49

Individualized RR LI Report: FSV-BA 

Total α-Carotene 

Apparent Precision, SD 

[Analyte], μg/mL 

193254255269281181222243283248258263280266277282271275279

Your [Analyte], μg/mL

Median [Analyte], μg/mL 

Apparent Precision, SD 

Long-term Precision, SD 

Median (50%) 

Concordance, SD 

3rd Quartile (75%) You, this RR You, >x, this RR NIST, this RR 

1st Quartile (25%) 

You, >x, past RRs You, past RRs Others, this RR 

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 

#279 #271 RR49, #275 RR50 Fresh frozen pair of #282 

#280 #248 RR44, #258 RR46, #263 RR47 SRM 968c Lv I 

#281 #193 RR30, #254 RR45, #255 RR46, #269 RR49 ~30% of retinol as 13-cis isomer 

#282 #266 RR48, #277 RR50 Lyophilized pair of #279 

#283 #181 RR28, #222 RR37, #243 RR43 

 Individualized Report Page 8 / 12 

D9
 

 Set 1 of 49

Individualized RR LI Report: FSV-BA 

trans-Lycopene 

Apparent Precision, SD 

[Analyte], μg/mL 

193254255269281181222243283248258263280266277282271275279

Your [Analyte], μg/mL

Median [Analyte], μg/mL 

Apparent Precision, SD 

Long-term Precision, SD 

Median (50%) 

Concordance, SD 

3rd Quartile (75%) You, this RR You, >x, this RR NIST, this RR 

1st Quartile (25%) 

You, >x, past RRs You, past RRs Others, this RR 

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 

#279 #271 RR49, #275 RR50 Fresh frozen pair of #282 

#280 #248 RR44, #258 RR46, #263 RR47 SRM 968c Lv I 

#281 #193 RR30, #254 RR45, #255 RR46, #269 RR49 ~30% of retinol as 13-cis isomer 

#282 #266 RR48, #277 RR50 Lyophilized pair of #279 

#283 #181 RR28, #222 RR37, #243 RR43 

 Individualized Report Page 9 / 12 

D10
 

 Set 1 of 49

Individualized RR LI Report: FSV-BA 

Total β-Cryptoxanthin 

Apparent Precision, SD 

[Analyte], μg/mL 

193254255269281181222243283248258263280266277282271275279

Your [Analyte], μg/mL

Median [Analyte], μg/mL 

Apparent Precision, SD 

Long-term Precision, SD 

Median (50%) 

Concordance, SD 

3rd Quartile (75%) You, this RR You, >x, this RR NIST, this RR 

1st Quartile (25%) 

You, >x, past RRs You, past RRs Others, this RR 

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 

#279 #271 RR49, #275 RR50 Fresh frozen pair of #282 

#280 #248 RR44, #258 RR46, #263 RR47 SRM 968c Lv I 

#281 #193 RR30, #254 RR45, #255 RR46, #269 RR49 ~30% of retinol as 13-cis isomer 

#282 #266 RR48, #277 RR50 Lyophilized pair of #279 

#283 #181 RR28, #222 RR37, #243 RR43 

 Individualized Report Page 10 / 12 

D11
 

 Set 1 of 49

Individualized RR LI Report: FSV-BA 

Total Lutein&Zeaxanthin 

Apparent Precision, SD 

[Analyte], μg/mL 

193254255269281181222243283248258263280266277282271275279

Your [Analyte], μg/mL

Median [Analyte], μg/mL 

Apparent Precision, SD 

Long-term Precision, SD 

Median (50%) 

Concordance, SD 

3rd Quartile (75%) You, this RR You, >x, this RR NIST, this RR 

1st Quartile (25%) 

You, >x, past RRs You, past RRs Others, this RR 

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 

#279 #271 RR49, #275 RR50 Fresh frozen pair of #282 

#280 #248 RR44, #258 RR46, #263 RR47 SRM 968c Lv I 

#281 #193 RR30, #254 RR45, #255 RR46, #269 RR49 ~30% of retinol as 13-cis isomer 

#282 #266 RR48, #277 RR50 Lyophilized pair of #279 

#283 #181 RR28, #222 RR37, #243 RR43 

 Individualized Report Page 11 / 12 

D12
Set 1 of 49 

Individualized Round Robin LI Report: FSV-BA
 

Graphical Comparability Summary
 

Total Retinol α-Tocopherol Total β-Carotene 

D13

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 RR16 

The following five items were included in each package shipped to an RR16 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
... 

0 

0 

NIST CENTENHIAL fll' 

January 25, 2002 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standards and Technology 

Gaithersburg, Maryland 20888-

The enclosed group of samples constitutes Vitamin C Round Robin 16 of the 2002 Micronutrients 

Measurement Quality Assurance Program. Three vials of frozen serum (test samples) and a vial of solid 

ascorbic acid (control sample) are enclosed. Please follow the attached protocol when you analyze these 

samples. 

In RR15 we noted that several of the laboratories reported high blank values. We also noted that by 

correcting for the discrepancy between the assay values and the calculated values for the calibration 

solutions we were able to reduce the CV for the entire group by a factor of three. This would suggest 

that some laboratories need to examine their assay methods for errors due to high solvent }?lanks and that 

the standards should be prepared by weight as the calibration solutions are prepared. We hope that by 

drawing attention to these techniques we can improve the overall laboratory performance. 

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, oremail: srminfo@nist.gov) 

Return your results using the attached form by April 8, 2002. We also request that you send us a 

representative chromatogram from the analysis of each sample and indicate whether peak height or peak 

area was used in the calculation of the ascorbic acid concentration. Your results will be kept 

confidential. 

Please send your results to: 

Micronutrients Measurement Quality Assurance Program 

NIST 

100 Bureau Drive, Stop 8392 

Gaithersburg, MD 20899-8392 

If you have any questions or concerns please call me at 301-975-3137, or contact me by Fax: 301- 977-

0685 or e-mail: sam.margolis@nist.gov. 

Thank you for your participation. We look forward to receiving your results. 

Sincerely, 

~Ph.D. Research Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosure 

NISI 

E2
 

 

 

 

 

 

 

Protocol for analyzing samples 

The control sample consists of a sample of solid ascorbic acid in an amber vial and should be used in 

the following manner (please record your mass on the attached report form): 

1.	 Prepare 250 mL of 5% metaphosphoric acid (MPA) in distilled water. 

2.	 Weigh 180-220 mg of the solid ascorbic acid sample to 0.1 mg (if possible), dissolve it in 

5% MPA in a 100 mL volumetric flask, and dilute to the 100 mL mark. Weigh the 

amount of MPA solution that was added. This will be referred to as the Stock 

Solution. 

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

Dilute Solution 1: Weigh 0.500 mL of the stock solution into a 100 mL volumetric 

flask. Then dilute with 5% MPA solution to 100 mL mark and weigh the amount of 

MPA solution that was added. 

Dilute Solution 2: Weigh 0.250 mL of the stock solution into a 100 mL volumetric 

flask. Then dilute with 5% MPA solution to 100 mL mark and weigh the amount of 

MPA solution that was added. 

Dilute Solution 3: Weigh 0.125 mL of the stock solution into a 100 mL volumetric 

flask. Then dilute with 5% MPA solution to 100 mL mark and weigh the amount 

ofMPA solution that was added. 

4.	 Record the ultraviolet absorbance spectrum of Dilute Solution 1 against 5% MPA 

solution as the blank using paired cuvettes. Record the wavelength in the region of 240­

245 nm at which you observe the maximum absorbance and record the absorbance at that 

wavelength. 

5.	 Record the absorbance of the sample at 242, 243 and 244 nm. 

6.	 Measure the concentration of the ascorbic acid in all three dilute solutions and the 5% 

MPA diluent in duplicate along with the ampouled test samples using your usual 

methods. 

The purpose of measuring the absorbance at the wavelength maximum is to check the concentration 

of your sample. If your spectrophotometer is properly calibrated, the maximum absorbance should 

be between 243 and 244 nm. If the concentration is correct, the molar extinction coefficient (E1

%) of 

ascorbic acid at this wavelength (using a cell with a 1 cm path length) should be close to 550 ± 30 

nm. The extinction coefficient of your solution can be calculated using the following equation: 

E1% dl/g·cm = Observed Absorbanceλmax 

(g AA/100 mL stock)(g stock in 100 mL dilute solution)

 (g AA stock solution) + (g MPA solution in 100 mL dilute solution 1) 

E3
 

The test samples are in sealed ampoules and were prepared by adding equal volumes of 10% 

metaphosphoric acid 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 AA should be reported. The test 

samples sho_uld be defrosted by warming at 20 °C for not more than 10 min otherwise some 

irreversible degradation may occur. 

Each test sample should contain between 0 and 100 μmol of ascorbic acid/L of solution. The total 

ascorbic acid in each ampoule should be measured in duplicate by the method(s) used in your 

laboratory. Please report your results in μg/L of sample. 

E4
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

REPORT OF ANALYSIS
 

NAME: 

ADDRESS: 

Method of Analysis: 

Please note the type of method that you use. 

Please attach representative chromatograms. 

Method used for calculating ascorbic acid concentration. 

Was SRM 970 used to validate your method or value-assign your in-house controls? 

Peak height Peak area 

Manufacturer of ascorbic acid used to make in-house standards 

Were samples frozen upon receipt? Yes No 

Date of Analysis: 

PREPARATION OF STOCK SOLUTION AND DILUTED SOLUTION 

STOCK SOLUTION 

Mass of ascorbic acid in the Stock Solution mg 

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

DILUTE SOLUTION 1 

Mass of added stock solution (0.5 mL) mg 

Mass of 5% MPA 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 

Wavelength of maximum absorbance nm 

Calculated molar absorptivity dL/g·cm 

DILUTE SOLUTION 2 

Mass of added stock solution (0.250 mL) mg 

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

DILUTE SOLUTION 3 

Mass of added stock solution (0.125 mL) mg 

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

COMMENTS: (use other side if necessary) 

E5
 

REPORT OF ANALYSIS
 

RESULTS (μmol/L of Sample)
 

DILUTE SOLUTION 1 

REPLICATE 1 μmol/L of dilute solution 1 

REPLICATE 2 μmol/L of dilute solution 1 

DILUTE SOLUTION 2 

REPLICATE 1 μmol/L of dilute solution 2 

REPLICATE 2 μmol/L of dilute solution 2 

DILUTE SOLUTION 3 

REPLICATE 1 μmol/L of dilute solution 3 

REPLICATE 2 μmol/L of dilute solution 3 

5% MPA SOLUTION (DILUENT) 

REPLICATE 1 μmol/L of diluent 

REPLICATE 2 μmol/L of diluent 

TEST SAMPLE #1 

REPLICATE 1 μmol/L of Sample 1 

REPLICATE 2 μmol/L of Sample 1 

TEST SAMPLE #14 

REPLICATE 1 μmol/L of Sample 14 

REPLICATE 2 μmol/L of Sample 14 

TEST SAMPLE #53 

REPLICATE 1 μmol/L of Sample 53 

REPLICATE 2 μmol/L of Sample 53 

Return by April 8, 2002 to: Fax: 301-977-0685 Micronutrients 

Micronutrients Measurement Quality Assurance Program E-mail: sam.margolis@nist.gov 

NIST, 100 Bureau Drive, Stop 8392 

Gaithersburg, MD 20899-8392 

E6
 

 

 

 

Participant #: ________ Date: _____________ 

Vitamin C Round Robin 16
 

NIST Micronutrients Measurement Quality Assurance Program
 

Packing List and Shipment Receipt Confirmation Form
 

This box contains (we hope) one vial each of the following four VitC M2QAP samples: 

Sample Form 

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

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

VitC:51 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 samples VitC:1, VitC:11, and VitC:51 arrived frozen 

4) Store the samples upright 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 four vials intact? Yes | No 

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

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

4) Did samples VitC:1, VitC:11, and VitC:51 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 will help control M2QAP expenses. 

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 RR16 

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
June 19, 2002 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standards and Technology 

Gaithersburg, Maryland 20899-0001 

Enclosed is the summary report of the results for Round Robin 16 (RR16) 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 accuracy and repeatability. As in previous reports, the estimated 

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

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

RR16 consists of three unknowns (test samples) and one solid reference ascorbic acid for 

preparation of 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 cons~ltation. 

As a reminder, please return the intent-to-participate forms for the 2003 QA program to us by no 

later than September 1, 2002. The program will consist of two round robin studies for the fatsoluble vitamins and carotenoids and one study for vitamin C in serum. To participate in the fatsoluble vitamins and carotenoids in serum studies, the participation fee is $1600 for U.S. 

laboratories and $2000 for non-U.S. laboratories. To participate in the vitamin C in serum study, 

the participation fee is $800 for U.S. laboratories and $1000 for non-U.S. laboratories. 

Please contact us if you have questions. 

Sincerely, ' ~ 

anice Brown Thomas 

Research Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

Phone: 301-975-3120 

E-mail: jbthomas@nist.g-0v 

Fax: 301-977-0685 

Enclosures 

/er-.J. fJ1~r ;~ Sam A. Margolis, Ph.D. 

Research Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

Phone: 301-975-3137 

E-mail: sam.margolis@nist.gov 

Fax: 301-977-0685 

NISI 

F2
 

 

The NIST M2QAP Vitamin C Round Robin 16 (RR16) report consists of 

Page 

1 

2 

3 

“Individualized” Report 

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

solid ascorbic acid control sample, the SRM 970 Level 1 test samples distributed in RR11 

through RR16, and for two recently prepared test samples. 

Graphical summary of your RR 16 sample measurements. 

Graphical summary of your RR 16 control solution measurements. 

Page “All Lab” Report 

1 A listing of all results and statistics for Total Ascorbic Acid [TAA] in the RR16 samples 

and control solutions, the density of the 5% metaphosphoric acid (MPA) used to prepare the 

control solutions, the maximum absorbance reported between 243 nm and 245 nm for 

control solution #1, and the molar extinction coefficient. 

Test Samples. Three unknowns were distributed in RR16. 

S16:1 SRM 970 Level 1 

S16:2 Serum 11, a “blank” prepared from an unaugmented serum pool. 

S16:3 Serum 51, prepared by augmentation with solid, high-purity ascorbic acid from a serum pool. 

Qualitative Observations. 

1)	 Nearly all participants successfully prepared the four (three “Dilute Solutions” and the 5% MPA 

“Diluent”) control solutions. The criteria used to evaluate this success are: the weight of 100 mL of 

5% MPA (it should be about 103 gm), the observed wavelength maximum, the observed absorbance 

at that maximum, and the calculated E1% of “Dilute Solution #1” (they should be: 243 to 244 nm, 0.5 

to 0.6 OD, and 530 to 590 dL/g·cm), and the extent of correlation between the expected and observed 

[TAA] for the four materials (R2 as close to 1.0 as possible). 

2)	 Two participants initially reported results for the three Dilute Solutions that differed significantly 

from those expected from the material weights. Starting with RR17, we are asking that you calculate 

the expected [TAA] for all control solutions and compare them to your measured results. We ask 

that you analyze the test samples only after you are satisfied that your measurement system is 

performing properly. 

3)	 There has been a general improvement in measurement system calibration, as judged by the 

Calibration Parameters (intercepts close to 0.0 and slopes close to 1.0) calculated from the control 

samples. For the first time, the overall among-participant agreement (concordance) was not 

improved by “correcting” the reported test sample results with the observed Calibration Parameters. 

Quantitative Results 

1)	 There is no sign of degradation (change in median [TAA] or increase in estimated standard 

deviation) in SRM 970 Level 1 since their Certification in 1998. We will continue to periodically 

monitor these materials. 

F3
 

Appendix G. “All-Lab Report” for RR16 

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
 

 

NIST Micronutrients Measurement Quality Assurance Program for Total Ascorbic A

"Round Robin" 16 - March 2002 

Control / Calibration Samples MPA Dilute Solution 1 

G2

Calibration Parameters Density Spectrophotometry Mea

Gravimetric, μmol/L Measured, μmol/L 

E1% Lab Date [Dil1] [Dil2] [Dil3] MPA Ctrl:1 Ctrl:2 Ctrl:3 Ctrl:4 Inter Slope R2 SEE g/mL S16:1 

λmax Amax 

VC-MA 18/11/02 56.7 28.3 13.8 0 60.9 28.9 14.6 0.0 -0.35 1.07 0.999 0.9 1.032 242. 0.5754 576.5 8.8 

VC-MB 08/02/02 58.1 29.1 14.7 0 55.5 25.1 13.2 1.4 -0.03 0.94 0.995 2.0 1.033 245. 0.6023 589.0 9.4 

VC-MC 04/02/02 56.4 28.1 14.1 0 57.7 27.7 14.3 -0.56 1.03 0.999 0.8 1.032 243. 0.5715 575.0 6.7 

VC-ME 05/04/02 55.4 28.4 14.4 0 55.4 28.2 13.8 0.0 -0.28 1.00 1.000 0.3 1.032 243.6 0.5648 578.6 - 

VC-MG 26/03/02 55.7 28.5 14.3 0 50.7 25.5 12.7 0.0 -0.24 0.91 1.000 0.3 1.033 243.7 0.533 543.3 12.4 

VC-MH 11/03/02 56.0 27.8 13.8 0 55.4 27.5 13.8 0.0 0.05 0.99 1.000 0.0 1.033 243. 0.553 560.7 7.6 

VC-MI 26/03/02 56.7 28.6 13.9 0 61.5 29.5 13.9 0.0 -0.77 1.09 0.999 1.0 1.031 7.5 

VC-ML 10/06/02 59.1 29.5 14.8 0 57.7 35.9 15.9 0.0 2.00 0.98 0.982 4.1 1.034 242. 0.5907 567.6 7.1b 

VC-MM 10/06/02 6.4b 

VC-MO 04/04/02 56.3 28.4 14.0 0 67.1 26.0 15.3 0.0 -2.07 1.18 0.983 4.6 1.038 242. 0.5269 531.0 8.0 

VC-MQ 23/04/02 2.8 5.6 11.2 2.7 5.6 12.2 0.0 -0.21 1.09 0.998 0.3 243.4 0.520 518.7 9.4 

VC-MR 26/02/02 56.6 28.9 14.0 0 59.0 35.0 17.0 0.0 1.93 1.04 0.991 2.9 1.032 244. 0.557 558.6 9.0 

VC-MT 05/04/02 55.2 27.7 14.2 0 44.0 23.7 12.9 2.1 2.23 0.76 1.000 0.3 1.031 244. 0.578 594.8 nq 

VC-MY 08/04/02 56.5 27.1 14.0 0 244. 1.220 1226 11.6 

83.9c 74.1c 75.0c 83.5c 1.107c 

VC-NH 19/02/02 52.6 26.2 13.1 0 51.2 25.7 12.9 0.08 0.97 1.000 0.1 1.032 243. 0.5231 564.4 7.7 

VC-NI 08/04/02 55.6 27.8 13.9 0 47.9 25.0 12.6 0.0 0.45 0.86 0.999 0.6 1.023 243. 0.531 542.7 10.6 

NIST 27/02/02 54.4 27.3 13.5 0 54.6 26.0 14.7 0.0 0.20 0.99 0.998 1.2 1.031 243. 0.5381 561.3 8.6 

N 15 15 15 13 N 14 15 15 15 13 

Average 52.5 26.5 14.0 0.3 Average 1.032 243.2 0.6015 606.9 9.0 

SD 14.9 6.7 1.4 0.7 SD 0.003 0.9 0.1730 172.6 1.7 

Min 2.7 5.62 12.2 0.0 Min 1.023 242.0 0.5200 518.7 6.7 

%25 51.0 25.27 12.9 0.0 %25 1.032 242.5 0.5320 551.0 7.7 

Median 55.5 27.50 13.8 0.0 Median 1.032 243.0 0.5648 567.6 8.8 

%75 59.9 28.86 14.6 0.0 %75 1.033 243.9 0.5767 577.6 9.4 

Max 67.1 35.90 17.0 2.1 Max 1.038 245.0 1.2200 1226 12.4 

eSD 7.0 2.89 1.3 0.0 eSD 0.001 1.5 0.0384 16.3 1.7 

CV 13 11 10 CV 0 7 3 20 

a Suspect sample; data not included in statistical summaries. 

b Samples thawed in shipment; data not included in statistical summaries. 

c Contol sample preparation error; data not included in statistical summaries. 

All LAb Report 
Appendix H. Representative “Individualized Report” for RR16 

Each participant in RR16 received an “Individualized Report” reflecting their reported 

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

“VC-MA”. 

H1
 

 

 

 

 

 

 

 

 

 

 

 

 

Set 1 of 17 

Vitamin C 'Round Robin' 16 Report: Participant VC-MA
 

Date 

09/23/98 

04/02/99 

09/17/01 

09/27/01 

09/18/01 

11/18/02 

Method 

HPLC-EC (Height) 

HPLC-EC (Height) 

HPLC-EC (Height) 

HPLC-EC (Height) 

HPLC-EC (Height) 

HPLC-EC (Height) 

RR 

11 

12 

13 

14 

15 

16 

Control 

55 mmol/L 

55 mmol/L 

55 mmol/L 

55 mmol/L, Crtl:1 

55 mmol/L, Crtl:1 

55 mmol/L, Crtl:1 

RR 

11 

11 

12 

12 

13 

14 

15 

16 

Sample 

SRM Lv 1, A 

SRM Lv 1, B 

SRM Lv 1, A 

SRM Lv 1, B 

SRM Lv 1, S13-1 

SRM Lv 1, S14-3 

SRM Lv 1, S15:1 

SRM Lv 1, S16:1 

16 S16:2, Serum 11 

16 S16:3, Serum 51 

AA MPA Stock MPA [AA] mmol/L 

mg g mg g Calc Obs 

200.0 103.09 526.0 102.45 57.8 6.1 

215.0 103.10 517.1 102.52 61.1 53.1 

200.8 103.16 508.0 102.58 56.0 55.4 

200.3 103.23 510.0 102.31 56.1 57.1 

200.5 103.12 506.0 102.19 55.8 57.9 

200.0 103.00 515.0 102.65 56.7 60.9 

A242 A243 A244 A245 E1%max 

OD OD OD OD dL/gcm 

0.5461 

0.5754 

0.0525 

0.0721 

0.5650 

0.5409 

0.5465 

0.5449 

0.0527 

0.0721 

0.5232 

0.5193 

0.5461 

0.5465 

572 

548 

557 

577 

563 ±14 

[TAA] mmol/Lsample Grand Average 

Rep1 Rep2 Factor Mean SDdup 

15.5 13.9 0.5 7.4 0.6 

14.0 14.5 0.5 7.1 0.2 

14.5 15.8 0.5 7.6 0.5 

16.1 15.1 0.5 7.8 0.3 

8.4 8.5 1.0 8.5 0.1 

8.0 7.7 1.0 7.8 0.2 

8.9 8.7 1.0 8.8 0.1 

8.8 8.8 1.0 8.8 0.0 

Mean SDrepeat SDreprod 

8.1 0.3 0.6 

0.0 0.1 1.0 0.0 0.0 

49.9 44.9 1.0 47.4 3.5 

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

Gaithersburg, MD 20899-8392 USA 

Micronutrients Measurement Quality Assurance Program 

National Institute of Standards and Technology 

100 Bureau Drive Stop 8392 

Individualized Report 

Email: david.duewer@nist.gov 

Fax: (301) 977-0685 

Page 1 / 2 

H2
 

 

 

 

 

 

Set 1 of 17 

Vitamin C 'Round Robin' 16 Report: Participant VC-MA 

Total Ascorbic Acid 

S11:1S12:1S13:1S14:3S15:1S16:1S16:2S16:3 

[Total Ascorbic Acid], μmol/L 

Your [Total Ascorbic Acid], μmol/L

Median [Total Ascorbic Acid], μmol/L 

SRM 970 Lv 1 Apparent Precision, SD 

Concordance, SD 

3rd Quartile (75%) You, RR 16 NIST, RR 16 Median (50%) You, RR 11-15 Others, RR 11-15 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 

S16:1 SRM 970 Level 1 

S16:2 Serum 11, no augmentation 

S16:3 Serum 51, augmented to 47.92 μmol/L sample 

Individualized Report Page 2 / 2 

H3