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Results for Round Robin LXXIII 

Fat-Soluble Vitamins and Carotenoids in Human Serum 

and Round Robin 38 Ascorbic Acid in Human Serum 

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David L. Duewer 

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Jeanice B. Thomas 

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NIST Micronutrients Measurement 

Quality Assurance Program 

Winter 2013 

Comparability Studies 

Results for Round Robin LXXIII 

Fat-Soluble Vitamins and Carotenoids in Human Serum 

and Round Robin 38 Ascorbic Acid in Human Serum 

David L. Duewer 

Jeanice B. Thomas 

Chemical Sciences Division 

Materials Measurement Laboratory 

http://dx.doi.org/10.6028/NIST.IR.7880-41 

November 2014 

U.S. Department of Commerce 

Penny Pritzker, Secretary 

National Institute of Standards and Technology 

Willie E. May, Acting Under Secretary of Commerce for Standards and Technology and Acting 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 2013 MMQAP measurement comparability improvement studies: 1) Round Robin LXXIII 

Fat-Soluble Vitamins and Carotenoids in Human Serum and 2) Round Robin 38 Total Ascorbic Acid 

in Human Serum. The materials for both studies were shipped to participants in January 2013; 

participants were requested to provide their measurement results by April 1, 2013. 

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

Round Robin 38: Vitamin C in Human Serum............................................................................... 2
 

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

Appendix A. Shipping Package Inserts for RR73........................................................................ A1
 

Appendix B. Final Report for RR73 ..............................................................................................B1
 

Appendix C. All-Lab Report for RR73 ..........................................................................................C1
 

Appendix D. Representative Individualized Report for RR73 ................................................... D1
 

Appendix E. Shipping Package Inserts for RR38 ......................................................................... E1
 

Appendix F. Final Report for RR38............................................................................................... F1
 

Appendix G. “All-Lab Report” for RR38..................................................................................... G1
 

Appendix H. Representative “Individualized Report” for RR38............................................... 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 LXXIII: Fat-Soluble Vitamins and Carotenoids in Human Serum 

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

LXXIII comparability study (hereafter referred to as RR73) received one lyophilized and four 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 2013. 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 RR73 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 All-Lab 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 the Individualized Report 

are described in detail elsewhere [3]. An example Individualized Report is reproduced as 

Appendix D. 

Round Robin 38: Vitamin C in Human Serum 

Participants in the MMQAP Vitamin C in Human Serum Round Robin 38 comparability study 

(hereafter referred to as RR38) received four frozen serum test samples and two frozen control sera. 

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 2013. 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). 

The final report delivered to every participant in RR38 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 All-Lab 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 the Individualized 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 RR73 

The following three items were included in each package shipped to an RR73 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
 
January 21, 2013 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standards and Technology 

Gaithersburg, Maryland 2089~ 

Enclosed are samples for the first fat-soluble vitamins and carotenoids in serum study (Round Robin 

LXXIII) for the 2013 NIST Micronutrients Measurement Qu(llity Assurance Program. The set of samples 

(Sera 392- 396) consists of one vial oflyophilized serum and one vial each of four liquid-frozen serum 

samples for analysis along with a form for reporting your results. These samples should be stored in the 

dark at or below -20 °C upon receipt. When reporting your results, please submit one value for each 

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

indicate this result on the form by using NQ (Not Quantified). Results are due to NIST by April 1, 2013. 

Results received more than two weeks after the due date may not be included in the summary report for 

this round robin study. The feedback report concerning the study will be distributed in May 2013. 

Samples should be allowed to stand at room temperature under subdued light until thawed. We 

recommend that sample mixing be facilitated with 3 to 5 min agitation in an ultrasonic bath or at least 15 

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.) 

Water should not be added to the liquid-frozen samples. 

For consistency, we request that laboratories use the following absorptivities (dL/g ·cm): retinol, 1843 at 

325 nm (ethanol); retinyl palmitate, 975 at 325 nm (ethanol); a.-tocopherol, 75.8 at 292 run (ethanol); ytocopherol, 91.4 at 298 run (ethanol); a.-carotene, 2800 at 444run(hexane);13-carotene, 2560 at 450 nm 

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

Please report your results for Round Robin LXXIII by e-mail to david.duewer@nist.gov or fax to 301-

977-0685. If you have questions or comments regarding this study, please call me at (301) 975-3120 oremail me at jbthomas@nist.go 

dt1M11 

J anice Brown Thomas 

P ogram Coordinator/Research Chemist 

nalytical Chemistry Division 

Material Measurement Laboratory 

NlSI A2
 
 

 

Participant #: ________ Date: _____________ 

Round Robin LXXIII: Human Sera 

NIST Micronutrients Measurement Quality Assurance Program 

Analyte 392 393 394 395 396 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 

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 

Phytoene 

Phytofluene 

* we prefer μg/mL 

W ere the samples frozen when received? Yes | No 

Comments: 

Mail: M2QAP Please return results by 

NIST, Stop 8392 1-April-2013 Fax: 301-977-0685 

Gaithersburg, MD 20899-8392 A3 Email: David.Duewer@NIST.gov 
 

 

 

 

Participant #: ________ Date: _____________ 

Fat-Soluble Vitamins Round Robin LXXIII 

NIST Micronutrients Measurement Quality Assurance Program 

Packing List and Shipment Receipt Confirmation Form 

This box contains: one vial each of the following five FSV M2QAP sera 

Serum Form Reconstitute? Vial/Cap 

#392 Lyophilized Yes 5 mL clear / silver 

#393 Liquid frozen No 5 mL clear / silver 

#394 Liquid frozen No 2 mL amber / blue 

#395 Liquid frozen No 2 mL clear / green 

#396 Liquid frozen No 2 mL clear / black 

Please 1) Open the pack immediately
 

2) Check that it contains all of the above samples
 

3) Check if the vials are intact
 

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

5) Email (david.duewer@nist.gov) or fax (301-977-0685) us the
 

following information: 

1) Date this shipment arrived: ___________________________ 

2) Are all five sera 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 serum 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 A4 Email: David.Duewer@NIST.gov 
Appendix B. Final Report for RR73

The following three pages are the final report for RR73 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
 
B2
 

 

 

 

The NIST MMQAP Round Robin LXXIII (RR73) report consists of: 

Page 

1-5 A listing of all results and statistics for analytes reported by more than one participant. 

6 A listing of the analytes reported by only one participant and a legend for the list of results 

and statistics. 

7 The text Comparability Summary (“Score Card”) of measurement performance. 

Page Individualized Report 

1 

2 to 

n 

n+1 

Samples. 

Serum 

392 

393 

394a 

394b 

395 

396 

All-Lab Report 

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

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

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

The graphical Comparability Summary (target plot) of measurement performance. 

Five samples were distributed to each participant in RR73. Unfortunately, the sample 

distributed as Serum 394 was a mixture of two materials. Fortunately, the two materials have 

distinctive levels for several analytes and we have been able to unambiguously identify who 

got which material. We have post-facto designated these two materials Serum 394a and Serum 

394b. The All Lab Report therefore lists values for six samples. The Individualized Reports 

for every participant reflect the results just for the five materials that they evaluated. 

Description Prior Distributions 

Lyophilized, multi-donor stripped serum augmented #224:RR38-9/96
 

with retinol, retinyl palmitate, α- and γ-tocopherol,
 

α- and β-carotene, lycopene, β-cryptoxanthin, lutein, 

and zeaxanthin prepared in 1995.
 

Liquid-frozen, multi-donor heparin-treated plasma First MMQAP distribution
 

material augmented with glycyrrhetinic acid prepared in
 

1989.
 

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

1999. #279:RR51-3/02, #296:RR54-9/03, 

#308:RR56-9/04 

Liquid-frozen, multi-donor serum augmented with #353:RR65-3/09, #371:RR68-9/10 

trans-β-carotene in a lipoprotein carrier prepared in 

2008. 

Fresh-frozen, native, multi-donor serum prepared in #382:RR71-3/12 

2011. This material has relatively high contents of 

α- and β-carotene. 

Fresh-frozen, native, multi-donor serum prepared in #385:RR71-3/12 

2011. 

B3
 
 

 

 

 

 

Results 

1)	 Serum 392. This serum was constructed to test whether it was practical to spike sera with very 

lipophilic analytes. While we did not fully achieve the targeted levels for the carotenoids, the 

augmentation method used appeared to be relatively effective. This distribution of the material was 

intended to access the material’s stability over time and storage. The median value for many, but not 

all, of the analytes is lower than that of 18 years ago. We speculate that due to the aging of the 

material, the augmented analytes in this lyophilized material have become more difficult to 

reconstitute and/or extract. 

2)	 Serum 393. This material was prepared as part of an investigation into the chemopreventative 

potential of glycyrrhetinic acid (the main metabolite of the glucoside glycyrrhizin obtained from 

licorice root, Glycyrriza glabra). This relatively polar compound’s absorbance maxima is at 248 nm 

and should not interfere with the analysis of the usual MMQAP analytes. However, if any of your 

results are uniquely high in Serum 393, please check the chromatogram for evidence of interference. 

If you find such evidence, please contact JBThomas@nist.gov. 

3)	 Sera 394a and 394b. We apologize for the confusion. We unintentionally combined amber vials with 

blue caps that were labeled “271” and “371”. The median levels and variability of the results for both 

“Serum 394” materials are essentially unchanged from their prior levels. 

4)	 Sera 395 and 396. The median levels and variability of the results for both of these relatively new 

materials are essentially unchanged from their prior levels. 

B4
 
Appendix C. “All-Lab Report” for RR73 

The following seven pages are the “All-Lab Report” for RR73 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. 

C1
 
Round Robin LXXIII Laboratory Results 

Total Retinol, μg/mL Retinyl Palmitate, μg/mL α-Tocopherol, μg/mL γ/β-Toco

C2

Lab 392 393 394a 394b 395 396 392 393 394a 394b 395 396 392 393 394a 394b 395 396 392 393 394

FSV-BA 0.724 0.262 0.470 0.452 0.484 0.011 0.048 0.078 0.056 0.031 4.09 8.53 6.95 10.78 7.11 0.84 4.33 2.0

FSV-BB 0.714 0.272 0.484 0.500 0.486 0.004 0.044 0.070 0.069 0.006 4.12 8.49 6.83 11.73 7.14 0.82 3.85 1.8

FSV-BC 0.717 0.289 0.489 0.463 0.513

FSV-BD
 0.623 0.226 0.436 0.401 0.412 4.10 7.40 6.30 9.30 6.10
 

FSV-BE
 0.660 0.220 0.300 0.440 0.450 4.20 9.00 8.5 12.50 7.80 0.70 3.70 

FSV-BF 0.550 0.240 0.240 0.280 0.270 4.30 7.30 5.2 9.10 6.40
 

FSV-BG
 0.698 0.265 0.470 0.474 0.480 0.049 nd 0.024 0.054 0.013 4.42 8.56 7.33 11.79 7.53 0.86 4.07 1.8

FSV-BH 0.684 0.229 0.481 0.486 0.455 4.03 8.88 6.73 11.51 7.15 0.75 4.16 1.8

FSV-BJ 0.756 0.260 0.465 0.480 0.474 4.18 8.39 7.34 12.27 7.87 0.78 4.33 1.9

FSV-BK 0.619 0.226 0.426 0.426 0.432 3.98 7.91 6.54 10.37 6.80

FSV-BL
 0.690 0.200 0.460 0.460 0.490 3.90 8.60 6.90 10.80 7.80

FSV-BM
 0.590 0.240 0.400 0.420 0.430 4.50 8.20 6.80 11.20 8.70

FSV-BN
 0.685 0.236 0.484 0.451 0.474 3.66 7.44 6.38 9.83 6.46 

FSV-BNa 0.717 0.256 0.516 0.489 0.504 4.15 8.19 7.00 10.81 7.13

FSV-BO
 0.660 0.240 0.320 0.470 0.500 4.10 8.70 8.4 11.60 7.70 0.90 3.70 

FSV-BP 0.657 0.194 0.505 0.456 0.482 4.37 8.51 7.78 12.39 7.72

FSV-BQ
 0.640 0.250 0.470 0.430 0.460 5.00 9.00 7.00 12.00 7.00

FSV-BR
 ≥0.65 ≥0.225 ≥0.46 ≥0.44 ≥0.45 4.20 8.10 7.40 11.33 7.40

FSV-BS

FSV-BT
 0.704 0.317 0.469 0.484 0.482 4.15 8.47 6.87 11.10 7.21 0.90 3.76 1.9

FSV-BU 0.400 0.280 0.490 0.460 0.520 5.28 10.00 7.04 12.24 7.63 0.98 4.70 1.8

FSV-BV 0.454 0.120 0.257 0.355 0.386 3.84 7.30 7.1 9.75 7.04 0.72 3.47 

FSV-BW 0.670 0.240 0.490 0.480 0.510 0.014 0.084 0.085 0.072 0.047 3.58 7.97 6.69 10.72 7.15 0.80 4.20 1.9

FSV-CD 0.628 0.245 0.348 0.470 0.518 0.120 nq nq 0.087 nq 5.85 10.46 10.2 13.02 9.49 1.02 4.22 

FSV-CE 0.635 0.224 0.313 0.422 0.177 3.51 6.38 6.1 11.23 3.96

FSV-CG
 0.664 0.273 0.324 0.463 0.475 3.86 7.13 7.4 10.82 7.04 0.83 3.62 

FSV-CI 0.641 0.231 0.459 0.438 0.445 0.007 0.043 0.083 0.047 0.014 4.09 8.12 6.43 10.14 6.57 0.60 2.92 1.3

FSV-CO 3.78 8.41 6.96 11.93 7.40 0.84 4.22 2.0

FSV-CZ 0.460 0.229 0.391 0.556 0.560 4.91 8.88 8.4 11.95 8.50 0.73 3.76 

FSV-DD 0.660 0.160 0.280 0.430 0.440

FSV-DV
 0.748 0.259 0.512 0.507 0.551 4.30 8.10 6.30 10.30 8.00

FSV-EE

FSV-EZ
 0.693 !0.699 0.459 0.463 0.469 <0.02 0.059 0.025 0.031 <0.02 4.30 8.89 7.64 11.66 7.73 0.75 3.84 1.7

FSV-FK 0.702 0.254 0.321 0.466 0.498 4.40 9.60 8.8 11.40 7.30

FSV-FZ
 0.641 0.365 0.445 0.524 0.440 0.006 0.037 0.047 0.047 0.019 3.97 8.62 7.15 11.21 7.53 0.74 4.06 1.8

N 31 30 21 10 31 31 8 5 7 0 8 6 31 31 22 9 31 31 18 18 

Min 0.400 0.120 0.400 0.240 0.280 0.177 0.047 0.004 0.024 0.031 0.006 6.38 3.51 6.30 5.2 9.10 3.96 2.92 0.60 1.

Median 0.660 0.240 0.470 0.317 0.463 0.475 0.074 0.007 0.043 0.055 0.017 8.47 4.15 6.92 8.4 11.23 7.30 3.96 0.81 1.

Max 0.756 0.365 0.516 0.391 0.556 0.560 0.120 0.014 0.084 0.087 0.047 10.46 5.85 7.78 10.2 13.02 9.49 4.70 1.02 2.

eSD 0.055 0.026 0.021 0.036 0.034 0.043 0.019 0.005 0.009 0.016 0.010 0.61 0.27 0.34 1.5 0.83 0.59 0.38 0.10 0.

eCV 8 11 4 11 7 9 26 70 21 30 63 7 6 5 18 7 8 10 12 

Npast 47 0 37 31 31 31 15 0 12 8 7 5 45 0 41 31 29 29 23 0 2

Medianpast 0.690 0.467 0.313 0.460 0.473 0.243 0.055 0.014 0.070 0.014 8.28 7.11 7.9 11.33 7.51 3.87 1.

SDpast 0.057 0.040 0.024 0.030 0.024 0.129 0.014 0.011 0.009 0.012 0.55 0.57 0.6 1.23 0.76 0.46 0.

NAV
 

NAU
 

0.660 0.240 0.470 0.317 0.463 0.475 

0.055 0.026 0.038 0.036 0.037 0.043 

0.074 0.007 0.043 0.055 0.017 

0.021 0.010 0.015 0.017 0.011 

8.47 4.15 6.92 8.4 11.23 7.30 

0.68 0.44 0.58 1.5 0.87 0.60 

3.96 0.81 1.8

0.38 0.10 0.2

All Lab Report 
Round Robin LXXIII Laboratory Results 

δ-Tocopherol, μg/mL Total β-Carotene, μg/mL trans-β-Carotene, μg/mL Total c

C3

Lab 392 393 394a 394b 395 396 392 393 394a 394b 395 396 392 393 394a 394b 395 396 392 393 

FSV-BA 0.040 0.117 0.749 0.083 0.126 0.299 0.019 0.332 0.636 0.052 0.014 0.309 0.286 0.597 0.045 0.013 0.005 

FSV-BB 0.046 0.129 0.686 0.093 0.093 0.323 0.014 0.319 0.705 0.048 0.011 0.301 0.311 0.668 0.047 0.011 0.003 

FSV-BC

FSV-BD

FSV-BE <0.02 0.290 0.300 0.670 0.050
 

FSV-BF 0.108 nq 0.255 0.393 0.056
 

FSV-BG 0.350 0.016 0.372 0.696 0.057
 

FSV-BH 0.381 nq 0.338 0.739 0.046
 

FSV-BJ 0.192 nq 0.280 0.555 0.034
 

FSV-BK

FSV-BL

FSV-BM

FSV-BN 0.293 0.012 0.318 0.609 0.045 

FSV-BNa 0.282 0.031 0.307 0.564 0.047 0.017 0.250 0.230 0.468 0.033 0.052 0.014 

FSV-BO 0.363 0.013 0.311 0.616 0.053
 

FSV-BP 0.222 0.053 0.203 0.651 0.329
 

FSV-BQ

FSV-BR

FSV-BS ≥0.443 nq ≥0.448 ≥0.762 ≥0.13 0.443 nq 0.448 0.762 0.130

FSV-BT 0.079 0.111 0.485 0.090 0.070 0.360 0.015 0.328 0.683 0.053 0.013 0.281 0.317 0.582 0.048 0.012 nq 

FSV-BU 0.335 0.018 0.316 0.664 0.065
 

FSV-BV 0.240 0.019 0.249 0.545 0.048 

FSV-BW 0.221 0.006 0.388 0.643 0.065
 

FSV-CD 0.427 0.066 0.387 0.801 0.114
 

FSV-CE nq nq 0.167 0.659 nq
 

FSV-CG 0.128 0.629 0.167 0.139 0.141 0.328 0.015 0.294 0.667 0.054 0.013 0.317 0.278 0.626 0.050 0.011 0.005 

FSV-CI 0.259 0.009 0.343 0.720 0.041
 

FSV-CO 0.347 0.021 0.354 0.705 0.061
 

FSV-CZ 0.632 0.088 0.279 0.674 0.120
 

FSV-DD

FSV-DV

FSV-EE

FSV-EZ <0.059 0.473 0.321 0.593 <0.059
 

FSV-FK

FSV-FZ 0.597 0.020 0.375 0.725 0.070 

N 4 4 3 2 5 4 22 17 15 7 22 21 6 5 5 1 6 6 5 4 

Min 0.485 0.040 0.111 0.167 0.083 0.070 0.108 0.006 0.203 0.249 0.393 0.034 0.230 0.011 0.250 0.468 0.033 0.011 0.003 

Median 0.658 0.062 0.117 0.167 0.093 0.109 0.325 0.018 0.328 0.294 0.666 0.053 0.314 0.013 0.301 0.278 0.612 0.047 0.012 0.005 

Max 0.749 0.128 0.129 0.167 0.659 0.141 0.632 0.088 0.388 0.387 0.801 0.329 0.443 0.017 0.448 0.762 0.130 0.052 0.014 

eSD 0.089 0.029 0.015 0.035 0.073 0.006 0.022 0.025 0.066 0.011 0.023 0.002 0.030 0.064 0.004 0.001 0.002 

eCV 14 46 16 32 23 35 7 9 10 20 7 13 10 10 8 10 37 

Npast 5 0 6 4 4 4 32 0 29 21 19 18 12 0 13 7 5 5 8 0 

Medianpast 0.750 0.132 0.087 0.081 0.067 0.624 0.350 0.305 0.653 0.055 0.587 0.323 0.288 0.634 0.054 0.027 

SDpast 0.119 0.053 0.016 0.065 0.048 0.103 0.040 0.053 0.122 0.007 0.103 0.027 0.027 0.126 0.004 0.019 

NAV

NAU
 

0.658 0.062 0.117 0.093 0.109 

0.023 

0.325 0.018 0.328 0.294 0.666 0.053 

0.073 0.008 0.047 0.043 0.090 0.011 

0.314 0.013 0.301 0.612 0.047 

0.034 0.007 0.032 0.064 0.009 

0.012 0.005 

0.004 

All Lab Report 
 

Round Robin LXXIII Laboratory Results 

Total α-Carotene, μg/mL Total Lycopene, μg/mL trans-Lycopene, μg/mL Total β-Cry

C4

Lab 392 393 394a 394b 395 396 392 393 394a 394b 395 396 392 393 394a 394b 395 396 392 393 39

FSV-BA 0.004 0.030 0.372 0.340 0.020 0.135 0.307 0.299 0.260 0.214 0.071 0.171 0.204 0.130 0.104 0.011 0.00.059 

FSV-BB 0.003 0.025 0.347 0.343 0.018 0.125 0.289 0.296 0.284 0.208 0.059 0.137 0.173 0.110 0.085 0.010 0.00.051 

FSV-BC

FSV-BD

FSV-BE

FSV-BF

FSV-BG 0.008 0.033 0.344 0.326 0.024 0.147 0.340 0.338 0.280 0.248 0.078 0.191 0.230 0.138 0.123 0.011 0.0

0.055 

FSV-BH 0.466 nq 0.022 0.367 0.018 0.165 0.387 0.469 0.352 0.272 0.082 nq 0.0

FSV-BJ 0.413 nq nq 0.383 nq 0.201 0.328 0.305 0.276 0.258 nq nq n

FSV-BK

FSV-BL

FSV-BM

FSV-BN 0.003 0.040 0.393 0.355 0.020 0.141 0.367 0.324 0.307 0.251 0.010 0.0

0.049 

FSV-BNa 0.374 nd 0.041 0.333 0.023 0.164 0.369 0.327 0.349 0.284 0.068 0.180 0.153 0.127 0.120 0.017 0.0

0.044 

FSV-BO

FSV-BP 0.051 nd 0.010 0.350 0.024 0.220 0.143 0.742 0.271 0.232 0.090 0.0

0.094 

FSV-BQ

FSV-BR

FSV-BS 0.073 0.068 0.620 0.432 0.041 0.267 0.815 0.565 0.399 0.452 0.136 0.348 0.315 0.159 0.188 0.069 0.

0.123 

FSV-BT 0.007 0.031 0.417 0.347 0.026 0.123 0.297 0.315 0.292 0.219 0.056 0.139 0.168 0.121 0.099 0.012 0.0

0.057 

FSV-BU 0.005 0.026 0.434 0.376 0.029 0.133 0.305 0.335 0.274 0.231 0.012 0.0

0.052 

FSV-BV 0.006 0.355 0.026 0.340 0.023 0.099 0.242 0.362 0.224 0.206 0.006 0.029 

FSV-BW 0.015 0.017 0.684 0.540 0.015 0.136 0.332 0.275 0.226 0.234

FSV-CD 0.597 nq 0.050 0.525 0.033 0.152 0.385 0.543 0.309 0.280 0.019 0.081 

FSV-CE

FSV-CG 0.005 0.471 0.042 0.459 0.030 0.154 0.367 0.513 0.340 0.273 0.083 0.264 0.274 0.157 0.131 0.020 0.069 

FSV-CI 0.008 0.028 0.333 0.338 0.020
 

FSV-CO 0.140 0.336 0.376 0.276 0.239
 

FSV-CZ

FSV-DD

FSV-DV

FSV-EE

FSV-EZ

FSV-FK

FSV-FZ

N

Min

Median

Max

eSD

eCV

Npast

Medianpast 

SDpast

16 11 12 3 16 15 

0.003 0.010 0.026 0.326 0.015 0.051 

0.006 0.029 0.042 0.353 0.023 0.403 

0.073 0.068 0.050 0.540 0.041 0.684 

0.002 0.008	 0.086 0.025 0.005 

21 41 29 7 21 

28 0 24 17 15 15 

0.428 0.030 0.033 0.384 0.025 

0.082 0.007 0.007 0.117 0.004 

16 16 13 3 16 16 

0.099 0.143 0.362 0.224 0.206 0.242 

0.144 0.332 0.513 0.282 0.243 0.331 

0.267 0.815 0.543 0.399 0.452 0.742 

0.022 0.052	 0.052 0.035 0.039 

16 15 16 12 16 

28 0 24 16 13 13 

0.377 0.353 0.506 0.278 0.237 

0.086 0.054 0.078 0.053 0.056 

7 7 6 1 7 7 

0.056 0.137 0.153 0.110 0.085 

0.071 0.176 0.274 0.130 0.120 0.204 

0.136 0.348 0.315 0.159 0.188 

0.017 0.038	 0.053 0.014 0.024 

26 24 22 10 20 

8 0 11 8 6 6 

0.288 0.186 0.234 0.132 0.119 

0.063 0.041 0.028 0.021 0.022 

13 12 

0.006 0.00.029 

0.012 0.00.057 

0.090 0.0.123 

0.005 0.00.018 

32 43 

20 0 

0.060 0.0

0.015 0.0

NAV

NAU
 

0.403 0.006 0.029 0.042 0.353 0.023 

0.100 0.003 0.010 0.088 0.008 

0.331 0.144 0.332 0.513 0.282 0.243 

0.074 0.038 0.074 0.065 0.058 

0.204 0.071 0.176 0.130 0.120 

0.053 0.017 0.038 0.023 0.024 

0.057 0.012 0.0

0.018 0.005 0.0

All Lab Report	 
 

Round Robin LXXIII Laboratory Results 

Total α-Cryptoxanthin, μg/mL Total Lutein, μg/mL Total Zeaxanthin, μg/mL Total Lutein

C5

Lab 392 393 394a 394b 395 396 392 393 394a 394b 395 396 392 393 394a 394b 395 396 392 393 39

FSV-BA 0.006 0.031 0.046 0.026 0.014 0.179 0.033 0.

FSV-BB 0.007 0.023 0.040 0.020 0.015 0.031 0.097 0.128 0.157 0.097 0.014 0.043 0.083 0.043 0.042 0.211 0.045 0.

FSV-BC

FSV-BD

FSV-BE

FSV-BF

FSV-BG 0.193 0.040 0.

FSV-BH 0.015 0.077 0.116 0.123 0.069 0.009 0.033 0.093 0.027 0.035 0.209 0.025 0.

FSV-BJ 0.144 nq 0.081 0.135 0.085
 

FSV-BK

FSV-BL

FSV-BM

FSV-BN 0.196 0.032 

FSV-BNa 0.040 0.143 0.133 0.087 0.020 0.064 0.028 0.032 0.208 0.061 

FSV-BO

FSV-BP 0.160 0.152 0.

FSV-BQ

FSV-BR

FSV-BS 0.054 0.258 0.212 0.252 0.170 0.095 0.121 0.126 0.094 0.102 0.338 0.149 0.

FSV-BT 0.006 0.024 0.040 0.022 0.019 0.201 0.042 0.

FSV-BU 0.216 0.040 0.

FSV-BV 0.197 0.026 

FSV-BW

FSV-CD 0.011 0.064 0.058 0.039 0.027 0.284 0.086 

FSV-CE

FSV-CG 0.237 0.051 

FSV-CI 0.019 0.070 0.135 0.129 0.068 0.011 0.021 0.077 0.015 0.024 0.212 0.030 0.0

FSV-CO

FSV-CZ

FSV-DD

FSV-DV

FSV-EE

FSV-EZ

FSV-FK

FSV-FZ

N 4 4 3 1 4 4 6 5 5 0 6 6 5 5 4 0 5 5 14 14 

Min 0.040 0.006 0.023 0.020 0.014 0.116 0.015 0.070 0.123 0.068 0.064 0.009 0.021 0.015 0.024 0.160 0.025 0.

Median 0.043 0.007 0.024 0.058 0.024 0.017 0.139 0.031 0.081 0.134 0.086 0.083 0.014 0.038 0.028 0.035 0.209 0.041 0.

Max 0.064 0.011 0.031 0.039 0.027 0.212 0.054 0.258 0.252 0.170 0.126 0.095 0.121 0.094 0.102 0.338 0.152 0.

eSD 0.005 0.000 0.004 0.003 0.012 0.017 0.016 0.012 0.021 0.015 0.008 0.016 0.019 0.011 0.018 0.016 0.

eCV 11 5 16 20 8 56 20 9 24 18 56 43 69 31 9 38 

Npast 4 0 6 5 4 4 14 0 16 8 4 4 11 0 14 7 0 0 20 0 

Medianpast 0.042 0.025 0.031 0.023 0.021 0.148 0.089 0.124 0.137 0.086 0.082 0.027 0.061 0.222 0.

SDpast 0.006 0.005 0.008 0.008 0.010 0.030 0.019 0.022 0.022 0.024 0.012 0.007 0.021 0.044 0.

NAV

NAU
 

0.043 0.007 0.024 0.024 0.017 0.139 0.031 0.081 0.134 0.086 

0.026 0.017 0.016 0.025 0.021 

0.083 0.014 0.038 0.028 0.035 

0.022 0.008 0.019 0.011 

0.209 0.041 0.

0.044 0.016 0.

All Lab Report 
 

Round Robin LXXIII Laboratory Results 

Coenzyme Q10, μg/mL Phylloquinone (K1), ng/mL 

C6

Lab 392 393 394a 394b 395 396 392 393 394a 394b 395 396 

FSV-BA

FSV-BB

FSV-BC

FSV-BD

FSV-BE 0.65 1.12 0.990 0.78 1.02 0.399 1.209 0.869 4.665 0.274 

FSV-BF

FSV-BG

FSV-BH

FSV-BJ 0.70 0.850 1.03 0.71 1.15
 

FSV-BK

FSV-BL

FSV-BM

FSV-BN

FSV-BNa

FSV-BO 0.49 0.80 0.890 0.62 0.79
 

FSV-BP

FSV-BQ

FSV-BR

FSV-BS

FSV-BT

FSV-BU

FSV-BV

FSV-BW 0.65 0.840 1.33 0.71 1.08
 

FSV-CD

FSV-CE

FSV-CG

FSV-CI 0.48 0.670 0.73 0.53 0.77 0.161 0.504 0.613 1.727 0.125 

FSV-CO

FSV-CZ 0.79 1.08 1.227 0.94 1.09
 

FSV-DD

FSV-DV

FSV-EE 0.56 0.860 0.88 0.66 1.02
 

FSV-EZ

FSV-FK

FSV-FZ

N

Min

Median

Max

eSD

eCV

Npast

Medianpast 

SDpast

NAV

NAU 

7 7 4 3 7 7

0.48 0.670 0.890 0.53 0.77 0.73 

0.65 0.845 0.990 0.71 1.02 1.03 

0.79 0.860 1.227 0.94 1.15 1.33 

0.13 0.015	 0.23 0.10 0.10 

22 20 2 15 10 

0 0 5 8 9 9

1.044 0.73 0.99 0.887 

0.136 0.07 0.03 0.171 

0.65 0.845 0.990 0.71 1.02 1.03 

0.13 0.23 0.10 0.10 

2 2 1 1 2 2 

0.161 0.613 1.727 0.125

0.280 0.504 0.869 3.196 0.200 0.911 

0.399 1.209 4.665 0.274

0 0 0 0 0 0 

All Lab Report	 
 

 

 

Round Robin LXXIII Laboratory Results
 

Analytes Reported By One Laboratory
 

Values in μg/mL 

Term 

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

Min Minimum (non-NIST) quantitative value reported 

Median Median (non-NIST) quantitative value reported

Max Maximum (non-NIST) quantitative value reported

eSD Adjusted median absolute deviation from the median of the non-NIST results

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

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

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

SDpast Pooled SD from past RR(s)

NAV NIST Assigned Value

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

= Median for analytes reported by ≥ 5 labs but not NIST 

NAU NIST Assigned Uncertainty: √(S 2

 + Sbtw 2)

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

 deviation between Median and NIST. The expected long-term SD, eSD,

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

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

nq Detected but not quantitatively determined

<x Concentration at or below the limit of quantification, x

≥x Concentration greater than or equal to x

! Discrepant value: damaged sample, interferent, instrument malfunction, etc.

italics Not explicitly reported but calculated by NIST from reported values

Analyte Code 392 393 394a 394b 395 396 

25-hydroxyvitamin D FSV-BH 0.021 0.023 0.008 0.021 0.006 

Phytoene FSV-BS 0.113 nq 0.140 nq 0.124 

Phytofluene FSV-BS 0.171 0.068 0.296 0.203 0.196 

trans-Retinol FSV-BR 0.650 0.225 0.460 0.440 0.450 

Legend 

Definition

C7
 

All Lab Report Page 6 / 7 
 

 

 

 

 

Lab 

FSV-BA 

FSV-BB 

FSV-BC 

FSV-BD 

FSV-BE 

FSV-BF 

FSV-BG 

FSV-BH 

FSV-BJ 

FSV-BK 

FSV-BL 

FSV-BM 

FSV-BN 

FSV-BNa 

FSV-BO 

FSV-BP 

FSV-BQ 

FSV-BR 

FSV-BS 

FSV-BT 

FSV-BU 

FSV-BV 

FSV-BW 

FSV-CD 

FSV-CE 

FSV-CG 

FSV-CI 

FSV-CO 

FSV-CZ 

Round Robin LXXIII Laboratory Results 

Comparability Summary 

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
 

2
 

2 2
 

1 1 1 1
 

4 2 3
 

1 1 1 1 1 1 1 1
 

1 1 1 1 1 2 2 1 1 3
 

1 1 1 2 1 1 1 1
 

1 1
 

1 1
 

2 2
 

1 2 1 1 1 1 1
 

1 1 2 2 1 1 1 1 1 1
 

1 1 1 1
 

1 2 4 3 4 4 4
 

1 2
 

1 1
 

4 4 4 4 4 4 4 4
 

2 1 1 1 1 1 1 1 1
 

3 2 2 1 1 1 1 1
 

4 2 1 1 1 2 2 1
 

1 1 1 2 3 1
 

1 3 2 4 2 1 2 3
 

4 4
 

1 2 1 1 1 1 1 2 2
 

1 1 3 1 1 1 1 1
 

1 1 1 1
 

3 2 2 4
 

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) summarizes your measurement 

performance for a given analyte relative to the consensus 

medians in this study. CS is the average distance (in units of 

standard deviation) of your measurement performance 

characteristics from the consensus performance. CS is 

calculated when the number of quantitative values you reported, 

Nyou, is at least two and at least six participants reported 

quantitative values for the analyte. 

We define CS as follows: 

FSV-DD MINIMUM 4,INTEGER 1 2
 

FSV-DV 2 1
 





 CS = + 2
 2 



 C + AP 

N 

∑ 

= 

you You
 

i 1
 

FSV-FZ 3 1 1 2
 Nyou 

FSV-EZ 4 1 1 3 −Median 
 i
 i
 

NAU FSV-FK 1 1
 i C = Concordance = 

32 31 18 23 6 16 16 14 6 5 14
 you

∑ 

= 









You 

i 1
 

% 1
 59 61 78 57 67 75 75 57 83 80 64
 NAU = NIST Assigned Uncertainty % 2
 19 32 17 17 17 6 13 29 0 0 7
 

% 3
 9 3 6 9 0 13 0 0 0 0 14
 For further details, please see 

n N 2









i i
 

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. 

% 4
 13 3 0 17 17 6 13 14 17 20 14
 

−Median
 

NAU i
 

1 TR aT g/bT bC tbC aC TLy TbX TLu TZ L&Z AP = Apparent Precision = Nyou −

C8
 

All Lab Report Page 7 / 7
 
 

Appendix D. Representative Individualized Report for RR73 

Each participant in RR73 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: 

• Total Retinol 

• Retinyl Palmitate 

• α-Tocopherol 

• γ/β-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 fourteen pages are the “Individualized Report” for the analytes evaluated 

by participant FSV-BA. 

D1
 
 

 

 Set 6 of 35 

Individualized Round Robin LXXIII Report: FSV

D

2

Analyte 

Total Retinol 

Retinyl Palmitate 

α-Tocopherol 

Ȗ/ȕ-Tocopherol 

β-Tocopherol 

Total ȕ-Carotene 

trans-ȕ-Carotene 

Total cis-ȕ-Carotene 

Total α-Carotene 

Total Lycopene 

trans-Lycopene 

Total ȕ-Cryptoxanthin 

Total α-Cryptoxanthin 

Total Lutein&Zeaxanthin 

Summary 

Serum 392 Serum 393 Serum 394a Serum 394b Seru

You NAV n You NAV n You NAV n You NAV n You 

0.724 0.675 31 0.262 0.243 31 0.470 0.470 21 0.317 10 0.452 

0.08 0.16 8 0.0 0.0 5 0.0 0.0 7 0.06 

8.53 8.37 31 4.09 4.15 31 6.95 6.88 22 8.40 9 10.78 

4.331 3.913 18 0.839 0.800 18 2.002 1.890 12 2.950 6 1.416 

0.749 0.704 4 0.040 0.062 4 0.117 0.117 3 2 0.083 

0.299 0.476 21 0.019 0.016 16 0.332 0.328 14 0.294 7 0.636 

0.286 0.450 6 0.014 0.013 5 0.309 0.301 5 1 0.597 

0.013 0.019 5 0.005 0.005 4 0.023 0.020 4 1 0.039 

0.372 0.421 15 0.004 0.006 11 0.030 0.030 11 0.042 3 0.340 

0.299 0.352 15 0.135 0.144 15 0.307 0.332 12 0.513 3 0.260 

0.204 0.246 7 0.071 0.071 7 0.171 0.176 6 1 0.130 

0.059 0.058 12 0.011 0.012 11 0.061 0.054 9 0.128 3 0.071 

0.046 0.042 4 0.006 0.007 4 0.031 0.024 3 1 0.026 

0.179 0.216 13 0.033 0.040 13 0.103 0.114 8 0.251 3 0.151 

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. 

Micronutrients Measurement Quality Assurance Program

National Institute of Standards and Technology 

100 Bureau Drive Stop 8392 

Gaithersburg, MD 20899-8392 USA 

Individualized Report 

Send corrections and/or updates to...
 Set 6 of 35 

Individualized RR LXXIII Report: FSV-BA

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 Comments History

#392 Lyophilized, augmented, multi-donor 38#224

#393 Fresh-frozen, native, multi-donor New

#394a Fresh-frozen, augmented, single-donor 49#271, 50#275, 51#279, 54#296, 56#308

#394b Fresh-frozen, augmented, multi-donor 65#353, 68#371

#395 Fresh-frozen, native, multi-donor 71#382

#396 Fresh-frozen, native, multi-donor 71#385

Total Retinol, μg/mL 224 392 393 271 275 279 296 308 394a 353 371 394b 382 395 385 396

[Analyte], μg/mL Apparent Precision, SD

Concordance, SD

Your [Analyte], μg/mL

Median [Analyte], μg/mL

Long-term Precision, SD

Apparent Precision, SD

You, this RR

You, past RRs Others, this RR

1st Quartile (25%)

Median (50%)

3rd Quartile (75%)

Expectation

You, ≥x, this RR

You, ≥x, past RRs

Individualized Report D3 Page 2 / 14
 
 Set 6 of 35 

Individualized RR LXXIII Report: FSV-BA

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 Comments History

#392 Lyophilized, augmented, multi-donor 38#224

#393 Fresh-frozen, native, multi-donor New

#394a Fresh-frozen, augmented, single-donor 49#271, 50#275, 51#279, 54#296, 56#308

#394b Fresh-frozen, augmented, multi-donor 65#353, 68#371

#395 Fresh-frozen, native, multi-donor 71#382

#396 Fresh-frozen, native, multi-donor 71#385

Retinyl Palmitate, μg/mL 224 392 393 271 275 279 296 308 394a 353 371 394b 382 395 385 396

[Analyte], μg/mL Apparent Precision, SD

Concordance, SD

Your [Analyte], μg/mL

Median [Analyte], μg/mL

Long-term Precision, SD

Apparent Precision, SD

You, this RR

You, past RRs Others, this RR

1st Quartile (25%)

Median (50%)

3rd Quartile (75%)

Expectation

You, ≥x, this RR

You, ≥x, past RRs

Individualized Report D4 Page 3 / 14
 
 Set 6 of 35 

Individualized RR LXXIII Report: FSV-BA

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 Comments History

#392 Lyophilized, augmented, multi-donor 38#224

#393 Fresh-frozen, native, multi-donor New

#394a Fresh-frozen, augmented, single-donor 49#271, 50#275, 51#279, 54#296, 56#308

#394b Fresh-frozen, augmented, multi-donor 65#353, 68#371

#395 Fresh-frozen, native, multi-donor 71#382

#396 Fresh-frozen, native, multi-donor 71#385

α-Tocopherol, μg/mL 224 392 393 271 275 279 296 308 394a 353 371 394b 382 395 385 396

[Analyte], μg/mL Apparent Precision, SD

Concordance, SD

Your [Analyte], μg/mL

Median [Analyte], μg/mL

Long-term Precision, SD

Apparent Precision, SD

You, this RR

You, past RRs Others, this RR

1st Quartile (25%)

Median (50%)

3rd Quartile (75%)

Expectation

You, ≥x, this RR

You, ≥x, past RRs

Individualized Report D5 Page 4 / 14
 
 Set 6 of 35 

Individualized RR LXXIII Report: FSV-BA

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 Comments History

#392 Lyophilized, augmented, multi-donor 38#224

#393 Fresh-frozen, native, multi-donor New

#394a Fresh-frozen, augmented, single-donor 49#271, 50#275, 51#279, 54#296, 56#308

#394b Fresh-frozen, augmented, multi-donor 65#353, 68#371

#395 Fresh-frozen, native, multi-donor 71#382

#396 Fresh-frozen, native, multi-donor 71#385

γ/β-Tocopherol, μg/mL 224 392 393 271 275 279 296 308 394a 353 371 394b 382 395 385 396

[Analyte], μg/mL Apparent Precision, SD

Concordance, SD

Your [Analyte], μg/mL

Median [Analyte], μg/mL

Long-term Precision, SD

Apparent Precision, SD

You, this RR

You, past RRs Others, this RR

1st Quartile (25%)

Median (50%)

3rd Quartile (75%)

Expectation

You, ≥x, this RR

You, ≥x, past RRs

Individualized Report D6 Page 5 / 14
 
 Set 6 of 35 

Individualized RR LXXIII Report: FSV-BA

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 Comments History

#392 Lyophilized, augmented, multi-donor 38#224

#393 Fresh-frozen, native, multi-donor New

#394a Fresh-frozen, augmented, single-donor 49#271, 50#275, 51#279, 54#296, 56#308

#394b Fresh-frozen, augmented, multi-donor 65#353, 68#371

#395 Fresh-frozen, native, multi-donor 71#382

#396 Fresh-frozen, native, multi-donor 71#385

Total β-Carotene, μg/mL 224 392 393 271 275 279 296 308 394a 353 371 394b 382 395 385 396

[Analyte], μg/mL Apparent Precision, SD

Concordance, SD

Your [Analyte], μg/mL

Median [Analyte], μg/mL

Long-term Precision, SD

Apparent Precision, SD

You, this RR

You, past RRs Others, this RR

1st Quartile (25%)

Median (50%)

3rd Quartile (75%)

Expectation

You, ≥x, this RR

You, ≥x, past RRs

Individualized Report D7 Page 6 / 14
 
 Set 6 of 35 

Individualized RR LXXIII Report: FSV-BA

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 Comments History

#392 Lyophilized, augmented, multi-donor 38#224

#393 Fresh-frozen, native, multi-donor New

#394a Fresh-frozen, augmented, single-donor 49#271, 50#275, 51#279, 54#296, 56#308

#394b Fresh-frozen, augmented, multi-donor 65#353, 68#371

#395 Fresh-frozen, native, multi-donor 71#382

#396 Fresh-frozen, native, multi-donor 71#385

trans-β-Carotene, μg/mL 224 392 393 271 275 279 296 308 394a 353 371 394b 382 395 385 396

[Analyte], μg/mL Apparent Precision, SD

Concordance, SD

Your [Analyte], μg/mL

Median [Analyte], μg/mL

Long-term Precision, SD

Apparent Precision, SD

You, this RR

You, past RRs Others, this RR

1st Quartile (25%)

Median (50%)

3rd Quartile (75%)

Expectation

You, ≥x, this RR

You, ≥x, past RRs

Individualized Report D8 Page 7 / 14
 
 Set 6 of 35 

Individualized RR LXXIII Report: FSV-BA

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 Comments History

#392 Lyophilized, augmented, multi-donor 38#224

#393 Fresh-frozen, native, multi-donor New

#394a Fresh-frozen, augmented, single-donor 49#271, 50#275, 51#279, 54#296, 56#308

#394b Fresh-frozen, augmented, multi-donor 65#353, 68#371

#395 Fresh-frozen, native, multi-donor 71#382

#396 Fresh-frozen, native, multi-donor 71#385

Total cis-β-Carotene, μg/mL 224 392 393 271 275 279 296 308 394a 353 371 394b 382 395 385 396

[Analyte], μg/mL Apparent Precision, SD

Concordance, SD

Your [Analyte], μg/mL

Median [Analyte], μg/mL

Long-term Precision, SD

Apparent Precision, SD

You, this RR

You, past RRs Others, this RR

1st Quartile (25%)

Median (50%)

3rd Quartile (75%)

Expectation

You, ≥x, this RR

You, ≥x, past RRs

Individualized Report D9 Page 8 / 14
 
 Set 6 of 35 

Individualized RR LXXIII Report: FSV-BA

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 Comments History

#392 Lyophilized, augmented, multi-donor 38#224

#393 Fresh-frozen, native, multi-donor New

#394a Fresh-frozen, augmented, single-donor 49#271, 50#275, 51#279, 54#296, 56#308

#394b Fresh-frozen, augmented, multi-donor 65#353, 68#371

#395 Fresh-frozen, native, multi-donor 71#382

#396 Fresh-frozen, native, multi-donor 71#385

Total α-Carotene, μg/mL 224 392 393 271 275 279 296 308 394a 353 371 394b 382 395 385 396

[Analyte], μg/mL Apparent Precision, SD

Concordance, SD

Your [Analyte], μg/mL

Median [Analyte], μg/mL

Long-term Precision, SD

Apparent Precision, SD

You, this RR

You, past RRs Others, this RR

1st Quartile (25%)

Median (50%)

3rd Quartile (75%)

Expectation

You, ≥x, this RR

You, ≥x, past RRs

Individualized Report D10 Page 9 / 14
 
 Set 6 of 35 

Individualized RR LXXIII Report: FSV-BA

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 Comments History

#392 Lyophilized, augmented, multi-donor 38#224

#393 Fresh-frozen, native, multi-donor New

#394a Fresh-frozen, augmented, single-donor 49#271, 50#275, 51#279, 54#296, 56#308

#394b Fresh-frozen, augmented, multi-donor 65#353, 68#371

#395 Fresh-frozen, native, multi-donor 71#382

#396 Fresh-frozen, native, multi-donor 71#385

Total Lycopene, μg/mL 224 392 393 271 275 279 296 308 394a 353 371 394b 382 395 385 396

[Analyte], μg/mL Apparent Precision, SD

Concordance, SD

Your [Analyte], μg/mL

Median [Analyte], μg/mL

Long-term Precision, SD

Apparent Precision, SD

You, this RR

You, past RRs Others, this RR

1st Quartile (25%)

Median (50%)

3rd Quartile (75%)

Expectation

You, ≥x, this RR

You, ≥x, past RRs

Individualized Report D11 Page 10 / 14
 
 Set 6 of 35 

Individualized RR LXXIII Report: FSV-BA

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 Comments History

#392 Lyophilized, augmented, multi-donor 38#224

#393 Fresh-frozen, native, multi-donor New

#394a Fresh-frozen, augmented, single-donor 49#271, 50#275, 51#279, 54#296, 56#308

#394b Fresh-frozen, augmented, multi-donor 65#353, 68#371

#395 Fresh-frozen, native, multi-donor 71#382

#396 Fresh-frozen, native, multi-donor 71#385

trans-Lycopene, μg/mL 224 392 393 271 275 279 296 308 394a 353 371 394b 382 395 385 396

[Analyte], μg/mL Apparent Precision, SD

Concordance, SD

Your [Analyte], μg/mL

Median [Analyte], μg/mL

Long-term Precision, SD

Apparent Precision, SD

You, this RR

You, past RRs Others, this RR

1st Quartile (25%)

Median (50%)

3rd Quartile (75%)

Expectation

You, ≥x, this RR

You, ≥x, past RRs

Individualized Report D12 Page 11 / 14
 
 Set 6 of 35 

Individualized RR LXXIII Report: FSV-BA

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 Comments History

#392 Lyophilized, augmented, multi-donor 38#224

#393 Fresh-frozen, native, multi-donor New

#394a Fresh-frozen, augmented, single-donor 49#271, 50#275, 51#279, 54#296, 56#308

#394b Fresh-frozen, augmented, multi-donor 65#353, 68#371

#395 Fresh-frozen, native, multi-donor 71#382

#396 Fresh-frozen, native, multi-donor 71#385

Total β-Cryptoxanthin, μg/mL 224 392 393 271 275 279 296 308 394a 353 371 394b 382 395 385 396

[Analyte], μg/mL Apparent Precision, SD

Concordance, SD

Your [Analyte], μg/mL

Median [Analyte], μg/mL

Long-term Precision, SD

Apparent Precision, SD

You, this RR

You, past RRs Others, this RR

1st Quartile (25%)

Median (50%)

3rd Quartile (75%)

Expectation

You, ≥x, this RR

You, ≥x, past RRs

Individualized Report D13 Page 12 / 14
 
 Set 6 of 35 

Individualized RR LXXIII Report: FSV-BA

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 Comments History

#392 Lyophilized, augmented, multi-donor 38#224

#393 Fresh-frozen, native, multi-donor New

#394a Fresh-frozen, augmented, single-donor 49#271, 50#275, 51#279, 54#296, 56#308

#394b Fresh-frozen, augmented, multi-donor 65#353, 68#371

#395 Fresh-frozen, native, multi-donor 71#382

#396 Fresh-frozen, native, multi-donor 71#385

Total Lutein&Zeaxanthin, μg/mL 224 392 393 271 275 279 296 308 394a 353 371 394b 382 395 385 396

[Analyte], μg/mL Apparent Precision, SD

Concordance, SD

Your [Analyte], μg/mL

Median [Analyte], μg/mL

Long-term Precision, SD

Apparent Precision, SD

You, this RR

You, past RRs Others, this RR

1st Quartile (25%)

Median (50%)

3rd Quartile (75%)

Expectation

You, ≥x, this RR

You, ≥x, past RRs

Individualized Report D14 Page 13 / 14
 
 Set 5 of 34

Total Retinol α-Tocopherol Total β-Carotene 

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

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

trans-Lycopene Total β-Cryptoxanthin Total α-Carotene 

Individualized Round Robin LXXIII Report: FSV-BA

Graphical Comparability Summary D1

5

5/17/2013 
 

 

 

 

Appendix E. Shipping Package Inserts for RR38 

The following three items were included in each package shipped to an RR38 participant: 

• Cover letter 

• Analysis of Control Materials and Test Samples 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. 

E1
	
January 21, 2013 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standards and Technology 

Gaithersburg, Maryland 20899-

The samples within ~s package constitute Vitamin C Round Robin 38 (RR38) of the 2013 

Micronutrients Measurement Quality Assurance Program. RR38 consists of one vial each of 

four frozen serum test samples (#381, #382 #383, and #384) and one vial each of two frozen 

control sera (CS#3 and CS#4). These materials are in sealed ampoules. They were prepared by 

adding equal volumes of 10% MP A to spiked human serum. We have checked the samples for 

stability and homogeneity. Only total ascorbic acid is stable. While these samples contain sonie 

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

analyzed and reported. 

Please use the control sera to validate the performance of your measurement system before you 

analyze the test samples. The target value for CS#3 is (15.5 ±1.6; 13.9 to 17.1) μmol/L and the 

target for CS#4 is (46.1±4.6;41.5 to 50.7) μmol/L. We expect your results for both of these 

controls to be with.in this ±10% target range. If your results are significantly outside this range, 

your analysis system may not be suited to the analysis of:MPA-preserved samples. In this case, 

please do not proceed to the analysis of the test samples but contact us at 301-975-3120 or 

jbthomas@nist.gov. 

The test samples and co:ntrol sera should be defrosted by warming at 20 °C for not more than 10 

min otherwise som~ irreversible degradation may occur. Please be aware that sample contact 

with any oxidant-contaminated surface (vials, glassware, ~tc.) may degrade your measurement 

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

Autosampler Vials", Clinical Chemistry 2001, 4 7(8), 1463-1464). You should suspect such 

degradation if you observe unusually large variation in replicate analyses. 

Please measure the total ascorbic acid in each ampoule in duplicate, reporting in units of μmoV(L 

sample solution) rather than μmol/(L serum used to prepare the sample). Please email 

(david.duewer@nist.gov) or fax (301-977-0685) your results to us as soon as possible but no 

later than April 1, 2013. 

If you have questions or comments regarding this study, please e-mail me atjbthomas@nist.gov 

or call me at (301) 975 3120. 

rown Thomas 

Coordinator/Research Chemist 

cal Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosure: RR38 Report Form for Control Material and Test Sample Analyses 

N•Si E2
 
SRM970 Lv1

Sam - 30's

SRM970 Lv2

Sam - 50's

Red

Orange

 

 

Participant #: ________ Date: _____________ 

Vitamin C Round Robin 38
 

NIST Micronutrients Measurement Quality Assurance Program
 

Packing List and Shipment Receipt Confirmation Form
 

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

Label Form
 

VitC #381 Liquid frozen (1:1 serum:10% MPA) 

VitC #382 Liquid frozen (1:1 serum:10% MPA) 

VitC #383 Liquid frozen (1:1 serum:10% MPA) 

VitC #384 Liquid frozen (1:1 serum:10% MPA) 

CS #3 Liquid frozen (1:1 serum:10% MPA) 

CS #4 Liquid frozen (1:1 serum:10% MPA) 

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) Email (david.duewer@nist.gov) or fax (301-977-0685) us the 

following information: 

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 6392 Fax: 301-977-0685 

Gaithersburg, MD 20899-6392 E3 Email: David.Duewer@NIST.gov 
Appendix F. Final Report for RR38

The following three pages are the final report for RR38 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
 
F2
 

 

 

 

 

 

 

 

The NIST MMQAP Vitamin C Round Robin 38 (RR38) report consists of: 

Page “Individualized” Report 

1 Summary of your reported values for the two serum control and four serum test samples. 

2 Graphical summary of your RR38 measurements. 

Page “All-Lab” Report 

1 A tabulation of results and summary statistics for total ascorbic acid [TAA] in the RR38 

control and test samples. Results and summary statistics are also presented for the test 

samples calibrated to the results for the control samples 

Serum-Based Samples. Two serum controls and four test samples were distributed in RR38. 

CS#3	 a (15.4 ±0.4) μmol/L material ampouled in 2009 

CS#4	 a (46.2 ±1.2) μmol/L material ampouled in 2009 

S38:1	 an unaugmented material (i.e., the [TAA] content is zero or nearly so), ampouled in 2001, 

previously distributed in RRs 16, 19, 21, 23, 26, and 29 

S38:2	 Ampouled in late 2009, previously distributed in RRs 32, 33, and 35 

S38:3	 Ampouled in late 2009, previously distributed in RRs 32, 35, and 36 

S38:4	 Ampouled in late 2009, previously distributed in RRs 34 and 36 

Results. 

1)	 The reported [TAA] contents of the two control sera, CS#3 and CS#4, are unchanged from the values 

estimated for these materials when they were distributed as unknowns. The expected [TAA] content 

and inter-participant standard deviation are estimated with the robust median and adjusted median 

absolute deviation (eSD) statistics. 

2)	 All participants reported either “zero” or credible limit-of-quantification (LoQ) values for the 

unaugmented (nominal zero-level) material, S38:1. We regard providing LoQ (i.e., “<x”) values to 

be the more informative reporting practice. 

3)	 The reported [TAA] contents of the three non-blank test samples, S38:2 to S38:4, are the same as 

estimated in previous studies. The robust inter-participant estimated coefficient of variation 

eCV = 100*eSD/Median 

pooled over these three materials is 8%. 

4)	 The results for two control sera with well-separated [TAA] levels enable calibration of the reported 

results for the unknowns to the function: 

[TAA]reportedCS = a + b*[TAA]referenceCS 

where [TAA]reportedCS are the reported values for the two control sera and [TAA]referenceCS are the 

established reference values for these materials. The calibrated values for unknown samples are then 

given by: 

[TAA]calibrated = ([TAA]reported – a) / b . 

F3
 
 

 

 

Figure 1 displays the eSD as a function of the Median values for the test samples distributed in RR37 

and RR38 for both the “as reported” and “after calibration” results. While there is as yet too little 

data to draw strong conclusions, calibration to the control materials appears to improve the pooled 

eCV of the seven test samples from about 7% to 5%. 

Reported 

Calibrated 

CV = 7 % 

CV = 5 % 

0 20 40 60
 

Estimated SD (eSD), 

μmol/L 

5
 

4
 

3
 

2
 

1
 

0 

Median, μmol/L 

Figure 1: Estimated Standard Deviation as a Function of Median Value 

Each symbol represents the summary statistics for one of the four test samples distributed in RR37 or 

one of the three non-blank test samples distributed in RR38. 

F4
 
 

Appendix G. “All-Lab Report” for RR38 

The following two pages are the “All-Lab Report” for RR38 as provided to all 

participants, with the following exceptions: 

• the participant identifiers (Lab) have been altered. 

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

• the Legend page has been added. 

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

identification codes assigned to laboratories. 

G1
 
Micronutrients Measurement Quality Assurance Program for Total Ascorb

"Round Robin" 38 - Winter 2013 

Samples Calibrated Results: [TAA]' = ([TAA]-a 

Lab Date 

Total Ascorbic Acid ([TAA]), μmol/L 

CS#3 CS#4 S38:1 S38:2 S38:3 S38:4 

VC-MB 27/02/13 

VC-MC 15/05/13 

VC-MG 03/04/13 

VC-MH 18/03/13 

VC-MI 29/03/13 

VC-MJ 05/03/13 

VC-MN 05/04/13 

VC-NF 28/03/13 

VC-NM 11/03/13 

13.9 45.4 

16.2 48.3 

15.1 46.6 

15.7 46.8 

14.6 58.8 

23.8 53.4 

15.5 43.5 

15.3 43.7 

12.7 42.5 

<5.2 21.7 30.2 57.0 

nd 24.0 35.5 57.2 

0.0 23.5 31.1 57.8 

<0.9 22.4 29.4 53.9 

<1.4 26.2 38.3 73.3 

<10 29.7 37.3 62.2 

0.0 23.3 31.2 57.7 

<1.7 24.0 30.1 53.6 

<5.7 21.2 28.3 52.8 

Parameters 

b a 

1.03 -2.0 

1.05 -0.1 

1.03 -0.8 

1.02 -0.1 

1.44 -7.8 

0.97 8.7 

0.92 1.3 

0.93 0.9 

0.97 -2.4 

[TAA]', μmol/L 

S38:1' S38:2' S38:3' 

<7.0 23.0 31.3 

nd 22.9 33.9 

0.8 23.7 31.1 

<0.9 22.0 29.0 

<6.4 23.6 31.9 

<1.3 21.6 29.5 

-1.4 24.1 32.6 

<0.9 24.8 31.4 

<8.4 24.3 31.6 

G

2

N

Average

SD

Min

%25

Median 

%75

Max

eSD

eCV 

9 9 

15.9 47.7 

3.1 5.3 

2 9 9 9 

0.0 24.0 32.4 58.4 

0.0 2.6 3.7 6.3 

12.7 42.5 

14.6 43.7 

15.3 46.6 

15.7 48.3 

23.8 58.8 

1.1 4.3 

7 9 

0.0 21.2 28.3 52.8 

22.4 30.1 53.9 

0.0 23.5 31.1 57.2 

24.0 35.5 57.8 

0.0 29.7 38.3 73.3 

1.7 2.6 4.8 

7 8 8 

2

-0.3 

1.6 

-1.4 

-0.3 

0.8 

9

23.3 

1.0 

21.6 

22.9 

23.6 

24.1 

24.8 

0.9 

4 

9

31.4 

1.5 

29.0 

31.1 

31.4 

31.9 

33.9 

0.8 

2 

All Lab Report 
Micronutrients Measurement Quality Assurance Program for Total Ascorb

G

3

Term 

Lab

Date 

b

a

N

Average 

SD 

Min

%25 

Median 

%75 

Max

eSD

eCV

nd

<x

"Round Robin" 38 - Winter 2013 

Legend 

Definition 

 Participant code

 Date results received at NIST

 Slope and Intercept of the line connecting the expected values

 for control samples CS#3 and CS#4 with the results reported

 by each participant 

 Number of quantitative values reported for this analyte

 Mean of the reported quantitative values

 Standard deviation of the reported quantitative values

 Minimum quantitative value reported

 First quartile of the reported quantitative values

 Median (second quartile) of the reported quantitative values

 Third quartile of the reported quantitative values

 Maximum quantitative value reported

 Robust standard deviation, estimated using the adjusted

 median absolute deviation from the median (MADe)

 Robust Coefficient of Variation, estimated as 100*eSD/Median

 Not determined

 Concentration less than x 

All Lab Report 
Appendix H. Representative “Individualized Report” for RR38 

Each participant in RR38 received an “Individualized Report” reflecting their reported 

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

“VC-MB”. 

H1
 
 

 

 

 Set 2 of 12 

Vitamin C "Round Robin" 38 Report: Participant VC-MB

[TAA] mmol/Lsample 

5 46.1 1.1 1.0 

01/14/11 34 S34:3 

06/13/11 35 S35:4 

08/06/12 37 CS#4 

02/27/13 38 CS#4 

02/08/02 16 S16:2 5 0.9 0.4 1.4 

05/01/03 19 S19:1 

07/14/04 21 S21:1 

05/25/05 23 S23:1 

11/26/06 26 S26:1 

06/20/08 29 S29:1 

01/02/00 38 S38:1 

01/13/10 32 S32:2 4 22.7 0.4 0.9 

07/23/10 33 S33:4 

06/13/11 35 S35:2 

02/27/13 38 S38:2 

01/13/10 32 S32:3 4 30.9 0.5 0.7 

06/13/11 35 S35:3 

03/07/12 36 S36:2 

02/27/13 38 S38:3 

01/14/11 34 S34:4 4 56.8 0.7 0.7 

03/07/12 36 S36:1 

03/07/12 36 S36:4 

02/27/13 38 S38:4 

Date RR Sample 

07/23/10 33 S33:3 

01/14/11 34 S34:2 

06/13/11 35 S35:1 

08/06/12 37 CS#3 

02/27/13 38 CS#3 

01/13/10 32 S32:4 

Rep1 Rep2 Fadj Mean SDdup 

13.4 13.4 1.0 13.4 0.0 

13.9 13.9 1.0 13.9 0.0 

15.0 15.5 1.0 15.2 0.4 

10.3 15.0 1.0 12.6 3.3 

13.9 13.9 1.0 13.9 0.0 

N Mean SDrepeat SDreprod 

5 13.8 1.5 1.2 

45.4 45.9 1.0 45.7 0.4 

45.4 45.9 1.0 45.7 0.4 

47.5 47.5 1.0 47.5 0.0 

44.9 48.0 1.0 46.5 2.2 

45.9 44.9 1.0 45.4 0.7 

3.1 2.0 0.5 1.3 0.4 

5.2 7.2 0.5 3.1 0.7 

<5.2 <5.2 1.0 

0.0 0.0 1.0 0.0 0.0 

0.0 0.0 1.0 0.0 0.0 

0.0 0.0 1.0 0.0 0.0 

<5.16 <5.16 1.0 

22.2 22.7 1.0 22.5 0.4 

23.2 22.7 1.0 23.0 0.4 

23.7 23.7 1.0 23.7 0.0 

21.2 22.2 1.0 21.7 0.7 

30.5 31.0 1.0 30.7 0.4 

32.0 31.5 1.0 31.7 0.4 

31.5 30.5 1.0 31.0 0.7 

29.9 30.5 1.0 30.2 0.4 

56.8 57.3 1.0 57.0 0.4 

57.8 56.8 1.0 57.3 0.7 

56.8 55.2 1.0 56.0 1.1 

57.3 56.8 1.0 57.0 0.4 

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

Micronutrients Measurement Quality Assurance Program Fax: (301) 977-0685
 

National Institute of Standards and Technology Email: david.duewer@nist.gov
 

H2
 

Individualized Report Page 1/2 
 Set 2 of 12 

Vitamin C "Round Robin" 38 Report: Participant VC-MB

Total Ascorbic Acid, μmol/mL

36

36

36

35

35

35

35

35

35

34

34

34

34

34

34

33

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

CS#3 Distributed as an unknown in RRs 33, 34, and 35. Distributed as a control in RR37.

CS#4 Distributed as an unknown in RRs 32, 34, and 35. Distributed as a control in RR37.

S38:1 Zero-level control serum, distributed in RRs 16, 19, 21, 23, 26, and 29

S38:2 Distributed in RRs 32, 33, and 35

S38:3 Distributed in RRs 32, 35, and 36

S38:4 Distributed in RRs 34 and 36

Comments

S33:3S34:2S35:1

37:CS#338:CS#3

S32:4S34:3S35:4

37:CS#438:CS#4

S32:2S33:4S35:2S38:2S32:3S35:3S36:2S38:3S34:4S36:1S36:4S38:4

[Total Ascorbic Acid], μmol/L

Your [Total Ascorbic Acid], μmol/L

Median [Total Ascorbic Acid], μmol/L

You, this RR

You, past RRs

NIST, RR 22

Others, this RR 1st Quartile (25%)

Median (50%)

3rd Quartile (75%) Apparent Precision, SD

Concordance, SD

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