[Total Retinol], μg/mL 

224392397357365375389398358364374386

[Total Ascorbic Acid], μmol/L 399

359

RR11 363RR12 373 RR13

RR14 379RR15 400RR16

RR23RR25RR29RR31

RR34RR36

RR37RR39

S25:3S29:4

S39:3S04:2S26:3S28:2S39:4 

VC RR 39
	

NISTIR 7880-42 

NIST Micronutrients Measurement 

Quality Assurance Program 

Summer 2013 

Comparability Studies 

Results for Round Robin LXXIV 

Fat-Soluble Vitamins and Carotenoids in Human Serum 

and Round Robin 39 Ascorbic Acid in Human Serum 

FSV RR LXXIV 

David L. Duewer 

RR18 401 RR19RR20RR22

Jeanice B. Thomas 

http://dx.doi.org/10.6028/NIST.IR.7880-42 

 

 

 

 

 

 

NISTIR 7880-42 

NIST Micronutrients Measurement 

Quality Assurance Program 

Summer 2013 

Comparability Studies 

Results for Round Robin LXXIV 

Fat-Soluble Vitamins and Carotenoids in Human Serum 

and Round Robin 39 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.7880-42 

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 LXXIV 

Fat-Soluble Vitamins and Carotenoids in Human Serum and 2) Round Robin 39 Total Ascorbic Acid 

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

participants were requested to provide their measurement results by September 30, 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 LXXIV: Fat-Soluble Vitamins and Carotenoids in Human Serum ...................... 1
	

Round Robin 39: Vitamin C in Human Serum............................................................................... 2
	

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

Appendix A. Shipping Package Inserts for RR74........................................................................ A1
	

Appendix B. Final Report for RR74 .............................................................................................. B1
	

Appendix C. All-Lab Report for RR74 .......................................................................................... C1
	

Appendix D. Representative Individualized Report for RR74 ................................................... D1
	

Appendix E. Shipping Package Inserts for RR39 ......................................................................... E1
	

Appendix F. Final Report for RR39............................................................................................... F1
	

Appendix G. “All-Lab Report” for RR39..................................................................................... G1
	

Appendix H. Representative “Individualized Report” for RR39............................................... 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 LXXIV: Fat-Soluble Vitamins and Carotenoids in Human Serum 

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

LXXIV comparability study (hereafter referred to as RR74) received one lyophilized and four 

liquid-frozen 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 June 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 RR74 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 39: Vitamin C in Human Serum 

Participants in the MMQAP Vitamin C in Human Serum Round Robin 39 comparability study 

(hereafter referred to as RR39) 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 June 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 RR39 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 RR74 

The following three items were included in each package shipped to an RR74 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
	
'June 1, 2013 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standard& and Technology 

Gaithersburg, Maryland 20899-

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

LXXIV) for the 2013 NIST Micronutrients Measurement Quality Assurance Program. The set of samples 

(Sera 397- 401) 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 each serum sample. If a value obtained is below your limit of quantification, please indicate 

this result on the form as "nq" (Not Quantified) or "<X" where x is your established limit of quantification. 

Results are due to NIST by September 30, 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 October 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 retinal 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): retinal, 1843 at 

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

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

Please report your results for Round Robin LXXIV 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 atjbthomas@nist.gov. 

J eani e Brown Thomas 

Pro am Coordinator/Research Chemist 

ytical Chemistry Division · 

Material Measurement Laboratory 

Enclosure 

N•Si A2
 
 

 

Participant #: ________ Date: _____________ 

Round Robin LXXIV: Human Sera 

NIST Micronutrients Measurement Quality Assurance Program 

Analyte 397 398 399 400 401 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 

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 30-Sep-2013 Fax: 301-977-0685 

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

 

 

 

Participant #: ________ Date: _____________ 

Fat-Soluble Vitamins Round Robin LXXIV
 

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 

#397 Lyophilized Yes 5 mL clear / silver 

#398 Liquid frozen No TBD 

#399 Liquid frozen No TBD 

#400 Liquid frozen No TBD 

#401 Liquid frozen No TBD 

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 RR74 

The following six pages are the final report for RR74 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
	
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

UNITED STATES DEPARTMENT OF COMMERCE
 

National Institute of Standards and Technology
 

Gaithersburg, Maryland 20899-8390 

December 3, 2013 

Dear Colleague: 

Enclosed is the summary report of the results for “Round Robin” LXXIV (RR74) of the 2013 NIST 

Micronutrients Measurement Quality Assurance Program (MMQAP) for the fat-soluble vitamins and 

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

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

graphical summary of your measurement comparability. RR74 (Sera 397 - 401) consisted of one vial of 

lyophilized serum and one vial each of four liquid-frozen serum samples. Details regarding the samples 

can be found in the enclosed report. 

Your overall measurement comparability is summarized in the “Score Card” summary, page 6 of the All 

Lab Report. Combined results rated 1 to 3 are within 1 to 3 standard deviations of the assigned value, 

respectively; those rated 4 are >3 standard deviations from the assigned value. Similar information is 

presented graphically in the “target plots” that are the last page of your Individualized Report. If you 

have concerns regarding your laboratory’s performance, please contact us for consultation. 

Samples for the 2014 MMQAP will be shipped starting January 27, 2014. We will ship the samples for 

both exercises for each study at the same time. Results are due in April for the first study; written 

feedback will be provided to laboratories in May. We will send you a notification around June about the 

reporting deadline for the second study. Please contact us immediately if this schedule is problematic for 

your laboratory. 

We have completed on-line documentation of data and reports for the MMQAP studies from 1996 to 

2012. For your convenience, enclosed are the links to these documents. Data summaries have been 

altered to ensure confidentiality of identification codes assigned to laboratories. We anticipate that the 

results for Round Robins 73 and 74 Fat-Soluble Vitamins and Carotenoids in Human Serum and Round 

Robins 38 and 39 Ascorbic Acid in Human Serum will be available online by spring 2014. 

If you have questions or concerns regarding this report, please contact David Duewer at 301-975-3935; email: david.duewer@nist.gov or me at 301-975-3120; e-mail: jbthomas@nist.gov; or fax: 301-977-0685. 

Sincerely, 

Jeanice Brown Thomas, M.B.A. David L. Duewer, Ph.D. 

Research Chemist Research Chemometrician 

Chemical Sciences Division Chemical Sciences Division 

Material Measurement Laboratory Material Measurement Laboratory 

Enclosures 

Cc: L.C. Sander 

B2`
	
 

 

 

 

 

 

 

 

MMQAP Comparability Studies (1996 to 2012) 

D.L. Duewer, M.C. Kline, K.E. Sharpless, J.M. Brown Thomas, S.A. Margolis, NIST Micronutrients 

Measurement Quality Assurance Program Winter, Spring, and Fall 1996 Comparability Studies: Results 

for Round Robin XXXVI, XXXVII, and XXXVIII Fat-Soluble Vitamins and Carotenoids in Human 

Serum and Round Robin 9 Ascorbic Acid in Human Serum, NIST Interagency/Internal Report (NISTIR) 

7880-28 

D.L. Duewer, M.C. Kline, K.E. Sharpless, J.M. Brown Thomas, S.A. Margolis, NIST Micronutrients 

Measurement Quality Assurance Program Winter, Spring, and Fall 1997 Comparability Studies: Results 

for Round Robin XXXIX, XL, and XLI Fat-Soluble Vitamins and Carotenoids in Human Serum and 

Round Robin 10 Ascorbic Acid in Human Serum, NIST Interagency/Internal Report (NISTIR) 7880-27 

D.L. Duewer, M.C. Kline, K.E. Sharpless, J.M. Brown Thomas, S.A. Margolis, NIST Micronutrients 

Measurement Quality Assurance Program Winter, Spring, and Fall 1998 Comparability Studies: Results 

for Round Robin XLII, XLIII, and XLIV Fat-Soluble Vitamins and Carotenoids in Human Serum and 

Round Robin 11 Ascorbic Acid in Human Serum, NIST Interagency/Internal Report (NISTIR) 7880-26 

David Lee Duewer, Sam A. Margolis, Katherine E Sharpless, Jeanice M Brown Thomas, NIST 

Micronutrients Measurement Quality Assurance Program Winter and Summer 1999 Comparability 

Studies: Results for Round Robin XLV and XLVI Fat-Soluble Vitamins and Carotenoids in Human 

Serum and Round Robin 12 Ascorbic Acid in Human Serum, NIST Interagency/Internal Report (NISTIR) 

7880-25 

D.L. Duewer, M.C. Kline, K.E. Sharpless, J.M. Brown Thomas, S.A. Margolis, NIST Micronutrients 

Measurement Quality Assurance Program Winter and Summer 2000 Comparability Studies: Results for 

Round Robins XLVII and XLVIII Fat-Soluble Vitamins and Carotenoids in Human Serum and Round 

Robin 13 Ascorbic Acid in Human Serum, NIST Interagency/Internal Report (NISTIR) 7880-24 

D.L. Duewer, K.E. Sharpless, J.M. Brown Thomas, S.A. Margolis, NIST Micronutrients Measurement 

Quality Assurance Program Winter 2001 Comparability Studies: Results for Round Robin XLIX 

Fat-Soluble Vitamins and Carotenoids in Human Serum and Round Robin 14 Ascorbic Acid in Human 

Serum, NIST Interagency/Internal Report (NISTIR) 7880-23 

D.L. Duewer, K.E. Sharpless, J.M. Brown Thomas, S.A. Margolis, NIST Micronutrients Measurement 

Quality Assurance Program Summer 2001 Comparability Studies: Results for Round Robin L Fat-Soluble 

Vitamins and Carotenoids in Human Serum and Round Robin 15 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-22 

D.L. Duewer, K.E. Sharpless, J.M. Brown Thomas, S.A. Margolis, 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. NIST 

Interagency/Internal Report (NISTIR) 7880-21 

D.L. Duewer, M.C. Kline, K.E. Sharpless, J.M. Brown Thomas, S.A. Margolis, NIST Micronutrients 

Measurement Quality Assurance Program Summer 2002 Comparability Studies: Results for Round Robin 

LII Fat-Soluble Vitamins and Carotenoids in Human Serum and Round Robin 17 Ascorbic Acid in 

Human Serum, NIST Interagency/Internal Report (NISTIR) 7880-20 

Cover Letter B3 2 / 4
	
 

 

 

 

 

 

 

 

 

 

 

 

 

D.L. Duewer, K.E. Sharpless, J.M. Brown Thomas, NIST Micronutrients Measurement Quality 

Assurance Program Winter 2003 Comparability Studies: Results for Round Robin LIII Fat-Soluble 

Vitamins and Carotenoids in Human Serum and Round Robin 18 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-19 

D.L. Duewer, K.E. Sharpless, J.M. Brown Thomas, NIST Micronutrients Measurement Quality 

Assurance Program Summer 2003 Comparability Studies: Results for Round Robin LIV Fat-Soluble 

Vitamins and Carotenoids in Human Serum and Round Robin 19 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-18 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Winter 2004 Comparability Studies: Results for Round Robin LV Fat-Soluble Vitamins and Carotenoids 

in Human Serum and Round Robin 20 Ascorbic Acid in Human Serum, NIST Interagency/Internal 

Report (NISTIR) 7880-17 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Summer 2004 Comparability Studies: Results for Round Robin LVI Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 21 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-16 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Winter 2005 Comparability Studies: Results for Round Robin LVII Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 22 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-15 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Summer 2005 Comparability Studies: Results for Round Robin LVIII Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 23 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-14 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Winter 2006 Comparability Studies: Results for Round Robin LIX Fat-Soluble Vitamins and Carotenoids 

in Human Serum and Round Robin 24 Ascorbic Acid in Human Serum, NIST Interagency/Internal 

Report (NISTIR) 7880-13 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Summer 2006 Comparability Studies: Results for Round Robin LX Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 25 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-12 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Winter 2007 Comparability Studies: Results for Round Robin LXI Fat-Soluble Vitamins and Carotenoids 

in Human Serum and Round Robin 26 Ascorbic Acid in Human Serum, NIST Interagency/Internal 

Report (NISTIR) 7880-11 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Summer 2007 Comparability Studies: Results for Round Robin LXII Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 27 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-10 

Cover Letter B4 3 / 4
	
 

 

 

 

 

 

 

 

 

 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Winter 2008 Comparability Studies: Results for Round Robin LXIII Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 28 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-9 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Summer 2008 Comparability Studies: Results for Round Robin LXIV Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 29 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-8 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Winter 2009 Comparability Studies: Results for Round Robin LXV Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 30 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-7 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Summer 2009 Comparability Studies: Results for Round Robin LXVI Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 31 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-6 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Winter 2010 Comparability Studies: Results for Round Robin LXVII Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 32 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-5 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Summer 2010 Comparability Studies: Results for Round Robin LXVIII Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 33 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-4 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Winter 2011 Comparability Studies: Results for Round Robin LXIX Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 34 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-3 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Summer 2011 Comparability Studies Results for Round Robin LXX Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 35 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-2 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Winter 2012 Comparability Studies Results for Round Robin LXXI Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 36 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Summer 2012 Comparability Studies, NIST Interagency/Internal Report (NISTIR) 7880-1 

Cover Letter B5 4 / 4
	
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 

The NIST MMQAP Round Robin LXXIV (RR74) report consists of:
	

Page
	

1-4 A listing of all results and statistics for analytes reported by more than one participant. 

5 The legend for the list of results and statistics. 

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

Page Individualized Report 

2 to 

n 

n+1 

Samples. 

Serum 

397 

398 

399 

400 

401 

Results 

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 RR74. 

Description
	

Lyophilized, multi-donor stripped serum augmented 

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

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

and zeaxanthin prepared in 1995. 

Fresh-frozen, native, multi-donor, prepared in 2009. 

This is Level I of SRM 968e. 

Fresh-frozen, native, multi-donor, prepared in 2009. 

This is Level II of SRM 968e. 

Fresh-frozen, native, multi-donor, prepared in 2009. 

This is Level III of SRM 968e. 

Liquid-frozen, multi-donor heparin-treated plasma 

material augmented with glycyrrhetinic acid prepared in 

1989. 

Prior Distributions
	

#224:RR38-9/96, #392:RR73-3/13 

#357:RR66-9/09, #365:RR67-3/10, 

#375:RR69-3/11, #389:RR72-9/12 

#358:RR66-9/09, #364:RR67-3/10, 

#374:RR69-3/11, #386:RR71-3/12 

#359:RR66-9/09, #363:RR67-3/10, 

#373:RR69-3/11, #379:RR70-9/11 

First MMQAP distribution 

1) Serum 397. This highly augmented experimental material was distributed in RR74 to confirm that 

the levels of retinyl palmitate, β-carotene, and total and trans-lycopene are less than they were in 1995 

but that the levels of the other analytes are largely unchanged. 

2) Sera 388 to 400. There have been no significant changes in either the level nor variability in any of 

the analytes in these SRM 968e materials. 

3) Serum 401. This is the second distribution of a material prepared as part of an investigation into the 

chemopreventative potential of glycyrrhetinic acid. This relatively polar compound’s absorbance 

maxima are at 248 nm and should not interfere with the analysis of the usual MMQAP analytes. The 

following “Youden Plots” provide a way to check for systematic biases in the analysis of these 

samples, plotting normalized values for serum 393 (Y-axis), a material with a different glycyrrhetinic 

Summary Report B6` 1 / 2 
 

 

 

 

 

 

 

 

 

 

 

 

acid concentration distributed in RR73, against those for serum 401 (X-axis) for each participant that 

reported both values. Each solid black circle represents the results reported by one participant. 

The z-score normalization was accomplished using the median as a robust estimator of location and 

the “MADe” (median absolute deviation from the median, adjusted to have the same coverage as a 

standard deviation) as a robust estimate of dispersion: z-score = (value – Median)/MADe. The solid 

red ellipse is a 95 % joint probability ellipse for the paired data given the number of pairs and a robust 

estimate of the “typical” between sera correlation for these two materials. Assuming that the results 

are normally distributed, about 95% of “typical” results should lie within the ellipse. 

The dashed line marks where the paired results are expected to cluster when there is significant 

systematic bias in a participant’s method. Since none of the paired results that lie outside the 95 % 

ellipse are close to this line, there is little evidence for such a bias in the analysis of total retinol, 

α- and γ/β-tocopherol, and total β-carotene. There are too few paired results to test for systematic 

bias in any of the other analytes. 

Total Retinol α-Tocopherol 

Serum 383, z-score Serum 383, z-score 

Serum 401, z-score Serum 401, z-score 

γ/β-Tocopherol Total β-Carotene 

Serum 383, z-score Serum 383, z-score 

Serum 401, z-score Serum 401, z-score 

Summary Report B7 2 / 2 
 

 

 

 

Appendix C. “All-Lab Report” for RR74 

The following six pages are the “All-Lab Report” for RR74 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 LXXIV Laboratory Results 

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

Lab 397 398 399 400 401 

C2

FSV-BA 0.345 0.499 0.637 0.469 0.744 

FSV-BB 0.338 0.461 0.625 0.474 0.711 

FSV-BC 0.349 0.499 0.637 0.433 0.661 

FSV-BD 0.357 0.510 0.626 0.462 0.660 

FSV-BE 0.348 0.513 0.642 0.477 0.677 

FSV-BF 0.320 0.460 0.530 0.370 0.480 

FSV-BG 0.363 0.523 0.654 0.509 0.709 

FSV-BJ 0.339 0.492 0.645 0.490 0.736 

FSV-BK 0.313 0.443 0.582 0.636 ­

FSV-BL
 0.370 0.520 0.690 0.460 0.690 

FSV-BM 0.330 0.480 0.620 0.450 0.500 

FSV-BN 0.301 0.434 0.541 0.427 0.567 

FSV-BO 0.324 0.464 0.547 0.450 0.590 

FSV-BR 0.350 0.510 0.650 0.450 0.610 

FSV-BT 0.340 0.495 0.608 0.460 0.703 

FSV-BU 0.353 0.504 0.636 0.348 0.533 

FSV-BV 0.344 0.453 0.548 0.371 0.568 

FSV-BW 0.370 0.520 0.690 0.480 0.770 

FSV-CE 0.300 0.440 0.540 0.380 0.560 

FSV-CG 0.363 0.508 0.582 0.425 0.640 

FSV-CI 0.358 0.513 0.664 0.380 0.547 

FSV-CO 

FSV-CZ 0.383 0.570 0.706 0.487 0.666 

FSV-DD 0.370 0.530 0.680 0.470 0.740 

FSV-DV 0.386 0.539 0.743 0.562 0.674 

FSV-EE

FSV-FK 0.372 0.501 0.651 0.484 0.691 

FSV-FZ 0.328 0.490 0.663 0.467 0.679 

397 398 399 400 401

0.082 0.024 0.075 0.156 0.039 

0.072 0.009 0.022 0.075 0.011 

0.047 0.010 0.032 0.105 0.011 

0.085 0.017 0.023 0.085 0.018 

0.104 0.011 0.028 0.109 0.022 

0.051 0.012 0.041 0.087 0.024 

397 398 399 400 401

9.65 7.03 10.91 19.9 5.38 

9.12 6.83 10.55 18.8 5.14 

9.50 8.00 10.60 18.2 6.40

7.92 6.20 10.34 19.6 4.53 

8.50 6.90 10.50 20.2 5.00

8.20 6.49 10.30 18.3 5.10 

7.72 6.30 10.38 21.0 5.36 

7.86 6.23 9.70 18.0 -

9.00 6.90 11.20 18.9 5.60

9.00 7.30 11.10 21.0 5.50

7.57 6.21 9.74 17.6 4.83

8.49 6.89 11.11 20.5 5.43 

10.40 7.00 10.30 18.0 6.70

8.86 6.88 9.86 18.4 5.21 

9.82 6.68 10.37 19.0 5.72 

8.42 6.32 8.95 14.9 4.49 

7.24 5.95 9.46 17.0 4.42 

10.15 7.98 11.02 21.3 6.22

5.20 5.24 7.56 11.0 3.61 

8.84 6.70 9.89 18.3 5.58 

7.86 6.70 9.86 19.2 5.26 

8.90 7.11 10.87 20.0 5.37 

7.70 5.80 9.40 18.5 5.40

8.20 6.40 10.10 18.0 4.90

8.67 6.58 10.58 19.7 5.25 

397 398 399 400 401

4.96 2.06 1.65 2.71 1.53 

4.29 1.84 1.41 2.33 1.31 

3.33 1.51 1.22 1.95 1.09

4.02 1.93 1.46 2.27 1.48

4.10 1.83 1.40 2.43 1.42

3.33 1.59 1.29 2.13 1.19

3.46 1.65 1.52 2.50 1.48 

4.60 1.74 1.35 2.18 1.43

4.44 1.76 1.30 1.96 1.20

3.98 1.71 1.24 2.09 1.25

2.70 1.66 1.29 1.51 1.06 

3.08 1.30 1.00 1.64 1.02

4.45 2.06 1.58 2.59 1.48

3.45 1.58 1.22 1.88 0.99

4.00 1.68 1.44 2.45 1.27

0

0

0

0

N 26 26 26 26 25 6 6 6 6 6 25 25 25 25 24 15 15 15 15 15 

Min 0.480 0.300 0.434 0.530 0.348 0.047 0.009 0.022 0.075 0.011 5.20 5.24 7.56 11.0 3.61 2.70 1.30 1.00 1.51 0.99 0

Median 0.664 0.348 0.500 0.637 0.460 0.077 0.012 0.030 0.096 0.020 8.50 6.70 10.34 18.8 5.31 4.00 1.71 1.35 2.18 1.27 0

Max 0.770 0.386 0.570 0.743 0.562 0.104 0.024 0.075 0.156 0.039 10.40 8.00 11.20 21.3 6.70 4.96 2.06 1.65 2.71 1.53 0

eSD 0.075 0.024 0.029 0.042 0.036 0.025 0.003 0.011 0.018 0.009 0.92 0.49 0.72 1.2 0.42 0.81 0.18 0.16 0.37 0.27 0

eCV 11 7 6 7 8 33 26 37 19 46 11 7 7 7 8 20 10 12 17 21 

Npast 39 31 32 32 0 12 7 8 10 0 38 31 32 32 0 21 18 18 19 0 

Medianpast 0.675 0.358 0.508 0.653 0.158 0.011 0.026 0.094 8.37 6.81 10.30 18.7 3.91 1.81 1.41 2.22 0

SDpast 0.056 0.029 0.044 0.055 0.092 0.005 0.009 0.027 0.58 0.56 0.78 1.5 0.42 0.16 0.12 0.20 0

NAV 0.348 0.500 0.637 0.460 0.664 0.012 0.030 0.096 0.020 0.077 6.70 10.34 18.8 5.31 8.50 1.71 1.35 2.18 1.27 4.00 

0

NAU 0.029 0.040 0.051 0.037 0.075 0.011 0.013 0.025 0.011 0.025 0.57 0.92 0.80 1.5 0.49 0.18 0.16 0.37 0.27 0.81 

All Lab Report 
Round Robin LXXIV Laboratory Results 

Total β-Carotene, μg/mL trans-β-Carotene, μg/mL Total cis-β-Carotene, μg/mL Total α-C

C3

Lab 397 398 399 400 401 397 398 399 400 401 397 398 399 400 401 397 398 

FSV-BA 0.099 0.245 0.425 0.060 0.303 0.089 0.234 0.403 0.051 0.287 0.010 0.016 0.011 0.022 0.009 0.008 0.38 

FSV-BB 0.091 0.227 0.361 0.049 0.328 0.086 0.219 0.347 0.046 0.317 0.005 0.011 0.008 0.014 0.004 0.005 0.40 

FSV-BC

FSV-BD

FSV-BE 0.081 0.257 0.427 0.042 0.253 

FSV-BF 0.078 0.262 0.379 0.053 0.219 

FSV-BG 0.100 0.259 0.450 0.054 0.398 0.009 

0.37 

FSV-BJ 0.49 nq 

FSV-BK

FSV-BL

FSV-BM

FSV-BN

0.062 0.261 0.504 0.067 0.348 

0.076 0.234 0.393 0.040 0.348 0.011 0.53 

FSV-BO 0.090 0.215 0.314 0.050 0.475 0.005 

0.41 

FSV-BR

FSV-BT 0.099 0.246 0.396 0.057 0.311 0.093 0.231 0.376 0.053 0.298 0.006 0.013 0.015 0.020 0.004 0.008 

0.34 

FSV-BU 0.087 0.240 0.395 0.064 0.365 0.008 

0.43 

FSV-BV 0.093 0.235 0.384 0.050 0.368 0.009 

0.53 

FSV-BW 0.089 0.243 0.464 0.040 0.214 0.009 

0.64 

FSV-CE 0.120 0.250 0.460 0.080 0.230 

FSV-CG 0.002 nd 0.002 nd nd 0.46 nq 

FSV-CI

0.062 0.162 0.231 0.033 0.265 0.062 0.160 0.231 0.033 0.263 

0.079 0.231 0.412 0.055 0.308 0.011 0.48 

FSV-CO 0.094 0.251 0.404 0.057 0.421 0.008 

0.46 

FSV-CZ 0.060 0.120 0.175 0.053 0.217 

FSV-DD

FSV-DV

FSV-EE

FSV-FK 0.097 0.196 0.334 0.046 0.228 

FSV-FZ 0.098 0.247 0.412 0.052 0.367 

N 19 19 19 19 19 4 4 4 4 4 4 3 4 3 3 13 11 

Min 0.214 0.060 0.120 0.175 0.033 0.263 0.062 0.160 0.231 0.033 0.002 0.005 0.002 0.014 0.004 0.34 0.005 

Median 0.311 0.090 0.243 0.396 0.053 0.293 0.087 0.225 0.362 0.048 0.012 0.006 0.010 0.020 0.004 0.46 0.008 

Max 0.475 0.120 0.262 0.504 0.080 0.317 0.093 0.234 0.403 0.053 0.016 0.010 0.015 0.022 0.009 0.64 0.011 

eSD 0.085 0.013 0.018 0.046 0.006 0.022 0.005 0.011 0.042 0.005 0.004 0.005 0.09 0.001 

eCV 27 15 7 12 12 8 6 5 12 11 31 51 20 19 

Npast 27 21 22 22 0 9 7 7 8 0 7 5 6 6 0 23 15 

Medianpast 0.475 0.090 0.240 0.396 0.450 0.083 0.216 0.348 0.019 0.005 0.013 0.018 0.41 0.008 

SDpast 0.089 0.013 0.032 0.068 0.075 0.006 0.026 0.061 0.014 0.003 0.004 0.005 0.08 0.004 

NAV

NAU
 

0.311 0.090 0.243 0.396 0.053 

0.085 0.016 0.036 0.056 0.011 

0.293 0.087 0.225 0.362 0.048 0.012 0.006 0.010 0.020 0.004 0.46 0.008 

0.11 0.004 

All Lab Report 
 

Round Robin LXXIV Laboratory Results 

Total Lycopene, μg/mL trans-Lycopene, μg/mL Total β-Cryptoxanthin, μg/mL Total α-Crypto

C4

Lab 397 398 399 400 401 397 398 399 400 401 397 398 399 400 401 397 398 3

FSV-BA 0.209 0.53 0.85 0.246 0.307 0.111 0.286 0.40 0.120 0.206 0.062 0.068 0.049 0.046 0.067 0.024 0.0.051 

FSV-BB 0.210 0.55 0.80 0.228 0.335 0.096 0.248 0.33 0.097 0.190 0.049 0.054 0.038 0.032 0.056 0.018 0.0.043 

FSV-BC

FSV-BD

FSV-BE

FSV-BF

FSV-BG 0.224 0.59 1.00 0.253 0.358 0.126 0.319 0.48 0.130 0.251 0.052 0.056 0.040 0.035 0.057 

FSV-BJ nq nq 0.034 nq nq 

FSV-BK

FSV-BL

FSV-BM

FSV-BN

0.211 0.59 1.47 0.308 0.341 

0.262 0.75 1.14 0.309 0.440 0.050 0.046 0.025 0.029 0.045 

FSV-BO 0.206 0.48 0.64 0.234 0.300 0.038 0.034 0.014 0.020 0.035 

FSV-BR

FSV-BT 0.135 0.34 0.53 0.162 0.201 0.117 0.299 0.46 0.137 0.177 0.031 0.031 0.026 0.020 0.038 0.013 0.

0.024 

FSV-BU 0.244 0.65 0.90 0.285 0.369 0.051 0.058 0.032 0.023 0.054 

FSV-BV 0.229 0.59 0.89 0.253 0.427 0.035 0.036 0.017 0.019 0.038 

FSV-BW 0.207 0.54 0.84 0.214 0.273 

FSV-CE

FSV-CG 0.188 0.46 0.62 0.201 0.288 0.095 0.240 0.28 0.099 0.221 0.043 0.049 0.033 0.030 0.041 

FSV-CI

FSV-CO 0.201 0.57 0.86 0.243 0.374 0.049 0.050 0.029 0.030 0.057 

FSV-CZ

FSV-DD

FSV-DV

FSV-EE

FSV-FK

FSV-FZ

N

Min

Median

Max

eSD

eCV

Npast

Medianpast

SDpast

12 12 12 12 12

0.135 0.34 0.53 0.162 0.201 

0.210 0.56 0.86 0.245 0.338 

0.262 0.75 1.47 0.309 0.440 

0.017 0.05 0.15 0.035 0.055 

16 8 9 17 14 

23 16 16 17 0 

0.223 0.61 0.95 0.352 

0.029 0.09 0.17 0.074 

5 5 5 5 5

0.095 0.240 0.28 0.097 0.177 

0.111 0.286 0.40 0.120 0.206 

0.126 0.319 0.48 0.137 0.251 

0.022 0.049 0.11 0.025 0.024 

12 20 17 27 21 

8 7 8 8 0 

0.115 0.293 0.41 0.246 

0.016 0.048 0.09 0.058 

10 10 11 10 10

0.031 0.031 0.014 0.019 0.035 

0.049 0.049 0.030 0.029 0.049 

0.062 0.068 0.049 0.046 0.067 

0.007 0.013 0.010 0.009 0.012 

24 14 27 32 29 

17 15 16 17 0 

0.052 0.054 0.033 0.058 

0.012 0.017 0.015 0.017 

3 3 

0.013 0.0.024 

0.018 0.0.043 

0.024 0.0.051 

4 5 

0.018 0.0.042 

0.003 0.0.005 

NAV

NAU
 

0.338 0.210 0.56 0.86 0.245 

0.075 0.051 0.11 0.16 0.058 

0.206 0.111 0.286 0.40 0.120 

0.037 0.022 0.052 0.11 0.025 

0.049 0.049 0.049 0.030 0.029 

0.012 0.012 0.013 0.010 0.009 

0.043 0.018 0.

All Lab Report 
 

Round Robin LXXIV Laboratory Results 

Total Lutein, μg/mL Total Zeaxanthin, μg/mL Total Lutein&Zeaxanthin, μg/mL Coenzyme Q10, μg/mL 

Lab 397 398 399 400 401 397 398 399 400 401 397 398 399 400 401 397 398 399 400 401 

FSV-BA 0.182 0.099 0.122 0.151 0.098 

FSV-BB 0.073 0.110 0.159 0.075 0.115 0.039 0.039 0.042 0.039 0.083 0.198 0.112 0.149 0.201 0.114 

FSV-BC

FSV-BD

FSV-BE 1.04 1.14 1.63 0.9

1.18 

FSV-BF

FSV-BG 0.196 0.102 0.136 0.171 0.105
 

FSV-BJ 0.067 0.097 0.152 0.069 0.138 0.87 0.82 0.93 0.9

1.19 

FSV-BK

FSV-BL

FSV-BM

FSV-BN 0.228 0.111 0.108 0.133 0.084 

FSV-BO 0.213 0.123 0.139 0.166 0.115 0.105 0.115 0.135 0.092 0.195 0.018 0.024 0.031 0.023 0.018 0.83 0.97 1.17 0.8

0.86 

FSV-BR

FSV-BT 0.079 0.082 0.103 0.068 0.128 0.032 0.025 0.024 0.027 0.069 0.197 0.111 0.107 0.127 0.095 0.78 1.03 1.83 0.8

1.02 

FSV-BU 0.193 0.134 0.129 0.181 0.098 

FSV-BV 0.261 0.134 0.139 0.156 0.117 

FSV-BW 0.56 0.72 0.79 0.2

0.27 

FSV-CE

FSV-CG 0.212 0.143 0.137 0.142 0.114 

FSV-CI 0.196 0.090 0.095 0.119 0.081 0.064 0.080 0.104 0.063 0.130 0.026 0.015 0.015 0.018 0.066 0.64 0.70 1.04 0.6

0.70 

FSV-CO 0.240 0.109 0.122 0.138 0.094 

FSV-CZ 1.02 1.42 2.02 1.1

1.32 

FSV-DD

FSV-DV

FSV-EE 0.87 1.02 1.35 0.8

0.98 

FSV-FK

FSV-FZ

C5

N 5 5 5 5 5 4 4 4 4 4 11 11 11 11 11 8 8 8 8 

Min 0.115 0.064 0.080 0.103 0.063 0.018 0.018 0.015 0.015 0.018 0.182 0.090 0.095 0.119 0.081 0.27 0.56 0.70 0.79 0.2

Median 0.130 0.073 0.097 0.135 0.069 0.068 0.029 0.025 0.028 0.025 0.198 0.111 0.129 0.151 0.098 1.00 0.85 0.99 1.26 0.8

Max 0.195 0.105 0.115 0.159 0.092 0.083 0.039 0.039 0.042 0.039 0.261 0.143 0.149 0.201 0.117 1.32 1.04 1.42 2.02 1.1

eSD 0.012 0.009 0.022 0.036 0.009 0.012 0.010 0.007 0.012 0.007 0.021 0.017 0.015 0.027 0.021 0.27 0.18 0.24 0.52 0.1

eCV 9 13 23 27 13 18 34 30 43 27 11 15 11 18 22 27 21 24 41 1

Npast 11 8 8 9 0 9 7 9 7 0 18 16 17 17 0 8 8 9 9 

Medianpast 0.146 0.078 0.090 0.121 0.081 0.035 0.030 0.027 0.215 0.111 0.127 0.147 1.03 0.87 0.96 1.38

SDpast 0.026 0.017 0.020 0.024 0.017 0.013 0.013 0.013 0.033 0.021 0.035 0.037 0.23 0.07 0.07 0.20

NAV

NAU 

0.130 0.073 0.097 0.135 0.069 0.068 0.029 0.025 0.028 0.025 0.198 0.111 0.129 0.151 0.098 1.00 0.85 0.99 1.26 0.8

0.024 0.015 0.022 0.036 0.014 0.041 0.023 0.027 0.032 0.021 0.27 0.18 0.24 0.52 0.1

All Lab Report 
 

 

 

Term 

N 

Min 

Median 

Max 

SD 

CV 

Npast 

Medianpast 

SDpast 

NIST 

NAV 

NAU 

-

nd 

nq 

italics

Round Robin LXXIV Laboratory Results 

Table 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 

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

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

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

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

 Pooled SD from past RR(s)

 Mean of NIST results 

 NIST Assigned Value

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

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

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.

 Not analyzed

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

 Detected but not quantitatively determined

 Not explicitly reported but calculated by NIST from reported values

C6
 

All Lab Report Page 5 / 6 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Lab 

FSV-BA 

FSV-BB 

FSV-BC 

FSV-BD 

FSV-BE 

FSV-BF 

FSV-BG 

FSV-BJ 

FSV-BK 

FSV-BL 

FSV-BM 

FSV-BN 

FSV-BO 

FSV-BR 

FSV-BT 

FSV-BU 

FSV-BV 

FSV-BW 

FSV-CE 

FSV-CG 

FSV-CI 

FSV-CO 

FSV-CZ 

FSV-DD 

FSV-DV 

FSV-FK 

FSV-FZ 

n 

Round Robin LXXIV Laboratory Results 

Comparability Summary 

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

1 1 2 1 1 1 2 1 

1 1 1 1 1 1 1 1 1 

1 

1 2 

1 1 1 1 

2 1 1 

1 1 1 1 1 1 1 1 

1 1 1 2 2 1 

2 1 

1 1 

2 1 

2 1 1 2 2 1 1 

2 1 1 2 1 1 2 2 1 

1 2 

1 1 1 1 1 2 2 1 1 

2 1 1 1 1 1 1 1 

2 2 1 1 1 1 2 1 

1 2 1 2 2 1 

2 2 2 

1 4 2 3 1 1 1 

2 1 2 1 2 1 1 

1 2 1 1 1 1 1 

2 1 1 3 

1 

2 2 

1 1 1 

1 1 1 1 

26 25 15 19 11 12 10 5 11 

Label 

Lab 

TR 

aT 

g/bT 

bC 

aC 

TLy 

TbX 

TLu 

L&Z 

n 

% 1 

% 2 

% 3 

% 4 

Definition 

Participant code 

Total Retinol 

α-Tocopherol 

γ/β-Tocopherol 

Total β-Carotene 

Total α-Carotene 

Total Lycopene 

 Total β-Cryptoxanthin 

Total Lutein 

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: 

∑ 

= 





 MINIMUM 4,INTEGER 1 

Nyou You 

i 1 

% 1 58 72 73 68 73 75 60 80 100 

+ C2 + AP2 



 





 







− 

CS = TR aT g/bT bC aC TLy TbX TLu L&Z 

Median i i

% 2 42 24 27 21 27 25 40 20 0 NAU i % 3 0 0 0 11 0 0 0 0 0 C = Concordance = 

N % 4 0 4 0 0 0 0 0 0 0 you 



 





N 

Youi 

NAU 

− M

AP = Apparent Precision = 

i 

1 

edian 

i 

− 



 



 

NAU = NIST Assigned Uncertainty 

you 

For further details, please see 

1i 

you

∑ 

= 

N 2

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. 

C7
 

All Lab Report Page 6 / 6 
 

 

 

 

Appendix D. Representative Individualized Report for RR74 

Each participant in RR74 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 

• Total α-Carotene 

• Total Lycopene 

• trans-Lycopene 

• Total β-Cryptoxanthin 

• Total Lutein 

• Total Lutein & Zeaxanthin 

• Coenzyme Q10 

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

participant FSV-BA. 

D1
	
 

D2

 Set 6 of 28

Individualized Round Robin LXXIV Report: FSV-BA

Summary 

Serum 397 Serum 398 Serum 399 Serum 400 

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

Total Retinol 0.744 0.664 26 0.345 0.348 26 0.499 0.500 26 0.637 0.637 26 

Retinyl Palmitate 0.08 0.08 6 0.0 0.0 6 0.1 0.0 6 0.16 0.10 6 

α-Tocopherol 9.65 8.50 25 7.03 6.70 25 10.91 10.34 25 19.92 18.77 25 

γ/β-Tocopherol 4.963 4.000 15 2.063 1.710 15 1.648 1.353 15 2.714 2.182 15 

δ-Tocopherol 0.848 0.559 4 0.089 0.089 3 0.078 0.078 3 0.241 0.201 3 

Total β-Carotene 0.303 0.311 19 0.099 0.090 19 0.245 0.243 19 0.425 0.396 19 

trans-β-Carotene 0.287 0.293 4 0.089 0.087 4 0.234 0.225 4 0.403 0.362 4 

Total cis-β-Carotene 0.016 0.012 4 0.010 0.006 3 0.011 0.010 4 0.022 0.020 3 

Total α-Carotene 0.382 0.459 13 0.008 0.008 11 0.028 0.031 11 0.017 0.017 11 

Total Lycopene 0.307 0.338 12 0.209 0.210 12 0.532 0.557 12 0.849 0.856 12 

trans-Lycopene 0.206 0.206 5 0.111 0.111 5 0.286 0.286 5 0.399 0.399 5 

Total β-Cryptoxanthin 0.067 0.049 10 0.062 0.049 10 0.068 0.049 11 0.049 0.030 10 

Total α-Cryptoxanthin 0.051 0.043 3 0.024 0.018 3 0.031 0.022 3 0.026 0.019 3 

Total Lutein&Zeaxanthin 0.182 0.198 11 0.099 0.111 11 0.122 0.129 11 0.151 0.151 11 

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

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

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

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

Micronutrients Measurement Quality Assurance Program

National Institute of Standards and Technology 

100 Bureau Drive Stop 8392 

Gaithersburg, MD 20899-8392 USA Email: 

Individualized Report 
 

 Set 6 of 28 

Individualized RR LXXIV Report: FSV-BA

Total Retinol, μg/mL 

[Analyte], μg/mL

Your [Analyte], μg/mL 

Median [Analyte], μg/mL 

224392397357365375389398358364374386399359363373379400401 

Apparent Precision, SD 

Apparent Precision, SD 

Long-term Precision, SD Concordance, SD 

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

Median (50%) You, past RRs 

1st Quartile (25%) Expectation 

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 

#397 Lyophilized, augmented, multi-donor 38#224, 73#392 

#398 Fresh-frozen, native, multi-donor: SRM 968e I 66#357, 67#365, 69#375, 72#389 

#399 Fresh-frozen, native, multi-donor: SRM 968e II 66#358, 67#364, 69#374, 71#386 

#400 Fresh-frozen, native, multi-donor: SRM 968e III 66#359, 67#363, 69#373, 70#379 

#401 Fresh-frozen, native, multi-donor Initial distribution 

You, ≥x, past RRs Others, this RR 

Individualized Report D3 Page 2 / 12 
 

 Set 6 of 28 

Individualized RR LXXIV Report: FSV-BA

Retinyl Palmitate, μg/mL Your [Analyte], μg/mL 

Apparent Precision, SD 

[Analyte], μg/mL

Median [Analyte], μg/mL 

224392397357365375389398358364374386399359363373379400401 

Apparent Precision, SD 

Long-term Precision, SD Concordance, SD 

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

Median (50%) You, past RRs 

1st Quartile (25%) Expectation 

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 

#397 Lyophilized, augmented, multi-donor 38#224, 73#392 

#398 Fresh-frozen, native, multi-donor: SRM 968e I 66#357, 67#365, 69#375, 72#389 

#399 Fresh-frozen, native, multi-donor: SRM 968e II 66#358, 67#364, 69#374, 71#386 

#400 Fresh-frozen, native, multi-donor: SRM 968e III 66#359, 67#363, 69#373, 70#379 

#401 Fresh-frozen, native, multi-donor Initial distribution 

You, ≥x, past RRs Others, this RR 

Individualized Report D4 Page 3 / 12 
 

 Set 6 of 28 

Individualized RR LXXIV Report: FSV-BA

α-Tocopherol, μg/mL Your [Analyte], μg/mL 

Apparent Precision, SD 

[Analyte], μg/mL

Median [Analyte], μg/mL 

224392397357365375389398358364374386399359363373379400401 

Apparent Precision, SD 

Long-term Precision, SD Concordance, SD 

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

Median (50%) You, past RRs 

1st Quartile (25%) Expectation 

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 

#397 Lyophilized, augmented, multi-donor 38#224, 73#392 

#398 Fresh-frozen, native, multi-donor: SRM 968e I 66#357, 67#365, 69#375, 72#389 

#399 Fresh-frozen, native, multi-donor: SRM 968e II 66#358, 67#364, 69#374, 71#386 

#400 Fresh-frozen, native, multi-donor: SRM 968e III 66#359, 67#363, 69#373, 70#379 

#401 Fresh-frozen, native, multi-donor Initial distribution 

You, ≥x, past RRs Others, this RR 

Individualized Report D5 Page 4 / 12 
 

 Set 6 of 28 

Individualized RR LXXIV Report: FSV-BA

γ/β-Tocopherol, μg/mL 

[Analyte], μg/mL

Your [Analyte], μg/mL 

Median [Analyte], μg/mL 

224392397357365375389398358364374386399359363373379400401 

Apparent Precision, SD 

Apparent Precision, SD 

Long-term Precision, SD Concordance, SD 

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

Median (50%) You, past RRs 

1st Quartile (25%) Expectation 

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 

#397 Lyophilized, augmented, multi-donor 38#224, 73#392 

#398 Fresh-frozen, native, multi-donor: SRM 968e I 66#357, 67#365, 69#375, 72#389 

#399 Fresh-frozen, native, multi-donor: SRM 968e II 66#358, 67#364, 69#374, 71#386 

#400 Fresh-frozen, native, multi-donor: SRM 968e III 66#359, 67#363, 69#373, 70#379 

#401 Fresh-frozen, native, multi-donor Initial distribution 

You, ≥x, past RRs Others, this RR 

Individualized Report D6 Page 5 / 12 
 

 Set 6 of 28 

Individualized RR LXXIV Report: FSV-BA

Total β-Carotene, μg/mL Your [Analyte], μg/mL 

Apparent Precision, SD 

[Analyte], μg/mL

Median [Analyte], μg/mL 

224392397357365375389398358364374386399359363373379400401 

Apparent Precision, SD 

Long-term Precision, SD Concordance, SD 

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

Median (50%) You, past RRs 

1st Quartile (25%) Expectation 

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 

#397 Lyophilized, augmented, multi-donor 38#224, 73#392 

#398 Fresh-frozen, native, multi-donor: SRM 968e I 66#357, 67#365, 69#375, 72#389 

#399 Fresh-frozen, native, multi-donor: SRM 968e II 66#358, 67#364, 69#374, 71#386 

#400 Fresh-frozen, native, multi-donor: SRM 968e III 66#359, 67#363, 69#373, 70#379 

#401 Fresh-frozen, native, multi-donor Initial distribution 

You, ≥x, past RRs Others, this RR 

Individualized Report D7 Page 6 / 12 
 

 Set 6 of 28 

Individualized RR LXXIV Report: FSV-BA

Total α-Carotene, μg/mL Your [Analyte], μg/mL 

Apparent Precision, SD 

[Analyte], μg/mL

Median [Analyte], μg/mL 

224392397357365375389398358364374386399359363373379400401 

Apparent Precision, SD 

Long-term Precision, SD Concordance, SD 

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

Median (50%) You, past RRs 

1st Quartile (25%) Expectation 

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 

#397 Lyophilized, augmented, multi-donor 38#224, 73#392 

#398 Fresh-frozen, native, multi-donor: SRM 968e I 66#357, 67#365, 69#375, 72#389 

#399 Fresh-frozen, native, multi-donor: SRM 968e II 66#358, 67#364, 69#374, 71#386 

#400 Fresh-frozen, native, multi-donor: SRM 968e III 66#359, 67#363, 69#373, 70#379 

#401 Fresh-frozen, native, multi-donor Initial distribution 

You, ≥x, past RRs Others, this RR 

Individualized Report D8 Page 7 / 12 
 

 Set 6 of 28 

Individualized RR LXXIV Report: FSV-BA

Total Lycopene, μg/mL Your [Analyte], μg/mL 

Apparent Precision, SD 

[Analyte], μg/mL

Median [Analyte], μg/mL 

224392397357365375389398358364374386399359363373379400401 

Apparent Precision, SD 

Long-term Precision, SD Concordance, SD 

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

Median (50%) You, past RRs 

1st Quartile (25%) Expectation 

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 

#397 Lyophilized, augmented, multi-donor 38#224, 73#392 

#398 Fresh-frozen, native, multi-donor: SRM 968e I 66#357, 67#365, 69#375, 72#389 

#399 Fresh-frozen, native, multi-donor: SRM 968e II 66#358, 67#364, 69#374, 71#386 

#400 Fresh-frozen, native, multi-donor: SRM 968e III 66#359, 67#363, 69#373, 70#379 

#401 Fresh-frozen, native, multi-donor Initial distribution 

You, ≥x, past RRs Others, this RR 

Individualized Report D9 Page 8 / 12 
 

 Set 6 of 28 

Individualized RR LXXIV Report: FSV-BA

trans-Lycopene, μg/mL 

[Analyte], μg/mL

Your [Analyte], μg/mL 

224392397357365375389398358364374386399359363373379400401

Median [Analyte], μg/mL 

Apparent Precision, SD 

Apparent Precision, SD 

Long-term Precision, SD Concordance, SD 

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

Median (50%) You, past RRs 

1st Quartile (25%) Expectation 

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 

#397 Lyophilized, augmented, multi-donor 38#224, 73#392 

#398 Fresh-frozen, native, multi-donor: SRM 968e I 66#357, 67#365, 69#375, 72#389 

#399 Fresh-frozen, native, multi-donor: SRM 968e II 66#358, 67#364, 69#374, 71#386 

#400 Fresh-frozen, native, multi-donor: SRM 968e III 66#359, 67#363, 69#373, 70#379 

#401 Fresh-frozen, native, multi-donor Initial distribution 

You, ≥x, past RRs Others, this RR 

Individualized Report D10 Page 9 / 12 
 

 Set 6 of 28 

Individualized RR LXXIV Report: FSV-BA

Total β-Cryptoxanthin, μg/mL 

[Analyte], μg/mL

Your [Analyte], μg/mL 

Median [Analyte], μg/mL 

224392397357365375389398358364374386399359363373379400401 

Apparent Precision, SD 

Apparent Precision, SD 

Long-term Precision, SD Concordance, SD 

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

Median (50%) You, past RRs 

1st Quartile (25%) Expectation 

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 

#397 Lyophilized, augmented, multi-donor 38#224, 73#392 

#398 Fresh-frozen, native, multi-donor: SRM 968e I 66#357, 67#365, 69#375, 72#389 

#399 Fresh-frozen, native, multi-donor: SRM 968e II 66#358, 67#364, 69#374, 71#386 

#400 Fresh-frozen, native, multi-donor: SRM 968e III 66#359, 67#363, 69#373, 70#379 

#401 Fresh-frozen, native, multi-donor Initial distribution 

You, ≥x, past RRs Others, this RR 

Individualized Report D11 Page 10 / 12 
 

 Set 6 of 28 

Individualized RR LXXIV Report: FSV-BA

Total Lutein&Zeaxanthin, μg/mL 

[Analyte], μg/mL

Your [Analyte], μg/mL 

224392397357365375389398358364374386399359363373379400401

Median [Analyte], μg/mL 

Apparent Precision, SD 

Apparent Precision, SD 

Long-term Precision, SD Concordance, SD 

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

Median (50%) You, past RRs 

1st Quartile (25%) Expectation 

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 

#397 Lyophilized, augmented, multi-donor 38#224, 73#392 

#398 Fresh-frozen, native, multi-donor: SRM 968e I 66#357, 67#365, 69#375, 72#389 

#399 Fresh-frozen, native, multi-donor: SRM 968e II 66#358, 67#364, 69#374, 71#386 

#400 Fresh-frozen, native, multi-donor: SRM 968e III 66#359, 67#363, 69#373, 70#379 

#401 Fresh-frozen, native, multi-donor Initial distribution 

You, ≥x, past RRs Others, this RR 

Individualized Report D12 Page 11 / 12 
 Set 6 of 29

Individualized Round Robin LXXIV Report: FSV-BA 

Graphical Comparability Summary
 

Total Retinol α-Tocopherol Total β-Carotene To

D13

Retinyl palmitate γ/β-Tocopherol Total Lutein tra

Total α-Carotene Total β-Cryptoxanthin Total Lutein&Zeaxanthin Co

[ILR7/17/2014 
 

 

 

 

Appendix E. Shipping Package Inserts for RR39 

The following three items were included in each package shipped to an RR39 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
	
June 1, 2013 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standards and Technology 

Gaithersburg. Maryland 20899-

The samples within this package constitute Vitamin C Round Robin 39 (RR.39) of the 2013 

Micronutrients Measurement Quality Assurance Program. RR.39 consists of one vial each of 

four frozen se~ test samples (#391, #392 #393, and #394) 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 vohim.es of 10% ~A to ~piked human serum. We have checked the samples for 

stapility and homogen~ity. Oply totai ascorbic acid is stable. While these samp!es contain some 

d~hydroasc9rbic acic.1, its content is variable. Therefore, only total a5corbic 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 Within this ±10% target range. If your results are significantly outside this range, 

your analysis system may not be suited to the analysis'ofMPA-preserved samples. In this case, 

please do n~t proc~ed to the analysis of the test samples but contact us at 301-975-3120 or 

jbthomas@:hist.gov. 

Jbe test samples and control sera should be defrosted by warming at 20 °C for not more than 10 

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

with any oxidant-contarninateq surface (vials, glassware, etc.) may degrade your measurement 

sy~tem' s performance (SA Margolis and E Park; "Stability of Ascorbic Acid in Solutions in 

Autosarripler Vials", Clinical Chemistry 2001, 47(8), 1463-1464). You should suspect such 

degradation if you observe unustμllly lar~e variation in replicate analyses. 

Please measure the total ascorbic acid in each ampoule in duplicate, reporting in units of μmol/{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 September 30, 2013. 

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

or call me at (301) 975-3120. 

· ce Brown Thomas"· 

rp am Coordinator/Research Chemist 

.AD.alytical Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosure: RR39 Report Form for Control Material and Test Sample Analyses 

NISI E2
 
 

 

 

 

 

 

 

Participant #: Date: 

Vitamin C Round Robin 39
 NIST Micronutrient Measurement Quality Assurance Program
 

Analysis of Control Materials and Test Samples
 

Sample Replicate 1 Replicate 2 Units
 

μmol/L of Sample Control serum CS#3 Target: (15.5 ±1.6) μmol/L 

μmol/L of Sample Control serum CS#4 Target: (46.1 ±4.6) μmol/L 

Test sample #391 μmol/L of Sample 

Test sample #392 μmol/L of Sample 

Test sample #393 μmol/L of Sample 

Test sample #394 μmol/L of Sample 

Were samples frozen upon receipt? Yes | No 

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

If “Other”, please describe: 

Nature of samples you typically analyze: native | MPA-preserved | DTT-preserved | Other 

If “Other”, please describe: 

COMMENTS: 

Please return by September 30 2013 

MMQAP Fax: 301-977-0685 

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

Gaithersburg, MD 20899-8392 

E3
 
 

 

SRM970 Lv1

Sam - 30's

SRM970 Lv2

Sam - 50's

Red

Orange

 

 

Participant #: ________ Date: _____________ 

Vitamin C Round Robin 39
 

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

VitC #392 Liquid frozen (1:1 serum:10% MPA) 

VitC #393 Liquid frozen (1:1 serum:10% MPA) 

VitC #394 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 E4 Email: David.Duewer@NIST.gov 
 

 

 

 

Appendix F. Final Report for RR39 

The following six pages are the final report for RR39 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
	
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

UNITED STATES DEPARTMENT OF COMMERCE
 

National Institute of Standards and Technology
 

Gaithersburg, Maryland 20899-8390 

December 3, 2013 

Dear Colleague: 

Enclosed is the summary report of the results for Round Robin 39 (RR39) for the measurement of total 

ascorbic acid (TAA, ascorbic acid plus dehydroascorbic acid) in human serum. Included in this report are 

a summary of data for all laboratories and an individualized summary of your laboratory’s measurement 

performance. The robust median is used to estimate the consensus value for all samples, the “adjusted 

median absolute deviation from the median” (MADe) is used to estimate the expected standard deviation, 

and we estimate the coefficient of variation (CV) as 100×MADe/median. 

RR39 consisted of four test samples (#391, #392 #393, and #394) and one vial each of two frozen control 

serum control samples (CS #3 and CS #4), and one vial of solid control material (Control) for preparation 

of TAA 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 www.nist.gov/srm; phone: 301-975-6776; fax: 301-948-3730. 

If your measured values do not agree with the certified values, we suggest that you contact us for 

consultation. 

Samples for the 2014 Micronutrients Measurements Quality Assurance Program (MMQAP) will be 

shipped starting January 27, 2014. We will ship the samples for both exercises for each study at the 

same time. Results are due in April for the first study; written feedback will be provided to laboratories in 

May. We will send you a notification around June about the reporting deadline for the second study. 

Please contact us immediately if this schedule is problematic for your laboratory. 

We have completed on-line documentation of data and reports for the MMQAP studies from 1996 to 

2012. For your convenience, enclosed are the links to these documents. Data summaries have been 

altered to ensure confidentiality of identification codes assigned to laboratories. We anticipate that the 

results for Round Robins 73 and 74 Fat-Soluble Vitamins and Carotenoids in Human Serum and Round 

Robins 38 and 39 Ascorbic Acid in Human Serum will be available online by Spring 2014. 

If you have questions or concerns regarding this report, please contact David Duewer at 

david.duewer@nist.gov or me at jbthomas@nist.gov, 301-975-3120, or fax: 301-977-0685. 

Sincerely, 

Jeanice Brown Thomas, M.B.A. David L. Duewer, Ph.D. 

Research Chemist Research Chemometrician 

Chemical Sciences Division Chemical Sciences Division 

Material Measurement Laboratory Material Measurement Laboratory 

Enclosures 

cc: L. C. Sander 

F2
 
 

 

 

 

 

 

 

 

 

MMQAP Comparability Studies (1996 to 2012) 

D.L. Duewer, M.C. Kline, K.E. Sharpless, J.M. Brown Thomas, S.A. Margolis, NIST Micronutrients 

Measurement Quality Assurance Program Winter, Spring, and Fall 1996 Comparability Studies: Results 

for Round Robin XXXVI, XXXVII, and XXXVIII Fat-Soluble Vitamins and Carotenoids in Human 

Serum and Round Robin 9 Ascorbic Acid in Human Serum, NIST Interagency/Internal Report (NISTIR) 

7880-28 

D.L. Duewer, M.C. Kline, K.E. Sharpless, J.M. Brown Thomas, S.A. Margolis, NIST Micronutrients 

Measurement Quality Assurance Program Winter, Spring, and Fall 1997 Comparability Studies: Results 

for Round Robin XXXIX, XL, and XLI Fat-Soluble Vitamins and Carotenoids in Human Serum and 

Round Robin 10 Ascorbic Acid in Human Serum, NIST Interagency/Internal Report (NISTIR) 7880-27 

D.L. Duewer, M.C. Kline, K.E. Sharpless, J.M. Brown Thomas, S.A. Margolis, NIST Micronutrients 

Measurement Quality Assurance Program Winter, Spring, and Fall 1998 Comparability Studies: Results 

for Round Robin XLII, XLIII, and XLIV Fat-Soluble Vitamins and Carotenoids in Human Serum and 

Round Robin 11 Ascorbic Acid in Human Serum, NIST Interagency/Internal Report (NISTIR) 7880-26 

David Lee Duewer, Sam A. Margolis, Katherine E Sharpless, Jeanice M Brown Thomas, NIST 

Micronutrients Measurement Quality Assurance Program Winter and Summer 1999 Comparability 

Studies: Results for Round Robin XLV and XLVI Fat-Soluble Vitamins and Carotenoids in Human 

Serum and Round Robin 12 Ascorbic Acid in Human Serum, NIST Interagency/Internal Report (NISTIR) 

7880-25 

D.L. Duewer, M.C. Kline, K.E. Sharpless, J.M. Brown Thomas, S.A. Margolis, NIST Micronutrients 

Measurement Quality Assurance Program Winter and Summer 2000 Comparability Studies: Results for 

Round Robins XLVII and XLVIII Fat-Soluble Vitamins and Carotenoids in Human Serum and Round 

Robin 13 Ascorbic Acid in Human Serum, NIST Interagency/Internal Report (NISTIR) 7880-24 

D.L. Duewer, K.E. Sharpless, J.M. Brown Thomas, S.A. Margolis, NIST Micronutrients Measurement 

Quality Assurance Program Winter 2001 Comparability Studies: Results for Round Robin XLIX 

Fat-Soluble Vitamins and Carotenoids in Human Serum and Round Robin 14 Ascorbic Acid in Human 

Serum, NIST Interagency/Internal Report (NISTIR) 7880-23 

D.L. Duewer, K.E. Sharpless, J.M. Brown Thomas, S.A. Margolis, NIST Micronutrients Measurement 

Quality Assurance Program Summer 2001 Comparability Studies: Results for Round Robin L Fat-Soluble 

Vitamins and Carotenoids in Human Serum and Round Robin 15 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-22 

D.L. Duewer, K.E. Sharpless, J.M. Brown Thomas, S.A. Margolis, 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. NIST 

Interagency/Internal Report (NISTIR) 7880-21 

D.L. Duewer, M.C. Kline, K.E. Sharpless, J.M. Brown Thomas, S.A. Margolis, NIST Micronutrients 

Measurement Quality Assurance Program Summer 2002 Comparability Studies: Results for Round Robin 

LII Fat-Soluble Vitamins and Carotenoids in Human Serum and Round Robin 17 Ascorbic Acid in 

Human Serum, NIST Interagency/Internal Report (NISTIR) 7880-20 

Cover letter F3 2 / 4
	
 

 

 

 

 

 

 

 

 

 

 

D.L. Duewer, K.E. Sharpless, J.M. Brown Thomas, NIST Micronutrients Measurement Quality 

Assurance Program Winter 2003 Comparability Studies: Results for Round Robin LIII Fat-Soluble 

Vitamins and Carotenoids in Human Serum and Round Robin 18 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-19 

D.L. Duewer, K.E. Sharpless, J.M. Brown Thomas, NIST Micronutrients Measurement Quality 

Assurance Program Summer 2003 Comparability Studies: Results for Round Robin LIV Fat-Soluble 

Vitamins and Carotenoids in Human Serum and Round Robin 19 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-18 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Winter 2004 Comparability Studies: Results for Round Robin LV Fat-Soluble Vitamins and Carotenoids 

in Human Serum and Round Robin 20 Ascorbic Acid in Human Serum, NIST Interagency/Internal 

Report (NISTIR) 7880-17 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Summer 2004 Comparability Studies: Results for Round Robin LVI Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 21 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-16 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Winter 2005 Comparability Studies: Results for Round Robin LVII Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 22 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-15 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Summer 2005 Comparability Studies: Results for Round Robin LVIII Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 23 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-14 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Winter 2006 Comparability Studies: Results for Round Robin LIX Fat-Soluble Vitamins and Carotenoids 

in Human Serum and Round Robin 24 Ascorbic Acid in Human Serum, NIST Interagency/Internal 

Report (NISTIR) 7880-13 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Summer 2006 Comparability Studies: Results for Round Robin LX Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 25 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-12 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Winter 2007 Comparability Studies: Results for Round Robin LXI Fat-Soluble Vitamins and Carotenoids 

in Human Serum and Round Robin 26 Ascorbic Acid in Human Serum, NIST Interagency/Internal 

Report (NISTIR) 7880-11 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Summer 2007 Comparability Studies: Results for Round Robin LXII Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 27 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-10 

Cover letter F4 3 / 4
	
 

 

 

 

 

 

 

 

 

 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Winter 2008 Comparability Studies: Results for Round Robin LXIII Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 28 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-9 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Summer 2008 Comparability Studies: Results for Round Robin LXIV Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 29 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-8 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Winter 2009 Comparability Studies: Results for Round Robin LXV Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 30 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-7 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Summer 2009 Comparability Studies: Results for Round Robin LXVI Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 31 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-6 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Winter 2010 Comparability Studies: Results for Round Robin LXVII Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 32 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-5 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Summer 2010 Comparability Studies: Results for Round Robin LXVIII Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 33 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-4 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Winter 2011 Comparability Studies: Results for Round Robin LXIX Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 34 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-3 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Summer 2011 Comparability Studies Results for Round Robin LXX Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 35 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880-2 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Winter 2012 Comparability Studies Results for Round Robin LXXI Fat-Soluble Vitamins and 

Carotenoids in Human Serum and Round Robin 36 Ascorbic Acid in Human Serum, NIST 

Interagency/Internal Report (NISTIR) 7880 

D.L. Duewer, J.M. Brown Thomas, NIST Micronutrients Measurement Quality Assurance Program 

Summer 2012 Comparability Studies, NIST Interagency/Internal Report (NISTIR) 7880-1 

Cover letter F5 4 / 4
	
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

1 

The NIST MMQAP Vitamin C Round Robin 39 (RR39) 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 RR39 measurements. 

Page “All-Lab” Report 

A tabulation of results and summary statistics for total ascorbic acid [TAA] in the RR39 

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 RR39. 

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 

S39:1 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 

S39:2 Ampouled in late 2009, previously distributed in RRs 32, 33, and 35
	

S39:3 Ampouled in late 2009, previously distributed in RRs 32, 35, and 36
	

S39:4 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 deviations are estimated with the robust median and adjusted median 

absolute deviation (eSD) statistics. 

2)		 There is no evidence for any significant change in the [TAA] level for any of the four test materials. 

3)		 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 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 . 

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

RR38, and RR39 for both the “as reported” and “after calibration” results. Calibration to the control 

materials improves the robust inter-participant estimated coefficient of variation 

eCV = 100*eSD/Median 

from about 9% to about 6%. 

Summary Report F6	 1 / 2
	
 

 

 

Estimated SD (eSD), 

μmol/L 

6 

5 

4 

3 

2 

1 

0 

Reported: Old 

Reported: New 

Calibrated: Old 

Calibrated: New 

CV = 9.0 % 

CV = 5.7 % 

0 20 40 60 

Median, μmol/L 

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

Each open symbol represents the summary statistics for a test sample distributed in RR37 or RR38; 

each solid symbol represents the statistics for a test sample in RR39. 

Summary Report F7 2 / 2
	
 

 

 

 

 

 

Appendix G. “All-Lab Report” for RR39 

The following two pages are the “All-Lab Report” for RR39 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 Ascor

"Round Robin" 39 - Summer 2013

All Lab Report 

Lab Date CS#3 CS#4 S39:1 S39:2 S39:3 S39:4 b a S39:1' S39:2' S39:3' S39

VC-MB 01/08/13 15.5 47.7 8.0 28.4 11.9 67.1 1.05 -0.8 8.4 27.7 12.1 64

VC-MC 17/06/13 15.6 46.7 7.8 26.4 11.0 68.4 1.02 -0.2 7.9 26.1 11.0 67

VC-MG 01/08/13 14.8 46.1 8.3 28.4 11.1 69.6 1.02 -1.1 9.1 28.8 11.9 69

VC-MH 10/07/13 14.9 43.9 8.1 25.4 12.0 64.2 0.95 0.1 8.3 26.6 12.5 67

VC-MI 23/09/13 10.8 43.3 8.3 28.2 6.0 72.6 1.06 -5.7 13.2 31.9 11.0 73

VC-MJ 31/07/13 21.0 51.4 12.3 33.5 17.3 82.7 0.99 5.6 6.7 28.1 11.8 77

VC-MN 30/09/13 14.0 41.0 7.7 24.5 14.7 59.6 0.88 0.3 8.4 27.4 16.4 67

VC-NM 16/09/13 12.3 39.5 7.3 23.6 9.2 59.1 0.89 -1.5 9.9 28.2 12.0 68

VC-NX 03/12/13 15.0 47.2 8.6 28.7 10.1 71.1 1.05 -1.4 9.4 28.6 10.9 68

N 9 9 9 9 9 9 9 9 9 

Average 14.9 45.2 8.5 27.4 11.5 68.2 9.0 28.1 12.2 69

SD 2.8 3.7 1.5 3.0 3.2 7.2 1.8 1.7 1.7 3

Min 10.8 39.5 7.3 23.6 6.0 59.1 6.7 26.1 10.9 64

%25 14.0 43.3 7.8 25.4 10.1 64.2 8.3 27.4 11.0 67

Median 14.9 46.1 8.1 28.2 11.1 68.4 8.4 28.1 11.9 68

%75 15.5 47.2 8.3 28.4 12.0 71.1 9.4 28.6 12.1 69

Max 21.0 51.4 12.3 33.5 17.3 82.7 13.2 31.9 16.4 77

eSD 1.1 3.2 0.4 2.7 1.5 6.2 1.1 1.0 0.9 1

eCV 7 7 5 9 13 9 13 3 8 

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

Total Ascorbic Acid ([TAA]), μmol/L Parameters [TAA]', μmol/L

G

2
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

"Round Robin" 39 - Summer 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 

All Lab Report 
Appendix H. Representative “Individualized Report” for RR39 

Each participant in RR39 received an “Individualized Report” reflecting their reported 

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

“VC-MB”. 

H1
	
 Set 2 of 10 

Vitamin C "Round Robin" 39 Report: Participant VC-MB 

13 28.5 1.3 2.2 

02/26/99 12 S12:2 

03/03/00 13 S13:2 

03/26/01 14 S14:4 

09/05/01 15 S15:2 

12/19/02 18 S18:3 

03/01/04 20 S20:4 

03/02/05 22 S22:4 

05/24/06 25 S25:2 

06/20/08 29 S29:3 

03/07/12 36 S36:3 

08/06/12 37 S37:3 

08/01/13 39 S39:2 

05/24/06 25 S25:3 3 11.3 0.2 0.5 

06/20/08 29 S29:4 

08/01/13 39 S39:3 

08/24/93 04 S04:2 4 67.0 2.6 3.2 

11/26/06 26 S26:3 

11/15/07 28 S28:2 

08/01/13 39 S39:4 

[TAA] mmol/Lsample 

Date RR Sample 

09/25/98 11 S11:1 

02/26/99 12 S12:1 

03/03/00 13 S13:1 

03/26/01 14 S14:3 

09/05/01 15 S15:1 

02/08/02 16 S16:1 

05/01/03 19 S19:4 

03/01/04 20 S20:3 

05/25/05 23 S23:4 

05/24/06 25 S25:1 

06/20/08 29 S29:2 

08/05/09 31 S31:3 

01/14/11 34 S34:1 

08/06/12 37 S37:1 

08/01/13 39 S39:1 

09/25/98 11 S11:2 

Rep1 Rep2 Fadj Mean SDdup 

25.0 25.0 0.5 12.5 0.0 

18.0 18.0 0.5 9.0 0.0 

24.0 24.0 0.5 12.0 0.0 

19.6 19.6 0.5 9.8 0.0 

25.8 23.7 0.5 12.4 0.7 

18.7 18.7 0.5 9.4 0.0 

19.6 19.6 0.5 9.8 0.0 

7.8 10.9 1.0 9.3 2.2 

7.7 7.7 1.0 7.7 0.0 

8.8 8.8 1.0 8.8 0.0 

8.3 7.7 1.0 8.0 0.4 

8.8 8.3 1.0 8.5 0.4 

7.7 7.7 1.0 7.7 0.0 

8.8 0.0 1.0 4.4 6.2 

8.3 7.7 1.0 8.0 0.4 

N Mean SDrepeat SDreprod 

15 9.2 1.7 2.1 

63.0 62.0 0.5 31.3 0.4 

55.0 55.0 0.5 27.5 0.0 

63.0 64.0 0.5 31.8 0.4 

60.9 59.9 0.5 30.2 0.4 

63.0 64.0 0.5 31.8 0.4 

55.8 54.7 0.5 27.6 0.4 

21.7 27.9 1.0 24.8 4.4 

28.4 28.4 1.0 28.4 0.0 

29.4 29.4 1.0 29.4 0.0 

26.8 26.8 1.0 26.8 0.0 

25.8 26.8 1.0 26.3 0.7 

25.8 27.9 1.0 26.8 1.5 

28.4 28.4 1.0 28.4 0.0 

10.8 10.8 1.0 10.8 0.0 

10.8 11.4 1.0 11.1 0.4 

11.9 11.9 1.0 11.9 0.0 

2.3 2.3 28.4 64.7 0.8 

70.7 71.2 1.0 71.0 0.4 

61.4 68.7 1.0 65.0 5.1 

67.1 67.1 1.0 67.1 0.0 

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 
 

 

 

NIST, RR 22

 Set 2 of 10 

Vitamin C "Round Robin" 39 Report: Participant VC-MB 

Total Ascorbic Acid, μmol/mL 

[Total Ascorbic Acid], μmol/L

RR11RR12RR13

RR14RR15RR16RR18RR19RR20RR22RR23RR25RR29RR31RR34RR36RR37RR39

S25:3S29:4S39:3S04:2S26:3S28:2S39:4 

Your [Total Ascorbic Acid], μmol/L 

Median [Total Ascorbic Acid], μmol/L 

Apparent Precision, SD 

Concordance, SD 

3rd Quartile (75%) You, this RR Median (50%) You, past RRs Others, this RR 1st Quartile (25%) 

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

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

Sample Comments 

S39:1 SRM970 Lv I - prepared 1998; distributed in RRs 11,12,13,14,15,16,19,20,23,25,29,31,34,37 

S39:2 SRM970 Lv II - prepared 1998; distributed in RRs 11,12,13,14,15,18,20,22,25,29,36,37 

S39:3 VitC #111 - prepared in 1989; distributed in RRs 25,29 

S39:4 VitC #112 - prepared in 1993; distributed in RRs 4,26,28 

7/17/2014 H3 ILR_RR39_VC-MB.XLS, Page 2 / 2