NISTIR 7880-14 

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 

David L. Duewer 

Jeanice B. Thomas 

 

 

 

 

 

 

NISTIR 7880-14
 

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 

David L. Duewer 

Jeanice B. Thomas 

Chemical Sciences Division 

Materials Measurement Laboratory 

June 2013 

 U.S. Department of Commerce 

Cameron F. Kerry, Acting Secretary 

 National Institute of Standards and Technology 

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

ii
	
 

 

Abstract 

The National Institute of Standards and Technology coordinates the Micronutrients Measurement 

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

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

Summer 2005 MMQAP measurement comparability improvement studies: 1) Round Robin LVIII 

Fat-Soluble Vitamins and Carotenoids in Human Serum and 2) Round Robin 23 Total Ascorbic Acid 

in Human Serum. The materials for both studies were shipped to participants in May 2005; 

participants were requested to provide their measurement results by September 12, 2005. 

Keywords 

Human Serum
	

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

SRM 3276
	

Total Ascorbic Acid
	

iii
	
 

 

 

Table of Contents 

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

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

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

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

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

Round Robin 23: Vitamin C in Human Serum............................................................................... 2
	

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

Appendix A. Shipping Package Inserts for RR58........................................................................ A1
	

Appendix B. Final Report for RR58 .............................................................................................. B1 

Appendix C. “All-Lab Report” for RR58 ...................................................................................... C1
	

Appendix D. Representative “Individualized Report” for RR58 ............................................... D1
	

Appendix E. Shipping Package Inserts for RR23 ......................................................................... E1
	

Appendix F. Final Report for RR23............................................................................................... F1
	

Appendix G. “All-Lab Report” for RR23..................................................................................... G1
	

Appendix H. Representative “Individualized Report” for RR23............................................... 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 LVIII: Fat-Soluble Vitamins and Carotenoids in Human Serum 

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

LVIII comparability study (hereafter referred to as RR58) received two ampoules of SRM 3276 

Carrot Extract in Sunflower Oil, two lyophilized human serum test samples, and three 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 

May 2005. The “carrot oil” ampoules were shipped in the same package, but isolated from the dry 

ice. 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 RR58 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 

1 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

commonly reported analytes. Anonymized results for the “carrot oil” are also included. This 

report is reproduced as Appendix C. 

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

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

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

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

Round Robin 23: Vitamin C in Human Serum 

Participants in the MMQAP Vitamin C in Human Serum Round Robin 23 comparability study 

(hereafter referred to as RR23) received four frozen serum test samples, two frozen control sera, and 

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

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

participants in May 2005. The communication materials included in the sample shipment are 

provided in Appendix E. 

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

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

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

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

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

serum measurements to the same reference standard. 

The final report delivered to every participant in RR23 consists of three documents: 

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

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

reproduced as Appendix F. 

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

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

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

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

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

is reproduced as Appendix H. 

2 
 

 

 

 

References 

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

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

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

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

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

Stability, Intralaboratory Repeatability, and Interlaboratory Reproducibility. Clin Chem 

1996;42(8):1257-1262. 

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

Measurement Quality Assurance Program: Helping Participants Use Interlaboratory Comparison 

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

1999;71(9):1870-1878. 

3 
 

 

 

Appendix A. Shipping Package Inserts for RR58 

The following four items were included in each package shipped to an RR58 participant: 

• Cover letter 

• Datasheet for SRM 3276 carrot Extract in Sunflower Oil 

• Datasheet for serum samples 

• Packing List and Shipment Receipt Confirmation Form 

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

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

the cardboard covering and the foam insulation. 

A1
May 9, 2005 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

NMianlll Institute of Standardll and Technology 

Gaithersburg, Maryland 20899-

Enclosed are two sets of samples for the second fat-soluble vitamins and carotenoids in serum round robin 

study (Round Robin L VIII) for the fiscal year (FY) 05 NIST Micronutrients Measurement Quality· 

Assurance Program. The first set consists of two ampoules of Standard Reference Material (SRM) 

3276 Carrot Extract in Sunflower Oil, which is being prepared as part of a collaborative effort among 

NIST, the Food and Drug Administration (FDA) and the National Institutes of Health's Office of Dietary 

Supplements (NIH/ODS). This material should be refrigerated upon receipt. The material was prepared 

by extracting carrots into sunflower oil and readily dissolves in ethanol. The "carrot oil" was spiked with 

2,6-di-tert-butyl-4-methylphenol (BHT) to a concentration of approximately 670 mg/kg. SRM 2376 was 

ampouled under argon in amber ampoules. Each ampoule contains approximately 1 mL of material. This 

material is very viscous, therefore we recommend that you weigh out your sample for analysis rather than 

relying on an accurate volumetric reading from a pipet. Your results should therefore be best expressed 

as mass fractions (ug/g). 

Please analyze a test portion from each of the two ampoules. We would like you to measure a-carotene, 

P-carotene (total, trans, and any other isomers that you are able to quantify), and tocopherols in this 

material. Also, feel free to report values for any other carotenoids that you see. When reporting your 

results, please submit one value for each analyte from each ampoule. Also, please submit a 

chromatogram of your carrot oil analyses and specify the chromatographic conditions used. 

The second set (Sera 314-318) consists of one vial of each of three liquid-frozen and two lyophilized 

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 your limit of quantification, please 

indicate this result on the form by using NQ (Not Quantified). Results are due to NIST by September 12, 

2005. Results received more than two weeks after the due date will not be included in the summary 

report for this round robin study. The feedback report concerning th,e study will be distributed in October. 

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

reconstitution, samples should be allowed to stand at room temperature under subdued ·light until thawed. 

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

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

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

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

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

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

is greater than 1.0 mL. Water should not be added to the liquid-frozen samples. 

For consistency, we request that laboratories use the following absorptivities (E 1 % 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); P-carotene, 2560 at 450 nm 

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

Please mail or fax your results for Round Robin L VITI and the carrot oil study to: 

Micronutrients Measurement Quality Assurance Program 

NIST 

100 Bureau Drive Stop 8392 

Gaithersburg, MD 20899-8392 

Fax: (301) 977-0685 N•Si 

A2
If you have questions or comments regarding this study, please call me at (301) 975-3120; e-mail me at 

jbthomas@nist.gov; or mail/fax queries to the above address. 

cl 

nice Brown Thom 

Research Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosures 

A3
 

 

 

Participant #: ________ Date: _____________ 

Round Robin LVIII: Carrot Oil 

NIST Micronutrients Measurement Quality Assurance Program 

Analyte Ampoule 1 Ampoule 2 Units* 

α-tocopherol
 

γ/β-tocopherol
 

δ-tocopherol
 

total β-carotene 

trans-β-carotene 

total cis-β-carotene 

9-cis-β-carotene 

13-cis-β-carotene 

15-cis-β-carotene 

total α-carotene 

trans-α-carotene 

Other measurands? 

* we prefer μg/g 

Method: 

Comments: 

Please attach representative chromatogram(s)!
 

Mail: M2QAP 

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

Gaithersburg, MD 20899-8392 12-Sep-2005 Email: David.Duewer@NIST.gov 

A4
 

 

Participant #: ________ Date: _____________ 

Round Robin LVIII: Human Sera 

NIST Micronutrients Measurement Quality Assurance Program 

Analyte 314 315 316 317 318 Units* 

total retinol 

trans-retinol 

didehydroretinol 

retinyl palmitate 

α-tocopherol 

γ/β-tocopherol 

δ-tocopherol 

total β-carotene 

trans-β-carotene 

total cis-β-carotene 

total α-carotene 

total lycopene 

trans-lycopene 

total β-cryptoxanthin 

total α-cryptoxanthin 

total lutein 

total zeaxanthin 

total lutein&zeaxanthin

 total coenzyme Q10 

ubiquinol (QH2) 

ubiquinone (Qox) 

phylloquinone (K1) 

25-hydroxyvitamin D 

Other measurands? 

Were the liquid frozen samples frozen when received? Yes | No 

* we prefer μg/mL 

Comments: 

Mail: M2QAP 

NIST, Stop 8392 

Gaithersburg, MD 20899-8392 

Please return results before 

12-Sep-2005

Fax: 301-977-0685 

Email: David.Duewer@NIST.gov 

A5
 

 

 

Participant #: ________	 Date: _____________ 

Fat-Soluble Vitamins Round Robin LVIII 

NIST Micronutrients Measurement Quality Assurance Program 

Packing List and Shipment Receipt Confirmation Form 

This box contains:	 two ampoules of carrot oil 

one vial each of the following five FSV M2QAP sera 

Serum Form Reconstitute? 

#314 Liquid frozen No 

#315 Liquid frozen No 

#316 

#317 

#318 

Liquid frozen 

Lyophilized 

Lyophilized 

No 

Yes (1 ml H2O) 

Yes (1 ml H2O) 

Please 1) Open the pack immediately 

2) Check that it contains all of the above samples 

3) Check if the ampoules and vials are intact 

4a) Store the carrot oil at 4  ̊C until analysis 

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

5) Complete the following information 

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

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

1) Date this shipment arrived: ___________________________ 

2) Are both carrot oil ampoules and 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 liquid frozen sera arrive frozen? Yes | No 

5a) At what temperature are you storing the carrot oil ampoules? _______  ̊C 

5b) 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 Email: David.Duewer@NIST.gov 

A6
 

 

 

 

Appendix B. Final Report for RR58 

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

•	 Cover letter. 

•	 An information sheet that: 

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

o	 describes the content of the “Individualized” report, 

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

if any, and 

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

participants. 

B1
November 8, 2005 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

NdiDnal lnmmt. af 8'andarde and Technalagy 

Gait.hersburg, Maryland 20899-

Enclosed is the summary report of the results for round robin LVIII (RR58) of the 2005 NIST 

Micronutrients Measurement Quality Assurance Program (M2

QAP) for the fat-soluble vitamins and 

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

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

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

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

exercise and the means from the analyses performed by NIST. 

Data for evaluating laboratory performance in RR58 are provided in the comparability summary (Score 

Card) on page 6 of the All Lab Report. Laboratory comparability is summarized as follows: 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. 

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

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

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

Samples for the first 2006 QA interlaboratory exercise will be shipped starting the last week of 

November 2005. We will send you a reminder via e-mail or fax a week prior to shipment. It is critical 

that you carefully inspect all samples upon arrival and that you promptly confirm to us that they have 

arrived. We will replace samples (lost or damaged in shipment or miss-packaged by us) only for 

participants who report the problem within one calendar week after the package arrives. 

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

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

Sincerely, 

ice Brown Thomas 

Research Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosures 

B2
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

The NIST M2QAP Round Robin LVIII (RR58) report consists of: 

Page
	

1-4 

5a 

5b 

6 

7 

“All Lab” Report
	

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

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

A legend for the above two lists. 

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

“Carrot Oil” results: mean values for all analytes reported by any participant. 

Page “Individualized” Report 

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

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

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

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

Samples. The five sera below were distributed in RR58. 

Serum
	

314 

315 

316 

317 

318 

Description
	

Fresh-frozen, native, multi-donor serum prepared in 

2005. This serum was expected to have moderate to 

high levels of many analytes. 

Fresh-frozen, native, multi-donor serum prepared in 

2005. This serum was prepared as a 77:110 

volumetric blend of sera #314:#316. 

Fresh-frozen, native, multi-donor serum prepared in 

2005. This serum was expected to have low levels 

of most analytes. 

Lyophilized blended serum, a 1:1 blend of the pools 

used to produce SRM 968c Levels I and II. 

Lyophilized blended serum with native carotenoid 

levels, augmented with trans-retinol and 

γ/β-tocopherol; SRM 968c Level I. 

Prior Distributions
	

None 

None 

None 

#248 RR44 (9/98) 

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

#263 RR47 (5/00), #280 RR51 (3/02), 

#304 RR46 (9/04) 

Results 

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

any measurand in either sera #317 nor #318. 

2)		 Relative Accuracy: Sera #314, #315, and #316 were prepared to evaluate the relative accuracy of 

your assays. Serum #314 was prepared from a serum pool known to have relatively high levels of 

many analytes. Serum #316 was prepared from a serum pool known to have relatively low levels of 

most analytes. Serum #315 was prepared as a 77:110 volumetric blend of the two pools. If your 

assay imprecision is small and the response is linear over the range from the low level of #316 to the 

B3
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

M2QAP Fat-Soluble Vitamin: Study LVIII Feedback 

high level of #314, assuming that the blend is equal to the sum of its parts, then the result for #315 

should be 77 187×#314 +110 187×#316 . Likewise, serum #317 was prepared as a 1:1 volumetric 

blend of the pools used to produce SRM 968c Levels I (serum #318) and II (serum #309 in RR57). 

With the same caveats as above (and with greater uncertainty since serum #309 was analyzed in the 

previous RR), the result for #317 should be 1 2×#309 +1 2×#318 . 

The median values for nearly all analytes follow the expected behavior with both blended sera. For 

total β-carotene and total α-carotene, the observed medians for the blends are a bit above the line 

connecting the respective endpoints; however, they are definitively in-between the endpoints. 

However, the behavior of γ/β-tocopherol is unexpected: the median value for #315 is larger than 

either #314 or #316. 

While the level of γ/β-tocopherol is relatively low in all three of these sera, it is well above the level 

where detection problems are expected. We obtain identical results with fluorescence detection as 

with absorbance and with peak height as with peak area, so it is unlikely to be an artifact of 

incomplete chromatographic separation or integration. We have also resolved the two isomers on a 

high-performance column and found that the ratio between the γ- and β-isomers is about the same in 

the two endpoints... and that both isomers are higher in #315 than in either endpoint. It really does 

look like the blending process either made the γ/β more readily extractable or that the relatively high 

level of α-tocopherol in #314 somehow suppresses the extraction of the γ/β. At any rate, we’re 

puzzled. Other ideas and suggestions are most welcome. 

3)		 Community Measurement Performance Characteristics: The graphs on the following four pages 

summarize the among-participant concordance, expected apparent precision, expected overall 

comparability, and number of participants reporting values for all of the “generally-reported” 

analytes. These summary graphs are described in detail in: Duewer DL, Kline MC, Sharpless KE, 

Brown Thomas J. NIST Micronutrients Measurement Quality Assurance Program: Characterizing 

the measurement community’s performance over time. Anal Chem 2000;72(17):4163-4170. 

The following table summarizes our interpretation of the information in these graphics: 

Analyte Comparability Relative to 2003 

Total Retinol		 Holding to slight improvement 

Retinyl palmitate		 Improving 

α-Tocopherol		 Declining after improvement 

γ/β-Tocopherol		 Holding to slight improvement 

Total β-Carotene		 Holding to slight decline 

Total α-Carotene Holding 

Total Lycopene Holding to slight decline 

trans-Lycopene Holding 

Total β-Cryptoxanthin Holding to slight decline 

Total Lutein Holding to slight improvement 

Total Zeaxanthin Holding 

Total Lutein&Zeaxanthin Holding 

We intend to investigate possible causes for the loss of α-tocopherol comparability in the coming 

year. 

B4
B5

M2QAP Fat-Soluble Vitamin: Study LVIII Feedback 

Median Performance, SD96:99 Median Performance, SD96:99 Median Performance, SD96:99 

Number Participants Number Participants Number Participants 

Apparent Imprecision 

|Discordance| 

Expected Deviation 

Number of Participants 

Total Retinol 

2 

40 

1 20 

0 

1986 1989 1992 1995 1998 2001 2004 

0 

Apparent Imprecision 

|Discordance| 

Expected Deviation 

Number of Participants 

Retinyl palmitate 

2 

40 

1 20 

0 

1986 1989 1992 1995 1998 2001 2004 

0 

Apparent Imprecision 

|Discordance| 

Expected Deviation 

Number of Participants 

α-Tocopherol 

2 

40 

1 20 

0 0

1986 1989 1992 1995 1998 2001 2004 
B6

M2QAP Fat-Soluble Vitamin: Study LVIII Feedback 

Median Performance, SD96:99 Median Performance, SD96:99 Median Performance, SD96:99 

Number Participants Number Participants Number Participants 

Apparent Imprecision 

|Discordance| 

Expected Deviation 

Number of Participants 

γ/β-Tocopherol 

2 

40 

1 20 

0 

1986 1989 1992 1995 1998 2001 2004 

0 

Apparent Imprecision 

|Discordance| 

Expected Deviation 

Number of Participants 

Total β-Carotene 

2 

40 

1 20 

0 

1986 1989 1992 1995 1998 2001 2004 

0 

Apparent Imprecision 

|Discordance| 

Expected Deviation 

Number of Participants 

Total α-Carotene 

2 

40 

1 20 

0 0

1986 1989 1992 1995 1998 2001 2004 
B7

M2QAP Fat-Soluble Vitamin: Study LVIII Feedback 

Median Performance, SD96:99 Median Performance, SD96:99 Median Performance, SD96:99 

Number Participants Number Participants Number Participants 

Apparent Imprecision 

|Discordance| 

Expected Deviation 

Number of Participants 

Total Lycopene 

2 

40 

1 20 

0 

1986 1989 1992 1995 1998 2001 2004 

0 

Apparent Imprecision 

|Discordance| 

Expected Deviation 

Number of Participants 

trans-Lycopene 

2 

40 

1 20 

0 

1986 1989 1992 1995 1998 2001 2004 

0 

Apparent Imprecision 

|Discordance| 

Expected Deviation 

Number of Participants 

Total β-Cryptoxanthin 

2 

40 

1 20 

0 0

1986 1989 1992 1995 1998 2001 2004 
B8

M2QAP Fat-Soluble Vitamin: Study LVIII Feedback 

Median Performance, SD96:99 Median Performance, SD96:99 Median Performance, SD96:99 

Number Participants Number Participants Number Participants 

Apparent Imprecision 

|Discordance| 

Expected Deviation 

Number of Participants 

Total Lutein 

2 

40 

1 20 

0 

1986 1989 1992 1995 1998 2001 2004 

0 

Apparent Imprecision 

|Discordance| 

Expected Deviation 

Number of Participants 

Total Zeaxanthin 

2 

40 

1 20 

0 

1986 1989 1992 1995 1998 2001 2004 

0 

Apparent Imprecision 

|Discordance| 

Expected Deviation 

Number of Participants 

Total Lutein&Zeaxanthin 

2 

40 

1 20 

0 0

1986 1989 1992 1995 1998 2001 2004 
 

 

 

 

 

 

 

 

 

 

 

 

M2QAP Fat-Soluble Vitamin: Study LVIII Feedback 

4)		 Carrot oil observations/conclusions: We appreciate the effort that all of you who evaluated the 

“carrot oil” ampoules put into your analyses! About half of you provided some results or reported 

that no results could be obtained using available methods. 

We chose not to provide specific instructions for the analysis of this material to prevent biasing your 

results. We wanted to get an idea of the handling and measurement capabilities for this matrix in the 

hands of experienced analysts. Unsurprisingly, those of you who also participate in our “food” SRM 

value assignment studies reported more complete sets of results than those who do not. We were 

somewhat surprised that more of you did not investigate dissolving the material in ethanol (or 

whatever alcohol is most compatible with your chromatographic liquid phase). This simplistic 

approach generally has worked well for us. 

Also surprisingly, the among-participant variation for the carotenoids was considerably smaller than 

for the tocopherols. We believe much of the scatter in the tocopherol results arises from incomplete 

chromatographic (baseline) separation... and the unusual and unexpected isomer ratios: only a trace 

of α-tocopherol level is present while both the δ- and γ-tocopherols are about 400 μg/g. We strongly 

suspect that the carrier for the carrot-extract is not predominantly “sunflower oil” as stated by the 

supplier. 

We intend to design a second study of this material, both to better characterize the material and to 

evaluate its potential for use as a calibrant. If we do ask you to evaluate this material again, we will 

provide detailed instructions. 

B9
 

 

 

 

 

 

Appendix C. “All-Lab Report” for RR58 

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

exceptions: 

• the participant identifiers (Lab) have been altered. 

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

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

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

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

summary results of the study. 

C1
Round Robin LVIII Serum Results 

All Values in μg/mL 

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

Lab 314 315 316 317 318 

C2

FSV-BA 0.541 0.491 0.384 0.700 0.872 

FSV-BB 0.533 0.486 0.396 0.709 0.868 

FSV-BC 0.565 0.497 0.409 0.697 0.875 

FSV-BD 0.460 0.420 0.360 0.610 0.780 

FSV-BE 0.538 0.481 0.384 0.680 0.880 

FSV-BF 0.534 ,474 0.383 0.700 0.870 

FSV-BG 0.574 0.501 0.383 0.682 0.904 

FSV-BH 0.578 0.491 0.411 0.752 0.885 

FSV-BI 0.493 0.434 0.339 0.571 0.739 

FSV-BJ 0.527 0.477 0.391 0.672 0.836 

FSV-BK 0.643 0.547 0.405 0.675 0.888 

FSV-BL 0.610 0.550 0.440 0.750 1.000 

FSV-BM 0.573 0.486 0.407 0.628 0.894 

FSV-BN 0.558 0.507 0.408 0.724 0.926 

FSV-BO 0.565 0.469 0.387 0.631 0.833 

FSV-BP 0.560 0.480 0.360 0.620 0.800 

FSV-BQ 0.574 0.539 0.403 0.737 0.894 

FSV-BR ≥0.540 ≥0.465 ≥0.415 ≥0.770 ≥0.880

FSV-BS ≥0.384 ≥0.320 ≥0.225 ≥0.529 ≥0.671

FSV-BT 0.536 0.458 0.355 0.661 0.866 

FSV-BU 0.535 0.518 0.402 0.721 0.923 

FSV-BV 0.670 0.605 0.479 0.862 1.089 

FSV-BW 0.530 0.490 0.400 0.660 0.830 

FSV-BX 0.555 0.483 0.370 0.684 0.899 

FSV-CC 0.570 0.510 0.410 0.730 0.910 

FSV-CD ≥0.572 ≥0.505 ≥0.394 ≥0.672 ≥0.842

FSV-CE 0.485 0.434 0.343 0.696 0.850 

FSV-CF 0.577 0.526 0.403 0.763 0.947 

FSV-CG 0.551 0.490 0.374 0.919 0.932 

FSV-CI 0.510 0.452 0.370 0.627 0.797 

FSV-CS 0.541 0.513 0.408 0.674 0.854 

FSV-CT 

FSV-CW 0.546 0.478 0.404 0.687 0.800 

FSV-CZ 0.520 0.480 0.380 0.660 0.850 

FSV-DA 0.537 0.471 0.374 0.644 0.827 

FSV-DB 0.542 0.476 0.356 0.652 0.835 

FSV-DD ≥0.589 ≥0.576 ≥0.438 ≥0.797 ≥1.099

FSV-DF 0.543 0.492 0.393 0.706 0.889 

FSV-DI 0.568 0.517 0.386 0.674 0.858 

FSV-DV 1.210 1.100 0.870 1.530 1.940 

FSV-DW 0.520 0.490 0.380 0.650 0.810 

314 315 316 317 318 

0.540 0.465 0.415 0.770 0.880 

0.384 0.320 0.225 0.529 0.671 

0.570 0.510 0.410 0.690 0.880 

0.572 0.505 0.394 0.672 0.842 

0.537 0.471 0.374 0.644 0.827 

0.589 0.576 0.438 0.797 1.099 

314 315 316 317 318 

0.104 0.051 0.012 0.064 0.039 

0.100 0.045 0.009 0.049 0.024 

0.103 0.056 0.024 0.049 0.041 

0.132 0.058 nd 0.055 0.035 

0.120 0.054 nq 0.057 0.037 

0.093 0.044 0.007 0.048 0.025 

0.121 0.061 nq 0.066 0.041 

0.139 0.072 0.012 0.058 0.027 

0.109 0.052 <0.01 0.054 0.033 

0.112 0.053 0.024 0.056 0.034 

0.091 0.040 0.004 0.040 0.021 

0.100 0.050 0.012 0.053 0.031 

314 315 316 317 318 

15.43 9.28 4.14 11.17 7.20 

16.47 9.29 4.18 12.10 7.71 

15.80 9.70 4.70 12.00 8.00 

17.70 10.00 4.40 13.10 8.40 

15.60 9.50 4.20 11.90 7.80 

17.07 9.80 5.16 12.65 8.89 

17.91 10.53 4.82 13.45 8.31 

14.59 8.53 3.73 10.22 6.53 

17.04 10.03 4.41 12.42 7.91 

16.19 9.26 3.57 10.39 6.99 

14.21 7.75 3.88 10.77 7.32 

15.00 9.80 4.80 11.30 7.60 

14.36 8.71 3.92 11.16 7.09 

14.69 8.31 4.13 10.06 6.85 

10.58 6.93 2.92 12.82 7.51 

13.30 8.00 3.30 9.50 6.10 

16.43 9.73 4.69 11.09 7.02 

15.86 9.78 4.49 10.56 7.41 

16.32 9.91 4.22 12.19 7.79 

16.59 9.90 4.37 11.71 8.15 

14.08 8.77 4.10 10.98 6.95 

16.57 9.35 4.02 12.10 7.82 

14.50 8.84 4.07 11.08 6.91 

17.13 9.76 4.18 12.62 7.28 

16.62 9.76 4.27 10.83 7.66 

14.70 9.40 5.20 11.70 7.80 

13.92 8.14 2.19 10.97 6.36 

15.38 9.37 4.18 11.91 7.24 

17.34 10.38 5.03 12.56 8.70 

19.80 9.25 2.73 12.36 6.85 

14.10 8.70 4.10 11.40 7.70 

16.24 9.62 4.35 11.68 7.31 

16.61 9.70 4.03 11.48 7.57 

16.15 9.63 4.18 12.00 7.37 

15.10 8.70 4.00 8.10 5.00 

22.39 11.36 5.40 12.84 7.66 

314 315 316 317 318 

1.50 1.84 1.75 2.69 3.94 

1.32 1.65 1.63 2.61 3.68 

1.40 1.70 1.70 2.80 4.20 

1.39 1.81 1.77 2.75 4.16 

1.57 1.74 1.75 2.75 4.00 

2.06 2.43 2.37 3.70 5.34 

1.48 1.71 1.69 2.47 3.53 

1.40 1.72 1.68 2.65 3.78 

1.18 1.46 1.44 2.26 3.30 

1.15 1.45 1.23 2.39 5.71 

1.50 1.80 1.73 2.59 3.71 

1.40 1.67 1.67 2.61 3.83 

1.55 1.89 1.83 2.76 4.27 

1.69 2.13 2.20 3.25 4.78 

1.58 1.89 1.74 2.75 4.07 

1.41 1.70 1.59 2.50 3.68 

1.44 1.74 1.67 2.87 3.85 

1.55 1.98 1.73 2.83 3.86 

1.98 2.28 2.42 2.94 4.23 

1.65 1.79 1.75 2.74 3.90 

1.42 1.81 1.76 2.61 3.88 

1.75 2.01 1.72 2.70 3.83 

1.31 1.66 1.61 2.51 3.67 

314 

0.10

0.09

0.13

0.15

0.10

0.07

nq 

0.10

N 36 35 36 36 36 6 6 6 6 6 12 12 8 12 12 36 36 36 36 36 23 23 23 23 23 

Min 0.460 0.420 0.339 0.571 0.739 0.384 0.320 0.225 0.529 0.671 0.091 0.040 0.004 0.040 0.021 10.58 6.93 2.19 8.10 5.00 1.15 1.45 1.23 2.26 3.30 0.07

Median 0.545 0.490 0.389 0.683 0.871 0.555 0.488 0.402 0.681 0.861 0.107 0.053 0.012 0.055 0.034 16.00 9.45 4.18 11.69 7.46 1.48 1.79 1.73 2.70 3.88 0.10

Max 1.210 1.100 0.870 1.530 1.940 0.589 0.576 0.438 0.797 1.099 0.139 0.072 0.024 0.066 0.041 22.39 11.36 5.40 13.45 8.89 2.06 2.43 2.42 3.70 5.71 0.15

SD 0.027 0.025 0.023 0.047 0.049 0.015 0.006 0.005 0.006 0.008 1.44 0.76 0.30 0.93 0.58 0.13 0.14 0.09 0.14 0.32 0.01

CV 5 5 6 7 6 0 0 0 0 0 14 11 42 11 25 9 8 7 8 8 9 8 5 5 8 1

Npast 0 0 0 46 42 0 0 0 0 8 0 0 0 14 13 0 0 0 46 45 0 0 0 23 25 

Medianpast 0.662 0.858 0.839 0.049 0.034 11.55 7.49 2.76 3.83 

SDpast 0.054 0.056 0.041 0.020 0.011 1.05 0.66 0.22 0.34 

NIST 0.557 0.496 0.394 0.681 0.844 15.99 9.42 3.98 12.21 7.52 1.43 1.82 1.72 2.73 4.00 0.10

NNIST 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 

Srep 0.010 0.009 0.005 0.018 0.009 0.21 0.21 0.07 0.12 0.03 0.02 0.03 0.03 0.05 0.05 0.01

Shet 0.003 0.008 0.001 0.033 0.010 0.11 0.05 0.02 0.12 0.15 0.01 0.01 0.03 0.02 0.08 0.00

SNIST 0.010 0.012 0.005 0.037 0.013 0.24 0.22 0.07 0.16 0.15 0.03 0.03 0.04 0.06 0.09 0.01

NAV 0.551 0.493 0.391 0.682 0.858 0.540 0.471 0.410 0.690 0.880 0.104 0.052 0.012 0.054 0.034 16.07 9.41 4.08 11.95 7.54 1.46 1.81 1.73 2.73 3.94 0.10

NAU 0.044 0.040 0.032 0.054 0.070 0.043 0.038 0.033 0.054 0.069 0.027 0.017 0.011 0.017 0.013 1.47 0.79 0.46 0.99 0.62 0.17 0.19 0.19 0.27 0.36 0.02

All Lab Report 
Round Robin LVIII Serum Results 

All Values in μg/mL 

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

Lab 314 315 316 317 318 

C3

FSV-BA 0.604 0.279 0.040 0.314 0.173 

FSV-BB 0.601 0.282 0.042 0.318 0.167 

FSV-BC 

FSV-BD 

FSV-BE 0.631 0.281 0.040 0.350 0.192 

FSV-BF 0.654 0.317 0.034 0.373 0.186 

FSV-BG 0.736 0.355 0.079 0.425 0.195 

FSV-BH 0.685 0.313 0.039 0.370 0.190 

FSV-BI 0.558 0.244 0.036 0.281 0.153 

FSV-BJ 0.593 0.267 0.037 0.319 0.161 

FSV-BK 

FSV-BL 

FSV-BM 

FSV-BN 0.558 0.262 0.042 0.323 0.163 

FSV-BO 0.558 0.212 0.043 0.276 0.139 

FSV-BP 0.279 0.350 nq 0.330 0.170 

FSV-BQ 

FSV-BR 

FSV-BS ≥0.621 ≥0.284 ≥0.064 ≥0.343 ≥0.202

FSV-BT 0.606 0.304 0.044 0.351 0.196 

FSV-BU 0.529 0.269 0.067 0.299 0.174 

FSV-BV 0.661 0.303 0.041 0.341 0.191 

FSV-BW 0.580 0.275 0.036 0.301 0.151 

FSV-BX ≥0.569 ≥0.258 ≥0.034 ≥0.302 ≥0.161

FSV-CC
 

FSV-CD
 0.729 0.298 0.045 0.337 0.169 

FSV-CE 0.684 0.310 0.050 0.292 0.171 

FSV-CF 

FSV-CG 0.571 0.260 0.035 0.319 0.159 

FSV-CI ≥0.613 ≥0.269 ≥0.039 ≥0.285 ≥0.162

FSV-CS 0.701 0.365 0.093 0.389 0.219 

FSV-CT 1.034 0.444 0.060 0.491 0.273 

FSV-CW ≥0.632 ≥0.291 ≥0.023 ≥0.330 ≥0.152

FSV-CZ 0.504 0.260 0.080 0.296 0.180 

FSV-DA 0.794 0.352 0.050 0.340 0.177 

FSV-DB 0.531 0.279 0.033 0.267 0.137 

FSV-DD 

FSV-DF 

FSV-DI 0.600 0.285 0.040 0.335 0.185 

FSV-DV 

FSV-DW 0.806 0.287 0.006 0.294 0.130 

314 315 316 317 318 

0.564 0.260 0.037 0.291 0.161 

0.569 0.267 0.039 0.300 0.157 

0.653 0.295 0.039 0.348 0.177 

0.517 0.242 0.037 0.293 0.150 

0.621 0.284 0.064 0.343 0.202 

0.564 0.284 0.042 0.326 0.183 

0.569 0.258 0.034 0.302 0.161 

0.530 0.241 0.032 0.296 0.147 

0.613 0.269 0.039 0.285 0.162 

0.645 0.335 0.082 0.357 0.200 

0.632 0.291 0.023 0.330 0.152 

0.738 0.326 0.045 0.308 0.158 

314 315 316 317 318 

0.040 0.018 0.003 0.022 0.013 

0.032 0.015 0.003 0.018 0.011 

0.032 0.018 nq 0.023 0.013 

0.044 0.023 0.008 0.033 0.016 

0.044 0.020 0.003 0.026 0.013 

0.041 0.019 0.003 0.023 0.012 

0.056 0.029 0.011 0.032 0.019 

0.057 0.026 0.006 0.032 0.019 

314 315 316 317 318 

0.127 0.057 0.006 0.056 0.015 

0.109 0.051 0.005 0.051 0.011 

0.127 0.059 0.008 0.052 0.016 

0.120 0.062 0.013 0.057 0.018 

0.122 0.053 nq 0.053 nq 

0.120 0.052 0.004 0.049 0.018 

0.119 0.052 0.010 0.052 0.012 

0.119 0.055 0.010 0.057 0.017 

0.132 0.057 nq 0.056 0.010 

0.112 0.029 nq 0.030 nq 

0.138 0.076 0.033 0.079 0.044 

0.121 0.063 0.008 0.061 0.022 

0.110 0.052 0.009 0.049 0.013 

0.096 0.042 0.004 0.040 0.010 

0.165 0.070 nq 0.056 nq 

0.125 0.055 0.009 0.054 0.013 

0.163 0.073 0.014 0.070 0.022 

0.145 0.065 0.006 0.069 0.018 

0.132 0.060 <0.009 0.057 0.024 

0.135 0.065 0.008 0.063 0.017 

0.143 0.069 0.011 0.067 0.022 

0.124 0.054 0.006 0.049 0.014 

0.148 0.056 0.011 0.048 0.016 

314 315 316 317 318 

0.379 0.274 0.165 0.425 0.360 

0.331 0.243 0.150 0.372 0.309 

0.331 0.256 0.150 0.405 0.371 

0.411 0.340 0.197 0.499 0.405 

0.276 0.186 0.114 0.291 0.246 

0.285 0.189 0.121 0.280 0.244 

0.324 0.228 0.146 0.387 0.319 

0.289 0.227 0.134 0.335 0.294 

0.333 0.204 0.173 0.351 0.296 

0.403 0.375 0.217 0.420 0.292 

0.497 0.359 0.257 0.538 0.493 

0.328 0.250 0.153 0.375 0.370 

0.352 0.272 0.189 0.408 0.354 

0.414 0.291 0.167 0.445 0.405 

0.288 0.206 0.125 0.324 0.273 

0.526 0.319 0.150 0.451 0.336 

0.342 0.238 0.128 0.386 0.313 

0.428 0.322 0.202 0.500 0.456 

0.369 0.244 0.120 0.335 0.318 

0.336 0.232 0.144 0.315 0.273 

0.297 0.232 0.138 0.313 0.275 

0.300 0.230 0.160 0.325 0.300 

0.349 0.217 0.157 0.292 0.247 

N 25 25 24 25 25 12 12 12 12 12 8 8 7 8 8 23 23 18 23 20 23 23 23 23 23 

Min 0.279 0.212 0.006 0.267 0.130 0.517 0.241 0.023 0.285 0.147 0.032 0.015 0.003 0.018 0.011 0.096 0.029 0.004 0.030 0.010 0.276 0.186 0.114 0.280 0.244 

Median 0.604 0.285 0.042 0.323 0.173 0.591 0.277 0.039 0.305 0.161 0.043 0.020 0.003 0.025 0.013 0.125 0.057 0.008 0.056 0.017 0.336 0.243 0.150 0.375 0.313 

Max 1.034 0.444 0.093 0.491 0.273 0.738 0.335 0.082 0.357 0.202 0.057 0.029 0.011 0.033 0.019 0.165 0.076 0.033 0.079 0.044 0.526 0.375 0.257 0.538 0.493 

SD 0.094 0.033 0.010 0.038 0.022 0.053 0.024 0.005 0.028 0.017 0.007 0.004 0.003 0.007 0.003 0.012 0.008 0.004 0.007 0.004 0.059 0.041 0.025 0.073 0.061 

CV 16 11 24 12 12 9 9 12 9 10 16 21 100 27 23 10 15 42 12 26 17 17 17 19 19 

Npast 0 0 0 31 30 0 0 0 14 14 0 0 0 10 9 0 0 0 26 26 0 0 0 25 25 

Medianpast 0.317 0.173 0.298 0.160 0.024 0.014 0.053 0.016 0.367 0.307 

SDpast 0.047 0.022 0.039 0.017 0.008 0.006 0.015 0.004 0.088 0.051 

NIST 0.599 0.307 nq 0.315 0.172 0.509 0.256 nq 0.272 0.162 0.090 0.052 nq 0.042 0.010 0.118 0.058 nq 0.059 nq
 

NNIST 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
 

Srep 0.016 0.017 0.013 0.003 0.024 0.009 0.014 0.005 0.020 0.022 0.003 0.003 0.005 0.005 0.005
 

Shet 0.003 0.014 0.007 0.005 0.005 0.000 0.001 0.002 0.008 0.014 0.005 0.007 0.001 0.005 0.000
 

SNIST 0.016 0.022 0.015 0.005 0.024 0.009 0.014 0.005 0.021 0.026 0.006 0.007 0.005 0.007 0.005
 

NAV 0.601 0.295 0.041 0.318 0.173 0.550 0.266 0.039 0.289 0.162 0.066 0.036 0.003 0.033 0.011 0.121 0.057 0.008 0.057 0.016 0.335 0.241 0.152 0.374 0.311 

NAU 0.094 0.045 0.010 0.047 0.027 0.085 0.033 0.008 0.040 0.019 0.040 0.035 0.003 0.015 0.008 0.035 0.017 0.004 0.017 0.006 0.075 0.057 0.039 0.082 0.070 

All Lab Report 
Round Robin LVIII Serum Results 

All Values in μg/mL 

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

Lab 314 315 316 317 318 

C4

FSV-BA 0.063 0.053 0.041 0.065 0.085 

FSV-BB 0.049 0.043 0.032 0.052 0.065 

FSV-BC 

FSV-BD 

FSV-BE 

FSV-BF 0.048 0.045 0.036 0.055 0.078 

FSV-BG 0.050 0.035 0.023 0.042 0.068 

FSV-BH 0.093 0.071 0.047 0.083 0.099 

FSV-BI 0.048 0.042 0.033 0.046 0.065 

FSV-BJ 0.045 0.040 0.035 0.053 0.070 

FSV-BK 

FSV-BL 

FSV-BM 

FSV-BN 0.050 0.045 0.036 0.057 0.076 

FSV-BO 0.053 0.041 0.036 0.053 0.065 

FSV-BP 0.057 0.056 0.020 0.110 0.072 

FSV-BQ 

FSV-BR 

FSV-BS 0.068 0.055 0.042 0.076 0.074 

FSV-BT 0.052 0.044 0.032 0.055 0.074 

FSV-BU 0.051 0.048 0.040 0.055 0.074 

FSV-BV 0.045 0.041 0.032 0.047 0.067 

FSV-BW 0.048 0.035 0.025 0.040 0.053 

FSV-BX 0.045 0.039 0.029 0.044 0.062 

FSV-CC 

FSV-CD 0.064 0.044 0.030 0.058 0.066 

FSV-CE 

FSV-CF 

FSV-CG 0.074 0.061 0.043 0.078 0.093 

FSV-CI 

FSV-CS 0.060 0.051 0.035 0.061 0.076 

FSV-CT 0.050 0.040 0.022 0.047 0.058 

FSV-CW 0.056 0.045 0.035 0.059 0.069 

FSV-CZ 

FSV-DA 0.067 0.054 0.037 0.059 0.073 

FSV-DB 0.061 0.047 0.031 0.039 0.070 

FSV-DD 

FSV-DF 

FSV-DI 

FSV-DV 

FSV-DW 0.082 0.064 0.059 0.067 0.083 

314 315 316 317 318 

0.027 0.018 0.012 0.023 0.027 

0.016 0.012 0.008 0.016 0.017 

0.019 0.015 0.011 0.021 0.024 

0.020 0.013 0.007 0.018 0.019 

0.017 0.015 0.009 0.021 0.022 

0.022 0.015 0.009 0.018 0.020 

314 315 316 317 318 

0.113 0.066 0.025 0.078 0.056 

0.126 0.085 0.039 0.097 0.066 

0.101 0.055 0.015 0.054 0.041 

0.100 0.056 0.017 0.055 0.042 

0.118 0.068 0.026 0.073 0.062 

0.113 0.065 0.028 0.070 0.052 

0.123 0.056 nq 0.057 0.043 

0.078 0.051 0.023 0.063 0.063 

0.136 0.066 0.030 0.076 0.073 

0.102 0.063 0.035 0.061 0.055 

0.111 0.065 0.024 0.067 0.050 

0.111 0.054 nq 0.053 0.044 

0.114 0.065 0.025 0.071 0.052 

0.114 0.067 0.028 0.075 0.058 

0.105 0.057 0.017 0.058 0.050 

0.113 0.037 0.015 0.032 0.014 

314 315 316 317 318 

0.028 0.025 0.024 0.046 0.047 

0.037 0.029 0.018 0.036 0.030 

0.024 0.017 0.013 0.028 0.032 

0.020 0.018 0.014 0.023 0.027 

0.040 0.025 0.015 0.038 0.036 

0.049 nd 0.015 0.025 0.040 

0.031 0.016 0.008 0.020 0.022 

0.035 0.027 0.022 0.033 0.191 

0.030 0.022 0.019 0.026 0.032 

0.022 0.020 0.017 0.023 0.026 

nq nq nq 0.016 0.019 

0.024 0.021 0.017 0.027 0.027 

0.041 0.030 0.021 0.033 0.037 

0.101 0.084 0.080 0.092 0.089 

314 315 316 317 318 

0.149 0.090 0.036 0.104 0.087 

0.141 0.091 0.049 0.124 0.103 

0.140 0.085 0.034 0.100 0.088 

0.142 0.096 0.047 0.111 0.077 

0.125 0.072 0.028 0.082 0.073 

0.120 0.074 0.031 0.078 0.069 

0.153 0.090 0.043 0.108 0.088 

0.172 0.056 nq 0.081 0.083 

0.230 0.120 0.030 0.160 0.083 

0.140 0.087 0.047 0.097 0.085 

0.115 0.069 0.033 0.086 0.089 

0.155 0.085 0.037 0.098 0.091 

0.145 0.086 0.037 0.093 0.089 

0.124 0.067 0.027 0.062 0.059 

0.171 0.093 0.052 0.109 0.264 

0.167 0.092 0.036 0.104 0.092 

0.184 0.110 0.048 0.132 0.117 

0.132 0.085 0.054 0.087 0.087 

0.132 0.085 0.041 0.090 0.076 

≥0.111 ≥0.054 nq 0.069 0.063 

0.138 0.086 0.042 0.098 0.079 

0.155 0.097 0.048 0.108 0.095 

0.159 0.092 0.038 0.099 0.091 

0.214 0.121 0.095 0.124 0.103 

N 24 24 24 24 24 6 6 6 6 6 16 16 14 16 16 13 12 13 14 14 23 23 22 24 24 

Min 0.045 0.035 0.020 0.039 0.053 0.016 0.012 0.007 0.016 0.017 0.078 0.037 0.015 0.032 0.014 0.020 0.016 0.008 0.016 0.019 0.115 0.056 0.027 0.062 0.059 

Median 0.052 0.045 0.035 0.055 0.071 0.020 0.015 0.009 0.020 0.021 0.113 0.064 0.025 0.065 0.052 0.031 0.023 0.017 0.028 0.032 0.145 0.087 0.039 0.098 0.087 

Max 0.093 0.071 0.059 0.110 0.099 0.027 0.018 0.012 0.023 0.027 0.136 0.085 0.039 0.097 0.073 0.101 0.084 0.080 0.092 0.191 0.230 0.121 0.095 0.160 0.264 

SD 0.011 0.009 0.005 0.011 0.008 0.003 0.001 0.002 0.002 0.003 0.008 0.008 0.007 0.013 0.011 0.012 0.006 0.004 0.009 0.009 0.021 0.006 0.010 0.016 0.010 

CV 20 20 14 21 11 13 9 20 11 14 7 12 28 20 22 38 24 25 32 28 14 7 25 16 11 

Npast 0 0 0 27 26 0 0 0 6 5 0 0 0 16 17 0 0 0 15 15 0 0 0 24 25 

Medianpast 0.058 0.073 0.018 0.021 0.071 0.055 0.026 0.032 0.102 0.092 

SDpast 0.010 0.012 0.002 0.005 0.016 0.013 0.009 0.009 0.032 0.017 

NIST
 

NNIST 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2
 

Srep
 

Shet
 

SNIST
 

NAV 0.052 0.045 0.035 0.055 0.072 0.020 0.015 0.009 0.020 0.021 0.113 0.064 0.025 0.065 0.052 0.031 0.023 0.017 0.028 0.032 0.144 0.087 0.041 0.098 0.087 

NAU 0.013 0.011 0.009 0.013 0.017 0.003 0.001 0.002 0.002 0.003 0.021 0.013 0.007 0.013 0.011 0.012 0.007 0.005 0.009 0.009 0.030 0.018 0.010 0.020 0.018 

All Lab Report 
Round Robin LVIII Serum Results
 

All Values in μg/mL
 

Ubiquinol Ubiquinone Phylloquinone (K1) x1000 

Lab 314 315 316 317 318 

C5

FSV-BA
 

FSV-BB
 

FSV-BC
 

FSV-BD
 

FSV-BE
 

FSV-BF
 

FSV-BG
 

FSV-BH
 

FSV-BI
 

FSV-BJ
 

FSV-BK
 

FSV-BL
 

FSV-BM
 

FSV-BN
 

FSV-BO
 

FSV-BP
 

FSV-BQ
 

FSV-BR
 

FSV-BS
 

FSV-BT
 

FSV-BU
 

FSV-BV
 

FSV-BW
 nd 0.195 0.488 0.472 0.452 

FSV-BX 

FSV-CC 

FSV-CD 

FSV-CE 

FSV-CF 

FSV-CG 

FSV-CI 

FSV-CS 

FSV-CT 

FSV-CW 

FSV-CZ 

FSV-DA 0.850 0.690 0.440 1.080 1.110 

FSV-DB 

FSV-DD 

FSV-DF 

FSV-DI 0.150 0.370 0.540 0.585 0.600 

FSV-DV 

FSV-DW 

314 315 316 317 318 

0.049 0.326 0.120 0.263 0.127 

0.310 0.220 0.050 0.160 0.105 

314 315 316 317 318 

1.571 0.774 0.154 1.116 1.063 

1.180 0.520 0.100 0.770 0.670 

0.890 0.490 0.220 0.730 0.740 

N 2 3 3 3 3 2 2 2 2 2 3 3 3 3 3 

Min 0.150 0.195 0.440 0.472 0.452 0.049 0.220 0.050 0.160 0.105 0.890 0.490 0.100 0.730 0.670 

Median 0.500 0.370 0.488 0.585 0.600 0.180 0.273 0.085 0.212 0.116 1.180 0.520 0.154 0.770 0.740 

Max 0.850 0.690 0.540 1.080 1.110 0.310 0.326 0.120 0.263 0.127 1.571 0.774 0.220 1.116 1.063 

SD 

CV 

Npast 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 

Medianpast 

SDpast 

NIST
 

NNIST
 

Srep
 

Shet
 

SNIST
 

NAV 0.370 0.488 0.585 0.600 1.180 0.520 0.154 0.770 0.740 

NAU 

All Lab Report 
 

 

 

 

 

Round Robin LVIII Serum Results
 

All Values in μg/mL
 

Analytes Reported By One Laboratory 

Analyte Code 314 315 316 317 318 

trans-Lutein 

25-hydroxyvitamin D 

Phytofluene 

Phytoene 

Retinyl stearate 

9-cis-Lycopene 

13-cis-Lycopene 

15-cis-Lycopene 

FSV-DA 

FSV-BN 

FSV-DA 

FSV-DA 

FSV-DA 

FSV-BN 

FSV-BN 

FSV-BN 

0.107 

0.0381 

0.051 

0.047 

0.040 

0.083 

0.045 

0.016 

0.061 

0.0200 

0.030 

0.028 

0.012 

0.065 

0.038 

0.022 

0.023 0.068 0.051 

0.0090 

0.013 0.049 0.039 

0.024 0.048 0.024 

nd 0.016 0.008 

0.041 0.103 0.086 

0.026 0.055 0.051 

0.008 0.014 0.013 

Term 

N 

Min 

Median 

Max 

SD 

CV 

Npast 

Medianpast 

SDpast 

NIST 

NNIST 

Srep 

Shet 

SNIST 

NAV 

NAU 

nd 

nq 

<x 

≥x

Legend 

Definition

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

 Minimum (non-NIST) quantitative value reported

 Median (non-NIST) quantitative value reported

 Maximum (non-NIST) quantitative value reported

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

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

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

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

 Pooled SD from past RR(s)

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

 Number of total vials analyzed in duplicate by NIST analysts

 W ithin-vial pooled standard deviation

 Among-vial pooled standard deviation 

2

)

0.5 Total standard deviation for NIST analyses: (Srep 2

 + Shet 

 NIST Assigned Value

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

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

2

)

0.5 NIST Assigned Uncertainty: (S2

 + Sbtw 

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

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

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

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

 Detected but not quantitatively determined

 Concentration at or below the limit of quantification, x

 Concentration greater than or equal to x

All Lab Report Page 5 / 7 

C6
 

 

 

 

 

 

 

 

Round Robin LVIII "Score Card" for Serum Samples
 

Comparability Summary
 

Lab 

FSV-BA 

FSV-BB 

FSV-BC 

FSV-BD 

FSV-BE 

FSV-BF 

FSV-BG 

FSV-BH 

FSV-BI 

FSV-BJ 

FSV-BK 

FSV-BL 

FSV-BM 

FSV-BN 

FSV-BO 

FSV-BP 

FSV-BQ 

FSV-BR 

FSV-BS 

FSV-BT 

FSV-BU 

FSV-BV 

FSV-BW 

FSV-BX 

FSV-CC 

FSV-CD 

FSV-CE 

FSV-CF 

FSV-CG 

FSV-CI 

FSV-CS 

FSV-CT 

FSV-CW 

FSV-CZ 

FSV-DA 

FSV-DB 

FSV-DD 

FSV-DF 

FSV-DI 

FSV-DV 

FSV-DW 

NIST 

n 

% 1
 

% 2
 

% 3
 

% 4
 

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

1 1 1 1 1 1 1 1 1 1 1
 

1 1 1 1 1 1 1 1 2 1 1
 

1
 

2 1 1
 

1 2 1 1
 

1 1 1 1 1 1 1 1
 

1 2 1 3 1 2 1 1 2 1
 

1 2 4 1 1 1 1 3
 

2 2 1 1 1 1 1 1 1 1
 

1 1 1 1 1 1 1 2 4 4
 

2 1
 

2 2 1
 

1 1
 

1 1 2 1 1 1 1 1 3
 

1 2 2 1 1 1 1 1 1
 

1 3 3 2 2 3 1
 

1 3 1 2 2
 

1 1 1 2 2
 

4 4 2 2 4 3 2 2 2 1
 

1 1 1 1 1 1 1 1
 

1 1 1 2 1 1 1
 

3 1 1 1 1 1 1 2
 

1 1 3 1 1 1 1
 

1 1 1 1 1 1 1 1
 

1 1 1
 

1 1 1 1 2 2 1 1
 

2 1 1 1 1 1
 

2 2 1
 

3 3 1 1 1 1 1 2
 

1 1 1 1 1 1 2
 

1 2 3 3 3 1 2 1
 

4 1 1 1 1 1
 

1 3 1 1 2 1 1 1 1 1
 

1 1 2
 

1 1 1 2 2 1 1 1
 

1 1 1 1 1 1 3 4 3
 

3
 

1 1
 

1 1 1 1 1 1 1 1
 

4 3
 

1 3 3 1 1 2
 

1 1 1 1 1 1
 

41 37 24 30 13 24 23 24 16 14 24
 

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

73 62 79 67 69 88 78 79 75 57 71
 

15 22 4 17 23 8 17 13 19 29 17
 

7 16 8 13 8 0 4 8 6 0 8
 

5 0 8 3 0 4 0 0 0 14 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) of summarizes your measurement 

performance for a given measurand, relative to the consensus 

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

that your measurement performance characteristics are from the 

consensus performance. CS is calculated when the number of 

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

two and the measurand has been reported by 10 or more 

participants. 

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

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

N  You i − Median i 

2
 

AP = Apparent Precision = ∑

yo u 

 

 (Ny ou − 1)  NAU i  i  

NAU = NIST Assigned Uncertainty, our estimate of the overall 

measurement standard deviation for each sample. The 

estimate includes serum heterogeneity, analytical 

repeatability, and among-participant reproducibility variance 

components. 

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

KE, Brown Thomas J, Gary KT. Micronutrients Measurement 

Quality Assurance Program: Helping participants use 

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

All Lab Report Page 6 / 7
 

C7
 

 

 

 

Appendix D. Representative “Individualized Report” for RR58 

Each participant in RR58 received an “Individualized Report” reflecting their reported 

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

five participants. The following analytes met this criterion in RR58: 

• Total Retinol 

• trans-Retinol 

• Retinyl Palmitate 

• α-Tocopherol 

• γ/β-Tocopherol 

• δ-Tocopherol 

• Total β-Carotene 

• trans-β-Carotene 

• Total cis-β-Carotene 

• α-Carotene 

• Total Lycopene 

• trans-Lycopene 

• Total β-Cryptoxanthin 

• Total α-Cryptoxanthin 

• Total Lutein 

• Total Zeaxanthin 

• Total Lutein & Zeaxanthin 

• Coenzyme Q10 

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

participant FSV-BA. 

D1
 

 Set 1 of 42 

Individualized Round Robin LVIII Report: FSV-BA 

Summary 

Serum 314 Serum 315 Serum 316 Serum 317 

D2

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

Total Retinol 0.541 0.551 36 0.491 0.493 35 0.384 0.391 36 0.700 0.682 36 

Retinyl Palmitate 0.10 0.10 12 0.1 0.1 12 0.0 0.0 8 0.06 0.05 12 

α-Tocopherol 15.43 16.07 36 9.28 9.41 36 4.14 4.08 36 11.17 11.95 36 

γ/β-Tocopherol 1.497 1.458 23 1.839 1.809 23 1.752 1.728 23 2.686 2.728 23 

δ-Tocopherol 0.109 0.103 7 0.113 0.111 7 0.098 0.101 7 0.342 0.334 8 

Total β-Carotene 0.604 0.601 25 0.279 0.295 25 0.040 0.041 24 0.314 0.318 25 

trans-β-Carotene 0.564 0.550 12 0.260 0.266 12 0.037 0.039 12 0.291 0.289 12 

Total cis-β-Carotene 0.040 0.066 8 0.018 0.036 8 0.003 0.003 7 0.022 0.033 8 

Total α-Carotene 0.127 0.121 23 0.057 0.057 23 0.006 0.008 18 0.056 0.057 23 

Total Lycopene 0.379 0.335 23 0.274 0.241 23 0.165 0.152 23 0.425 0.374 23 

trans-Lycopene 0.201 0.166 9 0.138 0.122 9 0.076 0.069 9 0.203 0.174 9 

Total β-Cryptoxanthin 0.063 0.052 24 0.053 0.045 24 0.041 0.035 24 0.065 0.055 24 

Total α-Cryptoxanthin 0.027 0.020 6 0.018 0.015 6 0.012 0.009 6 0.023 0.020 6 

Total Lutein&Zeaxanthin 0.149 0.144 23 0.09 0.09 23 0.04 0.04 22 0.104 0.098 24 

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

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

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

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

Micronutrients Measurement Quality Assurance Program 

National Institute of Standards and Technology 

100 Bureau Drive Stop 8392 

Gaithersburg, MD 20899-8392 USA Email: 

Individualized Report 
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.

 

 Set 1 of 42

Individualized RR LVIII Report: FSV-BA 

Total Retinol 

Apparent Precision, SD [Analyte], μg/mL

248258263280304318317247316315314 

Your [Analyte], μg/mL

Apparent Precision, SD 

Median [Analyte], μg/mL 

Long-term Precision, SD Concordance, SD 

3rd Quartile (75%) 

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

Median (50%) 

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

Serum History Comments 

#314 Fresh frozen Native, multi-source 

#315 Fresh frozen 77:110 blend of #314 and #316 

#316 Fresh frozen Native, multi-source 

#317 Lyophilized - 44:247 1:1 blend of SRMc Level I and II 

#318 Lyophilized - 44:248, 46:258, 47:263, 51:280, 56:304 Augmented, multi-source (SRM 968c Level I) 

 Individualized Report Page 2 / 15 

D3
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.

 

 Set 1 of 42

Individualized RR LVIII Report: FSV-BA 

Retinyl Palmitate 

[Analyte], μg/mL Apparent Precision, SD 

248258263280304318317247316315314 

Your [Analyte], μg/mL

Apparent Precision, SD 

Median [Analyte], μg/mL 

Concordance, SD 

3rd Quartile (75%) 

Long-term Precision, SD 

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

Median (50%) 

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

Serum History Comments 

#314 Fresh frozen Native, multi-source 

#315 Fresh frozen 77:110 blend of #314 and #316 

#316 Fresh frozen Native, multi-source 

#317 Lyophilized - 44:247 1:1 blend of SRMc Level I and II 

#318 Lyophilized - 44:248, 46:258, 47:263, 51:280, 56:304 Augmented, multi-source (SRM 968c Level I) 

 Individualized Report Page 3 / 15 

D4
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.

 

 Set 1 of 42

Individualized RR LVIII Report: FSV-BA 

α-Tocopherol 

[Analyte], μg/mL Apparent Precision, SD 

248258263280304318317247316315314 

Your [Analyte], μg/mL

Apparent Precision, SD 

Median [Analyte], μg/mL 

Concordance, SD 

3rd Quartile (75%) 

Long-term Precision, SD 

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

Median (50%) 

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

Serum History Comments 

#314 Fresh frozen Native, multi-source 

#315 Fresh frozen 77:110 blend of #314 and #316 

#316 Fresh frozen Native, multi-source 

#317 Lyophilized - 44:247 1:1 blend of SRMc Level I and II 

#318 Lyophilized - 44:248, 46:258, 47:263, 51:280, 56:304 Augmented, multi-source (SRM 968c Level I) 

 Individualized Report Page 4 / 15 

D5
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.

 

 Set 1 of 42

Individualized RR LVIII Report: FSV-BA 

γ/β-Tocopherol 

[Analyte], μg/mL

Your [Analyte], μg/mL

Apparent Precision, SD 

248258263280304318317247316315314 

Apparent Precision, SD 

Median [Analyte], μg/mL 

Concordance, SD 

3rd Quartile (75%) 

Long-term Precision, SD 

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

Median (50%) 

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

Serum History Comments 

#314 Fresh frozen Native, multi-source 

#315 Fresh frozen 77:110 blend of #314 and #316 

#316 Fresh frozen Native, multi-source 

#317 Lyophilized - 44:247 1:1 blend of SRMc Level I and II 

#318 Lyophilized - 44:248, 46:258, 47:263, 51:280, 56:304 Augmented, multi-source (SRM 968c Level I) 

 Individualized Report Page 5 / 15 

D6
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.

 

 Set 1 of 42

Individualized RR LVIII Report: FSV-BA 

δ-Tocopherol 

[Analyte], μg/mL

Your [Analyte], μg/mL

Apparent Precision, SD 

248258263280304318317247316315314 

Apparent Precision, SD 

Median [Analyte], μg/mL 

Long-term Precision, SD Concordance, SD 

3rd Quartile (75%) 

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

Median (50%) 

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

Serum History Comments 

#314 Fresh frozen Native, multi-source 

#315 Fresh frozen 77:110 blend of #314 and #316 

#316 Fresh frozen Native, multi-source 

#317 Lyophilized - 44:247 1:1 blend of SRMc Level I and II 

#318 Lyophilized - 44:248, 46:258, 47:263, 51:280, 56:304 Augmented, multi-source (SRM 968c Level I) 

 Individualized Report Page 6 / 15 

D7
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.

 

 Set 1 of 42

Individualized RR LVIII Report: FSV-BA 

Total β-Carotene 

[Analyte], μg/mL Apparent Precision, SD 

248258263280304318317247316315314 

Your [Analyte], μg/mL

Apparent Precision, SD 

Median [Analyte], μg/mL 

Concordance, SD 

3rd Quartile (75%) 

Long-term Precision, SD 

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

Median (50%) 

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

Serum History Comments 

#314 Fresh frozen Native, multi-source 

#315 Fresh frozen 77:110 blend of #314 and #316 

#316 Fresh frozen Native, multi-source 

#317 Lyophilized - 44:247 1:1 blend of SRMc Level I and II 

#318 Lyophilized - 44:248, 46:258, 47:263, 51:280, 56:304 Augmented, multi-source (SRM 968c Level I) 

 Individualized Report Page 7 / 15 

D8
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.

 

 Set 1 of 42

Individualized RR LVIII Report: FSV-BA 

trans-β-Carotene 

[Analyte], μg/mL Apparent Precision, SD 

248258263280304318317247316315314 

Your [Analyte], μg/mL

Apparent Precision, SD 

Median [Analyte], μg/mL 

Concordance, SD 

3rd Quartile (75%) 

Long-term Precision, SD 

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

Median (50%) 

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

Serum History Comments 

#314 Fresh frozen Native, multi-source 

#315 Fresh frozen 77:110 blend of #314 and #316 

#316 Fresh frozen Native, multi-source 

#317 Lyophilized - 44:247 1:1 blend of SRMc Level I and II 

#318 Lyophilized - 44:248, 46:258, 47:263, 51:280, 56:304 Augmented, multi-source (SRM 968c Level I) 

 Individualized Report Page 8 / 15 

D9
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.

 

 Set 1 of 42

Individualized RR LVIII Report: FSV-BA 

Total cis-β-Carotene 

Apparent Precision, SD [Analyte], μg/mL

248258263280304318317247316315314 

Your [Analyte], μg/mL

Apparent Precision, SD 

Median [Analyte], μg/mL 

Concordance, SD 

3rd Quartile (75%) 

Long-term Precision, SD 

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

Median (50%) 

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

Serum History Comments 

#314 Fresh frozen Native, multi-source 

#315 Fresh frozen 77:110 blend of #314 and #316 

#316 Fresh frozen Native, multi-source 

#317 Lyophilized - 44:247 1:1 blend of SRMc Level I and II 

#318 Lyophilized - 44:248, 46:258, 47:263, 51:280, 56:304 Augmented, multi-source (SRM 968c Level I) 

 Individualized Report Page 9 / 15 

D10
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.

 

 Set 1 of 42

Individualized RR LVIII Report: FSV-BA 

Total α-Carotene 

[Analyte], μg/mL

Your [Analyte], μg/mL

Apparent Precision, SD 

248258263280304318317247316315314 

Apparent Precision, SD 

Median [Analyte], μg/mL 

Concordance, SD 

3rd Quartile (75%) 

Long-term Precision, SD 

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

Median (50%) 

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

Serum History Comments 

#314 Fresh frozen Native, multi-source 

#315 Fresh frozen 77:110 blend of #314 and #316 

#316 Fresh frozen Native, multi-source 

#317 Lyophilized - 44:247 1:1 blend of SRMc Level I and II 

#318 Lyophilized - 44:248, 46:258, 47:263, 51:280, 56:304 Augmented, multi-source (SRM 968c Level I) 

 Individualized Report Page 10 / 15 

D11
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.

 

 Set 1 of 42

Individualized RR LVIII Report: FSV-BA 

Total Lycopene 

[Analyte], μg/mL

Your [Analyte], μg/mL

Apparent Precision, SD 

248258263280304318317247316315314 

Apparent Precision, SD 

Median [Analyte], μg/mL 

Long-term Precision, SD Concordance, SD 

3rd Quartile (75%) 

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

Median (50%) 

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

Serum History Comments 

#314 Fresh frozen Native, multi-source 

#315 Fresh frozen 77:110 blend of #314 and #316 

#316 Fresh frozen Native, multi-source 

#317 Lyophilized - 44:247 1:1 blend of SRMc Level I and II 

#318 Lyophilized - 44:248, 46:258, 47:263, 51:280, 56:304 Augmented, multi-source (SRM 968c Level I) 

 Individualized Report Page 11 / 15 

D12
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.

 

 Set 1 of 42

Individualized RR LVIII Report: FSV-BA 

trans-Lycopene 

[Analyte], μg/mL

Your [Analyte], μg/mL

Apparent Precision, SD 

248258263280304318317247316315314 

Apparent Precision, SD 

Median [Analyte], μg/mL 

Long-term Precision, SD Concordance, SD 

3rd Quartile (75%) 

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

Median (50%) 

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

Serum History Comments 

#314 Fresh frozen Native, multi-source 

#315 Fresh frozen 77:110 blend of #314 and #316 

#316 Fresh frozen Native, multi-source 

#317 Lyophilized - 44:247 1:1 blend of SRMc Level I and II 

#318 Lyophilized - 44:248, 46:258, 47:263, 51:280, 56:304 Augmented, multi-source (SRM 968c Level I) 

 Individualized Report Page 12 / 15 

D13
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.

 

 Set 1 of 42

Individualized RR LVIII Report: FSV-BA 

Total β-Cryptoxanthin 

[Analyte], μg/mL

Your [Analyte], μg/mL

Apparent Precision, SD 

248258263280304318317247316315314 

Apparent Precision, SD 

Median [Analyte], μg/mL 

Long-term Precision, SD Concordance, SD 

3rd Quartile (75%) 

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

Median (50%) 

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

Serum History Comments 

#314 Fresh frozen Native, multi-source 

#315 Fresh frozen 77:110 blend of #314 and #316 

#316 Fresh frozen Native, multi-source 

#317 Lyophilized - 44:247 1:1 blend of SRMc Level I and II 

#318 Lyophilized - 44:248, 46:258, 47:263, 51:280, 56:304 Augmented, multi-source (SRM 968c Level I) 

 Individualized Report Page 13 / 15 

D14
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.

 

 Set 1 of 42

Individualized RR LVIII Report: FSV-BA 

Total Lutein&Zeaxanthin 

[Analyte], μg/mL

Your [Analyte], μg/mL

Apparent Precision, SD 

248258263280304318317247316315314 

Apparent Precision, SD 

Median [Analyte], μg/mL 

Long-term Precision, SD Concordance, SD 

3rd Quartile (75%) 

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

Median (50%) 

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

Serum History Comments 

#314 Fresh frozen Native, multi-source 

#315 Fresh frozen 77:110 blend of #314 and #316 

#316 Fresh frozen Native, multi-source 

#317 Lyophilized - 44:247 1:1 blend of SRMc Level I and II 

#318 Lyophilized - 44:248, 46:258, 47:263, 51:280, 56:304 Augmented, multi-source (SRM 968c Level I) 

 Individualized Report Page 14 / 15 

D15
Set 1 of 41 

Individualized Round Robin LVIII Report: FSV-BA
 

Graphical Comparability Summary
 

Total Retinol α-Tocopherol Total β-Carotene Tot

D16

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

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

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

Individualized Report 
 

 

 

Appendix E. Shipping Package Inserts for RR23 

The following five items were included in each package shipped to an RR23 participant: 

•	 Cover letter 

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

Material
	

•	 Preparation and Validation of Ascorbic Acid Solid Control Material Datasheet 

•	 Analysis of Control Materials and Test Samples Datasheet 

•	 Packing List and Shipment Receipt Confirmation Form 

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

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

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

E1
May 11, 2005 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

National lnat:itul:e Df Standards and Technology 

Gaithersburg, Maryland 20899-

The samples within this package constitute Vitamin C Round Robin 23 (RR23) of the fiscal year (FY) 05 

Micronutrients Measurement Quality Assurance Program. 

RR23consists of four vials of frozen serum test samples (# 14, #31, #54, and #71 ), one vial of ascorbic acid 

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

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

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

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

mL volumetric measurements.) 

The two serum control materials are a new component of the M2

QAP for Vitamin C. Please use these 

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

target value and :::::95% confidence interval for Control #1 is 8.41 ±0.61 μmol/L sample; the target value and 

:::::95% confidence interval for Control #2 is 28.05 ±0.49 μmol/L sample. 

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

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

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

observe unusually large variation in replicate analyses. 

The report for RR22 was mailed the week of April 14, 2005. If you find your results for RR22 unsatisfactory, 

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

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

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

srminfo@nist.gov). 

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

Program please contact Jeanice Brown Thomas at tel: 301-975-3120, fax: 301-977-0685, or 

e-mail: jbthomas@nist.gov. 

We ask that you return your results for these RR23 samples before September 30, 2005. We would appreciate 

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

kept confidential. 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosures: Protocols, Preparation and Analysis of Control Materials and Analysis of Test Samples 

RR22 Report Form for Ascorbic Acid Solid Control Material Preparation 

RR22 Report Form for Control Material and Test Sample Analyses 

NISI 

E2
 

 

 

 

 

 

 

 

 

Micronutrient Measurement Quality Assurance Program for
 

Vitamin C
 

Please Read Through Completely BEFORE Analyzing Samples 

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

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

following manner: 

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

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

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

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

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

referred to as the “Stock Solution” below. 

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

which this maximum occurs. 

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

Dilute Solution #1 can be calculated: 

E3
 

 

 

 

 

 

 

 

 

 

 

 

 

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

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

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

absorbance axes of your spectrophotometer and repeat the measurements. 

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

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

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

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

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

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

precision is adequate? 

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

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

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

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

calculated values? 

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

system is performing properly! 

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

CS #2 (see protocol below). The target values for this materials is 28.1 ±1.0 μmol/L of sample. 

If your measured values are not close to this value, please review your sample preparation 

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

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

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

measurement system may not be suitable for MPA-preserved samples. Please contact us: 301-

975-3120 or Jeanice.BrownThomas@NIST.gov. 

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

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

Protocol for Analysis of the Serum Control Materials and Test Samples 

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

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

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

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

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

than 10 min otherwise some irreversible degradation may occur. 

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

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

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

E4
 

 

 

 

Participant #: Date: 

Vitamin C Round Robin 23 

NIST Micronutrient Measurement Quality Assurance Program 

Preparation and Validation of Ascorbic Acid Solid Control Material 

STOCK SOLUTION 

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

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

DILUTE SOLUTION 1 

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

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

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

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

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

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

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

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

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

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

DILUTE SOLUTION 2 

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

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

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

DILUTE SOLUTION 3 

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

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

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

Please return by Sept 12, 2005 

MMQAP Fax: 301-977-0685 

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

Gaithersburg, MD 20899-8392 

E5
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Participant #: Date: 

Vitamin C Round Robin 23 

NIST Micronutrient Measurement Quality Assurance Program
 

Analysis of Control Materials and Test Samples
 

Sample Replicate 1 Replicate 2 Units
 

Dilute Solution 1 μmol/L of Dilute Solution 

Dilute Solution 2 μmol/L of Dilute Solution 

Dilute Solution 3 μmol/L of Dilute Solution 

5% MPA Diluent μmol/L of Diluent 

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

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

Serum Test Sample #14 μmol/L of Sample 

Serum Test Sample #31 μmol/L of Sample 

Serum Test Sample #54 μmol/L of Sample 

Serum Test Sample #71 μmol/L of Sample 

Were samples frozen upon receipt? Yes | No 

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

If “Other”, please describe:
	

COMMENTS: 

Please return by Sept 12, 2005 

MMQAP Fax: 301-977-0685 

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

Gaithersburg, MD 20899-8392 

E6
 

 

 

 

Participant #: ________ Date: _____________ 

Vitamin C Round Robin 23
 

NIST Micronutrients Measurement Quality Assurance Program
 

Packing List and Shipment Receipt Confirmation Form
 

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

Sample Form 

VitC #14 Liquid frozen (1:1 serum:10% MPA) 

VitC #31 Liquid frozen (1:1 serum:10% MPA) 

VitC #54 Liquid frozen (1:1 serum:10% MPA) 

VitC #71 Liquid frozen (1:1 serum:10% MPA) 

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

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

Control Solid AA 

Please 1) Open the pack immediately 

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

3) Check if the samples arrived frozen 

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

5) Complete the following information 

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

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

1) Date this shipment arrived: ___________________________ 

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

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

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

4) Did the samples arrive frozen? Yes | No 

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

6) When do you anticipate analyzing these samples? ________________________ 

Your prompt return of this information is appreciated. 

The M2QAP Gang 

Mail: M2QAP 

NIST, Stop 8392 Fax: 301-977-0685 

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

E7
 

 

 

 

Appendix F. Final Report for RR23 

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

•	 Cover letter. 

•	 An information sheet that: 

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

o	 describes the content of the “Individualized” report, 

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

if any, and 

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

participants. 

F1
November 8, 2005 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

Nlleianal lnRitulia af SCandards and Technolagy 

Gaithersburg, Maryland 20899-

Enclosed is the summary report of the results for Round Robin 23 (RR23) for the measurement 

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

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

performance and interlaboratory accuracy and repeatability. The robust median is used to 

estimate the consensus· value for all samples, the median absolute deviation from the median 

(MADe) is used to estimate the expected standard deviation, and the coefficient of variation 

(CV) is defined as 1 OOxMADe/median. 

RR 23 consisted of four test samples (#14, #31, #54, and #71), two serum control materials, and 

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

samples can be found in the enclosed report. 

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

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

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

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

you contact us for consultation. 

Samples for the first vitamin C round robin study of the 2006 M2QAP (RR24) will be shipped starting 

the last week of November 2005. 

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

301-975-3935; e-mail: david.duewer@nist.gov or me at 301-975-3120; e-mail: 

jbthomas@nist.gov; or fax: 301-977-0685. 

ice Brown Thomas 

Research Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosures 

F2

N•SI 
 

 

 

 

 

 

 

 

 

 

 

 

The NIST M2QAP Vitamin C Round Robin 23 (RR23) report consists of 

Page “Individualized” Report 

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

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

samples. 

2 Graphical summary of your RR23 sample measurements. 

Page “All Lab” Report 

1 A tabulation of results and summary statistics for Total Ascorbic Acid [TAA] in the RR23 

samples and control/calibration solutions. 

Serum-based Samples. Two serum controls and four unknowns were distributed in RR23. 

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

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

S23:1 Serum 14, ampouled in late 2001, previously distributed as sample S19:1 (RR19, Sep-03) 

and S21:1 (RR21, Sep-04). A “blank” stripped serum. 

S23:2 Serum 31, ampouled in late 2001, previously distributed as sample S17:2 (RR17, Sep-02), 

S18:1 (RR18, Mar-03) S20:1 (RR20, Mar-04), and S22:1 (RR22, Mar-05). An augmented 

serum. 

S23:3 Serum 54, ampouled in late 2001, previously distributed as sample 16:3 (RR13, Mar-02), 

S17:3 (RR17, Sep-02), S20:2 (RR20, Mar-04), and S21:4 (RR21, Sep-04). An augmented 

serum. 

S23:4 Serum 71, SRM 970 level 1, ampouled in mid-1998. This material was distributed with 

identification in RR11 (Oct-98) and RR12 (Mar-99) and as samples S13-1 (RR13, Mar-00), 

S14-3 (RR14, Mar-01), S15:1 (RR15, Sep-01), S16:1 (RR16, Mar-02), S19:4 (Sep-03), and 

S20:3 (Mar-04). An augmented serum. 

Results. 

1)		 All participants who prepared the four control/calibration solutions (the three dilute solutions and the 

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

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

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

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

close to 0.0 and slopes close to 1.0), the measurement systems for all participants are well calibrated. 

3)		 There is no evidence of sample degradation with any of the samples distributed. 

4)		 The following Figure displays the expected %relative standard deviation or “coefficient of variation” 

(CV) for the control and unknown samples as a function of time for the past four years. The 

expected CV is estimated by pooling the individual CVs of all non-blank samples in a given study. 

The individual sample CVs are estimated as 100×MADe/median. The “error bars” span from the 

lowest to the highest observed CVs. 

While the data are as yet insufficient for any great confidence, the general reduction in the expected 

CV with time since the introduction of the control samples in 2004 suggests that analysis of the 

F3
 

controls helps control the observed variability of the unknown samples. Based on the convergence of 

the expected CV of the control materials with that for the unknowns, the currently achievable amonglaboratory CV for the analysis of total ascorbic acid is about 8%. 

8% 

0 

5 

10 

15 

20

Coefficient of Variation, %

Controls 

Unknowns 

Jan-02 Jan-03 Jan-04 Jan-05 

Date of Interlaboratory Study 

F4
 

 

 

Appendix G. “All-Lab Report” for RR23 

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

two exceptions: 

• the participant identifiers (Lab) have been altered. 

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

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

identification codes assigned to laboratories. 

G1
Micronutrients Measurement Quality Assurance Program for Total Ascorbic Acid 

"Round Robin" 22 - March 2005 

Control / Calibration Samples MPA Dilute Solution 1 Samples 

G2

Density 

Lab Date Dil:1 Dil:2 Dil:3 Dil:1 Dil:2 Dil:3 MPA Inter Slope R2 SEE g/mL λmax Amax E1% CS#1 CS#2 S23:1 S23:2 S23:3 S23:4 CS#

VC-MA 17/10/05 56.2 27.8 13.7 61.3 28.4 13.6 0.6 -0.59 1.09 0.998 1.5 1.031 244. 0.5621 567.9 9.4 30.0 0.0 24.9 49.3 8.7 9

VC-MB 25/05/05 59.3 29.1 15.1 56.3 26.1 13.4 0.0 -0.66 0.95 0.999 0.9 1.030 244. 0.6247 597.8 7.5 27.9 0.0 21.7 42.6 7.7 8

VC-MC 02/06/05 57.4 28.5 14.2 56.4 29.6 14.7 0.0 0.63 0.98 0.999 1.0 1.035 243. 0.5831 576.7 8.6 29.2 0.0 20.7 45.3 8.1 8

VC-ME 20/09/05 58.2 29.2 14.1 57.9 29.6 15.2 0.0 0.58 0.99 1.000 0.7 1.030 243.6 0.5798 565.5 8.2 26.8 0.0 21.8 46.9 8.9 7

VC-MG 22/09/05 57.0 29.8 15.8 56.1 28.0 13.9 0.0 -0.87 0.99 0.999 1.0 1.031 243.2 0.5420 539.5 8.0 30.1 0.0 24.8 54.2 7.9 9

VC-MH 03/10/05 47.2 23.5 11.6 45.9 24.0 13.0 0.0 0.95 0.96 0.998 1.1 1.029 243.9 0.4538 545.4 8.9 27.4 1.3 23.4 48.3 9.3 8

VC-MI 12/09/05 57.2 28.4 14.1 57.4 27.6 13.0 0.0 -0.67 1.01 0.999 0.7 1.025 8.5 28.1 0.0 19.3 43.3 8.2 9

VC-MJ 24/06/05 60.8 30.4 15.8 61.8 31.4 16.0 0.2 0.20 1.02 1.000 0.3 1.016 254.4 0.3680 343.9 10.6 30.3 3.8 24.6 48.7 11.4 10

VC-MK 09/09/05 59.5 29.6 14.5 60.1 31.3 16.8 1.9 2.25 0.97 1.000 0.4 1.031 244. 0.5947 567.5 12.0 33.6 3.8 23.3 52.5 12.7 10

VC-MP 12/08/05 8.4 28.0 0.0 21.6 46.2 8.5 

9 9 9 9 9 9 9 9 8 8 8 10 10 10 10 10 10 

57.0 28.5 14.3 57.0 28.4 14.4 0.3 1.029 245.0 0.5385 538.0 9.0 29.1 0.9 22.6 47.7 9.1 8

3.9 2.0 1.3 4.7 2.4 1.4 0.6 0.005 3.8 0.0854 80.5 1.4 2.0 1.6 1.9 3.7 1.6 0

47.2 23.53 11.6 45.9 24.00 13.0 0.0 1.016 243.0 0.3680 343.9 7.5 26.8 0.0 19.3 42.6 7.7 7

57.0 28.39 14.1 56.3 27.60 13.4 0.0 1.029 243.5 0.5200 543.9 8.2 27.9 0.0 21.6 45.5 8.1 8

57.4 29.14 14.2 57.4 28.35 13.9 0.0 1.030 244.0 0.5710 566.5 8.5 28.6 0.0 22.6 47.6 8.6 9

59.3 29.58 15.1 60.1 29.64 15.2 0.2 1.031 244.0 0.5860 570.1 9.3 30.0 0.9 24.3 49.1 9.2 9

60.8 30.38 15.8 61.8 31.40 16.8 1.9 1.035 254.4 0.6247 597.8 12.0 33.6 3.8 24.9 54.2 12.7 10

1.8 1.0 0.7 1.9 1.9 1.3 0.0 0.001 0.3 0.0391 23.2 0.7 1.9 0.0 2.1 3.0 0.8 1

3 3 5 3 7 9 0.12 0.12 6.8 4.1 8 7 9 6 10 1

MADe eSD 

CV CV 

Median Median 

%75 %75 

Max Max 

Min Min 

%25 %25 

N N 

Average Average 

SD SD 

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

All Lab Report 
Appendix H. Representative “Individualized Report” for RR23 

Each participant in RR23 received an “Individualized Report” reflecting their reported 

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

“VC-MA”. 

H1
 

Set 1 of 10 

Vitamin C "Round Robin" 23 Report: Participant VC-MA
 

Date RR Method 

03/20/03 18 HPLC-EC 

11/13/03 19 HPLC-EC 

02/23/04 20 HPLC-EC 

09/13/04 21 HPLC-EC 

03/08/05 22 HPLC-EC 

10/17/05 23 HPLC-EC 

MPA Dilute Solution 1 Control/Calibration Solutions 

Density Spectrophotometry Ymeas = Inter + Slope* Xgrav 

g/mL 

1.026 

1.026 

1.031 

1.030 

1.034 

1.030 

λmax Amax E1% 

244.0 0.509 563.1 

243.0 0.584 561.9 

243.0 0.552 560.7 

244.0 0.555 562.2 

243.0 0.559 562.9 

244.0 0.562 567.9 

Inter Slope R2 SEE 

-0.1 1.02 1.000 0.18 

1.1 1.03 0.998 1.24 

-0.4 1.05 1.000 0.65 

-0.1 0.99 1.000 0.10 

0.2 1.06 1.000 0.24 

-0.6 1.09 0.998 1.47 

Mean 1.029 243.5 0.55 563.1 0.65 

SD 0.003 0.5 0.02 2.5 0.58 

CV 0.29 0.22 4.4 0.4 

[TAA] mmol/Lsample 

4 27.9 0.6 1.9 

1 0.0 0.0 

4 23.9 0.6 1.1 

3 48.9 0.5 1.7 

3 8.4 0.3 0.4 

Date RR Sample 

02/23/04 20 CS#1 

09/13/04 21 CS#1 

03/08/05 22 CS#1 

10/17/05 23 CS#1 

02/23/04 20 CS#2 

09/13/04 21 CS#2 

03/08/05 22 CS#2 

10/17/05 23 CS#2 

11/13/03 19 S19:1 

09/13/04 21 S21:1 

10/17/05 23 S23:1 

03/20/03 18 S18:1 

02/23/04 20 S20:1 

03/08/05 22 S22:2 

10/17/05 23 S23:2 

02/23/04 20 S20:2 

09/13/04 21 S21:4 

10/17/05 23 S23:3 

11/13/03 19 S19:4 

02/23/04 20 S20:3 

10/17/05 23 S23:4 

Rep1 Rep2 Fadj Mean SDdup 

7.8 8.0 1.0 7.9 0.1 

8.1 7.9 1.0 8.0 0.1 

8.5 8.7 1.0 8.6 0.1 

9.3 9.5 1.0 9.4 0.1 

N Mean SDrepeat SDreprod 

4 8.5 0.1 0.7 

25.8 26.2 1.0 26.0 0.3 

26.2 27.2 1.0 26.7 0.7 

29.0 29.0 1.0 29.0 0.0 

29.4 30.5 1.0 30.0 0.8 

nd nd 1.0 

nd nd 1.0 

0.0 0.0 1.0 0.0 0.0 

22.7 23.7 1.0 23.2 0.7 

25.1 24.1 1.0 24.6 0.7 

22.7 22.7 1.0 22.7 0.0 

25.5 24.4 1.0 24.9 0.8 

50.6 50.0 1.0 50.3 0.4 

47.1 47.0 1.0 47.0 0.0 

49.8 48.8 1.0 49.3 0.7 

7.8 8.6 1.0 8.2 0.5 

8.3 8.1 1.0 8.2 0.1 

8.6 8.8 1.0 8.7 0.1 

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

Micronutrients Measurement Quality Assurance Program 

National Institute of Standards and Technology 

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

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

Individualized Report Page 1/2 

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Set 1 of 10 

Vitamin C "Round Robin" 23 Report: Participant VC-MA 

Total Ascorbic Acid 

S11:1S12:1S13:1S14:3S15:1S16:1S19:4S20:3S23:4S17:2S18:1S20:1S22:2S23:2S16:3S17:3S20:2S21:4S23:3 

[Total Ascorbic Acid], μmol/L 

Your [Total Ascorbic Acid], μmol/L

Median [Total Ascorbic Acid], μmol/L 

Apparent Precision, SD 

Concordance, SD 

3rd Quartile (75%) You, RR 22 NIST, RR 22 Median (50%) You, RR 17-21 Others, RR 22 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 

S23:1 Serum 14, a "blank" previously distributed in RRs 16, 19, 21, and 22 

S23:2 Serum 31, previously distributed in RRs 17, 18, 20, and 22 

S23:3 Serum 54, previously distributed in RRs 16, 17, 20, and 21 

S23:4 SRM 970 Level 1, previously distributed in RRs 11, 12, 13, 14, 15, 16, 19, and 20 

Individualized Report Page 2/2 

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