NISTIR 7880-28 

NIST Micronutrients Measurement 

Quality Assurance Program 

Winter, Spring, and Fall 1996 

Comparability Studies 

Results for Round Robin XXXVI, XXXVII, and XXXVIII 

Fat-Soluble Vitamins and Carotenoids in Human Serum 

and Round Robin 9 Ascorbic Acid in Human Serum 

David L. Duewer 

Margaret C. Kline 

Sam A. Margolis (Retired) 

Katherine E. Sharpless 

Jeanice B. Thomas 

 

 

 

 

 

 

NISTIR 7880-28 

NIST Micronutrients Measurement 

Quality Assurance Program 

Winter, Spring, and Fall 1996 

Comparability Studies 

Results for Round Robin XXXVI, XXXVII, and XXXVIII 

Fat-Soluble Vitamins and Carotenoids in Human Serum 

and Round Robin 9 Ascorbic Acid in Human Serum 

David L. Duewer 

Sam A. Margolis (Retired) 

Katherine E. Sharpless 

Jeanice B. Thomas 

Chemical Sciences Division 

Materials Measurement Laboratory 

Margaret C. Kline 

Biomolecular Measurement Division 

Material Measurement Laboratory 

July, 2013 

U.S. Department of Commerce 

Penny Pritzker, Secretary 

National Institute of Standards and Technology 

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

ii
 
 

 

 

 

 

 

Abstract 

The National Institute of Standards and Technology coordinates the Micronutrients Measurement 

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

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

Winter, Spring and Fall 1996 MMQAP measurement comparability improvement studies: 1) Round 

Robin XXXVI Fat-Soluble Vitamins and Carotenoids in Human Serum, 2) Round Robin XXXVII 

Fat-Soluble Vitamins and Carotenoids in Human Serum, 3) Round Robin XXXVIII Fat-Soluble 

Vitamins and Carotenoids in Human Serum, and 4) Round Robin 9 Ascorbic Acid in Human Serum. 

The materials for Round Robin XXXVI were shipped to participants in January 1996; participants 

were requested to provide their measurement results by March 15, 1996. The materials for Round 

Robin XXXVII were shipped to participants in April 1996; participants were requested to provide 

their measurement results by June 14, 1996. The materials for Round Robin XXXVIII were shipped 

to participants in July 1996; participants were requested to provide their measurement results by 

September 20, 1996. The sample materials for Round Robin 9 were distributed in May 1996 with 

results due by July 2, 1996. 

Keywords 

Human Serum 

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

Ascorbic Acid 

iii 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Table of Contents 

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

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

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

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

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

Round Robin XXXVII: Fat-Soluble Vitamins and Carotenoids in Human Serum .................... 2
 

Round Robin XXXVIII: Fat-Soluble Vitamins and Carotenoids in Human Serum................... 2
 

Round Robin 9: Vitamin C in Human Serum................................................................................. 3
 

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

Appendix A. Shipping Package Inserts for RR36........................................................................ A1
 

Appendix B. Final Report for RR36 ..............................................................................................B1
 

Appendix C. “All-Lab Report” for RR36 ......................................................................................C1
 

Appendix D. “Individualized Report” for RR36 ......................................................................... D1
 

Appendix E. Shipping Package Inserts for RR37 ......................................................................... E1
 

Appendix F. Final Report for RR37............................................................................................... F1
 

Appendix G. “All-Lab Report” for RR37...................................................................................... G1
 

Appendix H. “Individualized Report” for RR37 .......................................................................... H1
 

Appendix I. Shipping Package Inserts for RR38 ........................................................................... I1
 

Appendix J. Final Report for RR38 ................................................................................................ J1
 

Appendix K. “All-Lab Report” for RR38..................................................................................... K1
 

Appendix L. “Individualized Report” for RR38........................................................................... L1
 

Appendix M. Shipping Package Inserts for RR09 ....................................................................... M1
 

Appendix N. Final Report for RR09 ............................................................................................. N1
 

Appendix O. “All Lab Report” for RR09 ..................................................................................... O1
 

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 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 XXXVI: Fat-Soluble Vitamins and Carotenoids in Human Serum 

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

XXXVI comparability study (hereafter referred to as RR36) received four lyophilized human serum 

test samples for analysis. Unless multiple vials were previously requested, participants received one 

vial of each serum. These sera were shipped on dry ice to participants in January 1996. 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 RR36 has three sections: 

•	 A cover letter, a “Lies, Damned Lies, and Statistics” summary report that describes the 

samples and our analysis of the participants’ results, and a “Report of (Meta)Analysis” that 

presents a detailed analysis of measurements made by NIST analysts. This cover letter and 

associated reports are reproduced as Appendix B. 

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

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

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

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

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

1
 
 

 

 

 

 

 

 

 

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

analytes. 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 XXXVII: Fat-Soluble Vitamins and Carotenoids in Human Serum 

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

XXXVII comparability study (hereafter referred to as RR37) received four lyophilized human serum 

test samples 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 April 1996. 

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

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 RR37 has three sections: 

•	 A cover letter, a “Lies, Damned Lies, and Statistics” summary report that describes the 

samples and our analysis of the participants’ results, and a “Report of (Meta)Analysis” that 

presents a detailed analysis of measurements made by NIST analysts. This cover letter and 

associated reports are reproduced as Appendix F. 

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

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

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

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

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

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

analytes. 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 H. 

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

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

XXXVIII comparability study (hereafter referred to as RR38) received four lyophilized human 

serum test samples 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 

July 1996. The communication materials included in the sample shipment are provided in Appendix 

I. 

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. 

2
 
 

 

 

 

 

 

The final report delivered to every participant in RR38 has three sections: 

•	 A cover letter, a “Lies, Damned Lies, and Statistics” summary report that describes the 

samples and our analysis of the participants’ results, and a “Report of (Meta)Analysis” that 

presents a detailed analysis of measurements made by NIST analysts. This cover letter and 

associated reports are reproduced as Appendix J. 

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

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

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

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

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

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

analytes. 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 L. 

Round Robin 9: Vitamin C in Human Serum 

Participants in the MMQAP Vitamin C in Human Serum Round Robin 9 comparability study 

(hereafter referred to as RR09) received four frozen serum test samples and a solid ascorbic acid 

control material for analysis. These sample materials were shipped on dry ice to participants in May 

1996. The communication materials included in the sample shipment are provided in Appendix M. 

The test materials were prepared by adding equal volumes of 10 % metaphosphoric acid (MPA) to 

human serum that had been spiked with ascorbic acid. Participants were asked to provide two 

results for each vial. Participants were also asked to prepare and evaluate a standard solution of 50 

μmol ascorbic acid (AA) per L solution of 5 % by mass metaphosphoric acid. 

The final report delivered to all participants in RR09 consists of a cover letter and a series of Tables 

and Figures that summarize the results of the study. This report is reproduced as Appendix N. 

While not distributed to the participants in RR09, Appendix O is a modified “All Lab Report” that 

lists the results for the test materials transformed into units of μmol/mL sample. 

No “Individualized Report” was provided to the participants in RR09. 

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 1996;69(7):1406-1413. 

3
 
 

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. 

4
 
Appendix A. Shipping Package Inserts for RR36 

The following two items were included in each package shipped to an RR36 participant: 

• Cover letter 

• Datasheet 

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

samples themselves. 

A1
 
January 17, 1996 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standards and Technology 

Gaithersburg, Maryland 20899-

Enclosed is the set of samples for the first QA round robin exercise (Round Robin XXXVI) of FY96 . You 

will find one vial of four lyophilized serum samples for analysis along with a form for reporting your results. 

When reporting your results, please submit one value for each analyte for a given serum sample. If an 

obtained value is below your detection limit, please indicate this result on the form by using ND (Not 

Detected). For analytes not measured, please leave a blank. Results are due to NIST by March 15. Results 

received two weeks after the due date will not be included in the summary report for this round robin study. 

Results will be discussed at the QA workshop which will be held Saturday, April 13, as a pre-meeting in 

conjunction with Experimental Biology '96 in Washington, DC. Around mid-April written feedback 

concerning the study will be provided to participants who cannot attend the workshop. 

Samples should be reconstituted with 1.0 mL ofHPLC-grade water or equivalent. We recommend that 

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

with intermittent swirling. (CAUTION: Vigorous shaking will cause foaming and possibly interfere with 

accurate measurement. The rubber stopper contains phthalate esters which will lf?ach into the sample upon 

intermittent contact of the liquid sample with the stopper. These esters absorb strongly in the UV region and 

elute very near retinol in most HPLC systems creating analytical problems.) Pipette a known volume of 

serum from the vial for analysis since the final volume of the reconstituted sample is greater than 1.0 mL. For 

consistency, we request that laboratories use the following absorptivities (E 1% cm) in ethanol: retinol, 1850 

at 325 nm; retinyl palmitate, 975 at 325 nm; a-tocopherol, 75.8 at 292 nm; y-tocopherol, 91.4 at 298 nm; 

a-carotene, 2800 at 444 nm; !'-carotene, 2560 at 450 nm; lycopene (in hexane), 3450 at 472 nm. 

Please mail or FAX your results for Round Robin XXXVI to: 

Micronutrients Measurement Quality Assurance Program 

NIST 

Bldg.222,Rtn.B208 

Gaithersburg, MD 20899 

FAX: (301) 977-0685 

Also enclosed are housing information and instructions for those who plan to attend the workshop. There is 

no registration fee for the pre-meeting. However, if you plan on attending the Experimental Biology 

conference on April 14-17, a registration fee is required. Please contact the American Institute of Nutrition 

secretariat at (301)530-7050; FAX: (301)571-1892 for details regarding the conference. We will continue 

to update you with the details of the workshop as plans are finalized. If you have questions regarding this 

round robin exercise or the workshop, please call me at (301) 975-3120 or mail/FAX queries to the above 

address. L .../) 

incerely, I ~j} I /!P}t( aJ) 

anice Brown Thomas 

esearch Chemist 

nalytical Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosures 

cc: W.May 

S. Wise 

A2
 
 

 

NIST/NCI 

Micronutrients Measurement Quality Assurance Program 

Round Robin XXXVI Results from Laboratory #_____ 

Serum 

Analyte 215 216 217 218 Units* 

retinol 

retinyl palmitate 

α-tocopherol 

γ-tocopherol 

δ-tocopherol 

total β-carotene 

trans-β-carotene 

total cis-β-carotene 

total α-carotene 

total lycopene 

trans-lycopene 

β-cryptoxanthin 

lutein 

zeaxanthin 

lutein&zeaxanthin 

Other Analytes?
 

* We prefer mg/mL 

Today's Date: 

Comments? 

Mail: MMQAP, 222/B208 

NIST Please return results on-or-before Fax: 301-977-0685 

Gaithersburg, MD 20899 March 15, 1996 Email: David.Duewer@NIST.gov 

A3
 
Appendix B. Final Report for RR36

The following 20 pages are the final report for RR36 as provided to all participants: 

•	 Cover letter 

•	 A discussion entitled “Lies, Damn Lies, and Statistics” that: 

o	 describes the nature of the test samples and details any previous distributions 

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

participants 

• A “Report of (Meta)Analysis” that details the analysis of NIST measurements 

B1
 
April 23, 1996 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standard& and Technology 

Gaithersburg, Maryland 20899-

Enclosed is the summary report of the results for Round Robin XXXVI (Sera 215-218). 

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

comparability summary for evaluating laboratory performance; a summary of individual 

laboratory performance for the past three years; a summary of the interlaboratory accuracy and 

precision over the same period of time for the measurement of retinol, ex- and y-tocopherol, and 

~-carotene; and a graphical summary of the NIST assigned value vs. laboratory value for these 

analytes. The NIST assigned values are derived from the equally weighted results from the 

analyses performed by NIST and the laboratories that participated in this round robin exercise. 

In this round robin exercise, all serum samples were previously distributed. Serum 215 was 

distributed as Serum 170 in Round Robin XXVI; Serum 216 was distributed as Serum 182 in 

Round Robin XXVIII; Serum 217 as Serum 194 in Round Robin XXX; and Serum 218 as Serum 

199 in Round Robin XXXII. 

The overall laboratory performance for retinol, ex- and y-tocopherol, and ~-carotene for this 

round robin exercise is comparable to that of the overall interlaboratory performance over the 

past two years. In this round robin, the average estimated coefficient of variation (eCV) is about 

8% for both retinol and cx-tocopherol, and about 14% for y-tocopherol. The overall 

interlaboratory precision of retinol and cx-tocopherol measurements for the past two years 

averaged around 10%. The interlaboratory variation for total ~-carotene is about 19% for this 

round robin, as compared to the average eCV of around 21 % over the past two years, provided 

that the levels are above the limit of quantification. Over the past years, in exercises where the 

levels of ~-carotene were significantly lower (~100 ng/mL), a higher variation was obtained due 

to the difficulty of making measurements at levels ~100 ng/mL that appear to be at or below the 

limit of quantification for most laboratories. Similar findings are reported for retinyl palmitate, 

which was also at low concentrations in this exercise. 

Interlaboratory precision for total ex-carotene, ~-cryptoxanthin, total lycopene, lutein, and 

zeaxanthin continues to improve (provided that the levels of these analytes are above the limit of 

quantification). About 48% of the reporting laboratories submitted results for total lycopene with 

an average eCV of about 24%. Values are also reported for o-tocopherol, canthaxanthin, total 

carotenoids, cis-lutein and zeaxanthin, and coenzyme QlO. Laboratories are encouraged to 

report values for as many quantifiable analytes as possible. 

Data for evaluating laboratory performance in Round Robin XXXVI are provided in the 

comparability summary on page 6 of the report. The criteria used to summarize laboratory 

performance are as follows: results rated 1(within±1 SD of the assigned value) indicate 

EXCEPTIONAL performance, those rated 2 (within ± 2 SD) indicate ACCEPTABLE 

performance, results rated 3 (within± 3 SD of the assigned value) are MARGINAL, and those 

rated 4 (> 3 SD from the assigned value) indicate POOR performance relative to the current 

B2
 
state-of-the-practice for these measurements. 

If you have concerns regarding your laboratory performance or were rated "POOR" based on the 

criteria stated above, we suggest that you obtain a unit of SRM 968b, Fat-Soluble Vitamins and 

Cholesterol in Human Serum, and analyze all three levels. If with minor modifications, your 

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

consultation. 

Samples for Round Robin XXXVII and the food Round Robin IV (coordinated by Dr. Katherine 

Sharpless at 301/975-3121) will be shipped during the last week of April. The food round robin 

will be shipped only to the laboratories that indicate that they want samples. Results for both 

round robin exercises are due June 14; feedback to labs will be provided by July 26. 

The home page for the QA program is still under construction. Laboratories will be updated as 

to when it becomes available. Reprints are now available for the publication: Population 

Distributions and Intralaboratory Reproducibility for Fat-Soluble Vitamin-Related 

Compounds in Human Serum, Sharpless and Duewer, Anal Chem, vol. 67, pp. 4416-4422, 

1995. The following are forthcoming publications: Certification of Fat-Soluble Vitamins, 

Carotenoids, and Cholesterol in Human Serum: Standard Reference Material 968b, 

Brown Thomas et al., Fresenius J Anal Chem, 1996, Liquid Chromatographic Determination 

of Carotenoids in Human Serum Using an Engineered C30 Stationary Phase, Sharpless et 

al., J Chromatogr B:, 1996, and The Measurement of Ascorbic Acid in Human Plasma and 

Serum: Stability, lntralaboratory Repeatability, and Interlaboratory Reproducibility, 

Margolis and Duewer, Clin Chem, 1996. Please send reprint requests to: 

Micronutrients Measurement Quality Assurance Program 

National Institute of Standards and Technology 

Chemistry, B208 

Gaithersburg, MD 20899 

Fax: (301)977-0685 

· ce Brown Thomas 

search Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

cc: W.May 

B3
 
Lies, Damn Lies, and Statistics 

"Lies, Damned Lies, and Statistics" 

Mark Twain 

Page 1 

The attached N2M2QAP Round Robin XXXVI Report has the same form as RR XXXV' s. It 

includes the "All Lab" listing of everyone's results, your "Individualized" results, and our 

"(Meta)Analysis" of value and uncertainty assignments. 

The "All Lab" report has the following elements: 

Pa e Contents 

1-4 A listing of all results for analytes reported by at least two laboratories, plus 

essential summary statistics. 

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

Sb A Legend for the above two lists. 

6 The "Measurement Comparability Summary" (or "Score card") 

Your "Individualized" report has the following elements: 

Pa e Contents 

1 Your values, our assigned values, and the %bias between you and us 

2 %Bias barchart for retinol for your last 3 years' results 

3 %Bias barchart for a- and y-tocopherol for your last 3 years' results 

4 %Bias barchart for total and trans-p-carotene for your last 3 years' results 

S Our assigned value vs. your value scatterplots for retinol, a- and ytocopherol, and total and trans-p-carotene, again for your last 3 years' results 

6 Accuracy/Precision Summary, yet again for your last 3 years' results 

7 Comparison-to-Prior-Analyses plots for retinol, retinyl palmitate, a- and 

y-tocopherol, and total and trans-P-carotene 

8 Comparison-to-Prior-Analyses plots for total a-carotene, total lycopene, Pcryptoxanthin, lutein, zeaxanthin, and lutein & zeaxanthin 

The Comparison-to-Prior-Analyses plots on pages 7 and 8 show your individual results and a 

box-plot summary of the group's results, plotted against results from prior Round Robins: 

Serum 21S was distributed as 170 and 172 in RR XXVI. 

Serum 216 was distributed as 182 and 18S in RR XXVIII. 

Serum 217 was distributed as 194 in RR XXX. 

Serum 218 was distributed as 192 in RR XXX and 199 in RR XXXII. 

The horizontal lines represent the mean value over all the distributions for each serum. 

Note that sera 21S and 216 were previously distributed as same-exercise blind replicates. It is 

well worth your while to critically examine these plots. Differences between samples 170 and 

72 and between 182 and 18S speak to how well you can repeat your analyses when they are 

B4
 
Lies, Damn Lies, and Statistics Page 2 

performed within a very short time period (minutes to hours); this is short-term repeatability. 

Differences between/among 170, 172 and 215; 182, 185 and 216; 194 and 217; and 192, 199, 

and 218 speak to how well you can repeat your analyses when separated by a rather long time 

period (months to years); this is long-term repeatability. You will be hearing more about this. 

We are currently analyzing the past twelve years(!) of M2N2QAP interlaboratory comparison 

results. One aspect of the analysis of considerable interest is the relationship between 

interlaboratory variation (reproducibility eSD) and analyte concentration (median). The attached 

Table and Figures summarize the analysis. Note that: 1) the eSD has a low-concentration 

asymptote; 2) while all the high-concentration relationships appear linear, the slopes are different 

among the analytes; and 3) the "Coefficient of Variation" is -constant over the analytical range 

of clinical interest only for retinal and a-tocopherol. We are currently modifying our analysis of 

interlaboratory results for very low analyte concentrations. We also are examining our quality 

criteria for the different analytes. 

In our report for RR XXXV, we provided reference to some recent literature on the concentration 

of various fat-soluble vitamin-related compounds of interest. We apologize for switching the 

values for References S (Olmedilla, 1992) and 6 (Ascherio, 1992) in the associated table of 

summary values. Dr. Olmedilla provides an additional reference: 

Olmedilla B, Granado F, Blanco I, Rojas-Hidalgo E. Seasonal and sex-related variations 

in six serum carotenoids, retinol, and a-tocopherol. Am J Clin Nutr 1994; 60: 106-10. 

We would be most grateful if you would forward to us any pre/reprints you may have that are 

relevant to defining the analytical range for compounds of interest. We will provide a complete 

and updated summary with the RR XXX:Vill report. 

Your comments and suggestions are welcome. If you discover any errors in our recording or 

interpretation of your data, please let us know! 

~JL~ DaveDuewer 

Research Chemometrician 

David.Duewer@NIST.gov 

-/j"~~;a-._-

Margaret Kline 

Research Biologist 

Margaret.Kline@NIST.gov 

B5
 
Lies, Damn Ues, and Statistics Page 3 

Long-term Reproducibility as a Function of Analyte Concentration• 

eSD = ~L~ + CPo x [Analyte]"• )2 Trainingb Evaluationc 

Analyte Code Lqc Po P1 n ~soc n ~so~ 

Retinol R 0.020 (0.003) 0.088 (0.005) 1.17 (0.07) 39 1.2 76 1.4 

a-Tocopherol aT 0.41 (0.06) 0.03 (0.02) 1.3 (0.2) 39 1.3 76 1.5 

y-Tocopherol yT 0.10 (0.03) 0.07 (0.03) 1.0 (0.3) 39 1.4 36 1.7 

Total p-Carotene TpC 0.007 (0.003) 0.129 (0.008) 0.80 (0.07) 39 1.3 76 1.6 

trans-P-Carotene tPC 0.006 (0.003) 0.09 (0.01) 1.0 (0.2) 38 1.8 32 3.2 

Retinyl Palmitate RP 0.024 (0.003) 0.2 (0.S) 1 (2) 34 1.6 15 3.5 

Total a-Carotene aC 0.003 (0.002) 0.24 (0.01) 0.96 (0.02) 39 1.4 20 1.9 

P-Cryptoxanthin per 0.002 (0.003) 0.149 (0.006) 0.8 (0.1) 39 1.3 20 2.1 

Total Lycopene Ly 0 0.21 (0.02) 0.86 (0.05) 39 1.3 36 1.6 

a) Concentrations in μg/mL 

-· Results for samples distributed in RR XXVIl through RR XXXV were used to "train" the 

least-squares regression. 

c) Results for samples distributed in RR Vill through RR XXVI we used to evaluate the 

predictive utility of the regression models. 

d) The concentration-space "standard deviation" is an asymmetric factor, with ~SD spanning 

the region from (concentration I SD) to (concentration x SD). 

B6
 
Lies, Damn Lies, llld Statistics Page4 

1 Retinol 

0.1 

0.1 

0.01 

Total P-Carotene 

trans-P-Carotene 

l 1 

0.1 

1 

1 

10 10 

a-Tocopherol 

'Y'" Tocopherol 

3z 3 

33 

1 1 

Median (μg/mL) 

Dependence of Dispersion on Location: eSD as a Function of Concentration. 

100 

1 

0.1 

1 

0.1 

10 

These plots display the dependencies of eSD (0.741 x interquartile range) on the median estimate ·of analyte concentration. The data have been divided into three approximately equal-sized 

groups by: all data taken during 198~9 ("l"), 1990-92 ("2"), and 1993--95 ("3"). The lines 

represent least squares regression to the model: eSD = ~L~ + (~0 x Median!!• )2 , using just the 

most recent third of the data. Each axis of each scattergram spans the same 120-fold relative 

concentration range. 

B7
 
Lies. Damn Lies, and Statistics Pages 

0.01 0.1 0.01 0.1 

a-Carotene p-Cryptoxanthin 0.1 

0.01 

0.01 

0.001 

Lycopene Retinyl Palmita.te 

0.1 2 0.1 

0.01 0.01 

0.1 1 0.01 0.1 

Median (J.Lg/mL) 

Dependence of Dispersion on Location: eSD as a Function of Concentration. 

B8
 
Ues, Damn Ucs, and Statistics 

80 

' 60 I 

I 

• 

" 

-

~ .._ 

c: 

0 40 

·= ~ 'ti 

> 

~ 20 

c 

~ 

40 i ' .... 

e I I I 

\ \ I 

~ ' I 

(.) I 

I 

'i I 

8. 30 I 

I 

I 

~ I 

20 

10 

0.01 0.1 1 10 

Analyte Concentration (μg/mL) 

Dependence of Expected Coefficient of Variation on Analyte Concentration. 

Curves are displayed for eCV as calculated from all eSD regression models shown in the 

previous Figures. Dashed light lines span the entire range of analyte concentrations encountered 

during analysis of U.S. adult human sera; the solid dark lines span the central 90% of these 

measurements; the median is denoted as"•". 

B9
 
Reporl of(Meta)Analysisfor RR XXXVI Sera: 215-218 Page 1 

From: David L. Duewer Date: April 12, 1996 

To: Jeanice Brown Thomas, Margaret Kline, Willie E. May, Katherine E. Sharpless 

cc: Gary W. Kramer, Dennis J. Reeder, Stephen A. Wise 

Re: Value and Uncertainty Assignment for the NIST/NCI Micronutrient Measurement 

Quality Assurance Program's Round Robin XXXVI (RR36) Sera: 215 to 218. 

Background: Four sera were distributed in RR36. Serum 215 was distributed as 170 and 172 in 

RR26, serum 216 was distributed as 182 and 185 in RR28, serum 217 was distributed as 194 in 

RR30, and serum 218 was distributed as 192 in RR30 and 199 in RR32. Note that both sera 216 

and 217 were originally distributed as same-exercise blind replicates. 

Analysts NISTl and NIST3 independently extracted and analyzed two aliquots of three vials of 

each serum using normal procedures. Both analysts reported quantitative results for retinol, 

a-tocopherol, y-tocopherol, total~carotene, andtrans-~-carotene. Analyst NIST3 also reported 

results for retinyl palmitate, &-tocopherol, total a-carotene, trans-a-carotene, total lycopene, 

trans-lycopene, P-cryptoxanthin, "lutein", and "zeaxanthin". (NIST3 is uncertain about the 

isomeric composition of the lutein and zeaxanthin peaks.) 

Results: Table 1 presents the NIST data, summary statistics for the NIST data, summary results 

for the most recent previous exercise for each serum, summary results for RR36, and the NIST 

assigned values and uncertainties. Table 2 presents a compact summary of the assigned values 

and uncertainties for each analyte in each serum. 

The entries in Table 1 are as follows: 

• Individual NIST Analyst Data and Summary Statistics 

A: 1 to C:2 two aliquots (" 1" and "2") of three vials (A, B, and C) of each serum were 

extracted and analyzed. Each analyst analyzed a separate set of three vials. 

~ number of quantitative values for this analyte for this serum for this analyst 

M~ arithmetic average 

SD11 simple standard deviation 

SDrepx within-vial pooled standard deviation, reflecting variation in extraction, 

chromatography, peak integration, etc. 

SDbeix among-sample standard deviation, reflecting heterogeneity in preparing and 

reconstituting the serum samples 

SDNISTx ~SD~x +SD~ , total standard deviation. This value is ~ SD11 , as sample 

replicates reduce the true degrees of freedom. 

CV NJSTx 100 x SD NJSTIMean11 

• NIST Summary Statistics 

n number of quantitative values for this analyte for this serum 

Mean (MeanNISTt + MeanNISn)/2 or MeanNIST3 for analytes that NISTl did not report 

SDrep within-vial pooled standard deviation 

SDbet among-sample standard deviation 

SDan1 between-analyst standard deviation. This is estimated as the residual standard 

deviation for the linear regression of NISTl 's Mean11 values onto NIST3' s. For 

analytes that NISTl did not report, SDan1 is estimated from the regression of the 

RR35 interlaboratory Median (see below) onto NIST3's Mean11 values. The 

B10
 
Reportof(Meta)AnalysisforRRXXXVI Sera: 215-218 

regression model used to determine SD11111 is defmed to the right of this block. Details include: the model used, the parameters and standard errors on the 

parameters, and R2 for the regression. 

SDNIST ~SD!r, +SD~ + SD!m , total standard deviation for NIST analyses. 

CV NIST 100 x SD ms/Mean 

• Previous Round Robin Summary Statistics 

RR identifier of the Round Robin in which this serum was distributed 

Serum identifier of the serum 

Page2 

n., number of non-NIST laboratories reporting quantitative values for this analyte 

for this serum in this Round Robin 

MedianP median of the reported values. The median is a robust location estimate 

eSDP 0.741 x InterQuartile Range (IQR). The IQR is a robust dispersion estimate. The scale factor 0.741 is the expected ratio between SD and IQR for normal 

distributions. 

• Round Robin XXXVI Summary Statistics 

Du number of non-NIST laboratories reporting quantitative values for this analyte 

for this serum in this Round Robin 

Median0 median of the reported values 

eSD0 0.741 x InterQuartile Range (IQR) 

( IMedian0 -MedianP1~--n_+_nP ___ 2 . ) 

P(n;;;;;p) TDKST - ---· n., +n -2 2 tall 

{<n0 -l)eSD! +(nP -l)eso;)(_!_+_!_)' 0 

' 

no np 

This is the approximate probability that the median in RR35 is the same as it 

was in the previous RR. Where the hypothesis that Median0 = edi~ could be 

rejected with 95% confidence, the P(n=p) value would be flagged with an "*". 

TDIST is Excel®'s student's t function. 

( eSD2 ) P(n<p) FOIST -----}, Du-1, n.,-1 eSD0 

This represents the approximate probability that the interlaboratory variance in 

RR36 is smaller than it was in the previous RR. Where the hypothesis that 

eSD0 < eSDP can be rejected with 95% confidence, the P(n<p) value is flagged 

with an "*". FOIST is Excel®' s F-distribution function. 

SDlabs ~eSD! - SD~ , the residual non-NIST interlaboratory biases after correction 

for measurement-, sample-, and NIST-analyst-related sources of variance. 

When SDNIST is greater than eSD0 , so .. = 0. 

CV1abs 100 x SD~ediaJ\i 

•NIST Assigned Values and Uncertainties 

NA V (Mean + Median0 ) / 2, our best guess of the "true" analyte level 

NAU Maximum( 0.05 x NAV, ~SD~sT +SD~), our best guess for the "true" 

interlaboratory standard deviation characterizing measurement, sample 

heterogeneity, inter-analyst, and interlaboratory sources of variation. When 

SDlabs could not be determined, NAU is estimated as 

Maximum( 0.10 x NA V, ~2 SD~ST ). 

CV lOOxNAU /NAV 

B11
 
Report of (Meta)Analysis for RR XXXVI Sera: 215-218 Page 3 

Conclusions: All median values from RR36 (Medimlu) are statistically indistinguishable at the 

95% confidence level from the corresponding values (Medimlu) determined in previous exercises. 

Nearly all of the interlaboratory standard deviations from RR36 (eSD0 ) are likewise 

indistinguishable at the 95% confidence level from their previous values (eSD ). The few 

apparent increases are scattered across analytes and sera: there is no evidence for degradation of 

any of the sera during storage. 

The two sets of sera that were originally distributed as same-exercise blind duplicates provide a 

mechanism for examining both short- and long-term repeatability. While strictly a property of 

individual laboratories, we can easily evaluate the repeatability characteristic of an "average" 

participant. The following example is for retinol, with the first set of sera: 170 and 172 

distributed in RR26 and 215 distributed in RR36. 

Lab 

n 

Median 

IQR 

170 

0.69 

0.61 

0.67 

0.65 

0.60 

0.63 

0.67 

0.62 

0.76 

0.71 

0.64 

0.65 

0.67 

0.65 

0.61 

0.70 

0.68 

0.65 

0.69 

0.67 

0.59 

0.66 

0.69 

0.72 

0.68 

0.77 

0.77 

0.70 

0.68 

0.64 

0.68 

0.61 

32 

0.668 

0.047 

Mean 

0.68 

0.61 

0.68 

0.66 

0.60 

0.63 

0.67 

0.63 

0.72 

0.70 

0.65 

0.65 

0.67 

0.65 

0.62 

0.71 

0.71 

0.62 

0.69 

0.67 

0.60 

0.66 

0.69 

0.70 

0.70 

0.78 

0.77 

0.71 

0.67 

0.66 

0.67 

0.61 

32 

0.667 

0.053 

Lab 

32 Ratio 

-0.~ -0.011 o.026 0.49 

Amon -Exercise "Lon -Tenn,. 

170 172 215 Mean A 

0.69 0.68 0.67 0.67 0.02 

0.61 0.62 0.59 0.60 0.02 

0.67 0.69 0. 0.67 0.02 

0.60 0.60 ' 0. 0.60 

0.67 0.67 0.6 0.65 

0.62 0.64 0.63 0.63 

0.76 0.68 0.58 0.65 

o. 71 0.69 0.66 0.68 

0.65 0.65 0.65 0.65 

0.67 0.67 0.47 0.57 

0.65 0.65 0.65 0.65 

0.68 

0.65 

0.69 

0.59 

0.72 

0.77 

0.77 

0.70 

0.68 

0.64 

0.68 

0.61 

0.74 

0.60 

0.68 

0.60 

0.68 

0.79 

0.77 

0.72 

0.66 

0.67 

0.65 

0.61 

0.69 

0.63 

0. 

0. 

0.55 

0.70 

0.63 

0.67 

0.60 

0.62 

0.63 0.71 

0.62 0.69 

0. 0.68 

0.7 0.71 

0.75 0.70 

0.68 0.67 

0.55 0.58 

0.02 

-0.01 

0.03 

0.00 

0.15 

23 

0.670 

0.049 

23 

0.671 

0.045 

23 23 23 Ratio .-------~----, 

0.63 0.652 0.021 0.03 

0.061 ~---~~~ 0.055 0.061 1.11 

Where: MeanA = (X170+Xp~)/2, fl.A= X170-X1w MeanB =(Mean A +"'215)/2, and ll.B = MeanA-Xzis· 

The short- and long-term t>tas are more conveniently expressed relative to the sample 

concentration: (median ll.) I (median Mean). The corresponding repeatabilities are more 

conveniently expressed relative to the interlaboratory reproducibility: (IQR ll.) I (IQR Mean). 

B12
 
Report of(Meta)Analysisfor RR XXXVI Sera: 215-218 Page4 

In this example, the short-term repeatability is about one-half (0.49) of the interlaboratory 

reproducibility; the long-term repeatability is slightly LARGER ( 1.11) than the reproducibility. 

The following summarizes the fractional biases and repeatabilities for a number of analytes, 

where the short-term values have been pooled over the two same-exercise sets and the long-term 

have been pooled over the six different-exercise pairs. 

Bias 

Anal te N Short Lon Short Lon 

0.001 0.040 0.29 1.46 

-0.003 0.046 0.42 1.33 

0.007 0.043 0.48 1.48 

-0.007 0.017 0.50 1.55 

0.022 -0.023 0.35 0.79 

-0.006 0.030 0.26 1.76 

-0.007 -0.007 0.29 0.98 

0.045 0.015 0.37 0.77 

0.022 0.002 0.37 2.30 

a-Tocopherol 40 

Retinol 38 

Total p-Carotene 28 

y-Tocopherol 16 

Total a-Carotene 16 

Total Lycopene 16 

P-Cryptoxanthin 11 

Retinyl palmitate 8 

trans-p-Carotene 6 '---'-~~~~~~--'-~~~~~~~ 

Where "N'' is the average number of laboratories contributing data, the short- and long-term 

biases are (median A) I (median Mean), and the repeatabilities are (IQR A) I (IQR Mean). The 

long-term biases tend to be a little larger than the short-term, but this is at the "noise level" of the 

data. ALL short-term repeatabilities are much smaller than the reproducibility. ALL long-term 

repeatabilities are much larger than their short-term cousins; long-term repeatabilities for the 

data-rich analytes are considerably larger than the reproducibilities. 

The basic conclusion is that our "average" participant is as or more variable over time as the "in 

control" group of laboratories taken as a whole. Individual participants, of course, will have 

their own characteristic repeatabilities ... some much better and some rather worse than this 

"average" analysis. 

~We could "rank" individual laboratories by their long-term repeatabilities. ¢:: 

Is this desirable? 

Systematic constant and/or proportional biases are again apparent between the NISTl and NIST3 

analyses for many analytes. These biases are statistically significant when the standard errors for 

the intercept "a" and/or slope "b" regression parameters are small relative to the differences 

between the observed and expected 0.0 (intercept) and 1.0 (slope) values. 

This memo will be included as part of the Round Robin XXXVI report. 

Dave Duewer _, 

Reseach Busybody 

/u.,LA._ __ _ 

B13
 
Report of (Meta)Analysisfor RR XXXVI Sera: 215-218 

Table 1 

NIST Data and Calculations 

Retinol Retinyl Palmitate 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n,. 

Mean,. 

SD,. 

so_ 

SDhelx 

NISTl 

215 216 217 

0.707 0.548 0.425 

0.685 0.610 0.444 

0.674 0.554 0.445 

0.688 0.537 0.442 

0.675 0.547 0.445 

0.611 0.448 

5 6 6 

0.686 0.568 0.442 

0.013 0.033 0.008 

0.011 0.037 0.008 

0.011 0.019 0.006 

218 

1.071 

1.048 

1.021 

1.032 

0.993 

1.036 

6 

1.034 

0.026 

0.020 

0.023 

NIST3 NISTl 

215 216 217 218 215 216 217 218 

0.661 0.539 0.433 1.048 0.248 

0.660 0.540 0.443 1.075 0.228 

0.660 0.564 0.431 1.049 0.279 

0.702 0.562 0.424 1.035 0.249 

0.724 0.567 0.439 1.050 0.249 

0.686 0.565 0.443 1.049 0.230 

6 6 6 6 6 0 0 0 

0.682 0.556 0.436 1.051 0.247 

0.027 0.013 0.008 0.013 O.ot8 

0.023 0.001 0.005 0.012 0.017 

0.022 O.ot5 0.007 0.010 O.ot5 

S~ 0.015 0.042 0.010 0.031 0.032 O.ot5 0.009 0.016 0.022 

CVNISTx 2.2 7.4 2.3 3.0 4.7 2.7 2.1 1.5 9.0 

n 

Mean 

SD1e11 

SD bet 

SDaa1 

NIST 

11 12 12 

0.684 0.562 0.439 

0.019 0.026 0.007 

0.016 0.016 0.007 

0.006 0.006 0.006 

12 

1.042 

0.017 

0.017 

0.006 

SI>ms,. 0.025 0.031 0.012 0.025 

CVNIST 3.7 5.6 2.7 2.4 

RR XXVI XXVIIl xxx 

Serum 170 182 194 

np 33 43 43 

Medianp 0.668 0.550 0.430 

eSDp 0.035 0.051 0.037 

RRXXXVI 

n,, 

Median,, 

eSD8 

P(n=p) 

P{n<p) 

215 216 

45 45 

0.657 0.536 

0.055 0.039 

0.96 0.95 

0.00* 0.96 

217 

45 

0.425 

0.037 

0.98 

0.56 

XXXIl 

199 

39 

1.070 

0.075 

218 

45 

1.059 

0.082 

0.94 

1.00 

so .. 0.049 0.022 0.035 0.078 

cvllbs 7.4 4.2 8.2 7.4 

NIST3=a+b*NIST1 

a: -0.032 ±0.010 

b: 1.046 ±0.015 

R2: 0.999 

<-Current Results-> 

NIST 

8 0 0 0 

0.242 

0.016 

0.015 

0.022 

9.1 

XXVI XXVIII XXX XXXII 

170 182 194 199 

8 8 6 6 

0.307 0.08 0.04 0.05 

0.033 0.02 0.04 0.03 

215 

14 

0.300 

0.062 

0.95 

0.05* 

0.058 

19 

RRXXXVI 

216 217 218 

13 8 10 

0.06 0.02 0.03 

0.02 0.03 0.03 

0.77 0.79 0.56 

0.30 0.86 0.96 

NA V 0.670 0.549 0.432 1.051 <-Assignments-> I 0.271 

NAU 0.055 0.039 0.037 0.082 0.062 "'"""""~~~~~~~~ 

CV 8.2 7.0 8.5 7.8 23 

[36_dat]NISTtlt 

NIST3 

215 216 217 218 

0.226 

0.247 

2 0 0 

0.237 

0.015 

0.015 

Page 117 

0 

B14
 
A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n,. 

Mean,. 

SD,. 

so_ 

SI>i.ea 

215 

6.03 

6.43 

5.96 

5.79 

6.27 

5 

6.10 

0.25 

0.17 

0.22 

Report of (Meta)Analysis for RR XXXVI Sera: 215-218 

Table 1 

NIST Data and Calculations 

a-Tocopherol y-Tocopherol 

NISTl NIST3 NISTl 

216 217 218 215 216 217 218 215 216 217 218 215 

5.67 7.09 7.09 6.06 5.71 7.57 7.26 2.39 2.02 2.47 2.55 2.00 

5.93 6.77 6.99 6.19 5.71 7.28 6.97 2.36 2.25 2.77 2.27 2.01 

5.61 7.13 7.13 5.92 5.86 7.84 7.19 2.23 2.05 2.68 2.02 1.95 

5.25 6.95 7.23 6.05 5.83 7.45 7.06 2.00 2.10 3.16 2.22 1.99 

5.81 6.99 7.45 5.98 5.83 1.59 7.24 2.05 2.05 2.94 2.39 1.96 

5.83 6.80 6.89 6.51 5.73 7.56 7.51 2.13 2.59 2.15 2.07 

6 6 6 6 6 6 6 5 6 6 6 6 

5.68 6.95 7.13 6.13 5.78 7.55 7.21 2.21 2.10 2.77 2.27 2.00 

0.24 0.15 0.20 0.23 0.07 0.18 0.19 0.18 0.08 0.25 0.19 0.04 

0.18 0.17 0.24 0.25 0.04 0.20 0.17 0.09 0.10 0.27 0.17 0.05 

0.22 0.07 0.08 0.14 0.07 0.11 0.15 0.17 0.03 0.15 0.15 0.02 

NIST3 

216 217 218 

2.53 3.10 2.40 

2.52 3.02 2.34 

2.57 3.14 2.37 

2.52 3.07 2.37 

2.51 3.07 2.35 

2.51 3.12 2.39 

6 6 6 

2.53 3.09 2.37 

0.02 0.04 0.02 

0.02 0.05 0.03 

0.02 0.02 0.00 

SDmsr,. 0.28 0.29 0.18 0.25 0.29 0.08 0.23 0.22 0.20 0.11 0.31 0.23 0.05 0.03 0.05 0.03 

CVNISTX 4.6 5.0 2.6 3.5 4.7 1.4 3.0 3.1 8.9 5.0 11 10.0 2.6 1.2 1.7 1.3 

n 

Mean 

SD~ 

SDhet 

SD1111 

11 

6.11 

0.14 

0.20 

0.26 

NIST 

12 12 12 

5.73 7.25 7.17 

0.13 0.22 0.19 

0.16 0.22 0.13 

0.26 0.26 0.26 

SDms-r 0.35 0.33 0.40 0.35 

CVNIST 5.8 5.7 5.5 4.9 

RR XXVI XXV1II xxx 

Serum 

np 

MediaDo 

eSDp 

na 

MediaDo 

eSD0 

P(n=p) 

P(n<p) 

170 

35 

6.15 

0.63 

215 

43 

5.97 

0.44 

0.94 

0.99 

182 194 

43 43 

5.48 7.30 

0.40 0.55 

RRXXXVI 

216 217 

43 43 

5.47 7.18 

0.37 0.67 

1.00 0.97 

0.69 0.10 

XXXII 

199 

41 

7.25 

0.48 

218 

43 

7.01 

0.56 

0.93 

0.88 

SI>i.i,. 0.26 0.17 0.54 0.44 

cvlabs 4.3 3.1 7.5 6.3 

NIST3=a+b*NIST1 

a:O 

b: 1.03 ±0.02 

R2: 0.826 

<-Previous Results -> 

<-Current Results-> 

NAV 6.04 5.60 7.22 

NAU 0.44 0.37 0.67 

7.09 <-Assignments-> 

0.56 

CV 7.2 6.6 9.3 7.9 

[36_dat)NISTht 

NIST 

11 12 12 12 

2.10 2.31 2.93 2.32 

0.07 0.08 0.20 0.12 

0.22 0.16 0.12 0.10 

0.28 0.28 0.28 0.28 

0.36 0.33 0.36 0.32 

17 14 12 14 

XXVIXXVill xxx XXXII 

170 182 194 199 

12 16 20 18 

2.10 2.48 3.22 2.48 

0.26 0.12 0.38 0.27 

RRXXXVI 

215 

21 

1.97 

0.29 

0.88 

0.39 

0 

0 

216 

21 

2.50 

0.28 

0.97 

0.00* 

0 

0 

217 218 

21 21 

3.08 2.41 

0.33 0.35 

0.90 0.89 

0.73 O.ot* 

0 0.14 

0 5.6 

2.04 2.41 3.00 2.36 

0.36 0.33 0.36 0.35 

18 14 12 15 

NIST3=a+b*NIST1 

a:O 

b: 1.07 ±0.06 

R2:0.391 

Page 217 

B15
 
Report of(Meta)Analysis for RR XXXVI Sera: 215-218 

Table 1 

NIST lData and Calculations 

trans-Lycopene 

NISTl NIST3 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n,. 

Mean,. 

SD,. 

so,_ 

so.­

SDmm, 

CVNISTx 

215 

0 

216 217 

0 0 

NIST 

n 

Mean 

SD1e11 

SDhet 

SDw 

6 6 

0.116 0.137 

0.005 0.004 

0.002 0.003 

0.009 0.009 

Sl>msr 0.010 0.010 

CVNIST 8.9 7.5 

RR XXVI XXV1II 

Serum 170 182 

Dp 1 0 

Medianp 0.134 

6 

0.275 

0.002 

0.002 

0.009 

0.009 

3.3 

xxx 

194 

218 

0 

6 

0.323 

0.006 

0.004 

0.009 

0.012 

3.6 

XXXII 

199 

1 

0.353 

eSDp ________ __, 

n,. 

Medianp 

eso. 

P(n=p) 

P(n<p) 

RRXXXVI 

215 216 217 

7 7 7 

0.134 0.157 0.324 

0.026 0.013 0.014 

218 

7 

0.401 

0.075 

SD1abs 0.024 0.008 0.010 0.074 

cv..... 18 5.3 3.1 18 

215 216 217 218 

0.113 0.129 0.277 0.312 

0.124 0.138 0.275 0.324 

0.113 0.138 0.275 0.323 

0.117 0.141 0.278 0.330 

0.111 0.143 0.280 0.316 

0.119 0.134 0.267 0.332 

6 6 6 6 

0.116 0.137 0.275 0.323 

0.005 0.005 0.005 0.008 

0.006 0.005 0.006 0.009 

0.002 0.003 0.002 0.004 

0.006 0.006 0.006 0.010 

5.3 4.5 2.1 3.0 

NIST3=a+b*Median 

a: 0.018 ±0.016 

b: 0.772 ±0.050 

R2: 0.992 

<-Previous Results -> 

<-Current Results-> 

NAV 0.125 0.147 0.300 0.362 <-Assignments-> 

NAU 0.026 0.013 0.015 0.075 

CV 21 9.0 5.0 21 

[36_dll)NIS'l'lltt 

P-Cryptoxanthin 

NISTl NIST3 

215 216 217 218 

0 0 0 0 

NIST 

6 6 6 6 

0.049 0.034 0.034 0.044 

0.005 0.003 0.001 0.002 

0.003 0.002 0.001 0.004 

0.002 0.002 0.002 0.002 

0.007 0.004 0.003 0.005 

13 12 7.6 10 

XXVIXXVIII xxx XXXII 

170 182 194 199 

9 11 18 16 

0.073 0.042 0.056 0.071 

0.007 0.009 0.014 0.017 

RRXXXVI 

215 216 217 218 

17 17 17 17 

0.059 0.039 0.042 0.055 

0.016 0.012 0.014 0.019 

0.67 0.93 0.75 0.82 

0.02* 0.22 0.47 0.55 

0.014 0.011 0.014 0.018 

24 28 33 33 

0.054 0.037 0.038 0.050 

0.016 0.012 0.014 0.019 

29 32 37 37 

215 216 217 218 

0.048 0.038 0.037 0.041 

0.049 0.034 0.034 0.046 

0.057 0.033 0.034 0.040 

0.048 0.038 0.035 0.042 

0.041 0.032 0.037 0.050 

0.049 0.031 0.028 0.046 

6 6 6 6 

0.049 0.034 0.034 0.044 

0.005 0.003 0.003 0.004 

0.005 0.002 0.004 0.003 

0.003 0.002 0.001 0.004 

0.006 0.003 0.004 0.004 

12 9.9 12 10 

NIST3=a+b*Median 

a: 0.008 ±0.006 

b: 0.649 ±0.135 

R2:0.918 

Page617 

B16
 
Report of (Meta)Analysis for RR XXXVI Sera: 215-218 

Table 1 

NIST Data and Calculations 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

nx 

Meanx 

SDx 

so_ 

215 

0 

8-Tocopherol 

NISTl NIST3 

216 217 218 215 216 217 218 

0.08 0.12 0.13 0.13 

0.08 0.14 0.11 0.14 

0.07 0.13 0.12 I 0.14 

0.08 0.14 0.11 0.12 

0.09 0.12 0.10 0.12 

0.07 0.13 0.12 0.13 

0 0 0 6 6 6 6 

0.08 0.13 0.12 0.13 

0,01 0.01 0.01 0.01 

0.01 0.01 0.01 0.01 

0.00 0.01 0.00 0.01 

Total ~-Carotene 

NISTl NIST3 

215 216 217 218 215 216 217 218 

0.665 0.385 0.635 0.498 0.405 0.048 0.557 

0.598 0.450 0.613 0.600 0.407 0.047 0.578 

0.674 0.431 0.598 0.521 0.425 0.056 0.568 

0.666 0.447 0.585 0.555 0.435 0.057 0.562 

0.693 0.394 0.669 0.525 0.423 0.049 0.579 

0.443 0.571 0.583 0.420 0.052 0.561 

5 6 0 6 6 6 6 6 

0.659 0.425 0.612 0.547 0.419 0.052 0.567 

0.036 0.028 0.036 0.039 0.012 0.004 0.009 

0.028 0.034 0.041 0.050 0.004 0.002 0.012 

SI>i..ix 0.031 0.012 0.018 0.008 0.012 0.005 0.002 

SDmsrx 

CVNISTx 

0.01 0.01 0.01 0.01 0.042 0.036 0.045 0.051 0.013 0.005 0.012 

9.7 7.2 8.3 9.8 6.3 8.5 7.4 9.3 3.1 9.3 2.1 

n 

Mean 

SDreo 

SD bet 

SD1111 

6 

0.08 

0.01 

0.00 

0.03 

NIST 

6 6 6 

0.13 0.12 0.13 

0.01 0.01 0.01 

0.01 0.00 0.01 

0.03 0.03 0.03 

Sl>ms-r 0.03 0.03 0.03 0.03 

CV NIST 38 24 27 25 

RR XXVI XXVIII xxx 

Serum 

np 

Median, 

eSDp 

Dn 

Median, 

eSDa 

P(n=p) 

P(n<p) 

170 

215 

4 

0.15 

0.21 

182 194 

0 0 

RRXXXVI 

216 217 

4 4 

0.19 0.11 

0.17 0.16 

XXXII 

199 

1 

0.81 

218 

4 

0.12 

0.15 

SD1a11s 0.21 0.17 0.16 0.15 

CV1a11s 141 86 144 124 

NIST3=a+b*Median 

a: 0.11 ±0.07 

b: 0.02 ±0.47 

R2: 0.000 

<-Previous Results -> 

<-Current Results -> 

NAV 0.12 0.16 

NAU 0.21 0.17 

CV 190 100 

0.11 

0.16 

140 

0.13 <-Assignments-> 

0.15 

120 

(36_dal]NISTtxt 

NIST 

11 12 6 12 

0.603 0.422 0.052 0.590 

0.038 0.024 0.001 0.030 

0.008 0.012 0.005 0.002 

0.016 0.016 0.016 0.016 

o.042 0.032 o.op 0.034 

7.0 7.5 32 5.8 

XXVIXXVIII xxx XXXII 

170 182 194 199 

30 33 32 32 

0.602 0.430 0.060 0.593 

0.093 0.067 0.021 0.068 

RRXXXVI 

215 216 

31 30 

0.551 0.391 

0.090 0.071 

0.89 0.89 

0.58 0.37 

0.079 0.063 

14 16 

217 218 

31 30 

0.056 0.565 

0.014 0.098 

0.95 0.92 

0.98 0.29 

0 0.092 

0 16 

0.577 0.406 0.054 0.577 

0.090 0.071 0.017 0.098 

16 17 31 17 

NIST3=a+b*Median 

a:O 

b: 1.026 ±0.023 

R2: 0.993 

Page311 

B17
 
Report of(Meta)Analysis/or RR XXXVI Sera: 215-218 

Table 1 

NIST Data and Calculations 

trans-P-Carotene 

NISTl NIST3 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n,. 

Mean,. 

SD,. 

so_ 

so_ 

215 216 217 

0.539 0.344 

0.520 0.365 

0.515 0.343 

0.508 0.331 

0.548 0.381 

0.398 

5 6 0 

0.526 0.360 

0.017 0.026 

0.008 0.012 

0.018 0.027 

218 215 216 217 218 

0.598 0.480 0.393 0.052 0.509 

0.488 0.551 0.389 0.053 0.530 

0.488 0.495 0.390 0.060 0.517 

0.486 0.514 0.395 0.059 0.519 

0.528 0.505 0.399 0.052 0.507 

0.487 0.536 0.401 0.050 0.514 

6 6 6 6 6 

0.513 0.514 0.395 0.054 0.516 

0.045 0.026 0.005 0.004 0.008 

0.048 0.033 0.003 0.001 0.009 

0.028 0.008 .0.005 0.005 0.005 

snmm 0.020 0.029 

CVN!S'l'll 3.8 8.1 

0.056 0.034 0.006 0.005 0.010 

11 6.5 1.4 8.6 2.0 

n 

Mean 

SD1e11 

SD bet 

SD1111 

NIST 

11 12 6 

0.520 0.377 0.054 

0.023 0.009 0.001 

0.008 0.005 0.005 

0.024 0.024 0.024 

12 

0.514 

0.034 

0.005 

0.024 

SI>mn 0.034 0.026 0.025 0.042 

CV NIST 6.6 7 .0 46 8.3 

RR XXVI XXVIIl XXX XXXIl 

NIST3=a+b*Median 

a:O 

b: 0.928 ±0.035 

R2: 0.979 

Serum 170 182 194 199 <-Previous Results -> 

Dp 4 5 9 7 

Mediano 0.553 0.397 0.049 0.531 

eSD0 0.020 0.016 0.047 

RRXXXVI 

Dn 

Median. 

eSDn 

P(n=p) 

P(n<p) 

215 216 

11 11 

0.532 0.395 

0.079 0.041 

0.98 

0.09 

SDi.t,. 0.072 0.032 

cvllbs 13 8.1 

217 218 

11 11 

0.053 0.577 

0.015 0.081 

0.91 0.89 

0.58 0.39 

0 0.069 

0 12 

<-Current Results -> 

NA V 0.526 0.386 0.054 0.546 <-Assignments-> 

NAU 0.079 0.041 0.025 0.081 

CV 15 11 46 15 

[36_dalJNISTtxt 

Total a-Carotene 

NISTl NIST3 

215 216 217 

0 0 0 

NIST 

6 6 6 

0.028 0.022 0.013 

0.012 0.003 0.000 

0.003 0.003 0.002 

0.001 0.001 0.001 

0.012 0.004 0.002 

44 20 19 

XXVI XXVIII xxx 

170 182 194 

16 15 21 

0.024 0.016 0.012 

0.007 0.006 0.003 

RRXXXVI 

215 216 217 

23 21 21 

0.022 0.016 0.014 

0.008 0.004 0.007 

0.95 1.00 0.91 

0.34 0.86 o.oo• 

0 

0 

0 0.007 

0 50 

218 

0 

6 

0.039 

0.009 

0.013 

0.001 

0.015 

40 

XXXII 

199 

21 

0.017 

0.006 

218 

21 

0.019 

0.011 

0.96 

0.07 

0 

0 

0.025 0.019 0.013 0.029 

0.012 0.004 0.007 0.015 

50 23 55 53 

215 216 217 218 

0.019 0.021 0.014 0.042 

0.043 0.021 0.014 0.064 

0.020 0.017 0.011 0.028 

0.032 0.022 0.010 0.029 

0.023 0.029 0.013 0.040 

0.029 0.020 0.014 0.030 

6 6 6 6 

0.028 0.022 0.013 0.039 

0.009 0.004 0.002 0.014 

0.011 0.004 0.000 0.010 

0.003 0.003 0.002 0.013 

0.012 0.005 0.002 0.016 

41 23 15 41 

NIST3=a+b*Median 

a: -0.061 ±0.007 

b: 5.247 ±0.398 

R2: 0.989 

Pacc417 

B18
 
Report of (Meta)Analysis for RR XXXVI Sera: 215-218 

Table 1 

NIST Data and Calculations 

trans-a-Carotene 

NISTl NIST3 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n,. 

Mean,. 

SD,. 

so_ 

SDa.ec,. 

SDmsr,. 

CVNISTx 

n 

Mean 

SDiep 

SDhet 

SD1111 

SDms,-

CV NIST 

215 

0 

6 

0.03 

0.01 

0.00 

216 217 218 

0 0 0 

NIST 

6 6 6 

0.02 0.017 0.02 

0.01 0.002 0.01 

0.00 0.002 0.01 

RR XXV1 XXVII1 XXX XXXIl 

215 216 217 218 

0.02 0.02 0.017 0.02 

0.03 0.02 0.021 0.04 

0.02 0.01 0.016 0.02 

0.03 0.02 0.017 0.02 

0.03 0.03 0.017 0.02 

0.02 0.02 0.014 0.02 

6 6 6 6 

0.03 0.02 0.017 0.02 

0.00 0.00 0.002 0.01 

0.01 0.01 0.002 0.01 

0.00 0.00 0.002 0.01 

0.01 0.01 0.003 0.01 

23 27 16 46 

Serum 170 182 194 199 <-PreviousResults-> 

Dp 0 0 0 

MediaDp 

eSDp.__ _______ _ 

n. 

MediaDa 

eSD0 

P(n=p) 

P(n<p) 

SD1a11o 

CV1a11o 

215 

0 

RRXXXVI 

216 217 218 

0 0 0 

<-Current Results -> 

NAVI 0.03 0.02 0.017 0.021 <-Assignments-> 

NAU~----------' 

CV 

[36_dal)NISTlltt 

Total Lycopene 

NISTl NIST3 

215 216 217 

0 0 0 

NIST 

6 6 6 

0.222 0.247 0.59 

0.018 0.021 0.02 

0.016 0.006 0.01 

0.019 0.019 0.02 

0.031 0.029 0.03 

14 12 4.8 

XXVIXXVill xxx 

170 182 194 

16 16 23 

0.190 0.215 0.50 

0.061 0.051 0.13 

RRXXXVI 

215 216 217 

23 23 23 

0.186 0.191 0.46 

0.047 0.043 0.13 

0.98 0.87 0.93 

0.88 0.75 0.55 

0.035 0.033 0.13 

19 17 28 

0.204 0.219 0.52 

0.047 0.043 0.13 

23 20 2S 

218 

0 

6 

0.66 

0.03 

0.01 

0.02 

0.04 

5.6 

xxxn 

199 

22 

0.57 

0.13 

218 

23 

0.53 

0.12 

0.88 

0.86 

0.12 

22 

0.60 

0.12 

21 

215 216 217 218 

0.191 0.225 0.63 0.63 

0.216 0.274 0.59 0.68 

0.217 0.255 0.58 0.63 

0.243 0.246 0.59 0.67 

0.261 0.269 0.59 0.68 

0.200 0.211 0.58 0.65 

6 6 6 6 

0.222 0.247 0.59 0.66 

0.025 0.025 0.02 0.02 

0.027 0.031 0.02 0.03 

0.016 0.006 0.01 0.01 

0.031 0.032 0.02 0.03 

14 13 3.7 4.3 

NIST3=a+b*Median 

a:O 

b: 1.263 ±0.026 

R2:0.985 

Pate5/7 

B19
 
Report of(Meta)Anal.ysisfor RR XXXVI Sera: 215-218 

Table 1 

NIST Data and Calculations 

''Lutein" "Zeaxanthin" 

NISTl 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

Ds 

Means 

SDK 

so_ 

so.. 

SDmsr,. 

CVNISTJ< 

215 

0 

216 217 

0 0 

NIST 

n 

Mean 

SD1e11 

SD bet 

SDu1 

6 6 

0.108 0.042 

0.004 0.001 

0.002 0.002 

0.004 0.004 

SI>mn 0.006 0.005 

CVNIST 5.7 11 

RR XXVI XXVIII 

Serum 170 182 

Dp 4 7 

Medianp 0.109 0.040 

eSDp 0.003 

6 

0.074 

0.004 

0.003 

0.004 

0.007 

9.1 

xxx 

194 

14 

0.092 

0.036 

RRXXXVI 

n. 

Median. 

eSD. 

P(n=p) 

P(n<p) 

215 216 

12 12 

0.109 0.038 

0.014 0.005 

0.83 

0.17 

217 

12 

0.067 

0.009 

0.72 

1.00 

218 

0 

6 

0.080 

0.001 

0.003 

0.004 

0.005 

6.6 

XXXII 

199 

11 

0.090 

0.025 

218 

12 

0.073 

0.012 

0.74 

1.00 

SDlabo 0.012 0.002 0.006 0.010 

cvlabo 11 5.2 9.5 14 

NIST3 

215 216 217 218 

0.111 0.044 0.076 0.082 

0.107 0.042 0.077 0.083 

0.102 0.041 0.079 0.082 

0.108 0.043 0.071 0.080 

0.105 0.038 0.073 0.076 

0.112 0.042 0.068 0.076 

6 6 6 6 

0.108 0.042 0.074 0.080 

0.004 0.002 0.004 0.003 

0.004 0.002 0.004 0.001 

0.002 0.002 0.003 0.003 

0.005 0.002 0.005 0.003 

4.4 5.8 6.5 4.1 

NIST3=a+b*Median 

a: 0.010 ±0.006 

b: 0.917 ±0.082 

R2: 0.968 

<-Previous Results-> 

<-Current Results-> 

NA V 0.108 0.040 0.070 0.076 <-Assignments-> 

NAU 0.014 0.005 0.009 0.012 

CV 13 13 13 15 

(36_dat)NISTutt 

NISTl 

215 216 217 218 

0 0 0 0 

NIST 

6 6 6 6 

0.052 0.030 0.044 0.054 

0.004 0.002 0.001 0.001 

0.003 0.002 0.008 0.002 

0.004 0.004 0.004 0.004 

0.006 0.005 0.009 0.005 

12 16 20 8.9 

XXVIXXVill xxx XXXII 

170 182 194 199 

3 3 6 7 

0.040 0.030 0.034 0.030 

0.010 0.011 

RRXXXVI 

215 216 217 218 

8 8 8 8 

0.048 0.026 0.030 0.035 

0.015 0.003 0.007 0.012 

0.77 0.96 

0.80 0.31 

0.013 

28 

0 

0 

0 0.011 

0 33 

0.050 0.028 0.037 0.045 

O.ot5 0.005 0.009 0.012 

30 17 24 28 

NIST3 

215 216 217 218 

0.058 0.035 0.047 0.057 

0.053 0.031 0.048 0.056 

0.046 0.029 0.050 0.055 

0.052 0.030 0.049 0.053 

0.050 0.027 0.042 0.051 

0.055 0.032 0.028 0.052 

6 6 6 6 

0.052 0.030 0.044 0.054 

0.004 0.003 0.008 0.002 

0.004 0.003 0.006 0.001 

0.003 0.002 0.008 0.002 

0.005 0.003 0.010 0.003 

9.0 11 22 4.9 

NIST3=a+b*Median 

a: -0.049 ±0.008 

b: 2.956 ±0.255 

R2: 0.985 

Page7/7 

B20
 
Report of(Meta)Analysisfor RR XXXVI Sera: 215-218 

Table2 

Summary of Assigned Values and Uncertainties 

215 216 217 218 

Analyte NAV NAU CV NAV NAU CV NAV NAU CV NAV NAU CV 

Retinol 0.670 0.055 8.2 0.549 0.039 7.0 0.432 0.037 8.5 1.051 0.082 7 .8 

Retinyl Palmitate 0.271 0.062 23 

a-Tocopherol 6.04 0.44 7.2 5.60 0.37 6.6 7.22 0.67 9.3 7.09 0.56 7.9 

y-Tocopherol 2.04 0.36 18 2.41 0.33 14 3.00 0.36 12 2.36 0.35 15 

5-Tocopherol 0.12 0.21 190 0.16 0.17 100 0.11 0.16 140 0.13 0.15 120 

Total p-Carotene 0.577 0.090 16 0.406 0.071 17 0.054 0.017 31 0.577 0.098 17 

trans-P-Carotene 0.526 0.079 15 0.386 0.041 11 0.054 0.025 46 0.546 0.081 15 

Total a-Carotene 0.025 0.012 50 0.019 0.004 23 0.013 0.007 55 0.029 0.015 53 

trans-a-Carotene 0.03 0.02 0.017 0.02 

Total Lycopene 0.204 0.047 23 0.219 0.043 20 0.52 0.13 25 0.60 0.12 21 

trans-Lycopene 0.125 0.026 21 0.147 0.013 9.0 0.300 0.015 5.0 0.362 0.075 21 

p-Cryptoxanthin 0.054 0.016 29 0.037 0.012 32 0.038 0.014 37 0.050 0.019 37 

''Lutein" 0.108 0.014 13 0.040 0.005 13 0.070 0.009 13 0.076 0.012 15 

''Zeaxanthin" 0.050 0.015 30 0.028 0.005 17 0.037 0.009 24 0.045 0.012 28 

[36_dat]SummarvTxt "age II I 

B21
 
 

 

Appendix C. “All-Lab Report” for RR36 

The following 6 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 XXXVI Laboratory Results 

Values in μg/mL 

Total Retinol Retinyl Palmitate α-Tocopherol γ-Tocopherol

Lab 

FSV-BA 

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-BW 

FSV-BX 

FSV-BY 

FSV-BZ 

FSV-CA 

FSV-CB 

FSV-CC 

FSV-CD 

FSV-CF 

FSV-CG 

FSV-CH 

FSV-CK 

FSV-CM
 

FSV-CN
 

FSV-CQ
 

FSV-CR
 

FSV-CS
 

FSV-CT
 

FSV-CU
 

FSV-CX
 

FSV-DA
 

FSV-DB
 

FSV-DJ
 

FSV-DK
 

FSV-DM
 

FSV-DP
 

FSV-DS
 

FSV-DU
 

FSV-DX
 

FSV-EA
 

FSV-EH
 

FSV-EK
 

FSV-EL
 

215 216 217 218 

0.647 0.541 0.433 1.057 

215 216 217 218 215 216 217 218 215 216 217 218 

0.283 0.071 0.059 0.075 6.23 5.72 7.28 7.21 1.62 1.96 2.45 1.85 

0.624 0.530 0.415 1.054 5.65 5.00 6.74 6.31 

0.661 0.544 0.440 1.073 6.50 5.86 7.71 7.51 1.97 2.65 3.25 2.47 

0.630 0.505 0.439 0.959 6.26 5.45 6.77 7.01 1.83 2.33 2.78 2.19 

0.660 0.530 0.470 1.150 0.309 0.050 0.014 0.034 6.06 5.52 7.39 7.18 

0.666 0.499 0.416 1.065 0.357 0.048 nd nd 6.32 5.75 7.44 7.38 2.22 2.71 3.26 2.56 

0.591 0.501 0.396 0.981 0.352 0.043 nd nd 5.85 5.27 7.01 6.94 1.90 2.35 2.88 2.24 

0.629 0.522 0.418 1.021 0.313 nd nd nd 5.94 5.23 7.07 6.87 2.04 2.42 3.08 2.20 

0.657 0.584 0.462 1.194 5.89 5.26 6.90 6.92 

0.687 0.544 0.458 1.088 5.94 5.43 7.32 7.15 

0.688 0.530 0.410 0.950 5.90 5.70 8.60 8.80 

0.740 0.621 0.509 1.240 0.520 0.083 nd nd 6.63 6.10 7.95 7.64 2.42 3.25 3.62 2.78 

0.748 0.564 0.470 1.106 6.42 5.47 6.46 6.59 

0.656 0.533 0.435 0.961 5.93 5.72 7.05 7.01 

0.670 0.580 0.440 1.030 

0.740 0.580 0.430 1.060 

0.630 0.460 0.400 0.810 

4.90 3.90 5.40 5.50 

0.547 0.537 0.422 1.051 0.286 0.065 0.013 0.032 5.60 5.71 7.21 7.14 1.80 2.66 3.18 2.45 

0.640 0.547 0.511 1.381 6.01 5.24 7.35 6.17 1.90 2.38 3.26 2.78 

0.750 0.640 0.510 1.290 0.360 0.043 nd 0.034 6.40 5.50 7.30 6.90 1.60 1.80 2.20 1.70 

0.653 0.522 0.447 1.028 5.87 5.25 6.66 6.52 1.92 2.36 2.86 2.16 

0.665 0.523 0.417 1.054 0.322 0.068 0.011 0.025 6.18 5.57 7.18 7.24 2.12 2.52 3.00 2.41 

6.06 5.68 7.58 7.47 1.87 2.05 2.81 2.22 

0.597 0.476 0.351 0.890 5.18 4.91 5.85 6.21 

0.615 0.534 0.412 1.059 5.79 5.17 6.60 6.75 

0.722 0.556 0.434 1.072 5.04 4.57 5.74 5.74 

0.657 0.541 0.425 1.090 0.249 0.078 0.034 0.083 8.14 7.42 9.68 9.09 2.75 3.33 4.11 3.09 

0.705 0.580 0.463 1.141 6.90 6.10 8.20 8.00 

0.628 0.498 0.405 1.021 2.92 2.30 2.30 3.39 2.19 2.70 3.16 2.55 

0.550 0.450 0.340 0.820 5.97 5.09 6.22 6.24 2.10 2.50 2.90 2.32 

0.680 0.550 0.450 1.110 6.16 5.75 7.18 7.30 2.12 2.72 3.24 2.83 

5.30 6.20 7.70 6.50 

0.689 0.544 0.453 1.009 6.50 5.42 7.74 6.92 1.79 2.19 2.81 2.01 

0.577 0.454 0.389 0.931 6.11 5.03 7.03 7.28 

0.710 0.590 0.470 1.190 

0.678 0.562 0.424 1.120 

6.00 5.60 7.00 7.00 

0.693 0.573 0.416 1.119 6.25 5.66 7.43 7.34 

0.602 0.508 0.409 0.995 0.253 0.063 0.047 0.089 5.94 5.20 6.44 6.76 

0.700 0.560 0.480 1.170 0.290 0.030 0.050 0.040 6.30 5.53 7.20 7.05 2.24 2.72 3.54 2.66 

0.723 0.660 0.487 1.100 0.220 0.070 0.010 0.030 6.80 6.58 8.51 7.95 2.28 3.01 3.60 2.73 

0.735 0.610 0.475 1.155 6.43 6.03 7.72 7.60 

0.694 0.535 0.436 1.101 6.20 5.20 7.60 8.40 

0.550 0.510 0.390 1.090 0.140 0.024 nd 0.012 5.59 5.29 6.46 6.67 

0.630 0.536 0.425 1.074 

0.684 0.545 0.448 1.093 

5.46 5.27 6.61 7.04 

0.680 0.520 0.350 0.880 8.78 7.89 7.79 8.66 

1.079 0.619 0.481 1.272 11.74 6.48 9.07 8.52 

0.612 0.526 0.402 1.019 5.96 5.76 7.25 7.18 

0.570 0.500 0.400 0.940 5.10 4.80 6.10 6.10 2.50 3.10 3.60 3.00 

0.570 0.520 0.430 1.060 5.27 5.19 7.04 6.76 1.70 2.22 2.83 2.17 

0.578 0.504 0.407 0.994 

0.760 0.650 0.500 1.170 

5.34 5.22 6.18 6.43 1.49 2.05 2.43 1.89 

n 50 50 50 50 14 13 8 10 47 47 47 47 23 23 23 23 

Min 0.547 0.450 0.340 0.810 0.140 0.024 0.010 0.012 2.92 2.30 2.30 3.39 1.49 1.80 2.20 1.70 

Median 0.661 0.537 0.432 1.063 0.300 0.063 0.024 0.034 6.00 5.47 7.18 7.01 1.97 2.50 3.08 2.41 

Max 1.079 0.660 0.511 1.381 0.520 0.083 0.059 0.089 11.74 7.89 9.68 9.09 2.75 3.33 4.11 3.09 

eSD 0.052 0.039 0.035 0.082 0.072 0.022 0.020 0.011 0.47 0.40 0.77 0.55 0.27 0.33 0.36 0.37 

eCV 8 7 8 8 24 35 83 33 8 7 11 8 14 13 12 15 

NISTa
 

NISTb
 

NAV 

NAU 

0.686 0.568 0.442 1.034 0.247 nd nd nd 6.10 5.68 6.95 7.13 2.21 2.10 2.77 2.27 

0.682 0.556 0.436 1.051 0.237 nd nd nd 6.13 5.78 7.55 7.21 2.00 2.53 3.09 2.37 

0.672 0.549 0.435 1.052 0.300 0.063 0.024 0.034 6.06 5.60 7.22 7.09 2.03 2.41 3.00 2.36 

0.057 0.048 0.038 0.092 0.072 0.022 0.020 0.011 0.57 0.57 0.71 0.62 0.30 0.35 0.34 0.39 

All Lab Report C2 Page 1 / 6 
Round Robin XXXVI Laboratory Results 

Values in μg/mL 

δ-Tocopherol Total β-Carotene trans-β-Carotene Total cis-β-Carotene

Lab 215 216 217 218 215 216 217 218 215 216 217 218 215 216 217 218 

FSV-BA 0.600 0.442 0.067 0.604 0.572 0.423 0.062 0.577 0.028 0.019 0.005 0.027 

FSV-BD 0.458 0.331 0.048 0.468
 

FSV-BE
 0.656 0.458 0.066 0.668
 

FSV-BF
 0.566 0.419 0.068 0.570
 

FSV-BG
 0.636 0.082
 

FSV-BH
 0.578 0.401 0.051 0.590 0.549 0.385 0.051 0.557 0.029 0.016 nd 0.033 

FSV-BI 0.537 0.377 0.057 0.553
 

FSV-BJ
 0.662 0.473 0.063 0.637 

FSV-BK 

FSV-BL 

FSV-BM 

FSV-BN 0.118 0.183 0.082 0.108 0.619 0.462 0.054 0.644 0.590 0.440 0.054 0.610 0.029 0.022 nd 0.034 

FSV-BO 0.406 0.298 0.052 0.404
 

FSV-BP
 0.385 0.257 0.044 0.407
 

FSV-BQ
 

FSV-BR
 

FSV-BS
 0.630 0.447 0.110 0.625 0.603 0.416 0.080 0.598 0.027 0.031 0.030 0.027 

FSV-BT 0.706 0.605 0.538 0.521 0.469 0.376 0.049 0.541 0.444 0.362 0.048 0.509 0.025 0.014 0.001 0.032 

FSV-BU 0.495 0.345 0.051 0.514 

FSV-BW 0.480 0.330 0.050 0.500
 

FSV-BX
 0.442 0.366 0.086 0.549 

FSV-BY 0.098 0.098 0.073 0.076 0.571 0.424 0.056 0.628 0.540 0.395 0.053 0.597 0.031 0.029 0.003 0.031 

FSV-BZ 0.459 0.366 0.003 0.488 0.451 0.365 0.002 0.468 0.008 0.001 0.001 0.020 

FSV-CA 

FSV-CB 

FSV-CC 

FSV-CD >0.460 >0.315 >0.034 >0.398 0.460 0.315 0.034 0.398
 

FSV-CF
 

FSV-CG
 0.673 0.471 0.061 0.671
 

FSV-CH
 0.526 0.337 0.045 0.484
 

FSV-CK
 0.600 0.410 0.060 0.590 

FSV-CM 

FSV-CN >0.566 >0.365 >0.029 >0.467 0.566 0.365 0.029 0.467
 

FSV-CQ
 0.465 0.326 0.025 0.442
 

FSV-CR
 

FSV-CS
 

FSV-CT
 0.591 0.417 0.055 0.633
 

FSV-CU
 0.584 0.435 0.079 0.636 0.532 0.398 0.068 0.580 0.052 0.037 0.011 0.056 

FSV-CX 0.680 0.480 0.070 0.780
 

FSV-DA
 0.183 0.203 0.142 0.135 0.488 0.555 0.110 0.735 0.431 0.503 0.088 0.667 0.057 0.052 0.022 0.068 

FSV-DB 0.570 0.440 0.050 0.620 

FSV-DJ
 

FSV-DK
 0.510 0.350 0.040 0.500 

FSV-DM 0.551 0.412 0.058 0.578
 

FSV-DP
 

FSV-DS
 0.410 0.380 0.100 0.540
 

FSV-DU
 >0.630 >0.390 nd >0.650 0.630 0.390 nd 0.650
 

FSV-DX
 >0.456 >0.340 >0.041 >0.444 0.456 0.340 0.041 0.444
 

FSV-EA
 0.540 0.340 0.050 0.560
 

FSV-EH
 0.073 0.100 0.094 0.110 0.506 0.400 0.085 0.580 0.470 0.376 0.085 0.524 0.036 0.024 nd 0.056 

FSV-EK 0.447 0.354 0.088 0.500
 

FSV-EL
 

n 5 5 5 5 33 32 33 32 14 14 13 14 10 10 7 10 

Min 0.073 0.098 0.073 0.076 0.385 0.257 0.003 0.404 0.431 0.315 0.002 0.398 0.008 0.001 0.001 0.020 

Median 0.118 0.183 0.094 0.110 0.540 0.401 0.057 0.574 0.536 0.388 0.053 0.567 0.029 0.023 0.005 0.033 

Max 0.706 0.605 0.538 0.521 0.680 0.555 0.110 0.780 0.630 0.503 0.088 0.667 0.057 0.052 0.030 0.068 

eSD 0.067 0.123 0.031 0.037 0.089 0.069 0.013 0.091 0.099 0.035 0.022 0.075 0.004 0.011 0.006 0.008 

eCV 57 67 33 34 16 17 23 16 18 9 42 13 15 48 119 25 

NISTa 

NISTb 

NAV 

NAU 

0.659 0.425 nd 0.612 0.526 0.360 nd 0.513 0.133 0.065 nd 0.099 

0.080 0.130 0.117 0.132 0.547 0.419 0.052 0.567 0.514 0.395 0.054 0.516 0.033 0.024 -0.003 0.051 

0.099 0.157 0.105 0.121 0.573 0.411 0.056 0.582 0.529 0.382 0.052 0.541 0.057 0.034 0.004 0.054 

0.069 0.085 0.047 0.025 0.108 0.070 0.015 0.097 0.085 0.042 0.020 0.096 0.087 0.046 0.011 0.057 

All Lab Report C3 Page 2 / 6 
Lab 

FSV-BA 

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-BW 

FSV-BX 

FSV-BY 

FSV-BZ 

FSV-CA 

FSV-CB 

FSV-CC 

FSV-CD 

FSV-CF 

FSV-CG 

FSV-CH 

FSV-CK 

FSV-CM
 

FSV-CN
 

FSV-CQ
 

FSV-CR
 

FSV-CS
 

FSV-CT
 

FSV-CU
 

FSV-CX
 

FSV-DA
 

FSV-DB
 

FSV-DJ
 

FSV-DK
 

FSV-DM
 

FSV-DP
 

FSV-DS
 

FSV-DU
 

FSV-DX
 

FSV-EA
 

FSV-EH
 

FSV-EK
 

FSV-EL 

n 

Min 

Median 

Max 

eSD 

eCV 

NISTa 

NISTb 

NAV 

NAU 

Round Robin XXXVI Laboratory Results 

Values in μg/mL 

Total α-Carotene trans-α-Carotene Total Lycopene trans-Lycopene 

215 216 217 218 

0.031 0.014 0.012 0.019 

0.029 0.018 0.022 0.014 

0.026 0.017 0.039 0.037 

0.025 0.014 0.010 0.017 

0.022 0.012 0.011 0.014 

0.035 0.026 0.020 0.026 

0.026 0.016 0.013 0.015 

0.019 0.011 0.009 0.012 

0.019 0.015 0.013 0.029 

0.034 0.023 0.020 0.032 

0.019 0.013 0.016 0.018 

0.030 0.010 0.010 0.020 

0.021 0.017 0.016 0.017 

0.026 0.019 0.023 0.032 

0.022 0.019 0.014 0.032 

0.015 0.010 0.006 0.007 

0.035 0.027 0.024 0.031 

0.017 0.009 0.008 0.009 

nd nd nd nd 

0.010 <0.01 0.010 <0.01 

0.015 0.015 0.018 0.021 

nq nq nq nq 

0.015 nd nd 0.003 

0.031 0.028 0.031 0.026 

0.020 0.021 nd nd 

0.010 nd nd 0.010 

215 216 217 218 

0.03 0.02 0.02 0.03 

215 216 217 218 

0.144 0.155 0.36 0.44 

0.218 0.227 0.51 0.64 

0.213 0.179 0.63 0.65 

0.228 0.235 0.57 0.66 

0.120 0.130 0.31 0.35 

0.124 0.132 0.28 0.33 

0.267 0.276 0.63 0.71 

0.279 0.229 0.70 0.88 

0.175 0.188 0.39 0.50 

0.161 0.162 0.37 0.44 

0.154 0.178 0.42 0.50 

0.150 0.150 0.40 0.48 

0.129 0.327 0.64 0.74 

0.204 0.249 0.50 0.62 

0.190 0.191 0.44 0.48 

0.170 0.174 0.42 0.48 

0.204 0.189 0.46 0.53 

0.175 0.177 0.40 0.46 

0.164 0.165 0.46 0.51 

0.210 0.210 0.53 0.62 

0.118 0.213 0.59 0.58 

0.220 0.250 0.57 0.65 

0.217 0.204 0.45 0.62 

0.203 0.251 0.72 0.82 

0.186 0.191 0.33 0.43 

215 216 217 218 

0.135 0.152 0.304 0.37 

0.135 0.159 0.324 0.39 

0.128 0.148 0.335 0.42 

0.134 0.177 0.325 0.40 

0.019 0.157 0.255 0.55 

0.071 0.130 0.320 0.33 

0.188 0.210 0.448 0.55 

0.110 0.157 0.453 0.52 

24 21 21 22 1 1 1 1 25 25 25 25 8 8 8 8 19 19 19 19 

0.010 0.009 0.006 0.003 0.118 0.130 0.28 0.33 0.019 0.130 0.255 0.33 0.033 0.024 0.027 0.031 

0.022 0.016 0.014 0.019 0.031 0.018 0.015 0.025 0.186 0.191 0.46 0.53 0.131 0.157 0.325 0.41 0.059 0.039 0.042 0.055 

0.035 0.028 0.039 0.037 0.279 0.327 0.72 0.88 0.188 0.210 0.453 0.55 0.086 0.055 0.065 0.080 

0.009 0.004 0.006 0.011 0.046 0.043 0.12 0.13 0.019 0.010 0.023 0.09 0.016 0.010 0.013 0.018 

40 28 42 60 25 23 27 25 14 6 7 21 28 27 31 32 

β-Cryptoxanthin

215 216 217 218 

0.074 0.053 0.059 0.067 

0.045 0.030 0.034 0.040 

0.086 0.053 0.065 0.078 

0.070 0.044 0.043 0.055 

0.056 0.039 0.041 0.045 

0.058 0.034 0.040 0.050 

0.071 0.050 0.059 0.080 

0.054 0.034 0.033 0.042 

0.063 0.048 0.051 0.063 

0.033 0.033 0.051 0.055 

0.070 0.050 0.056 0.067 

0.049 0.035 0.030 0.039 

0.048 0.031 0.037 0.042 

0.064 0.041 0.044 0.058 

0.048 0.024 0.027 0.031 

0.060 0.040 0.040 0.050 

0.059 0.037 0.042 0.056 

0.084 0.055 0.065 0.076 

0.048 0.032 0.039 0.045 

0.028 0.022 0.013 0.039 

0.025 0.019 0.013 0.029 

0.012 0.007 0.007 0.022 

0.204 0.219 0.52 0.60 

0.055 0.063 0.16 0.16 

0.124 0.147 0.300 0.37 

0.029 0.035 0.075 0.12 

nd nd nd nd 

0.027 0.020 0.017 0.024 0.222 0.247 0.59 0.66 0.116 0.137 0.275 0.32 0.049 0.034 0.034 0.044 

0.054 0.037 0.038 0.050 

0.018 0.012 0.013 0.018 

All Lab Report C4 Page 3 / 6 
Round Robin XXXVI Laboratory Results 

Values in μg/mL 

α-Cryptoxanthin Lutein Zeaxanthin Lutein&Zeaxanthin 

Lab 215 216 217 218 215 216 217 218 215 216 217 218 215 216 217 218 

FSV-BA 0.202 0.098 0.143 0.154 

FSV-BD 0.106 0.037 0.058 0.064 0.042 0.021 0.021 0.024 0.148 0.058 0.079 0.088 

FSV-BE 

FSV-BF 

FSV-BG 

FSV-BH 0.108 0.039 0.057 0.070 0.049 0.027 0.020 0.022 0.157 0.066 0.077 0.092 

FSV-BI 0.106 0.037 0.067 0.069 0.047 0.023 0.028 0.035 0.153 0.067 0.098 0.106 

FSV-BJ
 

FSV-BK
 

FSV-BL
 

FSV-BM
 

FSV-BN
 0.028 0.010 0.017 0.016 0.111 0.037 0.068 0.075 0.073 0.030 0.043 0.047 0.184 0.067 0.111 0.122 

FSV-BO 0.102 0.044 0.071 0.073 

FSV-BP 

FSV-BQ 

FSV-BR 

FSV-BS 0.110 0.030 0.075 0.114
 

FSV-BT
 0.033 0.020 0.036 0.033 0.136 0.064 0.097 0.090 0.016 0.027 0.032 0.029 0.152 0.091 0.129 0.119 

FSV-BU 

FSV-BW 

FSV-BX 0.161 0.027 0.064 0.076 0.095 0.026 0.026 0.044 

FSV-BY 0.108 0.040 0.066 0.089 0.035 0.025 0.031 0.035 0.143 0.065 0.097 0.124 

FSV-BZ 0.086 0.047 0.059 0.061
 

FSV-CA
 

FSV-CB
 

FSV-CC
 

FSV-CD
 0.230 0.102 0.147 0.145 

FSV-CF 

FSV-CG 0.127 0.074 0.103 0.109 

FSV-CH 

FSV-CK 0.043 0.026 0.044 0.051 0.184 0.088 0.132 0.138 

FSV-CM 

FSV-CN 0.124 0.049 0.075 0.066
 

FSV-CQ
 

FSV-CR
 

FSV-CS
 

FSV-CT
 0.099 0.035 0.065 0.070
 

FSV-CU
 

FSV-CX
 0.160 0.080 0.110 0.120 

FSV-DA 0.126 0.042 0.078 0.082 0.056 0.035 0.041 0.052 0.182 0.077 0.119 0.134 

FSV-DB 0.140 0.070 0.096 0.100 

FSV-DJ 

FSV-DK 

FSV-DM 0.139 0.061 0.095 0.099 

FSV-DP 

FSV-DS 

FSV-DU 

FSV-DX 0.158 0.060 0.092 0.104 

FSV-EA 

FSV-EH 0.090 0.046 0.064 0.073 0.051 0.025 0.028 0.034 0.142 0.071 0.092 0.107 

FSV-EK 0.153 0.087 0.110 0.116 

FSV-EL 

n 3 3 3 3 14 14 14 14 9 9 9 9 17 17 17 17 

Min 0.028 0.010 0.017 0.016 0.086 0.027 0.057 0.061 0.016 0.021 0.020 0.022 0.102 0.044 0.071 0.073 

Median 0.033 0.020 0.036 0.033 0.109 0.040 0.067 0.074 0.049 0.026 0.028 0.035 0.153 0.070 0.098 0.109 

Max 0.043 0.026 0.044 0.051 0.184 0.088 0.132 0.138 0.095 0.035 0.043 0.052 0.230 0.102 0.147 0.154 

eSD 0.019 0.008 0.012 0.012 0.010 0.003 0.006 0.013 0.017 0.013 0.018 0.016 

eCV 17 21 18 17 21 10 21 37 11 19 18 15 

NISTa 

NISTb 

NAV 

NAU 

0.108 0.042 0.074 0.080 0.052 0.030 0.044 0.054 0.160 0.072 0.118 0.134 

0.108 0.041 0.070 0.077 

0.024 0.009 0.016 0.017 

0.051 0.028 0.036 0.045 

0.014 0.008 0.015 0.017 

0.156 

0.033 

0.071 

0.015 

0.108 

0.025 

0.121 

0.029 

All Lab Report C5 Page 4 / 6 
Term 

n 

Min 

Median
 

Max
 

eSD 

eCV 

NAV 

NAU 

nd 

nq 

>x 

<x 

italics

Round Robin XXXVI Laboratory Results 

Analytes Reported By One Laboratory
 

Values in μg/mL
 

Analyte 

cis-(Lutein&Zeaxanthin) 

Coenzyme Q10 

Canthaxanthin 

Total Carotenoids 

Code 215 216 217 218 

FSV-BT 0.058 0.035 0.097 0.099 

FSV-CH 0.340 0.343 0.566 0.419 

FSV-CD nd nd 0.053 0.050 

FSV-BT 1.031 0.813 0.916 1.485 

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 

 Estimated standard deviation, calculated from the median absolute deviation

 from the median of the non-NIST results

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

 NIST Assigned Value, our estimate of the "true" analyte concentration

 NIST Assigned Uncertainty, our estimate of the total (serum hetergeniety and

 inter- and intra-laboratory) standard deviation 

 For details on how we assign these quantities, see the "Report of (Meta)Analysis."

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

 Detected but not quantitatively determined

 Concentration greater than or equal to x

 Concentration at or below the limit of detection, x

 Not explicitly reported but calculated by NIST from reported values

All Lab Report C6 Page 5 / 6 
 

 

 

Round Robin XXXVI Laboratory Results
 

Comparability Summary
 

Lab 

FSV-BA
 

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-BW 

FSV-BX 

FSV-BY 

FSV-BZ 

FSV-CA 

FSV-CB 

FSV-CC 

FSV-CD 

FSV-CF 

FSV-CG 

FSV-CH 

FSV-CK 

FSV-CM 

FSV-CN 

FSV-CQ 

FSV-CR 

FSV-CS 

FSV-CT 

FSV-CU 

FSV-CX 

FSV-DA 

FSV-DB 

FSV-DJ 

FSV-DK 

FSV-DM 

FSV-DP 

FSV-DS 

FSV-DU 

FSV-DX 

FSV-EA 

FSV-EH 

FSV-EK 

FSV-EL 

NISTa 

NISTb 

R aT gT bC tbC 

1 1 1 1 1 

1 2 1 1 

1 1 2 

2 1 

2 1 2 

2 1 1 1 

2 1 2 

1 1 1 1 

2 1 2 1 1 

1 1 1 1 1 

2 3 2 1 

2 2 1 2 

2 2 1 4 3 

1 1 

1 3 

2 1 1

3

3 1 2 1

4 2 1 2

3 1 1 

1 1 2 2 

1 1 2 2 

1 

3 2 3 

1 1 3 1 2 

1 3 4 2 

1 4 1 

1 2 2 

2 4 3 

3 2 1 1 1 

1 1 

2 

1 1 

2 1 1 1 

2 1 

1 

1 1 1 

2 2 2 3 

2 1 3 2 

3 2 2 

2 1 1 

1 3 2 1 

3 2 2 4 3 

1 2 

1 

3 4 2 2 2 

4 4 1 2 

2 1 

2 2 3 2 

2 2 

2 2 

3 2 

1 1 1 1 1 

1 1 1 1 1 

n 46 44 22 32 13 

StS 

1 43 55 55 47 46 

2 41 34 36 38 46 

3 20 9 14 9 15

4 4 9 0 9 0 

% Observed 

Label 

Lab

R 

aT 

gT 

bC 

tbC 

n 

Definition 

 laboratory number 

 "Standard Score" for Retinol 

"Standard Score" for α-Tocopherol

"Standard Score" for γ-Tocopherol

 "Standard Score" for Total β-Carotene

"Standard Score" for trans-β-Carotene

 number of (non-NIST) laboratories providing data for this analyte 

"Standard Score" 

Given that our knowledge of the shape, location, and width of the measurement distributions is 

approximate and that a limited number of labs are involved, we summarize comparability with the 

following four-level "Standard Score" (StS)... 

StS 

1

 2

 3

 4

where: 

StV 

NAV 

NAU 

t (1-α,n-1) 

Expected 

68.2 % 

27.3 % 

 4.3 % 

0.3 %

Definition

 All StV within ±t (1-0.683,n-1) {i.e., ±1 SD} 

 All StV within ±t (1-0.954,n-1) {i.e., ±2 SD} 

 All StV within ±t (1-0.997,n-1) {i.e., ±3 SD} 

 At least one StV > ±t (1-0.997,n-1) {i.e., >3 SD} 

 Standardized Value, the distance in standard deviation units your

 value is from the "true" concentration: StV = (your value - NAV) / NAU 

 NIST Assigned Value, our estimate of the "true" analyte concentration

 NIST Assigned Uncertainty, our estimate of the total (serum heterogeniety and iterand intra-laboratory) measurement standard deviation.

 Two-tailed Student's t for coverage of ±1, ±2, and ±3 NAU about 

 NAV, assuming a normal population of size n 

For details on the NIST Assigned quantities, see this Round Robin

"Report of (Meta)Analysis." 

's 

These are the observed and normal-population-expected proportions of each 

Standard Score (StS), based upon each laboratory's largest StV for the four sera. 

All Lab Report C7 Page 6 / 6 
 

Appendix D. Representative “Individualized Report” for RR36 

Each participant in RR36 received an “Individualized Report” reflecting their reported 

results. Each report included a detailed analysis of the results they reported for some or 

all of the following analytes: 

• Retinol 

• Retinol palmitate 

• α-Tocopherol 

• γ-Tocopherol 

• Total β-Carotene 

• trans-β-Carotene 

• Total α-Carotene 

• Total Lycopene 

• β-Cryptoxanthin 

• Lutein 

• Zeaxanthin 

• Lutein & Zeaxanthin 

The following 8 pages are the “Individualized Report” for the analytes evaluated by 

participant FSV-BA. 

D1
 
11/04/ 1996 

Individualized Round Robin XXXVI Report to: FSV-BA 

Your Data, NIST Assigned Values, and %Differences 

Serum215 

Analytel You NAY %A n 

Retinol .65 .67 -3 44 

Retinyl Palmitate .28 .27 4 14 

a-Tocopherol 6.23 6.05 3 42 

y-Tocopherol 1.62 2.05 -21 20 

Total P-Carotene .60 .58 3 30 

trans-p-Carotene .57 .53 9 11 

Total a-Carotene .03 .03 19 22 

trans-Lycopene .14 .13 8 7 

. P-Cryptoxanthin .07 .05 37 16 

"Lutein&Zeaxanthin" .20 16 

Serum216 

!You NAY %A n I 

.54 .55 -1 44 

.07 13 

5.72 5.61 2 42 

1.96 2.41 -19 20 

.44 .41 8 29 

.42 .39 10 11 

.01 .02 -26 20 

.15 .15 3 7 .05 .04 43 16 

.10 16 

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

Serum217 

I You NAY %A n I 

.43 .43 0 44 .06 8 

7.28 7.22 1 42 

2.45 3.02 -19 20 

.07 .05 24 30 

.06 .05 15 11 

.01 .01 -8 20 

.30 .30 1 7 

.06 .04 55 16 

.14 16 

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

%4 : Percent difference between your value and the NA V 

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

Please check our recorded values against your records. 

Serum 218 

I You NAY %A n I 

1.06 1.05 l 44 

.08 10 

7.21 7.09 2 42 

1.85 2.38 -22 20 

.60 .58 4 29 

.58 .55 6 11 

.02 .03 -34 20 

.37 .36 3 7 

.07 .05 40 16 .15 16 

Send corrections to: NNMMQAP 222JB208, NIST, Gaithersburg, MD 20899; fax 301-977-0685; email David.Duewer@NIST.gov 

Pagel / 8 

D2
 
50 

25 

> 

x 

x 

> v < I z I 

i 0 

8 

* 8 

-

<J 

-25 -50 

11/04/1, 

Individualized Round Robin XXXVI Report to: FSV-BA 

Retinol, %.l\ in Round Robin XXVII - XXXVI 

""""' 

1 1 1 1 1 

7 7 7 7 7 

3 4 5 6 7 

x 

x 

v 

I 

1 1 1 1 1 

8 8 8 8 8 

1 2 3 4 5 

x 

xi I · I X · :.· X "" I 

x " m.,.,,,,, x ' I ml I ram.,...,I. I 

1 1 1 1 1 

8 8 8 8 9 

6 7 8 9 0 

1 1 1 1 

9 9 9 9 

1 2 3 4 

I 1 1 1 

9 9 9 9 

5 6 7 8 

Serum 

I 2 2 2 

9 0 0 0 

9 0 1 2 

x x x 

I 

I I 

2 2 2 2 

0 0 0 0 

3 4 5 6 

2 2 2 2 

0 0 0 l 

7 8 9 0 

2 2 2 2 

I I 1 l 

1 2 3 4 

2 2 2 2 

I 1 I I 

5 6 7 8 

.. Pa&e218 

D3
 
50 

25 

> < 

-

> < z 

I 

0 

8 

* 8 

-

1 <:] 

-25 -50 J 

11/04/1996 

Individualized Round Robin XXXVI Report to: FSV-BA 

Tocopherols, %i:\ in Round Robin XXVII - XXXVI 

__ lilm& __ .....1111 mmnrrz•••nlWlmm &, •• & &•11• - • ··-·. •tmwrm & !Ni _ rm = ·- w: -

II i:w 

• g-Tocopherol !ID a-Tocopherol 

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 

7 7 7 7 7 8 8 8 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 9 0 0 0 0 0 0 0 0 0 0 1 I 1 1 1 1 1 I I 

3 4 5 6 7 I 2 3 4 5 6 7 8 9 0 I 2 3 4 5 6 7 8 9 0 I 2 3 4 5 6 7 8 9 0 I 2 3 4 5 6 7 8 

Serum 

hge3/8 

D4
 
50 

25 

-

z 

I 

0 

8 

* 8 

-

<] 

-25 

-50 J 

11/04/19< 

Individualized Round Robin XXXVI Report to: FSV-BA 

b-Carotene, %Li in Round Robin XXVII - XXXVI 

• all-trans-b-Carotene rm Total b-Carotene 

1 1 1 1 1 I 1 I 1 1 I I 1 1 1 I I 1 I 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 

7 7 7 7 7 8 8 8 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 9 0 0 0 0 0 0 0 0 0 0 1 I I I 1 1 1 1 1 

3 4 5 6 7 I 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 I 2 3 4 5 6 7 8 9 0 I 2 3 4 5 6 7 8 

Serum 

Page4/H 

D5
 
- ±20% 

-- ±50% 

, 

, 

, 

. 

, 

. 

. 

, 

• • , 

, 

, 

, 

- ±20% 

-- ±50% 

ll/0411996 

, , 

, 

, 

, 

• , 

, 

Individualized Round Robin XXXVI Report to: FSV-BA 

NIST Assigned Values Vs Laboratory Values 

, 

, 

. 

, 

. 

, 

, 

• 

Retinol 

, 

, 

, 

, 

, 

, 

• 

, 

. 

, 

, 

, 

. 

. 

, 

, 

, 

a-Tocopherol / 

, 

• , 

. 

. 

, 

, 

• , • 

. 

, 

, 

, 

, 

. 

. 

, 

, 

, 

• 

• • • 

• .

, 

, 

• , 

, 

. 

• , 

A Total 

e trans 

-- ±50% 

- ±20% 

-- ±50% 

, 

, 

b-Carotene 

. 

. 

• • . 

, 

. 

, 

, 

, 

. 

• , 

. 

, 

, 

, 

, 

. 

. 

, 

. 

, 

. 

• , 

Legend 

Shaded Symbols: Round Robin XXVII-XXXV 

Black Symbols: Round Robin XXXVI 

Ordinate: NIST Assigned Value 

Abscissa: Your reported concentration 

Interpretation 

Adequately intercomparable data are within 

±20% lines. If you have data scattered outside 

±50% lines, your measurement system is 

not consistent with those of most participating 

laboratories. If your data are systematically 

higher or lower than the NAV, your system 

may be consistent but your results are biased . 

If your data show increased scatter at low 

concentrations, your "limit of quantification" 

may not be what you think it is. 

If there are one or two "wild" outliers, they 

might be calculation or transcription errors . 

We would appreciate hearing from you about 

any such problems . 

, 

, 

• 

PageS/8 

D6
 
11/04/19' 

Individualized Round Robin XXXVI Report to: FSV-BA 

Accuracy/Precision Summary 

xxvn 

xxvm 

XXIX 

xxx 

XXXI 

xxxn 

XXXIIl 

XXXIV 

xxxv 

XXXVI 

Ret 

mA vli 

-1 3 

0 4 

4 4 

9 4 

5 3 

-3 2 -2 2 

4 4 

6 4 

-1 2 

a Toe 

mA vli 

0 3 

1 2 

0 3 

4 7 

-2 5 

-1 1 

0 2 

-4 1 

-2 14 

2 1 

gToc -

mA vli 

-6 1 

1 4 

9 6 

-3 7 -1 5 -3 3 

11 11 

3 2 3 8 

-20 2 

(Traditional) Performance Criteria 

Total 

mA vli 

6 3 

1 7 

5 4 

9 12 

9 9 

8 4 

12 13 

6 3 

1 4 

10 10 

The absolute value of %!1 of every measurement has 

traditionally been evaluated as follows ... 

%!1 I Evaluation 

0-5% Exceptional 

6-10% Acceptable 

11-20% Marginal 

>20% Poor 

More representative criteria need to be established, 

factoring in each serum's analyte level and the 

analyte distribution in adult human populations. 

Stay tuned, we're working on it. .. 

trans 

mA vli 

5 3 

0 3 

3 3 9 12 

9 10 

13 4 

12 6 

9 4 

6 3 

10 4 

Legend 

Ret Retinol 

a Toe a-Tocopherol 

gToc g-Tocopherol 

Total Total b-Carotene 

trans all-trans-b-Carotene 

mA Mean difference, the average %!1 for all sera of a given RR, where 

%!1 = lOO(Your value - NAV) I NA V 

vli Difference variability, one standard deviation of %!1 for all sera of a 

NAV NIST Assigned Value, our best estimate of analyte concentration ... 

NA V = (NISTs average-of-averages + Round Robin median) / 2 

Interpretation 

Accuracy and precision are separate but kindred aspects of measurement 

comparison. We estimate accuracy as mA, the average %!1, and precision 

as vli, the standard deviation of %!1, for all sera of a Round Robin. 

It's best to be accurate and precise (small mA, small vli)! 

RR 

Good precision (small vli) with poor accuracy (large mA) is better than the 

converse: at least such values are internally consistent and may be relatable to 

others' values once the relative biases have been detennined. 

Poor precision (large vli) suggests that your measurement system is not in 

adequate control for the analyte levels examined. 

Pl&e618 

D7
 
Individualized Round Robin XXXVI Report to: FSV-BA 

Comparisons to Prior Analyses 

j 0 -·El -IS Fil t!t c::i.. 0 

II) 8 fii;)f!t fo-4 b 

r---r--1 r---r--1 ,---, r---r--1 

r---r--1 r---r--1 ,---, r---r--1 I 

170 172 21S 182 18S 216 194 217 192 199 218 

170 172 21S 182 18S 216 194 217 192 199 218 

I 

-11-ii- I 

.9 

• ttoff - ..... e Jn i -&2ff fl.. - • • ·.:i 

• 

r-o-o r---r--1 ,---, r-o-o 

r-11 r---r--1 ,---, r---r--1 

170 172 21S 182 18S 216 194 217 192 199 218 

170 172 21S 182 18S 216 194 217 192 199 218 

11/04/1996 

-lil-IWl1' 

-IMl!l1!t 

.9 

u 

I 

cc. 

ta 

..... 

0 

fo-4 

I 

I r---r--1 r-11 ,---, r-11 

170 172 21S 182 18S 216 194 217 192 199 218 

I 

I -••-!-

0 

c: 

II) 

..... 

at 

I 

cc. 

I 

Cll 

r-o-o r-o-o .-. r-o-o 

170 172 21S 182 18S 216 194 217 192 199 218 

Page7/8 

D8
 
J 

:: t:l 

.... 

11/04/19' 

Individualized Round Robin XXXVI Report to: FSV-BA 

Comparisons to Prior Analyses (Continued) 

,---,----, ,---,----, r--i ,---,----, 

170 172 21S 182 18S 216 194 217 192 199 218 

------tJ-

_J-Q-

,---,----, ,---,----, r--i ,---,----, 

170 172 21S 182 18S 216 194 217 192 199 218 

Hg BBff i 

$ 

.. 

l 

,---,----, ,---,----, ,---, ,---,----, 

170 172 21S 182 18S 216 194 217 192 199 218 

a U - - - -

-----1 LI 

,---,----, ,---,----, r--i ,---,----, 

170 172 21S 182 185 216 194 217 192 199 218 

t:l 

.-----ill .-----ill ,---, .------i.------

170 172 215 182 185 216 194 217 192 199 218 

• 

'= -A-nll • D 

1 -B-g - 01] . 

1A1J 

,---,----, ,---,----, r--i .------i.------

170 172 215 182 185 216 194 217 192 199 218 

Page8/8 

D9
 
 

 

Appendix E. Shipping Package Inserts for RR37 

The following two items were included in each package shipped to an RR37 participant: 

• Cover letter 

• Datasheet 

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

samples themselves. 

E1
 
April 15, 1996 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standards and Technology 

Gaithersburg. Maryland 20899-

Enclosed is the set of samples for round robin exercise (Round Robin XXXVII) . You will find 

one vial of four lyophilized serum samples for analysis along with a form for reporting your 

results. When reporting your results, please submit one value for each analyte for a given serum 

sample. If an obtained value is below your detection limit, please indicate this result on the 

form by using ND (Not Detected). For analytes not measured, please leave a blank. Results are 

due to NIST by June 14. Results received two weeks after the due date will not be included in 

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

provided around July 26. 

Samples should be reconstituted with 1.0 mL ofHPLC-grade water or equivalent. We 

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

least 30 min at room temperature with intermittent swirling. (CAUTION: Vigorous shaking 

will cause foaming and possibly interfere with accurate measurement. The rubber stopper 

contains phthalate esters which will leach into the sample upon intermittent contact of the liquid 

sample with the stopper. These esters absorb strongly in the UV region and elute very near 

retinol in most HPLC systems creating analytical problems.) Pipette a known volume of serum 

from the vial for analysis since the final volume of the reconstituted sample is greater than 1.0 

mL. For consistency, we request that laboratories use the following absorptivities (E 1 % cm) in 

ethanol: retinol, 1850 at 325 nm; retinyl palmitate, 975 at 325 nm; cx-tocopherol, 75.8 at 292 

nm; y-tocopherol, 91.4 at 298 nm; ex-carotene, 2800 at 444 nm; ~-carotene, 2560 at 450 nm; 

lycopene (in hexane), 3450 at 472 nm. 

Please mail or FAX your results for Round Robin XXXVII to: 

Micronutrients Measurement Quality Assurance Program 

NIST 

Bldg.222,Rm.B208 

Gaithersburg, MD 20899 

FAX: (301) 977-0685 

If you have questions regarding this round robin exercise, please call me at (301) 975-3120; 

e-mail: jeanice.brown-thomas@nist.gov; or mail/FAX queries to the above address. 

· ce Brown Thomas 

arch Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

cc: W. May 

S. Wise 

E2
 
 

 

NIST/NCI 

Micronutrients Measurement Quality Assurance Program 

Round Robin XXXVII Results from Laboratory #_____ 

Serum 

Analyte 219 220 221 222 Units* 

retinol 

retinyl palmitate 

α-tocopherol 

γ-tocopherol 

δ-tocopherol 

total β-carotene 

trans-β-carotene 

total cis-β-carotene 

total α-carotene 

total lycopene 

trans-lycopene 

β-cryptoxanthin 

lutein 

zeaxanthin 

lutein&zeaxanthin 

Other Analytes?
 

* We prefer mg/mL 

Today's Date: 

Comments? 

Mail: MMQAP, 222/B208 

NIST Please return results on-or-before Fax: 301-977-0685 

Gaithersburg, MD 20899 June 14, 1996 Email: David.Duewer@NIST.gov 

E3
 
Appendix F. Final Report for RR37

The following 15 pages are the final report for RR37 as provided to all participants: 

•	 Cover letter 

•	 A discussion entitled “Lies, Damn Lies, and Statistics” that: 

o	 describes the nature of the test samples and details any previous distributions 

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

participants 

• A “Report of (Meta)Analysis” that details the analysis of NIST measurements 

F1
 
July 25, 1996 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standards and Technology 

Gaithersburg, Maryland 20899-

Enclosed is the summary report of the results for Round Robin XXXVII (Sera 219-222). 

Included in this report are: a sum'mary of data for all laboratories; the measurement 

comparability summary for evaluating laboratory performance; a summary of individual 

laboratory performance for the past three years; a summary of the interlaboratory accuracy 

and precision over the same period of time for the measurement of retinol, a- and ytocopherol, and trans- and total J)-carotene; and a graphical summary of the NIST assigned 

value vs. your laboratory value for these analytes. As in previous reports, the NIST assigned 

values are derived from the equally weighted results from the analyses performed by NIST 

and the laboratories that participated in this round robin exercise. 

There were three new sera (Serum 219-221) in this round robin exercise. Serum 222 was 

previously distributed as Serum 181 in Round Robin XXVIII. The new sera contained 

augmented levels of retinol, retinyl palmitate, and/or 8-, y-, a-tocopherol. Specifically, the 

levels of 8- and y-tocopherol and J)-carotene were augmented in Serum 219 through the use 

of a commercial dietary supplement. The levels of 8-tocopherol, a-carotene, and lutein were 

augmented in Serum 220. Serum 221 contained augmented levels of a-tocopherol and retinyl 

palmitate. 

In this round robin exercise, the average estimated coefficient of variation ( eCV) is about 9% 

for retinol and a- and y-tocopherol. This is comparable to the overall laboratory performance 

(approximately 10%) for these analytes over the past two years. The interlaboratory variation 

for total J)-carotene is about 13 % for this round robin, as compared to the average eCV of 

about 19% for Round Robin XXXVI, and 21% over the past two years. In previous exercises 

where the levels of J)-carotene were significantly lower c::;100 ng/mL), a higher variation was 

obtained due to the difficulty of making measurements at levels that appear to be at or below 

the limit of quantification for most laboratories. In this exercise, the variation for J)-carotene 

in the sera with augmented levels of J)-carotene appear to be similar to that in the low level 

sera. The same observations hold true for retinyl palmitate. These observations will be 

further evaluated in future studies. 

Approximately 10% of the laboratories reported values for 8-tocopherol with an eCV of about 

18%. The eCVs for total a-carotene and lutein were 34% and 21 %, respectively. Values for 

two additional analytes (phytofluene and a-cryptoxanthin) were reported in this study. We 

continue to encourage laboratories to report values for as many quantifiable analytes as 

possible. 

Data for evaluating laboratory performance in Round Robin XXXVII are provided in the 

comparability summary on page 6 of the report. The criteria used to evaluate laboratory 

performance are as follows: results rated 1 (within 1 SD of the assigned value) indicate 

EXCEPTIONAL performance, results rated 2 (within 2 SD) indicate ACCEPTABLE 

performance, results rated 3 (within 3 SD of the assigned value) are MARGINAL, and those 

F2
 
rated 4 (>3 SD from the assigned value) indicate POOR performance relative to the current 

state-of-the-practice for these measurements. 

If you have concerns regarding your laboratory performance or were rated "POOR'' based on 

the criteria stated above, we suggest that you obtain a unit of SRM 968b, Fat-Soluble 

Vitamins and Cholesterol in Human Serum, and analyze all three levels. If, with minor 

modifications, your measured values do not agree with the certified values, we suggest that 

you contact us for consultation. 

Samples for Round Robin XXXVIII and the food Round Robin 5 (coordinated by Dr. 

Katherine Sharpless at 301/975-3121) were shipped during mid-July. Results for both round 

robin exercises are due September 20; feedback to labs will be provided around October 25. 

Based on the positive feedback that we received at the NIST/NCI Micronutrients 

Measurement Quality Assurance (QA) Workshop held this past April, we will try to continue 

to hold our workshops in conjunction with national clinical meetings. We are currently 

looking into hosting our next QA workshop at the American Association for Clinical 

Chemistry meeting, which will be held in Atlanta, Georgia during July 20-24, 1997. We will 

keep you informed of the workshop plans as they are finalized. 

We also plan to hold the Fat-soluble Vitamin and Carotenoid Analysis Tutorial again this fall 

at NIST, provided there is adequate interest. The scheduled date for the session is October 25, 

1996. This tutorial is intended primarily for new laboratories, new laboratory personnel, or 

those currently experiencing difficulties with their analysis. As in past years, this session will 

include a discussion of calibration, sample preparation, and chromatographic techniques for 

measuring fat-soluble vitamins and carotenoids in serum. 

Please complete the enclosed tutorial registration form and mail/fax it to: NIST/NCI 

Micronutrients Measurement Quality Assurance Program, NIST, Chem B208, Gaithersburg, 

MD 20899; FAX#: 301/977-0685 by October 4, 1996. 

If you have questions, please contact me at 301/975-3120; FAX: 301/977-0685; e-mail: 

jeanice.brown-thomas@nist.gov. 

t'~:{~~ (X;~~own Thomas 

Research Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

cc: w. May 

S. Wise 

F3
 
Lies, Damn Lies, and Statistics 

"Lies, Damned Lies, and Statistics" 

Mark Twain 

The attached N2M2QAP Round Robin XXXVII Report includes the "All Lab" listing of 

everyone's results, your "Individualized" results, and our "(Meta)Analysis" of value and 

uncertainty assignments. 

The "All Lab" report has the following elements: 

Pa e Contents 

1-4 A listing of all results for analytes reported by at least two laboratories, plus 

essential summary statistics. 

Stop A list of results for the four analytes reported by only one labora~ory. 

Shot A Legend for the above two lists. 

6 The "Measurement Comparability Summary" (or "Score card") 

Your "Individualized" report has the following elements: 

Pa e Contents 

1 Your values, our assigned values, and the %bias between you and us 

2-4 %Bias barchart for retinol, a- and y-tocopherol, and total and trans-1}-carotene 

for your last 3 years' results 

S Our assigned value vs. your value scatterplots for retinol, a- and ytocopherol, and total and trans-~carotene, again for your last 3 years' r~sults 

6 Accuracy/Precision Summary, yet again for your last 3 years' results 

7 &8 "Comparisons" plots for retinol, retinyl palmitate, a- and y-tocopherol, total 

and trans-~arotene, total a-carotene, total lycopene, f}-cryptoxanthin, lutein, 

zeaxanthin, and lutein & zeaxanthin 

Page I 

The "Comparisons"_plots on pages 7 and 8 show your individual results relative to a box-plot 

summary of the group's results. Serum 222 was distributed as #181 in RR XXVIll. The 

horizontal line on the left side of each plot is the average of the RR XXVill and XXXVII 

interlaboratory medians. 

Sera 219, 220, and 221 are experiments in analyte augmentation. They started life as the same 

(rather boring) low-carotenoid serum pool. All three were augmented to various levels _of retinol, 

retinyl palmitate, and/or a-, y-, and ~tocopherol. Serum 219 was also augmented with an extract 

very rich in !}-carotene and Serum 220 with an extract rich in a-carotene and lutein. None of the 

analytes in any of these sera showed "excess" heterogeneity. Only one of you commented on the 

presence of "odd" extra peaks. Given better characterized sources for the various analytes, we 

believe we can now (affordably) create more interesting and analytically challenging samples. 

F4
 
Lies, Damn Lies, and Statistics Page 2 

Retinyl palmitate remains a difficult analyte: both the very high 1.5 μg/mL level in serum 221 

and the reliably detected 0.10 μg/mL in serum 222 had CVs of about 20%. The low levels (0.03-

0.04 μg/mL) levels in sera 219 and 220 are below the group's limit of reliable detection, let alone 

quantification. 

All of you recognized the exceptionally high ~-carotene level of serum 219, with most of you 

quite close to the 3.7 μg/mL median. Several of you commented that this was above the linear 

part of your calibration. However, there were a few values much above the median that were 

reported without comment. Because the ~-carotene level for serum 219 was so very high with 

this serum, we have excluded it from the "Score Card" calculations. We encourage you to report 

values as "greater-than-or-equal to·(~)" when you realize that you are above your calibration 

limits: "3.7" and"~ 3" are more obviously related than are "3.7" and "7.9". In the future, only 

labs that appropriately flag their suspect data and/or note the problem in the "Comments" space 

will be excused from strict application of the Score Card's rules! 

The high 8-tocopherol levels in sera 219 and 220 did not adversely affect quantification of aand/or y-tocopherol. Excellent! We are a bit surprised that none of you commented on the 

unusual tocopherol patterns ... are such oddities routine in practice or have you become blase 

about-th~ N2M2QAP weirdnesses? More qualitative feedback on "things you find odd about the 

samples" would be appreciated! 

Your comments and suggestions are welcome. If you discover any errors in our recording or 

interpretation of your data, please let us know! 

DaveDuewer 

Research Chemometrician 

David.Duewer@NIST.gov 

'#~ Margaret Kline 

Research Biologist 

Margaret.Kline@NIST.gov 

F5
 
Report of ( Meta)Analysis for RR XXXVI Sera: 215-218 Page 1 

From: David L. Duewer Date: July 22, 1996 

To: Jeanice Brown Thomas, Margaret Kline, Willie E. May, Katherine E. Sharpless 

cc: Gary W. Kramer, Dennis J. Reeder, Stephen A. Wise 

Re: Value and Uncertainty Assignment for the NIST/NCI Micronutrient Measurement 

Quality Assurance Program's Round Robin XXXVII (RR37) Sera: 219 to 222. 

Background: Four sera were distributed in RR37. Serum 222 was distributed as #181 in RR28. 

Sera 219, 220, and 221 were prepared for this exercise from the same low-carotenoid serum 

pool. All three sera were augmented to various levels of retinol, retinyl palmitate, and/or a-, y-, 

or 5-tocopherol. Serum 219 was augmented to a very high trans-p-carotene level with an extract 

of a commercial dietary supplement. Sera 220 and 221 were augmented with plant extracts, with 

serum 220 achieving desired a-carotene and lutien levels. A different augmentation technique 

was evaluated with each of these three sera. 

Analysts NIST 1 and NIST3 independently extracted and analyzed aliquots of three vials of each 

serum using normal procedures. Both analysts reported quantitative results for retinol, 

a-tocopherol, y-tocopherol, totalp-carotene, andtrans-P-carotene. Analyst NIST3 also reported 

results for retinyl palmitate, 5-toeopherol, total a-carotene, trans-a-carotene, total lycopene, 

trans-lycopene, ~ryptoxanthin, "lutein", and "zeaxanthin". Due to detector malfunction, 

NIST3 had ·to analyse three or four aliquots of several vials to fully characterize each sample. 

When more than two values for an analyte were reported for a given vial, only the minimum and 

maximum of the reported values have been used in this data analysis. 

Results: Table 1 presents the NIST data, suinmary statistics for the NIST data, summary r~sults for the most recent previous exercise for each serum, summary results for RR37, and the NIST 

assigned values and uncertainties. Table 2 presents a compact summary of the assigned values 

and uncertainties for each analyte in each serum. The entries in Tables 1 and 2 are defined as 

follows: 

• Individual NIST Analyst Data and Summary Statistics 

A: 1 to C:2 two aliquots (" l" and "2") of three vials (A, B, and C) of each serum were 

extracted and analyzed. Each analyst analyzed a separate set of three vials. 

fix number of quantitative values for this analyte for this serum for this analyst 

Me~ arithmetic average 

SDx simple standard deviation 

so... within-vial pooled standard deviation, reflecting variation in extraction, 

chromatography, peak integration, etc. 

SDbeU among-sample standard deviation, reflecting heterogeneity in preparing and 

reconstituting the serum samples 

SDNISTx ~SD~x + SD~cx, total standard deviation. This value is~ SD", as sample 

replicates reduce the true degrees of freedom. 

CV NISTx 100 x SD NtSTJMeanx 

• NIST Summary Statistics 

n number of quantitative values for this analyte for this serum 

Mean {MeanNISTI + MeanN15n}/2 or MeanNisn for analytes that NIST 1 did not report 

SDrep within-vial pooled standard deviation 

SDhet among-sample standard deviation 

F6
 
Report of ( Meta)Analysis for RR XXXVI Sera: 2 I 5-2 I 8 Paiie 2 

SDan1 between-analyst standard deviation. This is the residual standard deviation for 

the linear regression of NIST I's Meanx values to NIST3 's or, for analytes that 

NIST! did not report, to the interlaboratory Median (see below). The regression 

model used to determine SDu1 is defined to the right of this block. Details 

include: the model used, the parameters and standard errors on the parameters, 

and R2 for the regression. 

SDNIST ~SD~ +SD~ + SD!ru , total standard deviation for NIST analyses. 

CV NIST I 00 x SD Nis,IMean 

• Previous Round Robin Summary Statistics 

RR identifier of the Round Robin in which this serum was distributed 

Serum identifier of the serum 

~ · number of non-NIST laboratories reporting quantitative values for this analyte 

for this serum in this Round Robin 

MedianP median of the reported values. The median is a robust location estimate. 

eSDP 0.741 x InterQuartile Range (IQR). The IQR is a robust dispersion estimate. 

The scale factor 0.741 is the expected ratio between SD and IQR for normal 

distributions. 

• Round Robin XXXVI Summary Statistics 

I\ number of non-NIST laboratories reporting quantitative values for this analyte 

for this serum in this Round Robin · Median. median of the reported values 

eSD. 0.741 x InterQuartile Range. (IQR) 

( IMedian11 - MedianPl"'1-n.-+-nP ___ 2. ) 

P(n=p) TDIST . , ~+n11 -2, 2 μill 

(<n. -l)eSD! +(nP - l)eSD~{ _!_ + _!_J 

\n11 nP 

This is the approximate probability that the current median is the same as it was 

in the previous RR. Where the hypothesis that Medi~ = Medi~ could be 

rejected with 95% confidence, the P(n=p) value would be flagged with an"*". 

TDIST is Excel*'s student's t function. 

( eSD2 ) P(n<p) FOIST --f, n11-l, ~-1 

eSD0 

cv1abs 

This represents the approximate probability that the current interlaboratory 

variance is smaller than it was in the previous RR. Where ~e hypothesis that 

eSD. < eSDP can be rejected with 95% confidence, the P(n<p) value is flagged 

with an"*". FOIST is Excef1 's F-distribution function. 

~eSD! -SD!nsr, the residual non-NIST interlaboratory biases after correction 

for measurement-, sampl~. and NIST-analyst-related sources of variance. 

When SDNJST is greater than eSD11 , so .. = 0. 

100 x SD...JMediaJ\ 

F7
 
Report of ( Meta)Analysis for RR XXXVI Sera: 215-218 

• NIST Assigned Values and Uncertainties 

NA V (Mean+ Mediann) I 2, our best guess of the "true" analyte level 

NAU Maximum(0.05 x NAV, ~SD~isT + SD~abs ), our best guess for the "true" 

interlaboratory standard deviation characterizing measurement, sample 

heterogeneity, inter-analyst, and interlaboratory sources of variation. When 

SD1.ba could not be determined, NAU is estimated as 

Maximum(0.10 x NAV, ~2 SD~ST ). 

CV lOOxNAU/NAV 

Page 3 

Conclusions: The current interlaboratory median (Mediann) and standard deviations (eSDn) for 

serum 222 are statistically indistinguishable at the 95% confidence level from those of RR28 

(Medi~ and eSDP). Thus there is no evidence of degradation during the past three years storage 

at -75 °l,;. . 

The ratio between the repeatability (SD rep) and heterogeneity (SD11e1) components of variation in 

the NIST measurements are roughly comparable for all analytes in all sera. The augmentation 

techniques used with sera 219-221 seem not to have compromised sample homogeneity. 

This memo will be included as part of the Round Robin XXXVII report. 

Dave . 

Reseach Busybody 

F8
 
Report of(Meta)Analysisfor RR XXXVll Sera: 219-222 

Table 1 

NIST Data and Calculations 

Retinol Retinyl Palmitate 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n, 

Mean, 

so. 

SD,..0, 

SD11ou 

NISTl 

219 220 221 

0.782 0.584 0.622 

0.821 0.479 0.670 

0.791 0.529 0.644 

0.744 0.511 0.710 

0.769 0.506 0.695 

0.810 0.474 0.655 

6 6 6 

0.786 0.514 0.666 

0.028 0.040 0.033 

0.030 0.045 0.037 

0.017 0.021 0.017 

222 

0.448 

0.474 

0.497 

0.513 

0.502 

0.475 

6 

0.485 

0.024 

0.017 

0.022 

NIST3 

219 220 221 222 

0.705 0.459 0.644 0.450 

0.852 0.472 0.666 0.495 

0.732 0.444 0.638 0.466 

0.693 0.473 0.633 0.471 

0.801 0.465 0.661 0.478 

0.705 0.457 0.665 0.481 

6 6 6 6 

0.748 0.462 0.651 0.474 

0.064 O.Qll 0.015 0.015 

0.073 0.013 0.009 0.019 

0.033 0.004 0.014 0.006 

s~. 0.035 0.050 o.041 0.028 0.081 0.014 0.011 0.019 

CVNIS'l'l 4.4 9.8 6.2 5.7 11 3.0 2.6 4.1 

NIST NIST3=a+b*NIST1 

n 12 12 12 12 

Mean 0.767 0.488 0.659 0.479 a: 0 

SDreo 0.050 0.034 0.027 0.018 b: 0.954 ±0.016 

SO. 0.024 0.020 0.016 O.Q15 R2: 0.960 

SD11111 0.020 0.020 0.020 0.020 

SI>msr 0.059 0.045 0.037 0.031 

CVNIST 7.7 9.2 5.7 6.4 

RR XXVIII 

Serum 

no 

181 <- Previous Results -> 

Medianu 

eSD0 

n. 

Medianu 

eSD. 

P(n=p) 

P(n<p) 

so .... cv .... 

NAV 

NAU 

CV 

(37 _dll)NIS'IUt 

219 

45 

0.817 

0.068 

0.033 

4.1 

0.792 

0.068 

8.5 

44 

0.483 

0.064 

RRXXXVIl 

220 221 222 <-Current Results -> 

45 44 45 

0.489 0.673 0.470 

0.040 0.063 0.050 

0.96 

0.95 

0 0.051 0.039 

0 7.6 8.3 

0.488 0.666 0.475 <-Assignments-> 

0.045 0.063 0.050 

9.1 9.5 10 

NISTl NIST3 

219 220 221 222 219 220 221 

1.03 0.114 1.73 

1.12 0.112 1.93 

1.02 0.116 

1.35 0.114 1.72 

1.24 0.112 

1.05 0.110 

0 0 6 6 0 0 3 

1.14 0.113 1.79 

0.13 0.002 0.12 

0.16 0.001 0.10 

0.05 0.002 

0.17 0.002 

15 2.2 

NIST 

0 0 9 11 

1.46 0.116 

0.14 0.017 

0.08 0.012 

0.16 0.021 

11 18 

xxvm 

181 

8 

0.13 

0.03 

RRXXXVIl 

219 220 221 2Z2 

10 11 13 14 

0.03 0.03 1.52 0.097 

0.01 0.02 0.31 0.019 

0.53 

0.95 

0.27 0 

18 0 

1.49 0.1061 

0.31 0.021: 

21 20 

222 

0.109 

0.109 

0.151 

0.118 

0.103 

5 

0.118 

0.019 

O.Q18 

0.012 

0.022 

18 

Paae 117 

F9
 
A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n. 

Mean, 

so. 

SOreo• 

sei219 

7.86 

7.43 

7.27 

7.63 

8.09 

8.92 

6 

7.87 

0.59 

0.41 

0.56 

Report of (Meta)Analysisfor RR XXXVll Sera: 219-222 

Table 1 

NIST Data and Calculations 

a-Tocopherol y-Tocopherol 

NISTl NIST3 NISTl NIST3 

220 221 222 219 220 221 222 219 220 221 222 219 220 221 222 

11.44 17.1 7.69 8.32 10.83 16.3 6.21 7.12 4.46 1.88 2.22 8.76 3.77 1.79 2.22 

11.33 16.7 7.62 8.29 11.64 17.7 6.56 7.79 3.18 1.97 2.32 8.70 3.96 1.85 2.32 

11.74 16.9 7.33 7.69 11.50 16.9 6.90 8.02 3.52 1.97 2.62 8.41 4.02 1.82 2.38 

11.16 17.1 7.70 8.50 11.72 17.6 7.30 7.11 3.47 2.29 2.58 8.62 4.03 1.86 2.36 

11.49 16.9 7.15 8.15 11.06 17.3 7.19 7.15 4.12 1.87 2.59 8.42 3.99 1.86 2.38 

11.44 17.3 7.18 7.81 10.51 16.6 7.15 7.59 3.65 1.84 2.51 8.12 3.92 1.84 2.39 

6 6 6 6 6 6 6 6 6 6 6 6 6 6 6 

11.43 17.0 7.44 8.13 11.21 17.1 6.89 7.46 3.74 1.97 2.48 8.50 3.95 1.84 2.34 

0.19 0.2 0.25 0.32 0.48 0.6 0.43 0.40 0.47 0.17 0.16 0.24 0.10 0.03 0.07 

0.24 0.2 0.15 0.36 0.41 0.7 0.22 0.50 0.56 0.14 0.05 0.15 0.08 0.03 0.04 

0.04 0.1 0.25 0.16 0.41 0.2 0.44 0.10 0.21 0.14 0.18 0.23 0.08 0.01 0.06 

s0mnx o.69 0.25 o.3 0.29 o.40 o.58 0.1 0.49 o.51 o.60 0.20 0.18 0.21 0.12 o.04 0.08 

CVNIST• 8.8 2.2 1.5 3.9 4.9 5.2 4.3 7.1 6.8 16 10 7.4 3.2 2.9 1.9 3.3 

n 

Mean 

SOreo 

so .... S01111 

s~ 

CVNIST 

12 

8.00 

0.44 

0.41 

0.36 

0.70 

8.8 

NIST 

12 12 12 

11.32 17.0 7.17 

0.30 o.s 0.22 

0.27 0.2 0.42 

0.36 0.4 0.36 

0.55 0.7 0.60 

4.8 3.9 8.3 

NIST3=a+b*NIST1 

a:O 

b: 0.99 ±0.02 

R2: 0.987 

12 

7.98 

0.36 

0.16 

0.06 

0.40 

5.0 

NIST 

12 12 12 

3.84 1.90 2.41 

0.40 0.10 0.05 

0.17 0.11 0.15 

0.06 0.06 0.06 

0.44 0.16 0.16 

11 8.5 6.8 

RR 

Serum 

xxvm xxvm 

n,, 

Median,, 

eSO. 

P(n=p) 

P(n<p) 

219 

42 

7.30 

0.58 

RRXXXVII 

220 221 

42 41 

10.96 17.3 

0.79 1.7 

so...,. 0 0.58 1.6 

cv..... 0 5.3 9.2 

NA V 7 .65 11.14 17 .2 

NAU 0.70 0.79 1.7 

CV 9.2 7.1 10 

(37 _dal)NISTul 

181 <-Previous Results -> 181 

44 16 

7.11 2.28 

0.53 0.16 

RRXXXVII 

222 <-Cunent Results -> 219 220 221 222 

42 22 22 21 22 

7.06 8.39 3.60 1.86 2.31 

0.60 0.61 0.33 0.26 0.17 

0.98 0.96 

0.21 0.46 

0 

0 

0.46 0 0.20 0.02 

5.5 0 11 1.0 

7.11 -Assignments-> 8.18 3.72 1.88 

0.60 0.61 0.44 0.26 

8.4 7.5 12 14 

2.36 

0.17 

7.0 

NIST3=a+b*NIST1 

a: -0.62 ±0.06 

b: 1.22 ±0.01 

R2: 1.000 

f'aael/7 

F10
 
Report of(Meta)Analysisfor RR XXXVll Sera: 219-222 

Table 1 

NIST Data and Calculations 

~Tocopherol Total ~-Carotene 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n. 

Mean1 

so. 

SO re"" 

so._ 

219 

3.51 

3.66 

3.48 

3.57 

3.09 

3.16 

6 

3.41 

0.23 

0.08 

0.25 

NISTl 

220 221 

7.44 0.89 

7.48 0.93 

8.71 0.85 

7.41 0.92 

8.78 0.81 

7.88 0.82 

6 6 

7.95 0.87 

0.64 0.05 

0.65 0.03 

0.45 0.05 

SI>ms,-1 0.26 0.79 0.06 

CVNISTI 7.7 9.9 6.9 

n 

Mean 

SO rep 

so... 

S01111 

12. 

3.36 

0.06 

0.04 

0.04 

NIST 

12 12 

8.98 0.91 

0.47 0.04 

0.13 0.08 

0.04 0.04 

222 

0 

6 

0.195 

0.017 

0.018 

0.038 

NIST3 NISTl 

219 220 221 222 219 220 221 

3.37 9.86 0.88 0.156 3.70 0.559 

3.32 10.20 0.95 0.194 4.09 0.489 

3.26 10.17 0.87 0.197 3.60 0.491 

3.33 10.10 0.93 0.207 3.87 0.494 

3.28 10.00 1.10 0.199 3.54 0.496 

3.25 9.77 0.98 0.219 3.77 0.509 

6 6 6 6 6 6 0 

3.30 10.02 0.95 0.195 3.76 0.506 

0.05 0.17 0.08 0.021 0.20 0.027 

0.04 0.17 0.06 O.ot8 0.21 0.029 

0.04 0.13 0.08 O.ot8 0.12 0.016 

0.06 0.21 0.09 0.025 0.25 0.033 

1.7 2.1 10.0 13 6.5 6.6 

NIST 

a: -0.032 ±0.026 

b: 1.235 ±0.006 

R1: 1.000 

10 12 

3.74 0.475 

0.18 0.027 

0.10 0.055 

0.05 0.046 

6 

0.080 

0.002 

0.008 

0.046 

222 

0 

6 

0.063 

0.003 

0.004 

0.046 

SI>ms,- 0.08 0.49 0.09 0.046 0.22 0.076 0.046 0.046 

CV NIST 2.5 5.4 10 23 . 5.8 16 58 73 

RR 

Serum 

XXVIII 

. LJ <-Provious Results-> 

n. 

Median. 

eSO. 

P(n=p) 

P(n<p) 

219 

5 

2.74 

0.44 

RRXXXVIl 

220 221 

5 4 

8.13 0.78 

0.96 0.34 

SOw. 0.44 0.82 0.33 

cvlabl 16 10 42 

NA V 3.05 8.55 0.85 

NAU 0.44 0.96 0.34 

CV 15 11 40 

(37 _dll)Nlrnsl 

222 

5 

0.170 

0.045 

0 

0 

<-Current Results -> 

RRXXXVII 

219 220 

28 28 

3.85 0.541 

0.30 0.101 

0.21 0.066 

5.4 12 

221 

27 

0.082 

0.009 

0 

0 

0.183 <-Assignments-> 3.79 0.508 0.081 

0.046 0.30 0.101 0.046 

25 7.9 20 57 

XXVIII 

181 

33 

0.087 

0.022 

222 

28 

0.077 

0.012 

0.89 

1.00 

0 

0 

0.070 

0.046 

66 

219 

3.46 

3.82 

3.81 

3.82 

4 

3.73 

0.18 

0.15 

NIST3 

220 221 222 

0.422 0.076 0.055 

0.397 0.080 0.062 

0.395 0.073 0.065 

0.433 0.073 0.066 

0.538 0.091 0.066 

0.475 0.086 0.067 

6 6 6 

0.443 0.080 0.063 

0.055 0.007 0.005 

0.032 0.003 0.003 

0.055 0.008 0.004 

0.063 0.008 0.005 

14 11 8.4 

a: -0.029 ±0.028 

b: 0.975 ±0.014 

R1: 0.999 

""" 3 / 7 

F11
 
Report of (Meta)Analysisfor RR XXXVll Sera: 219-222 

Table 1 

NIST Data and Calculations 

trans-~-Carotene Total a-Carotene 

NISTl NIST3 NISTl NIST3 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n, 

Mean, 

SD, 

SD,_ 

so._ 

219 

3.27 

3.57 

3.11 

3.35 

3.22 

3.37 

6 

3.31 

0.16 

0.17 

0.10 

220 221 

0.452 

0.412 

0.410 

0.397 

0.420 

0.422 

6 0 

0.419 

0.019 

0.017 

0.014 

SDNIST• 0.19 0.022 

CVNim 5.8 5.3 

n 

Mean 

SDreo 

so. 

so .... 

11 

3.41 

0.14 

0.12 

0.05 

NIST 

12 6 

0.419 0.080 

0.020 0.002 

0.050 0.008 

0.047 0.047 

222 

0 

6 

0.064 

0.003 

0.004 

0.047 

219 220 221 222 219 220 221 

3.24 0.401 0.076 0.055 0.133 0.274 

3.52 0.381 0.080 0.062 0.146 0.235 

3.52 0.370 0.073 0.065 0.145 0.233 

0.407 0.073 0.066 0.138 0.212 

3.69 0.503 0.091 0.066 0.148 0.238 

3.57 0.451 0.086 0.067 0.135 0.226 

5 6 6 6 6 6 0 

3.51 Q.419 0.080 0.064 0.141 0.236 

0.16 0.050 0.007 0.005 0.006 0.021 

0.12 0.027 0.003 0.003 0.008 0.019 

0.12 0.050 0.008 0.004 0.001 0.016 

0.18 0.057 0.008 0.005 0.008 0.025 

5.0 14 10 8.3 5.8 11 

NIST3=a+b*Median NIST 

a:O 

b: 0.990 ±0.013 

R2: 0.998 

11 

0.127 

0.012 

0.007 

0.017 

12 6 

0.239 0.013 

0.017 0.001 

0.006 0.002 

0.017 0.017 

222 

0 

6 

0.013 

0.002 

0.001 

0.017 

SDNIST 0.19 0.072 0.047 0.047 0.022 0.025 0.017 0.017 

CVNIST 5.7 17 59 74 18 10 130 130 

RR 

Serum 

RRXXXVIl 

na 

Mediana 

eSDa 

P(n=p) 

P(n<p) 

219 

14 

3.53 

0.27 

220 

14 

0.503 

0.094 

so.. 0.19 0.060 

cv .. 5.4 12 

221 

13 

0.076 

0.008 

0 

0 

NA V 3.47 0.461 0.078 

NAU 0.27 0.094 0.047 

CV 7.9 20 61 

[37 _da]NISThu 

xxvm 

181 <- Previous Results-> 

5 

0.085 

0.005 

222 

14 

0.072 

0.010 

0.48 . 

0.10 

0 

0 

<-Current Results -> 

RRXXXVIl 

219 220 

24 24 

0.110 0.329 

0.023 0.084 

0.006 0.080 

5.8 24 

221 

21 

0.013 

0.007 

0 

0 

xxvm 

181 

15 

0.018 

0.006 

222 

21 

0.016 

0.005 

0.91 

0.72 

0 

0 

0.068 <-Assignments-> 0.118 0.284 0.013 0.014 

0.047 0.023 0.084 0.017 0.017 

69 20 30 130 120 

219 220 221 222 

0.092 0.245 0.011 0.011 

0.129 0.239 0.012 0.014 

0.122 0.223 0.011 0.012 

0.249 0.013 o.oi5 

0.114 0.264 0.015 0.013 

0.104 0.231 0.015 0.014 

5 6 6 6 

0.112 0.242 0.013 0.013 

O.Ql5 0.014 0.002 0.001 

0.016 0.017 0.001 0.002 

0.007 0.006 0.002 0.001 

0.017 0.018 0.002 0.002 

15 7.6 16 13 

NIST3=a+b*Median 

a:O 

b: 0.764 ±0.050 

R2: 0.950 

Pqe4/7 

F12
 
Report of(Meta)Analysisfor RR XXXVll Sera: 219-222 

Table 1 

NIST Data and Calculations 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

nx 

Mean. 

so. 

SDieox 

SD11eu 

s~STx 

CVNISTx 

n 

Mean 

SDieo 

SD11e1 

SDan1 

s~ 

CVNIST 

RR 

Serum 

Do 

Median0 

eSD0 

n. 

• 

Median. 

eSD 

P(n=p) 

P(n<p) 

SD1a111 

cvllbl 

219 

0 

5· 

0.09 

0.01 

0.00 

trans-a-Carotene 

NIST! NIST3 

220 

0 

6 

0.2 

0.0 

0.0 

221 

0 

NIST 

6 

0.013 

0.001 

0.001 

222 

0 

6 

0.013 

0.002 

0.001 

XXVIII 

219 220 221 222 

0.08 0.2 0.011 O.otl 

0.10 0.2 0.014 0.014 

0.10 0.2 0.012 0.012 

0.2 0.01~ O.ot5 

0.09 0.3 O.ot5 0.013 

0.09 0.2 0.015 0.014 

5 6 6 6 

0.09 0.2 0.013 0.013 

0.01 0.0 0.002 0.001 

0.01 0.0 0.001 0.002 

0.00 0.0 0.001 0.001 

0.01 0.0 0.002 0.002 

9.4 6.5 15 14 

u<-Pn:vious Rcsul!S -> 

RRXXXVII 

219 220 221 222 <-Current Results -> 

0 0 0 0 

NA VI 0.09 0.2 0.013 o.o13r- Assignments-> 

NAU~.~~~~~~~_. 

CV 

(37 _da)NISTW 

Total Lycopene 

NIST! NIST3 

219 220 221 

0 0 0 

NIST 

6 6 6 

0.363 0.343 0.323 

0.007 0.010 0.008 

0.005 0.009 0.006 

0.002 0.002 0.002 

0.009 0.013 0.010 

2.4 3.9 3.2 

RRXXXVII 

219 220 221 

24 24 23 

0.280 0.256 0.237 

0.052 0.048 0.043 

0.051 0.046 0.042 

18 18 18 

0.321 0.300 0.280 

0.052 0.048 0.043 

16 16 15 

222 

0 

6 

0.512 

0.018 

0.036 

0.002 

0.040 

7.8 

XXVIII 

181 

16 

0.468 

0.100 

222 

24 

0.448 

0.040 

0.93 

1.00 

0.002 

0.4 

8.4 

219 220 221 222 

0.351 0.329 0.313 0.450 

0.367 0.340 0.323 0.491 

0.370 0.337 0.315 0.526 

0.366 0.353 0.328 0.536 

0.372 0.360 0.334 0.532 

0.349 0.343 0.325 0.536 

6 6 6 6 

0.363 0.343 0.323 0.512 

0.010 0.011 0.008 0.035 

0.012 0.010 0.008 0.017 

0.005 0.009 0.006 0.036 

0.013 0.013 0.010 0.040 

3.5 3.9 3.0 7.8 

NIST3=a+b*Median 

a: 0.114 ±0.004 

b: .0.888 ±0.012 

R2: 0.999 

Pqe5/7 

F13
 
Report of(Meta)Analysisfor RR XXXVl/ Sera: 219--222 

Table 1 

NIST Data and Calculations 

trans-Lycopene ~-Cryptoxanthin 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

nx 

Meanx 

SDx 

SD,....x 

SDbeU 

SI>tam 

CVNISTx 

n 

Mean 

so,..11 

SI>i..t 

SDon1 

snmn 

CV NIST 

219 

0 

6 

0.155 

0.003 

0.005 

0.008 

0.009 

6.0 

NISTl 

220 221 222 

0 0 0 

NIST 

6 6 6 

0.150 0.153 0.232 

0.007 0.005 0.009 

0.003 0.003 0.019 

0.008 0.008 0.008 

0.010 0.009 0.022 

7.0 6.1 9.4 

RR XXVIII 

Serum 

np 

Median11 

eSD11 LJ 

n. 

Medianp 

eso. 

P(n=p) 

P(n<p) 

219 

7 

0.157 

0.028 

RRXXXVIl 

220 221 222 

7 6 7 

0.172 0.153 0.311 

0.032 0.027 0.074 

SD* 0.026 0.030 0.025 0.071 

cv...,. 17 17 16 23 

NAV 0.156 0.161 0.153 

NAU 0.028 0.032 0.027 

CV 18 20 17 

(37 _dll)NIS'IUI 

NIST3 

219 220 221 222 

0.152 0.145 0.148 0.201 

0.159 0.151 0.158 0.221 

0.150 0.144 0.148 0.237 

0.151 0.155 0.152 0.242 

0.165 0.154 0.159 0.247 

0.155 0.152 0.153 0.245 

6 6 6 6 

0.155 0.150 0.153 0.232 

0.006 0.005 0.005 0.018 

0.005 0.005 0.005 0.008 

0.005 0.003 0.003 0.019 

0.007 0.006 0.006 0.020 

4.4 3.8 3.8 8.8 

NIST3=a+b*Median 

a: 0.070 ±0.012 

b: 0.518 ±0.057 

R2: 0.953 

<-Previous Results -> 

<-Current Results -> 

<-Assignments-> 

NISTl 

219 220 221 

0 0 0 

NIST 

6 6 6 

0.065 0.059 0.060 

0.006 0.001 0.000 

0.003 0.001 0.001 

0.004 0.004 0.004 

0.007 0.004 0.004 

12 7.1 6.6 

RRXXXVII 

219 220 221 

19 19 18 

0.075 0.075 0.073 

0.025 0.022 0.020 

0.023 0.022 0.019 

31 29 27 

0.070 0.067 0.066 

0.025 0.022 0.020 

35 33 30 

222 

0 

6 

0.049 

0.004 

0.004 

0.004 

0.007 

15 

XXVIII 

181 

11 

0.070 

0.012 

222 

19 

0.070 

0.019 

0.99 

0.05 

0.018 

25 

0.059 

0.019 

32 

NIST3 

219 220 221 222 

0.065 0.058 0.060 0.040 

0.067 0.060 0.061 0.047 

0.062 0.060 0.060 0.049 

0.072 0.061 0.060 0.054 

0.066 0.060 0.060 0.050 

0.058 0.056 0.058 0.052 

6 6 6 6 

0.065 0.059 0.060 0.049 

0.005 0.002 0.001 0.005 

0.005 0.002 0.001 0.004 

0.003 0.001 0.001 0.004 

0.006 0.002 0.001 0.006 

9.1 3.8 2.0 12 

. NIST3=a+b*Median 

a: -0.128 ±0.068 

b: 2.545 ±0.933 

R2: 0.621. 

Pqe6/7 

F14
 
Report of(Meta)Analysisfor RR XXXVI/ Sera: 219-222 

Table 1 

NIST Data and Calculations 

"Lutein" "Zeaxanthin" 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n, 

Mean, 

so. 

SD..,0, 

SD11e1a 

SDmsr, 

CV NIST• 

n 

Mean 

SD..,0 

SD11e1 

SD1111 

219 

0 

6 

0.084 

0.001 

0.003 

0.002 

NISTl 

220 221 222 

0 0 0 

NIST 

6 6 6 

0.122 0.084 0.085 

0.002 0.002 0.002 

0.002 0.002 0.002 

0.002 0.002 0.002 

SDmsr 0.004 0.004 0.003 0.004 

CVNIST 4.2 3.3 3.7 4.2 

XXVIII 

NIST3 

219 220 221 222 

0.084 0.119 0.082 0.081 

0.086 0.120 0.086 0.086 

0.080 0.120 0.082 0.085 

0.081 0.124 0.082 0.085 

0.086 0.126 0.086 0.090 

0.084 0.123 0.084 0.085 

6 6 6 6 

0.084 0.122 0.084 0.085 

0.003 0.003 0.002 0.003 

0.001 0.002 0.002 0.003 

0.003 0.002 0.002 0.002 

0.003 0.003 0.002 0.004 

3.4 2.7 2.8 4.1 

NIST3=a+b*Median 

a:O 

b: 1.024 ±0.012 

. R2: 0.973 

RR 

Serum 181 <-Previous Results -> 

RRXXXVIl 

219 220 221 

n. 13 13 12 

0.080 0.120 0.084 

• 0.017 0.025 0.016 

Median. 

eSD 

P(n=p) 

P(n<p) 

SD1a11o 

cv .... 0.017 0.025 0.016 

21 21 19 

7 

0.068 

O.ot5 

222 

13 

0.081 

0.019 

0.74 

0.27 

0.019 

23 

<-Current Results-> 

NAV 0.082 0.121 0.084 0.083 <-Assignments-> 

NAU 0.017 0.025 0.016 0.019 

CV 21 21 19 23 

(37 _dll)NIST!xt 

NISTl 

219 220 221 

0 0 0 

NIST 

6 6 6 

0.046 0.051 0.049 

0.001 0.002 0.002 

0.002 0.001 0.001 

0.003 0.003 0.003 

. 0.003 0.003 0.004 

7.4 6.3 7.4 

RRXXXVIl 

219 220 221 

11 11 10 

0.044 0.045 0.046 

0.022 0.021 0.023 

0.022 0.020 0.022 

49 45 49 

222 

0 

6 

0.047 

0.001 

0.001 

0.003 

0.003 

6.9 

XXVIII 

~ 

~ 

222 

10 

0.039 

0.013 

0.013 

33 

0.045 0.048 0.048 0.043 

0.022 0.021 0.023 0.013 

49 43 48 31 

NIST3 

219 220 221 222 

0.046 0.052 0.048 0.044 

0.048 0.049 0.052 0.047 

0.045 0.051 0.050 0.046 

0.043 0.053 0.047 0.047 

0.047 0.052 0.048 0.049 

0.045 0.051 0.050 0.047 

6 6 6 6 

0.046 0.051 0.049 0.047 

0.002 0.001 0.002 0.002 

0.001 0.002 0.002 0.002 

0.002 0.001 0.001 0.001 

0.002 0.002 0.002 0.002 

4.6 3.3 4.7 4.2 

NIST3=a+b*Median 

a: 0.031 ±0.020 

b: 0.401 ±0.457 

R2: 0.077 

Pqc7/7 

F15
 
Report of (Meta)Analysisfor RR XXXVll Sera: 219-222 

Table 2 . 

Summary of NIST Assigned Values and Uncertainties 

219 220 221 222 

Analyte NAV NAU CV NAV NAU CV NAV NAU CV NAV NAU CV 

Retinol 0.792 0.068 8.5 0.488 0.045 9.1 0.666 0.063 9.5 0.475 0.050 10 

Retinyl Palmitate 1.49 0.31 21 0.106 0.021 20 

a-Tocopherol 7.65 0.70 9.2 11.14 0.79 7.1 17.2 1.7 10 7.11 0.60 8.4 

y-Tocopherol 8.18 0.61 7.5 3.72 0.44 12 1.88 0.26 14 2.36 0.17 7.0 

6-Tocopherol 3.05 0.44 15 8.55 11 0.85 0.34 40 0.183 0.046 25 

Total p-Carotene 3.79 0.30 7.9 0.508 0.101 20 0.081 0.046 57 0.070 0.046 66 

trans-p-Carotene 3.47 0.27 7.9 0.461 0.094 20 0.078 0.047 61 0.068 0.047 69 

Total a-Carotene 0.118 0.023 20 0.284 0.084 30 0.013 0.017 130 0.014 0.017 120 

trans-a-Carotene 0.09 0.2 0.013 0.013 

Total Lycopene 0.321 0.052 16 0.300 0.048 16 0.280 0.043 15 0.480 0.040 8.4 

trans-Lycopene 0.156 0.028 18 0.161 0.032 20 0.153 0.027 17 0.272 0.074 27 

P-Cryptoxanthin 0.070 0.025 35 0.067 0.022 33 0.066 0.020 30 0.059 0.019 32 

"Lutein" 0.082 0.017 21 0.121 0.025 21 0.084 0.016 19 0.083 0.019 23 

"Zeaxanthin" 0.045 0.022 49 0.048 0.021 43 0.048 0.023 48 0.043 0.013 31 

l37_datjSummaryTxl """'"' 

F16
 
 

Appendix G. “All-Lab Report” for RR37 

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. 

G1
 
Round Robin XXXVII Laboratory Results 

Values in μg/mL 

Retinol Retinyl Palmitate α-Tocopherol γ-Tocopherol

Lab 

FSV-BA 

FSV-BD 

FSV-BE 

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-BW 

FSV-BX 

FSV-BY 

FSV-BZ 

FSV-CA 

FSV-CB 

FSV-CC 

FSV-CF 

FSV-CH 

FSV-CK 

FSV-CM 

FSV-CN 

FSV-CP 

FSV-CQ 

FSV-CR 

FSV-CS 

FSV-CU 

FSV-CX 

FSV-DA 

FSV-DB 

FSV-DJ 

FSV-DK 

FSV-DM 

FSV-DP 

FSV-DS 

FSV-DX 

FSV-EH 

FSV-EI 

FSV-EL 

FSV-FY 

219 220 221 222 

0.835 0.526 0.691 0.502 

219 220 221 222 219 220 221 222 219 220 221 222 

0.009 0.008 1.37 0.012 7.24 10.71 16.2 6.91 8.37 3.77 1.87 2.45 

0.782 0.486 0.674 0.481 6.82 9.62 15.9 6.88 

0.872 0.521 0.682 0.456 7.26 10.76 16.8 6.78 8.02 3.35 1.60 2.27 

0.860 0.510 0.710 0.520 0.031 0.020 1.52 0.085 7.38 11.21 17.4 7.52 7.34 3.31 1.63 2.29 

0.702 0.384 0.524 0.440 0.038 0.030 1.18 0.113 7.75 11.46 17.9 7.65 8.71 3.81 1.94 2.59 

0.796 0.459 0.628 0.419 nd nd 1.82 0.127 7.47 10.74 15.8 6.32 7.70 3.38 1.47 2.05 

0.825 0.499 0.692 0.478 nd nd 1.25 0.095 7.98 11.60 18.3 7.20 9.34 4.08 2.16 2.53 

0.806 0.522 0.623 0.545 6.03 9.94 15.9 5.84 

0.773 0.458 0.687 0.487 7.75 12.06 19.0 7.75 

0.658 0.355 0.556 0.416 8.30 14.30 19.2 7.30 

0.847 0.473 0.653 0.463 0.029 0.011 1.67 0.085 6.95 10.38 16.2 6.67 7.90 3.32 1.77 2.26 

0.725 0.430 0.653 0.464 7.19 11.37 18.6 7.28 

0.769 0.439 0.541 0.416 8.39 13.10 19.4 8.86 

0.760 0.520 0.670 0.510 

0.880 0.540 0.754 0.508 

0.920 0.520 0.720 0.470 

8.01 11.70 18.1 8.00 

0.888 0.495 0.689 0.612 

0.843 0.502 0.733 0.539 

0.042 0.051 1.67 0.097 8.18 11.39 17.3 6.66 8.82 3.94 2.10 2.43 

0.760 0.420 0.620 0.430 0.030 0.022 1.44 0.097 7.28 11.16 17.9 6.60 8.83 3.80 2.00 2.51 

1.169 0.573 1.005 0.639 12.10 17.53 26.6 10.81 11.86 5.07 2.59 3.26 

0.784 0.489 0.666 0.457 0.021 0.012 1.75 0.120 7.49 10.71 17.5 7.07 8.11 3.35 1.74 2.32 

6.60 10.00 14.9 6.05 7.10 3.58 2.11 1.92 

0.701 0.402 0.510 0.391 6.60 9.86 14.0 6.45 

0.723 0.419 0.571 0.407 6.28 10.42 18.0 6.29 

0.892 0.471 0.690 0.452 7.89 12.91 20.1 7.65 

0.700 0.456 0.641 0.441 7.50 11.80 18.7 7.60 

0.700 0.410 0.590 0.400 6.32 9.61 16.0 6.79 7.66 3.43 1.75 2.25 

0.860 0.502 0.707 0.453 7.29 11.16 16.3 7.34 8.42 4.00 2.17 2.48 

7.00 11.40 18.7 7.10 

0.790 0.480 0.640 0.480 7.65 11.46 17.8 6.83 8.48 3.40 1.51 2.25 

8.13 12.11 19.6 8.16 7.85 3.82 1.78 2.42 

0.841 0.546 0.736 0.501 6.95 10.26 15.7 6.49 

0.830 0.480 0.710 0.520 

0.832 0.508 0.715 0.485 

7.30 11.40 17.2 7.10 

0.811 0.485 0.640 0.459 0.284 0.073 1.05 0.111 7.16 10.65 15.2 7.07 

0.830 0.490 0.680 0.490 0.392 0.047 1.52 0.123 7.54 11.06 19.6 7.47 7.82 3.13 1.78 1.98 

0.810 0.510 0.660 0.470 nd 0.090 1.60 0.100 7.16 11.00 16.7 7.05 8.41 3.74 1.86 2.51 

0.930 0.560 0.760 0.530 7.86 10.91 18.2 7.93 

1.070 0.600 0.800 0.570 9.68 13.16 18.5 7.44 

0.880 0.500 0.700 0.540 nd nd 0.70 0.053 7.30 9.90 17.1 7.10 8.40 3.50 1.80 2.10 

0.817 0.515 0.672 0.482 

0.774 0.462 0.609 0.448 

6.99 10.69 17.1 6.94 

0.639 0.390 0.532 0.380 6.40 9.02 13.5 6.48 

0.884 0.509 0.717 0.469 6.37 10.13 14.7 5.90 

0.840 0.470 0.530 0.046 0.035 0.097 7.08 10.22 6.23 6.53 3.25 2.09 

0.701 0.438 0.611 0.397 

0.770 0.440 0.570 0.430 

7.48 10.85 16.8 7.05 8.72 3.76 2.41 2.29 

0.829 0.501 0.682 0.488 6.97 10.71 16.8 6.79 8.41 3.62 1.92 2.43 

n 45 45 44 45 10 11 13 14 42 42 41 42 22 22 21 22 

Min 0.639 0.355 0.510 0.380 0.009 0.008 0.70 0.012 6.03 9.02 13.5 5.84 6.53 3.13 1.47 1.92 

Median 0.817 0.489 0.673 0.470 0.035 0.030 1.52 0.097 7.30 10.96 17.3 7.06 8.39 3.60 1.86 2.31 

Max 1.169 0.600 1.005 0.639 0.392 0.090 1.82 0.127 12.10 17.53 26.6 10.81 11.86 5.07 2.59 3.26 

eSD 0.070 0.046 0.059 0.047 0.014 0.027 0.23 0.019 0.52 0.82 1.7 0.60 0.65 0.33 0.21 0.24 

eCV 9 9 9 10 40 89 15 20 7 8 10 9 8 9 11 10 

NISTa
 

NISTb
 

NAV
 

NAU
 

0.786 0.514 0.666 0.485 nd nd 1.14 0.113 7.87 11.43 17.0 7.44 7.46 3.74 1.97 2.48 

0.748 0.462 0.651 0.474 nd nd 1.79 0.118 8.13 11.21 17.1 6.89 8.50 3.95 1.84 2.34 

0.792 0.488 0.666 0.475 0.035 0.030 1.52 0.097 7.65 11.14 17.2 7.11 8.18 3.72 1.88 2.36 

0.077 0.052 0.064 0.050 0.014 0.027 0.23 0.019 0.80 0.89 1.7 0.62 0.89 0.49 0.26 0.26 

All Lab Report G2 Page 1 / 6 
Round Robin XXXVII Laboratory Results 

Values in μg/mL 

δ-Tocopherol Total β-Carotene trans-β-Carotene Total cis-β-Carotene

Lab 219 220 221 222 219 220 221 222 219 220 221 222 219 220 221 222
 

FSV-BA
 3.76 0.37 0.088 0.090 3.66 0.36 0.080 0.083 0.10 0.011 0.008 0.007 

FSV-BD 3.87 0.49 0.083 0.066
 

FSV-BE
 2.98 0.37 0.082 0.073
 

FSV-BG
 3.82 0.33 0.075 0.078
 

FSV-BH
 3.82 0.61 0.076 0.073 3.70 0.60 0.076 0.073 0.12 0.011 nd nd 

FSV-BI 4.10 0.49 0.081 0.071
 

FSV-BJ
 3.54 0.53 0.096 0.087 

FSV-BK 

FSV-BL 

FSV-BM 

FSV-BN 2.74 8.1 0.718 0.109 3.73 0.60 0.077 0.080 3.46 0.58 0.067 0.069 0.27 0.020 0.010 0.011 

FSV-BO 2.94 0.28 0.055 0.053
 

FSV-BP
 3.97 0.69 0.085 0.070
 

FSV-BQ
 

FSV-BR
 

FSV-BS
 4.07 0.63 0.140 0.170 3.88 0.59 0.120 0.110 0.19 0.040 0.020 0.060 

FSV-BT 4.38 10.9 1.666 0.494 3.71 0.52 0.081 0.076 3.60 0.51 0.078 0.074 0.11 0.009 0.004 0.002 

FSV-BU 4.67 0.60 0.087 0.082 

FSV-BW 6.05 0.71 0.089 0.085
 

FSV-BX
 7.98 1.19 0.220 0.317 

FSV-BY 3.17 9.2 0.851 0.180 3.95 0.34 0.084 0.078 3.63 0.32 0.073 0.068 0.31 0.013 0.011 0.011 

FSV-BZ 3.48 0.66 >0.150 0.152 3.18 0.64 0.150 0.126 0.30 0.021 nd 0.026 

FSV-CA 

FSV-CB 

FSV-CC 

FSV-CF 

FSV-CH 3.65 0.59 0.074 0.070
 

FSV-CK
 4.58 0.59 0.087 0.083 

FSV-CM 

FSV-CN >4.59 >0.496 >0.081 >0.068 4.59 0.50 0.081 0.068
 

FSV-CP
 3.88 0.62 0.082 0.063
 

FSV-CQ
 6.02 0.64 0.040 0.051
 

FSV-CR
 

FSV-CS
 

FSV-CU
 >4.04 >0.434 >0.087 >0.079 4.04 0.43 0.087 0.079
 

FSV-CX
 3.76 0.60 0.110 0.090
 

FSV-DA
 2.57 7.9 0.690 0.120 3.32 0.53 0.078 0.071 3.04 0.51 0.070 0.071 0.28 0.020 0.008 nd
 

FSV-DB
 5.84 0.58 0.010 0.080 

FSV-DJ
 

FSV-DK
 3.90 0.42 0.090 0.090 

FSV-DM 4.01 0.49 0.072 0.073
 

FSV-DP
 

FSV-DS
 2.64 0.36 0.075 0.059
 

FSV-DX
 >3.31 >0.365 >0.071 >0.046 3.31 0.37 0.071 0.046
 

FSV-EH
 2.46 7.5 0.170 3.64 0.50 0.110 3.34 0.47 0.097 0.30 0.030 0.010 

FSV-EI 3.68 0.55 0.068 0.068 3.39 0.54 0.066 0.064 0.29 0.012 0.002 0.004 

FSV-EL 

FSV-FY >3.21 >0.494 >0.063 >0.054 3.21 0.49 0.063 0.054 

n 5 5 4 5 29 29 27 29 14 14 13 14 10 10 7 8 

Min 2.46 7.5 0.690 0.109 2.64 0.28 0.010 0.051 3.04 0.32 0.063 0.046 0.10 0.009 0.002 0.002 

Median 2.74 8.1 0.785 0.170 3.82 0.55 0.082 0.078 3.53 0.50 0.076 0.072 0.28 0.017 0.008 0.011 

Max 4.38 10.9 1.666 0.494 7.98 1.19 0.220 0.317 4.59 0.64 0.150 0.126 0.31 0.040 0.020 0.060 

eSD 0.41 1.0 0.074 0.28 0.09 0.010 0.012 0.30 0.11 0.009 0.011 0.05 0.007 0.004 0.007 

eCV 15 12 44 7 17 13 15 8 21 12 15 18 45 56 71 

NISTa 

NISTb 

NAV
 

NAU
 

3.41 7.9 0.871 nd 3.76 0.51 nd nd 3.31 0.42 nd nd 0.45 0.088 nd nd 

3.30 10.0 0.952 0.195 3.73 0.44 0.080 0.063 3.51 0.42 0.080 0.063 0.22 0.024 0.000 0.000 

3.05 8.6 0.183 3.79 0.51 0.081 0.071 3.47 0.46 0.078 0.068 0.32 0.036 

0.62 1.7 0.048 0.42 0.11 0.017 0.019 0.33 0.11 0.011 0.012 0.16 0.054 

All Lab Report G3 Page 2 / 6 
Lab 

FSV-BA 

FSV-BD 

FSV-BE 

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-BW 

FSV-BX 

FSV-BY 

FSV-BZ 

FSV-CA 

FSV-CB 

FSV-CC 

FSV-CF 

FSV-CH 

FSV-CK 

FSV-CM 

FSV-CN 

FSV-CP 

FSV-CQ 

FSV-CR 

FSV-CS 

FSV-CU 

FSV-CX 

FSV-DA 

FSV-DB 

FSV-DJ 

FSV-DK 

FSV-DM 

FSV-DP 

FSV-DS 

FSV-DX 

FSV-EH 

FSV-EI 

FSV-EL 

FSV-FY 

n 

Min 

Median 

Max 

eSD 

eCV 

NISTa 

NISTb 

Round Robin XXXVII Laboratory Results 

Values in μg/mL 

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

219 220 221 222 

0.116 0.22 0.013 0.015 

219 220 221 222 219 220 221 222 219 220 221 222 

0.157 0.172 0.161 0.324 0.093 0.093 0.084 0.086 

0.204 0.183 0.204 0.34 0.056 0.056 0.057 0.056 

0.090 0.13 0.021 0.034 0.279 0.178 0.230 0.43 

0.128 0.44 0.011 0.013 0.302 0.304 0.290 0.56 0.095 0.092 0.092 0.096 

0.101 0.30 0.012 0.013 0.215 0.218 0.221 0.38 0.082 0.078 0.074 0.059 

0.122 0.37 0.031 0.020 0.140 0.164 0.154 0.28 

0.093 0.40 0.010 0.009 0.272 0.237 0.236 0.44 0.126 0.131 0.133 0.237 0.062 0.057 0.058 0.053 

0.108 0.18 0.013 0.009 0.397 0.274 0.253 0.45 0.054 0.056 0.054 0.053 

0.132 0.47 0.029 0.016 0.313 0.286 0.284 0.61 0.080 0.078 0.074 0.079 

0.140 0.39 0.040 0.040 0.100 0.100 0.110 0.45 0.120 0.090 0.090 0.090 

0.078 0.31 0.016 0.020 

0.082 0.31 0.011 0.014 

0.244 0.251 0.237 0.46 0.183 0.192 0.185 0.370 0.098 0.094 0.095 0.084 

0.118 0.42 0.081 0.064 1.385 0.376 0.107 0.29 0.105 0.105 0.077 0.122 

0.076 0.14 0.010 0.018 0.307 0.287 0.298 0.52 0.168 0.175 0.182 0.311 0.063 0.064 0.066 0.066 

0.114 0.24 0.028 0.025 0.312 0.294 0.300 0.42 

0.107 0.36 0.010 0.017 0.229 0.223 0.236 0.49 

0.150 0.43 0.017 0.019 0.276 0.229 0.217 0.38 0.075 0.073 0.068 0.072 

0.132 0.33 nd nd 0.266 0.263 0.262 0.45 0.072 0.071 0.065 0.064 

0.110 0.35 0.018 0.030 0.131 0.139 0.141 0.25 0.068 0.075 0.071 0.061 

0.060 0.28 <0.01 <0.01 0.310 0.240 0.270 0.44 0.130 0.110 0.120 0.080 

0.095 0.33 0.009 0.011 0.280 0.260 0.260 0.46 0.130 0.140 0.140 0.240 0.060 0.060 0.060 0.070 

nq nq nq nq 

0.110 0.22 0.009 0.010 

0.326 0.273 0.356 0.46 0.117 0.106 0.102 0.111 

0.117 0.32 0.016 0.014 0.290 0.269 0.227 0.46 

0.258 0.250 0.262 0.44 

0.130 0.38 nd 0.430 0.450 0.76 0.280 0.290 0.470 0.066 0.064 0.057 

0.081 0.33 0.012 0.015 0.306 0.308 0.296 0.57 0.146 0.142 0.144 0.253 0.064 0.061 0.061 0.059 

24 24 21 21 24 24 23 24 7 7 6 7 19 19 18 19 

0.060 0.13 0.009 0.009 0.100 0.100 0.107 0.25 0.126 0.131 0.133 0.237 0.054 0.056 0.054 0.053 

0.110 0.33 0.013 0.016 0.280 0.256 0.237 0.45 0.157 0.172 0.153 0.311 0.075 0.075 0.073 0.070 

0.150 0.47 0.081 0.064 1.385 0.450 0.356 0.76 0.280 0.290 0.185 0.470 0.130 0.110 0.120 0.122 

0.026 0.08 0.005 0.006	 0.049 0.047 0.049 0.05 0.039 0.044 0.024 0.087 0.022 0.022 0.018 0.019 

24 25 38 37 18 19 21 10 25 26 16 28 30 30 25 28 

NAV
 

NAU
 

0.141 0.24 nd nd 

0.112 0.24 0.013 0.013 0.363 0.343 0.323 0.51 0.155 0.150 0.153 0.232 0.065 0.059 0.060 0.049 

0.119 0.28 0.013 0.015 0.321 0.300 0.280 0.48 0.156 0.161 0.153 0.272 0.070 0.067 0.066 0.059 

0.033 0.11 0.007 0.006 0.089 0.088 0.085 0.11 0.032 0.039 0.031 0.093 0.026 0.025 0.022 0.024 

All Lab Report G4	 Page 3 / 6 
Round Robin XXXVII Laboratory Results 

Values in μg/mL 

Lutein Zeaxanthin Lutein&Zeaxanthin Coenzyme Q10 

Lab 219 220 221 222 219 220 221 222 219 220 221 222 219 220 221 222 

FSV-BA 0.192 0.271 0.191 0.188
 

FSV-BD
 0.096 0.139 0.095 0.081 0.044 0.042 0.050 0.041 0.140 0.181 0.145 0.081 

FSV-BE 

FSV-BG 

FSV-BH 0.074 0.105 0.074 0.064 0.031 0.035 0.040 nd 0.105 0.140 0.114 0.064 

FSV-BI 0.074 0.106 0.068 0.055 0.032 0.038 0.036 0.025 0.106 0.144 0.104 0.055 

FSV-BJ 

FSV-BK 

FSV-BL 

FSV-BM 

FSV-BN 0.052 0.087 0.052 0.055 0.020 0.022 0.025 0.019 0.072 0.109 0.077 0.075
 

FSV-BO
 0.116 0.159 0.116 0.085
 

FSV-BP
 

FSV-BQ
 

FSV-BR
 

FSV-BS
 0.070 0.160 0.090 0.080
 

FSV-BT
 0.136 0.171 0.131 0.130 0.029 0.025 0.028 0.023 0.165 0.196 0.160 0.152 

FSV-BU 

FSV-BW 

FSV-BX 0.160 0.310 0.200 0.160 0.080 0.068 0.080 0.046 0.240 0.378 0.280 0.160 

FSV-BY 0.073 0.121 0.074 0.063 0.042 0.050 0.042 0.031 0.115 0.171 0.116 0.063 

FSV-BZ 0.096 0.108 0.088 0.085
 

FSV-CA
 

FSV-CB
 

FSV-CC
 

FSV-CF
 

FSV-CH
 0.950 1.080 1.060 0.760 

FSV-CK 0.169 0.218 0.174 0.139 

FSV-CM 

FSV-CN 0.071 0.112 0.073 0.064
 

FSV-CP
 0.143 0.192 0.146 0.113
 

FSV-CQ
 

FSV-CR
 

FSV-CS
 

FSV-CU
 

FSV-CX
 0.140 0.160 0.140 0.070
 

FSV-DA
 0.080 0.120 0.080 0.090 0.050 0.060 0.060 0.040 0.130 0.180 0.140 0.130
 

FSV-DB
 0.141 0.174 0.147 0.106 

FSV-DJ 

FSV-DK 

FSV-DM 0.158 0.194 0.157 0.120 

FSV-DP 

FSV-DS 

FSV-DX 0.130 0.159 0.128 0.101
 

FSV-EH
 0.080 0.120 0.083 0.046 0.045 0.037 0.126 0.165 0.083 1.200 1.200 0.910 

FSV-EI 0.103 0.142 0.098 0.101 0.072 0.072 0.070 0.064 0.175 0.214 0.168 0.101 

FSV-EL 

FSV-FY 

n 13 13 12 13 11 11 10 10 17 17 16 17 2 2 1 2 

Min 0.052 0.087 0.052 0.055 0.020 0.022 0.025 0.019 0.072 0.109 0.077 0.055 0.95 1.08 0.76 

Median 0.080 0.120 0.084 0.081 0.044 0.045 0.046 0.039 0.140 0.174 0.143 0.101 1.075 1.140 1.060 0.835 

Max 0.160 0.310 0.200 0.160 0.158 0.194 0.157 0.120 0.240 0.378 0.280 0.188 1.200 1.200 0.910 

eSD 0.015 0.022 0.016 0.025 0.019 0.022 0.023 0.016 0.037 0.026 0.039 0.043 

eCV 19 19 19 31 44 49 51 40 26 15 27 43 

NISTa
 

NISTb
 

NAV
 

NAU
 

0.084 0.122 0.084 0.085 0.046 0.051 0.049 0.047 0.129 0.173 0.133 0.085 

0.082 0.121 0.084 0.083 

0.018 0.027 0.019 0.020 

0.045 0.048 0.048 0.043 

0.022 0.021 0.023 0.014 

0.135 

0.037 

0.174 

0.038 

0.138 

0.035 

0.117 

0.046 

All Lab Report G5 Page 4 / 6 
Round Robin XXXVII Laboratory Results 

Analytes Reported By One Laboratory 

Values in μg/mL 

Term 

n 

Min 

Median
 

Max
 

eSD 

eCV 

NAV 

NAU 

nd 

nq 

>x 

<x 

italics

Analyte Code 219 220 221 222 

Phytofluene FSV-DA 0.040 0.060 0.050 0.040 

α-Cryptoxanthin FSV-BN 0.043 0.046 0.042 0.025 

trans-α-Carotene NISTb 0.090 0.237 0.013 0.013 

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 

 Estimated standard deviation, calculated from the median absolute deviation

 from the median of the non-NIST results

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

 NIST Assigned Value, our estimate of the "true" analyte concentration

 NIST Assigned Uncertainty, our estimate of the total (serum hetergeniety and

 inter- and intra-laboratory) standard deviation 

 For details on how we assign these quantities, see the "Report of (Meta)Analysis."

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

 Detected but not quantitatively determined

 Concentration greater than or equal to x

 Concentration at or below the limit of quantification, x

 Not explicitly reported but calculated by NIST from reported values

All Lab Report G6 Page 5 / 6 
Round Robin XXXVII Laboratory Results
 

Comparability Summary
 

Lab 

FSV-BA 

FSV-BD 

FSV-BE 

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-BW 

FSV-BX 

FSV-BY 

FSV-BZ 

FSV-CA 

FSV-CB 

FSV-CC 

FSV-CF 

FSV-CH 

FSV-CK 

FSV-CM 

FSV-CN 

FSV-CP 

FSV-CQ 

FSV-CR 

FSV-CS 

FSV-CU 

FSV-CX 

FSV-DA 

FSV-DB 

FSV-DJ 

FSV-DK 

FSV-DM 

FSV-DP 

FSV-DS 

FSV-DX 

FSV-EH 

FSV-EI 

FSV-EL 

FSV-FY 

NISTa 

NISTb 

R aT gT bC* tbC* Label 

1 1 1 2 2 Lab 

1 2 2 1 R 

2 1 1 2 aT 

1 1 gT 

3 1 1 bC 

2 2 3 tbC 

1 1 2 2 n 

2 2 1 2 2 

Definition

 laboratory number 

 "Standard Score" for Retinol 

 "Standard Score" for α-Tocopherol

 "Standard Score" for γ-Tocopherol

 "Standard Score" for Total β-Carotene

 "Standard Score" for trans-β-Carotene

 number of (non-NIST) laboratories providing data for this analyte 

1 2 1 1 2 * Ratings based on sera 220-222 only, due to the extremely high trans-β-carotene concentration of 

3 4 2 1 

1 1 4 4 

2 1 2 4 4 

2 3 

1 2 

2 2 1 

2 

3 1 1 

2 1 1 

2 1 1 1

4 4 1

1 1 2 2

2

3 2 2 

2 2 1 1 2 

2 2 2 1 2 

2 1 4 3 

2 2 3 

1 1 2 

1 1 1 1 

1 1 

2 

2 1 

1 1 

1 

1 2 2 

1 2 1 1 

1 1 4 

2 2 1 

4 3 1 1 1 

2 2 

1 1 

1 1 2 

3 3 2 2 3 

2 2 2 1 

2 2 

2 1 1 2 

2 

1 1 

1 1 1 1 1 

1 1 1 1 1 

n 45 42 22 29 14 

StS 

1 

2 

3 

4 

All Lab Report 

% Observed 

40 48 55 48 29 68.2 % 

44 40 41 31 50 27.3 % 

11 7 0 7 14 4.3 % 

4 5 5 14 7 0.3 %

serum 219. 

"Standard Score" 

Given that our knowledge of the shape, location, and width of the measurement distributions is 

approximate and that a limited number of labs are involved, we summarize comparability with the 

following four-level "Standard Score" (StS)... 

StS 

1 

2 

3 

4 

where: 

StV 

NAV 

NAU 

t (1-α,n-1) 

Expected 

Definition

 All StV within ±t (1-0.683,n-1) {i.e., ±1 SD} 

 All StV within ±t (1-0.954,n-1) {i.e., ±2 SD} 

 All StV within ±t (1-0.997,n-1) {i.e., ±3 SD} 

 At least one StV > ±t (1-0.997,n-1) {i.e., >3 SD} 

 Standardized Value, the distance in standard deviation units your 

 value is from the "true" concentration: StV = (your value - NAV) / NAU

 NIST Assigned Value, our estimate of the "true" analyte concentration

 NIST Assigned Uncertainty, our estimate of the total (serum heterogeniety and iter- and 

intra-laboratory) measurement standard deviation.

 Two-tailed Student's t for coverage of ±1, ±2, and ±3 NAU about 

 NAV, assuming a normal population of size n 

For details on the NIST Assigned quantities, see this Round Robin's 

"Report of (Meta)Analysis." 

These are the observed and normal-population-expected proportions of each Standard 

Score (StS), based upon each laboratory's largest StV for the four sera. 

G7 Page 6 / 6 
 

Appendix H. Representative “Individualized Report” for RR37 

Each participant in RR37 received an “Individualized Report” reflecting their reported 

results. Each report included a detailed analysis of the results they reported for some or 

all of the following analytes: 

• Retinol 

• Retinol palmitate 

• α-Tocopherol 

• γ-Tocopherol 

• Total β-Carotene 

• trans-β-Carotene 

• Total α-Carotene 

• Total Lycopene 

• β-Cryptoxanthin 

• Lutein 

• Zeaxanthin 

• Lutein & Zeaxanthin 

The following 8 pages are the “Individualized Report” for the analytes evaluated by 

participant FSV-BA. 

H1
 
Individualized Round Robin XXXVII Report to: FSV-BA 

Your Data, NIST Assigned Values, and %Differences 

Serum219 Serum220 Serum221 Serum222 

Anal te You NAV %A n I You NAV %A n I I You NA V %A n I I You NAV %A n I 

Retinol .84 .79 5 45 .53 .49 8 45 .69 .67 4 44 .50 .48 6 45 

Retinyl Palmitate .01 10 .01 11 1.37 1.49 -8 13 .01 .11 -89 14 

a-Tocopherol 7.24 7.65 -5 42 10.71 11.14 -4 42 16.18 17.20 -6 41 6.91 7.11 -3 42 

y-Tocopherol 8.37 8.18 2 22 3.77 3.72 1 22 1.87 1.88 -1 21 2.45 2.36 4 22 

Total 13-Carotene 3.76 3.79 -1 28 .37 .51 -27 28 .09 .08 9 27 .09 .07 29 28 

trans-fl-Carotene 3.66 3.47 5 14 .36 .46 -22 14 .08 .08 3 13 .08 .07 22 14 

Total cis-13-Carotene .10 9 .01 9 .01 6 .01 7 

Total a-Carotene .12 .12 -2 24 .22 .28 -22 24 .01 .01 0 21 .02 .01 7 21 

trans-Lycopene .16 .16 1 7 .17 .16 7 7 .16 .15 5 6 .32 .27 19 7 

13-Cryptoxanthin .09 .07 33 19 .09 .07 39 19 .08 .07 27 18 .09 .06 46 19 

"Lutein&Zeaxanthin" .19 17 .27 17 .19 16 .19 17 

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

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

%A : Percent difference between your value and the NA V 

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

Please check our recorded values against your records. 

Send corrections to: NNMMQAP 222/B208, NIST, Gaithersburg, MD 20899; fax 301-977-0685; email David.Duewer@NIST.gov 

7119196 Pagel / 8 

H2
 
50 

25 

> x < x 

v -.. 

I > 

I 

d 

0 

* 8 

<I 

-25 

-50 

1119196 

Individualized Round Robin XXXVII Report to: FSV-BA 

Retinol, %Li in Round Robin XXVIII - :XXXVII 

1 1 1 1 1 

8 8 8 8 8 

1 2 3 4 5 

1 1 1 1 1 

8 8 8 8 9 

6 7 8 9 0 

1 1 1 1 

9 9 9 9 

1 2 3 4 

1 1 1 1 

9 9 9 9 

5 6 7 8 

1 2 2 2 

9 0 0 0 

9 0 1 2 

2 2 2 2 

0 0 0 0 

3 4 5 6 

Serum 

2 2 2 2 

0 0 0 1 

7 8 9 0 

2 2 2 2 

1 1 1 1 

1 2 3 4 

2 2 2 2 

1 1 1 1 

5 6 7 8 

2 2 2 2 

1 2 2 2 

9 0 1 2 

Pa&e218 

H3
 
50 

25 

- v 

I I z I 

d, 

0 

* 8 

-

<'.] 1 

-25 -50 J 

7119196 

Individualized Round Robin XXXVII Report to: FSV-BA 

Tocopherols, %L\ in Round Robin XXVIII - XXXVII 

x x 

x x x x x Xu x x x x x x x J X X x x I i •• _g 1LY .. v .. Jc .... x I I I I I . - ::.:-: ....... -- -

• g-Tocopherol m a-Tocopherol 

1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 

8 8 8 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 9 0 0 0 0 0 0 0 0 0 0 1 1 1 1 1 1 1 1 1 1 2 2 2 

1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 

Serum 

Page3 / 8 

H4
 
50 

25 

> < > < z 1l 

d, 

0 

* 8 

-

<l 

-25 

-50 J 

1119196 

Individualized Round Robin XXXVII Report to: FSV-BA 

b-Carotene, %Li in Round Robin XXVIII - XXXVII 

-· x Lii 1 - it - : .. {:; ::::..:: ll lll I 

• trans-b-Carotene m Total b-Carotene 

I I I I I I I I I I I I I I I I I I I 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 

8 8 8 8 8 8 8 8 8 9 9 9 9 9 9 9 9 9 9 0 0 0 0 0 0 0 0 0 0 I I I I I I I I I I 2 2 2 

I 2 3 4 5 6 7 8 9 0 I 2 3 4 5 6 7 8 9 0 I 2 3 4 5 6 7 8 9 0 I 2 3 4 5 6 7 8 9 0 I 2 

Serum 

Page4/ 8 

H5
 
1119196 

Individualized Round Robin XXXVII Report to: 

- ±20% 

-- ±50% 

Retinol 

, 

, 

. 

, 

, 

, 

, 

, , 

• .

. 

, 

. 

, 

, 

, 

, 

. 

• .

, 

, 

• • 

, 

• 

. 

, 

, 

. 

• • 

. 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

a-Tocopherol 

- ±20% 

-- ±50% 

, 

• . 

. 

• • . 

, 

, 

, 

• • , 

• , • 

. 

• • .

• 

NIST Assigned Values Vs Laboratory Values 

, 

, 

, 

, 

, 

• . 

, 

, 

, 

, 

, 

, 

, 

, 

, 

• , 

A Total 

e trans 

-- ±50% 

- ±20% 

-- ±50% 

r-Tocopherol 

• • 

. 

. 

. 

, 

. 

. 

. 

, 

, 

. 

. 

, 

, .•A, 

• 

• • . 

• , 

• 

. 

, 

, 

. 

, 

• • 

, 

• . 

. 

. 

. 

. 

. 

. 

. 

• • • , 

, 

. 

, 

, 

. 

. 

, 

. 

. 

Legend 

Shaded Symbols: RR XXVIII-XXXVI 

Black Symbols: RR XXXVII 

Ordinate (X-axis): NIST Assigned Value 

Abscissa (Y-axis): Your reported value 

Inte!P_retation 

Adequatefy-intercomparable data are within 

±20% lines. If you have data scattered outside 

±50% lines, your measurement system is 

not consistent with those of most participating 

laboratories. If your data are systematically 

higher or lower than the NA V, your system 

may be consistent but your results are biased . 

If your data show increased scatter at low 

concentrations, your "limit of quantification" 

may not be what you think it is. 

If there are one or two "wild" outliers, they 

might be calculation or transcription errors . 

We would appreciate hearing from you about 

any such problems . 

Page 5/ 8 

H6
 
7119196 

Individualized Round Robin XXXVII Report to: FSV-BA 

Accuracy /Precision Summary 

xxvm 

XXIX 

xxx 

XXXI 

XXXII 

xxxm 

XXXIV 

xxxv 

XXXVI 

XXXVII 

'Ret 

vll. 

0 4 

4 4 

9 4 

5 3 

-3 2 -2 2 

4 4 

6 4 

-1 2 

6 2 

a Toe 

vll. 

1 2 

0 3 

4 7 

-2 5 

-1 1 

0 2 

-4 1 

-2 14 

2 1 

-4 1 

gToc 

vll. 

1 4 

9 6 

-3 7 

-1 5 

-3 3 

11 11 

3 2 3 8 

-19 2 

2 2 

(Traditional) Performance Criteria 

Total 

vll. 

1 7 

5 4 

9 12 

9 9 

8 4 

12 13 

6 3 

1 4 

10 9 

2 23 

The absolute value of %/l. of every measurement has 

traditionally been evaluated as follows ... 

%!!. I Evaluation 

0-5% Exceptional 

6-10% Acceptable 

11-20% Marginal 

>20% Poor 

More representative criteria need to be established, 

factoring in each serum's analyte level and the 

analyte distribution in adult human populations. 

Stay tuned, we're working on it. .. 

trans 

vll. 

0 3 

3 3 

9 12 9 10 

13 4 

12 6 

9 4 

6 3 

11 3 

2 18 

Legend -

Ret Retinol 

a Toe a-Tocopherol 

gToc y-Tocopherol 

Total Total Ji-Carotene 

trans trans-p-Carotene 

Mean difference, the average %/l. for all sera of a given RR, where 

%/l. = 1 OO(Your value - NA V) I NA V 

vll. Difference variability, one standard deviation of %/l. for all sera of a 

NAY NIST Assigned Value, our best estimate of analyte concentration ... 

NA V = (NISTs average-of-averages + Round Robin median) I 2 

Interpretation 

Accuracy and precision are separate but kindred aspects of measurement 

comparison. We estimate accuracy as the average %/l., and precision 

as vA, the standard deviation of%!!., for all sera of a Round Robin. 

It's best to be accurate and precise small vll.)! 

RR 

Good precision (small vll.) with poor accuracy is better than the 

converse: at least such values are internally consistent and may be relatable to 

others' values once the relative biases have been determined. 

Poor precision (large vll.) suggests that your measurement system is not in 

adequate control for the analyte levels examined. 

Page 6/ 8 

H7
 
Individualized Round Robin XXXVII Report to: FSV-BA 

Comparisons -

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7119196 Page7/8 

H8
 
Individualized Round Robin XXXVII Report to: FSV-BA 

Comparisons (Continued) 

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7119196 Pa&e 8 / 8 

H9
 
 

 

Appendix I. Shipping Package Inserts for RR38 

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

• Cover letter 

• Datasheet 

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

samples themselves. 

I1
 
July 9, 1996 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standards and Technology 

Gaithersburg, Maryland 20899-

Enclosed is the set of samples for Round Robin XXXVIII. You will find one 'vial each of four 

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

reporting your results, please submit one value for each analyte for a given serum sample. If an 

obtained value is below your detection limit, please indicate this result on the form by using ND 

(Not Detected). For analytes not measured, please leave a blank. Results are due to NIST by 

September 20. Results received two weeks after the due date will not be included in the 

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

provided around October 25. 

Samples should be reconstituted with 1.0 mL ofHPLC-grade water or equivalent. We 

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

least 30 min at room temperature with intermittent swirling. (CAUTION: Vigorous shaking 

will cause foaming and possibly interfere with accurate measurement. The rubber stopper 

contains phthalate esters which will leach into the sample upon intermittent contact of the liquid 

sample with the stopper. These esters absorb strongly in the UV region and elute very near 

retinol in most HPLC systems creating analytical problems.) Pipette a known volume of serum 

from the vial for analysis since the final volume of the reconstituted sample is greater than 1.0 

mL. For consistency, we request that laboratories use the following absorptivities (E 1 % cm) in 

ethanol: retinal, 1850 at 325 nm; retinyl palmitate, 975 at 325 nm; cx-tocopherol, 75.8 at 292 

nm; y-tocopherol, 91.4 at 298 nm; ex-carotene, 2800 at 444 nm; ~-carotene, 2560 at 450 nm; 

lycopene (in hexane), 3450 at 472 nm. 

Please mail or FAX your results for Round Robin XXXVIII to: 

Micronutrients Measurement Quality Assurance Program 

NIST 

Bldg.222,Rm.B208 

Gaithersburg, MD 20899 

FAX: (301) 977-0685 

If you have questions regarding this round robin exercise, please call me at (301) 975-3120; 

e-mail: jeanice.brown-thomas@nist.gov; or mail/FAX queries to the above address. 

· ce Brown Thomas 

esearch Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

cc: S. Wise 

N•Si 

I2
 
 

 

NIST/NCI 

Micronutrients Measurement Quality Assurance Program 

Round Robin XXXVIII Results from Laboratory #_____ 

Serum 

Analyte 223 224 225 226 Units* 

retinol 

retinyl palmitate 

α-tocopherol 

γ-tocopherol 

δ-tocopherol 

total β-carotene 

trans-β-carotene 

total cis-β-carotene 

total α-carotene 

total lycopene 

trans-lycopene 

β-cryptoxanthin 

lutein 

zeaxanthin 

lutein&zeaxanthin 

Other Analytes?
 

* We prefer mg/mL 

Today's Date: 

Comments? 

Mail: MMQAP, 222/B208 

NIST Please return results on-or-before Fax: 301-977-0685 

Gaithersburg, MD 20899 September 20, 1996 Email: David.Duewer@NIST.gov 

I3
 
Appendix J. Final Report for RR38

The following 19 pages are the final report for RR38 as provided to all participants: 

•	 Cover letter 

•	 A discussion entitled “Lies, Damn Lies, and Statistics” that: 

o	 describes the nature of the test samples and details any previous distributions 

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

participants 

• A “Report of (Meta)Analysis” that details the analysis of NIST measurements 

J1
 
November 6, 1996 

Dear Colleague: 

UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standards and Technology 

Gaithersburg, Maryland 20899-

This report summarizes both overall and individual laboratory performance for the three round 

robin exercises conducted during 1996. Included in this report are: tabular summaries of data for 

Round Robins XXXVI, XXXVII, and XXXVIII; a graphical summary of the interlaboratory 

median vs. individualized laboratory data for retinol, a- and y-tocopherol, and total and trans-Pcarotene; percent bias charts for retinol, a- and y-tocopherol, and trans- and total P-carotene; and 

a summary of individual laboratory performance for the past three years. Tabular data only are 

provided for a-carotene, P-cryptoxanthin, lutein, lycopene, retinyl palmitate, and zeaxanthin. 

Over the past three years the overall interlaboratory precision has remained at an average 

estimated coefficient of variation ( eCV) of about 10% for retinol and a-tocopherol measurements 

and approximately 21 % for P-carotene during the same period of time. The eCV for ytocopherol has remained at about 10% over the past two years. 

In Round Robin XXXVI (Sera 215-218), all serum samples were previously distributed. Serum 

215 was distributed as Serum 170 in Round Robin XXVI; Serum 216 was distributed as Serum 

182 inRoundRobin:XXVIII; Serum217 as Serum 194 inRoundRobin:XXX; and Serum218 as 

Serum 199 in Round Robin XXXII. The overall laboratory performance for retinol, a- and ytocopherol, and P-carotene for this exercise was comparable to that of the overall interlaboratory 

performance over the past three years. 

Round Robin XXXVII (Sera 219-222) consisted of three new sera. Serum 222 was previously 

distributed as Serum 181 in Round Robin XXVIII. Sera 219-222 contained augmented levels of 

retinol, retinyl palmitate, and/or o-, y-, and a-tocopherol. Results from this exercise indicated 

that the variation for P-carotene and retinyl palmitate in the sera with augmented levels of these 

analytes appeared to be similar to that of sera with low levels of P-carotene. In previous 

exercises where the levels of P-carotene were significantly lower ( s; 100 ng/mL ), a higher 

variation was observed due to the difficulty of making measurements at levels that appeared to 

be at or below the limit of quantification for most laboratories. 

Round Robin XXXVIII (Sera 223-226) consisted of all new sera. Sera 223 and 225 are blind 

duplicates of a serum pool with augmented levels of retinyl palmitate. Serum sample 224 

(obtained from the same pool used to make Sera 223 and 225) contained augmented levels of 

retinol, retinyl palmitate, a- and y-tocopherol, trans-a- and P-carotene, trans-lycopene, Pcryptoxanthin, lutein, and zeaxanthin. Serum 226 was a newly designed serum sample from a 

delipidized serum pool augmented with normal-to-high levels of all routinely measured analytes. 

This serum pool also contained trace amounts of dimethyl sulfoxide and cholesterol, which 

probably accounted for some reports of a gel-like consistency of the serum as well as observed 

particulate matter during extraction. Due to these observations, the results from this serum 

sample were not included in the overall laboratory performance for Round Robin XXXVIII or in 

the comparability summary (scorecard) in the attached report. 

J2
 
In Round Robin XXXVIII, the interlaboratory precision (excluding the results from Serum 226) 

was about 8% for retinol, 10% for y-tocopherol, and about 6% for a-tocopherol. The average 

estimated coefficient of variation (eCV) for P-carotene was about 14%. The overall laboratory 

precision for retinyl palmitate and lycopene was about 39% and 19%, respectively. We will 

continue to evaluate ways to improve the interlaboratory comparability for these analytes in 

future studies. 

Data for evaluating your laboratory's performance in Round Robin XXXVIII are provided in the 

comparability summary on page 6 of the report. The criteria used to summarize laboratory 

performance are as follows: results rated 1(within±1 SD of the assigned value) indicate 

EXCEPTIONAL performance, those rated 2 (within± 2 SD) indicate ACCEPTABLE 

performance, a rating of 3 (within± 3 SD of the assigned value) is MARGINAL performance, 

and 4 (> 3 SD from the assigned value) indicates POOR performance relative to the current 

state-of-the-practice for these measurements. 

If you have concerns regarding your laboratory performance or were rated "POOR" based on the 

criteria stated above, we suggest that you obtain a unit of SRM 968b, Fat-Soluble Vitamins and 

Cholesterol in Human Serum, and analyze all three levels. If with minor method modifications, 

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

consultation. 

As mentioned in a previous mailing, the participation fees for the 1997 QA program for non-NCI 

funded laboratories will be $400 for US labs and $900 for non-US labs. An invoice to that effect 

will be mailed in January. Also, as a reminder, to participate in the 1997 program your intent-toparticipate form should be returned to us no later than November 29, 1996. 

The 1997 QA Program will consist of three round robin exercises for the analysis of fat-soluble 

vitamins and carotenoids in serum, two exercises for the analysis of ascorbic acid in serum, and 

two exercises for the analysis of fat-soluble vitamins and carotenoids in food. The FY97 program 

thrusts will continue to focus on methods d{'.velopment for the measurement of 

difluoromethylornithine, epigallocatechin gallate, and 4-hydroxyphenylretinamide in serum. 

Other program thrusts will be addressed upon NCI's request. 

The first set of samples for the fat-soluble vitamins in serum analysis will be distributed during 

the week of January 27. Results are due by March 21; written feedback will be provided to labs 

by April 18. The second· set of samples will be shipped the week of April 28 with results due by 

June 13 and feedback to labs by July 25. The third set of samples will be shipped the week of 

July 28. Results will be due by September 19. Feedback will be provided to the laboratories 

around October 27. 

The round robin studies for the measurement of fat-soluble vitamins and carotenoids in food will 

also be scheduled in April and July to coincide with the second and third serum round robin 

studies. The coordinator of these exercises is Dr. Katherine Sharpless (301/975-3121). 

J3
 
The fust set of samples for the measurement of ascorbic acid in serum will be distributed in 

November 1996. The second set will be distributed in May. These round robin studies are being 

coordinated by Dr. Sam Margolis (301/975-3137). 

The Fat-Soluble Vitamins and Carotenoid Analysis Tutorial session was held on October 25, 

1996 at NIST. As in past years, the session was well-attended and provided a great opportunity 

for new laboratories to discuss in detail their measurement techniques. 

Plans are still underway for hosting our next QA workshop at the American Association for 

Clinical Chemistry meeting, which will be held in Atlanta, Georgia during July 20-24, 1997. We 

will keep you informed of the workshop plans as they are finalized. 

Certificates of participation in the FY96 QA Program will be distributed in January 1997. The 

homepage section for the QA program is still under construction. We anticipate that it will 

become available in January 1997. Lastly, for your convenience, we have enclosed reprints from 

some of our most recent publications. Please feel free to contact us for additional copies. 

Sincerely, 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosures 

cc: W.E.May 

S.A. Wise 

J4
 
Lies, Damn Lies, and Statistics 

"Lies, Damned Lies, and Statistics" 

Benjamin Disraeli 

Page I 

The attached N2M2QAP Round Robin XXXVID Report includes the standard "All Lab" listing 

of everyone's results, your "Individualized" results, and our '"(Meta)Analysis" of value and 

uncertainty assignments. 

Pa e "All Lab" Re ort Contents 

1-4 A listing of all results for analytes reported by at least two laboratories, plus 

essential summary statistics 

5a A list of results for the four analytes reported by only one laboratory. 

5b A legend for the above two lists 

6 The "Measurement Comparability Summary" (or "Score Card") 

Pa e "Individualized" Re ort Contents 

1 your values, our assigned values, and the %bias between the two 

2-4 %Bias barchart for retinol, ex- and y-tocopherol, and total and trans-~-carotene 

for your last 3 years' results 

5 Our assigned value vs. your value scatterplots for retinol, a- and ytocopherol, and total and trans-~-carotene, also for your last 3 years' results 

6 Accuracy/Precision Summary, yet again for your last 3 years' results 

7-8 "Comparisop.s" plots for retinol, retinyl palmitate, a- and y-tocopherol, total 

and trans-~-carotene, total ex-carotene, total lycopene, ~-cryptoxanthin, lutein, 

zeaxanthin, and lutein & zeaxanthin 

All samples distributed in this exercise were newly prepared. The samples labeled as sera #223 

and #225 are blind duplicates, prepared from a retinyl palmitate-augmented but otherwise 

"normal" serum pool. Serum #224 started off as a rather boring low-carotenoid pool and was 

augmented with retinol, retinyl palmitate, a- and y-tocopherol, trans-a- and trans-~-carotene, 

trans- lycopene, ~-cryptoxanthin, lutein, and zeaxanthin! 

Serum #226 ... sigh ... was an attempt to create a totally "known" material starting from 

delipidized serum. While we did achieve (nearly) the intended average level for all analytes, we 

introduced considerable vial-to-vial heterogeneity. Many of you reported suspended solids: we 

suspect that the apparently incorporated cholesterol used as an analyte-carrier sometimes 

"unincorporated" during freeze-drying .... Maybe there was a little dimethyl sulfoxide left in 

some of the vials, too .... We learned a lot from the experiment, but we apologize for the 

troubles it caused you! While we report all the data for this serum, none of the serum #226 

results are used in our various performance calculations. 

J5
 
Lies, Damn Lies, and Statistics Page 2 

We believe that the results for serum #224 document our ability to "build" a normal serum pool 

to rather high carotenoid levels. Using the graphical analysis previously described in the 

RRXXXVII report, Figures 1 and 2 document the estimated standard deviation for the 

RRXXXVIII sera relative to their expected values for retinol, total ~-carotene, o:-tocopherol, 

y-tocopherol, total a-carotene, total lycopene, ~-cryptoxanthin, and retinyl palmitate. In these 

figures, results from the first 4 years ('86-'89) of the N2M2QAP exercises are denoted "1", those 

from the '90-'92 exercises are denoted "2", and '93-'95 are denoted "3". The lines denote the 

best-fit sigmoidal curve to the past three years' data. The solid diamonds are samples #223, 224, 

and 225. With the exception of retinyl palmitate, the observed eSDs for these samples are about 

as expected from the historical relationships. The solid circles denote the sample #226 data: the 

excess eSD from sample heterogeneity is apparent for all analytes. 

Note that the observed eSD for retinyl palmitate depends slightly, if at all, on the observed 

median concentration. While it may be possible to qualitatively determine whether or not an 

individual has taken retinyl palmitate supplements using current measurement techniques, the 

values reported for this analyte should not be regarded as even "semi-quantitative." 

Why did we distribute the blind replicates, samples #223 and 225? Several reasons, but mostly 

that this is our way of getting the same type of "complete replicate measurements" from all 

participants. It also-provides you a "pure" mechanism for demonstrating your sameday/instrument/analyst analytical precision (repeatability). (Contrast this with the "Score Card", 

where "accuracy" - or at least agreement with the rest of the participants - is the dominant 

consideration.) No matter what the actual analyte concentrations may be, you should get very 

similar results for two random samples drawn from the same (hopefully) homogenous pool. For 

a single analyte, lvalue 1 - value21 is an adequate metric. However, the standard deviation 

2 2 L ( valuei - (value, + value2 )/2) I 1 al I 

·=i va ue1 - v ue 2 SD12 = I = {;::\ 2 -1 -v2 

. is equally good and facilitates generalization to more than two replicates. When comparing 

across two or more analytes, it is convenient to express any intralaboratory measurement 

differences as a fraction of the observed interlaboratory eSD: F = SD12 • 

eSD 

Table 1 lists all the reported quantitative values for samples #223 and 225 for retinol, 

o:-tocopherol, y-tocopherol, and total ~-carotene. (OK, I cheat: I've lumped some trans-~­

carotene values in with the total ~-carotene.) Table 1 also presents the individual analyte F 

values and a bounded average F for each participant: Favg = ~min(Fp4) /n . The "min(Fi,4)" 

J6
 
Lies, Damn Lies, and Statistics Page 3 

insures that a single very unlikely difference will have the same influence (four interlaboratory 

eSDs) no matter how "very unlikely" the difference. The Favg values are sorted from "best" to 

"least good". The number of individual analyte F values (n) contributing to Favg is also listed. (A 

corollary to Murphy's Law - "Things that can go wrong, will go wrong." - is "The more things 

that can go wrong, the more things that will go wrong." Thus, a good Favg with four analytes is 

"better" than the same Favg with only one or two analytes.) 

More than 80% of the Favg values are 0.5 or smaller, indicating that the very large majority of you 

have excellent short-term control over your measurement processes. We believe that data 

transcription errors may account for some of the the larger Favg values. In any case, the two 

largest values represent two quite distinct situations. Laboratory 62 has excellent repeatability 

for all analytes except total ~-carotene, for which very different values were reported (0.16 and 

0.40); since all analytes (except retinyl palmitate) were "native" in this serum, we believe the 

0.40 value to be an isolated error. In contrast, all of the analyte values reported by Laboratory 

113 for sample #225 are considerably larger than those reported for #223; this indicates a 

sample-wide problem such as reconstitution volume or internal standard quantification. 

Of course, it is always possible (ahem) that a few of our samples are unusually different from the 

rest. Hence, you should neither take undue pride in a single very good Favg value nor be unduly 

al~ed by a single "less good" Favg· We will continue to periodically include such pairs as part 

of the N2M2QAP and we encourage you to use truly "blind" replicates as part of your internal 

quality control efforts. (And we are developing methods for indirectly estimating both shortterm and long-term repeatabilities without necessarily using blind replicates.) 

Oh, yes. You may have noted listings for "Lab 17. l ". This participant submitted results for two 

methods, one established (" 17") and one experimental (" 17. l "). Both performed well, with the 

edge to the experimental! We're happy to help you evaluate new methods, but we do ask that 

you share the nature of the different submitted data sets with us. (If we don't have this 

information, we average the values to give a single result.) 

Your comments and suggestions are welcome. If you discover any errors in our recording or 

interpretation of your data, please let us know! 

Dave Duewer 

Research Chemometrician 

David.Duewer@NIST.gov 

Research 

~~ Biologist 

Margaret.Kline@NIST.gov 

J7
 
Lies, Damn Lies, and Statistics 

IO IO 

t Retinol a-Tocopherol 

0.1 

Total ~-Carotene y-Tocopherol 

0.1 • 

3 

0.01 

3 

0.1 1 

Median (μg/mL) 

Figure 1 

Observed RR XXXVIII eSDs Relative to Their Expected Values 

for Retinol, Total ~-Carotene, ~-Tocopherol, and y-Tocopherol 

Page 4 

100 

0.1 

0.1 

to 

J8
 
Lies, Damn Lies, and Statistics 

0.01 

0.001 

0.1 

0.01 

0.01 0.1 

ex-Carotene 

2 

Lycopene 

0.1 

O.ot 

p-Cryptoxanthin 

Retinyl Palmhate 

O.ot 

Median (μg/mL) 

Figure 2 

1 

-

3 

3 

. ., 'J - 3 ... 

,, 

L. I'') 

L 

~ ~ 

1~33 

3 

3 

0.1 

Observed RR XXXVIII eSDs Relative to Their Expected Values 

0.1 

• 

• 332 

for Total a-Carotene, Total Lycopene, b-Cryptoxanthin, and Retinyl Palmitate 

Page 5 

0.1 

0.01 

0.1 

0 

Cll 

a.> 

0.01 

J9
 
. __ .,.,_ 

Lies, Damn Lies, and Statistics Page 6 

Table 1. Short-Term Repeatabilities from Sample #223 and 225 Blind Replicates 

Retinol 

Lab 223 225 

0.53 0.53 

0.52 0.50 

0.54 0.54 

0.49 0.48 

0.49 0.49 

0.56 0.55 

0.44 0.44 

0.50 0.49 

0.44 0.49 

0.41 0.43 

0.56 0.55 

0.52 0.54 

0.50 0.55 

0.55 0.54 

0.48 0.48 

0.46 0.50 

0.49 0.50 

0.35 0.39 

0.51 0.53 

0.45 0.43 

0.60 0.62 

0.55 0.55 

0.45 0,63 

0.52 0.59 

0.53 0.53 

0.53 0.52 

0.33 0.30 

0.50 0.52 

0.52 0.53 

0.52 0.54 

0.77 0.75 

0.44 0.47 

0.49 0.50 

0.51 0.43 

0.48 0.48 

0.51 0.51 

0.51 0.51 

0.50 0.51 

0.42 0.40 

0.44 0.45 

0.49 0.50 

0.47 0.48 

0.47 0.47 

0.50 0.50 

0.53 0.55 

0.49 0.53 

NSV 0.51 0.51 

NSU 0.04 0.05 

F 

0.00 

0.22 

0.02 

0.13 

0.00 

0.17 

0.08 

0.02 

0.79 

0.37 

0.17 

0.48 

0.86 

0.02 

0.03 

0.67 

0.13 

0.74 

0.34 

0.24 

0.24 

0.00 

3.03 

i.13 

O.Q7 

0.19 

0.37 

0.45 

0.17 

0.34 

0.34 

0.47 

0.17 

1.26 

0.00 

0.00 

0.03 

0.17 

0.37 

0.10 

0.12 

0.17 

0.03 

O.Q7 

0.34 

0.66 

a-Tocopherol 

223 225 F 

7.65 7.51 0.16 

8.14 7.94 0.25 

7.91 7.79 0.15 

7.34 7.59 0.29 

8.00 7.80 0.24 

7.97 7.80 0.20 

7.31 7.30 0.01 

7.69 7.64 0.06 

8.00 7.85 0.18 

5.94 6.00 O.Q7 

7.91 7.88 0.04 

7.70 7.34 0.42 

7.81 7.89 0.09 

9.04 9.91 1.02 

6.87 7.70 0.98 

8.67 8.86 0.22 

7.64 7.60 0.05 

8.89 8.77 0.14 

8.30 8.42 0.14 

7.34 7.35 0.01 

7.97 8.00 0.04 

7.37 7.07 0.35 

8.64 8.85 0.25 

7.74 7.70 0.05 

6.74 9.45 3.19 

7.39 7.12 0.32 

8.01 8.14 0.15 

6.08 6.26 0.21 

7.64 8.18 0.64 

7.50 7.10 0.47 

9.80 10.60 0.94 

8.10 8.30 0.24 

7.50 7.50 0.00 

7.59 7.14 0.54 

7.54 8.50 1.13 

8.00 8.10 0.12 

8.50 7.34 1.37 

9.24 8.99 0.29 

7.24 7.41 0.20 

7.58 7.14 0.52 

8.30 8.20 0.12 

7.44 7.34 0.12 

7.57 7.91 0.41 

7.93 7.88 

0.58 0.62 

y-Tocopherol 

223 225 

1.67 1.65 

1.64 1.58 

1.72 1.69 

1.68 1.74 

1.93 1.90 

1.76 1.70 

1.52 1.56 

1.58 1.58 

1.50 1.20 

1.57 1.81 

1.75 1.88 

1.37 1.55 

1.55 1.59 

1.62 1.59 

1.64 2.28 

1.69 1.83 

1.03 0.96 

1.95 2.04 

1.74 1.54 

1.71 1.71 

2.05 2.00 

1.74 1.74 

0.13 0.20 

F 

0.09 

0.25 

0.10 

0.26 

0.13 

0.26 

0.17 

0.00 

1.29 

0.99 

0.56 

0.77 

0.17 

0.13 

2.74 

0.61 

0.30 

0.39 

0.86 

0.00 

0.21 

Total ~-Carotene 

223 225 

0.175 0.170 

0.193 0.183 

0.197 0.194 

0.173 0.178 

0.169 0.156 

0.087 0.067 

0.186 0.184 

0.170 0.171 

0.141 0.161 

0.160 0.400 

0.180 0.186 

0.155 0.173 

0.090 0.085 

0.139 0.153 

0.171 0.167 

0.130 0.170 

0.230 0.220 

0.166 0.169 

0.150 0.150 

0.146 0.203 

0.210 0.210 

0.166 0.178 

0.117 0.124 

0.145 0.136 

0.156 0.163 

0.155 0.155 

0.157 0.160 

0.175 0.176 

0.172 0.177 

0.158 0.150 

0.228 0.212 

0.220 0.210 

0.190 0.190 

0.169 0.163 

0.170 0.172 

0.019 O.ot8 

F 

0.19 

0.38 

0.11 

0.19 

0.50 

0.76 

0.08 

0.04 

0.77 

4.00 

0.23 

0.69 

0.19 

0.54 

0.15 

1.53 

0.38 

0.11 

0.00 

2.18 

0.00 

0.46 

0.27 

0.34 

0.25 

0.00 

0.11 

0.03 

0.19 

0.31 

0.61 

0.38 

0.00 

0.23 

Combined 

Lab n F---

1 0.03 

1 0.03 

4 0.04 

1 0.07 

4 0.07 

2 0.08 

2 0.08 

3 0.09 

1 0.09 

4 0.10 

4 0.11 

2 0.12 

3 0.14 

3 0.14 

3 0.15 

2 0.16 

1 0.17 

1 0.17 

4 0.17 

3 0.20 

3 0.20 

2 0.21 

4 0.23 

4 0.25 

4 0.27 

3 0.28 

4 0.28 

3 0.29 

2 0.29 

3 0.31 

4 0.32 

4 0.32 

4 0.34 

2 0.35 

4 0.39 

2 0.40 

3 0.43 

4 0.48 

4 0.48 

2 0.57 

3 0.60 

2 0.64 

3 0.65 

4 0.73 

2 0.75 

4 0.76 

4 0.88 

4 1.05 

4 2.79 

J10
 
Report of (Meta)Analysisfor RR XXXVIII Sera: 223-226 Page 1 

From: David L. Duewer Date: October 30, 1996 

To: Jeanice Brown Thomas, Margaret Kline, Willie E. May, Katherine E. Sharpless, 

Gary W. Kramer, Dennis J. Reeder, Stephen A. Wise 

Re: Value and Uncertainty Assignment for the NIST/NCI Micronutrient Measurement 

Quality Assurance Program's Round Robin XXXVIII (RR38) Sera: 223 to 226. 

Background: Four samples representing three newly prepared sera were distributed in RR38. 

(While distributing at least one "old" sera in each RR is desirable, we have insufficient quantity 

of "interesting" materials to be compulsive about it.) All three of the new sera were designed to 

test one or more aspects of our "designer serum" program for the cost-effective construction of 

the next generation of sRM® 968. 

The samples labeled #223 and #225 are blind duplicates from a single preparation of a retinyl 

palmitate-augmented serum. Serum #224 was constructed from the "normal" serum pool used 

for the RR37 sera (#219, 220, and 221), augmented with retinol, retinyl palmitate, a-tocopherol, 

y-tocopherol, Mocopherol, ~-carotene,a-carotene, lycopene, zeaxanthin, and lutein. Serum #226 

is a "completely artificial" construct, created from a lipid-stripped serum pool augmented with 

the above commonly reported analytes. 

Both NISTl and NIST3 analysts reported residual solids in one-or-more vials of serum, as did 

many RR38 participants. Two participants reported a gel-like consistency for the reconstituted 

serum. Several analyte carriers were used in the construction of serum #226, including dimethyl 

sulfoxide and cholesterol. 

Results: Table 1 presents the NIST data, summary statistics for the NIST data, summary results 

for RR38, and the NIST assigned values and uncertainties. Table 2 presents a compact summary 

of the assigned values and uncertainties for each analyte in each serum. Because of presumptive 

heterogeneity, all values for serum #226 are presented in italics. The entries in Tables 1 and 2 

are defined as follows: 

• Individual NIST Analyst Data and Summary Statistics 

A: 1 to C:2 two aliquots (" 1" and "2") of three vials {A, B, and C) of each serum were 

extracted and analyzed. Each analyst analyzed a separate set of three vials. 

nx number of quantitative values for this analyte for this serum for this analyst 

Me~ arithmetic average 

SDx simple standard deviation 

SDrepx within-vial pooled standard deviation, reflecting variation in extraction, 

chromatography, peak integration, etc. 

SD11eix among-sample standard deviation, reflecting heterogeneity in preparing and 

reconstituting the serum samples 

SDNISTx ~SD~px + SD~tx , total standard deviation. This value is~ SDx, as sample 

replicates reduce the true degrees of freedom. 

CV NISTx 100 x SD NisT/Meanx 

• NIST Summary Statistics 

n number of quantitative values for this analyte for this serum 

Mean (MeanNisn + MeanNisTI)/2 or MeanNISTI for analytes that NISTl did not report 

SDrep within-vial pooled standard deviation 

SD11e1 among-sample standard deviation 

SD801 between-analyst standard deviation. This is the residual standard deviation fo.r 

regression of NIST3's Meanx values to NISTl 's or, for analytes that NISTl did 

not report, to the interlaboratory Median (see below). The model used to 

determine SDan1 is defined to the right of this block. Details include: model 

used, parameters and standard errors on the parameters, and R2 • 

J11
 
Report of ( Meta)Analysis for RR XXXVIII Sera: 223-226 

SDNIST ~SD~p +SD~, +so~. ' total standard deviation for NIST analyses. 

CV NIST 100 x SD ms/Mean 

• Round Robin XXXVIII Summary Statistics 

Page 2 

n0 number of non-NIST laboratories reporting quantitative values for this analyte 

for this serum in this Round Robin 

Median0 median of the reported values 

eSD0 0.741 x InterQuartile Range (IQR) 

SD1abs ~eSD! -SD~T, the residual non-NIST interlaboratory biases after correction 

for measurement-, sample-, and NIST-analyst-related sources of variance. 

When SDNIST is greater than eSD0 , SD1abs = 0. 

CV1abs 100 x SD1abs/Medial\. 

• NIST Assigned Values and Uncertainties 

NA V (Mean + Median0 ) / 2, our best guess of the "true" analyte level 

NAU Maximum(0.05 x NAV, ~SD~isT + SD~bs ), our best guess for the "true" 

interlaboratory standard deviation characterizing measurement, sample 

heterogeneity, interanalyst, and interlaboratory sources of variation. When 

SD1abs could not be determined, NAU is estimated as 

Maximum(0.10 x NAV, ~2 SD~tsT ). 

CV lOOxNAU /NAV 

Conclusions: The blind replicate samples, labeled as sera #223 and #225, have nearly identical 

NA Vs - the expected result for blind duplicates! The NAUs for the two samples are also similar, 

although those for #225 are generally slightly larger: this may indicate an analysis-order effect. 

The historical data may be able to shed some light on this possibility. In any case, the NAUs for 

sera #223/225 and #224 are typical of those previously observed for the NA V levels of each 

analyte. (The "Lies, Damn Lies, and Statistics" report for this RR will include discussions of 

short-term repeatability and the historical relationship between analyte level and eSD.) 

The NA Us for sera #226 are considerably larger than expected, with a large heterogeneity 

component. This is doubtless related to the reported "undissolved solids" (cholesterol carrier 

that escaped filtration?) None of the reported values for this serum will be used in any of the 

laboratory performance metrics. [As a statistical aside, the values for serum #226 were also not 

used in evaluating the between-analyst standard deviation, SD ant· Since samples #223 and #225 

are duplicates of the same serum, the regression-determined values for this variance component 

are not as well determined as is typical. The low R2 value for a-tocopherol is a consequence of 

the similar levels for this analyte in serum #223/225 and #224.] Serum #226 should NOT be 

distributed again! The remaining vials should be discarded. 

Although it does not appear that we can construct a completely "known concentration" serum, 

the successful augmentation of various carotenoids in sera #223/225 and #224 indicates that we 

do now have the technology to convert "routine" to "high" carotenoid levels in our serum pools. 

This memo will be included as part of the Round Robin XXXVID report. 

~h+{~~),,~ ,4--~ -

• 

J12
 
Report of ( Meta)Analysis for RR XXXVIJI Sera: 223-226 

Table I 

NIST Data and Calculations 

Retinol Retinyl Palmitate 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

nx 

Means 

SDx 

SDreox 

SD11e1x 

223 

0.522 

0.521 

0.542 

0.581 

0.553 

0.573 

6 

0.549 

0.025 

O.ot8 

0.024 

NISTl 

224 225 226 223 

0.694 0.475 0.319 0.496 

0.663 0.553 0.339 0.512 

0.661 0.535 0.380 0.514 

0.699 0.506 0.350 0.491 

0.717 0.562 0.332 0.489 

0.730 0.529 0.355 0.495 

6 6 6 6 

0.694 0.527 0.346 0.500 

0.028 0.032 0.021 0.011 

0.021 0.037 0.017 0.012 

0.026 0.017 0.018 0.006 

NIST3 NISTl 

224 225 226 223 224 225 226 

0.606 0.314 0.149 0.308 0.147 0.33 

0.613 0.502 0.326 0.153 0.245 0.146 0.31 

0.660 0.518 0.325 0.154 0.274 0.142 0.30 

0.642 0.510 0.317 0.152 0.304 0.145 0.35 

0.611 0.497 0.319 0.147 0.292 0.151 0.34 

0.607 0.491 0.315 0.146 0.297 0.149 0.34 

6 5 6 6 6 6 6 

0.623 0.503 0.319 0.150 0.287 0.147 0.33 

0.023 0.011 0.005 0.003 0.024 0.003 0.02 

0.008 0.004 0.006 0.002 0.029 0.002 0.02 

0.024 0.010 0.002 0.003 0.009 0.003 0.01 

SDmsrx 0.030 0.033 0.040 0.025 0.013 0.026 O.ot 1 0.006 0.004 0.030 0.004 0.02 

CVNIS'l'x 5.4 4.7 7.6 7.3 2.7 4.1 2.2 1.9 2.5 10 2.5 7.1 

NIST NIST3=a+b*NIST1 NIST 

n 

Mean 

so .. 0 

SD11e1 

SDan1 

12 

0.524 

0.016 

0.013 

O.ot5 

12 

0.658 

0.017 

0.020 

0.015 

11 12 

0.515 0.333 

0.026 0.013 

0.011 0.022 

0.015 0.015 

SDNIST 0.026 0.030 0.032 0.030 

CV NIST 4.9 4.5 6.2 8.9 

RRXXXVIII 

223 224 225 226 

n. 44 44 44 43 

Median. 0.498 0.691 0.506 0.308 

eSD0 0.039 0.056 0.045 0.059 

so ..... 0.030 0.047 0.031 0.051 

cv ..... 6.0 6.8 6.2 16 

NAV 0.511 0.675 0.510 0.320 

NAU 0.039 0.056 0.045 0.059 

CV 7.7 8.3 8.8 18 

(38_dal]NIST!xt 

a: 0.092 ±0.067 

b: 0.762 ±0.114 

R2: 0.957 

<-Current Results-> 

<-Assignments-> 

9 

0.152 

0.001 

0.003 

0.003 

0.004 

2.9 

223 

14 

0.092 

0.040 

0.040 

43 

0.122 

0.040 

33 

9 10 JO 

0.306 0.150 0.21 

0.022 0.012 0.02 

0.010 0.005 0.15 

0.003 0.003 0.00 

0.024 0.013 0.15 

8.0 8.9 72 

RRXXXVIII 

224 225 226 

14 14 14 

0.244 0.104 0.25 

0.094 0.036 0.16 

0.091 0.034 0.06 

37 32 23 

0.275 0.127 0.23 

0.094 0.036 0.16 

34 29 71 

NIST3 

223 224 225 226 

0.161 0.08 

0.155 0.316 0.134 0.08 

0.153 0.342 0.166 0.13 

0.153 0.320 0.150 0.11 

3 3 4 4 

0.153 0.326 0.153 0.10 

0.001 0.014 0.014 0.03 

0.000 0.011 0.016 0.01 

0.007 0.03 

0.017 0.03 

11 31 

NIST3=a+b*NIST1 

a: -0.032 ±0.005 

b: 1.249 ±O.OZ4 

R2: 0.999 

Paac I 17 

J13
 
A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n. 

Mean1 

so. 

SD re.,. 

SD11e1x 

Report of(Meta)Analysisfor RR XXXV/11Sera:223-226 

Table I 

NIST Data and Calculations 

a-Tocopherol "(· Tocopherol 

NISTl NIST3 NISTl NIST3 

223 ' 224 225 226 223 224 225 226 223 224 225 226 223 224 225 226 

8.76 8.19 7.89 18.5 8.13 8.71 19.7 1.71 3.79 1.77 4.05 1.83 4.32 3.63 

8.37 8.17 8.95 19.2 7.50 8.63 7.39 17.4 1.74 3.72 1.90 4.30 1.79 4.33 1.76 3.38 

7.88 8.55 7.82 20.1 8.20 8.89 7.82 18.3 1.83 3.67 1.74 3.92 1.80 4.25 1.82 3.39 

8.26 8.84 7.92 18.7 7.92 8.70 7.60 18.3 1.82 4.06 1.84 4.48 1.85 4.27 1.79 3.38 

8.67 8.75 8.31 16.7 8.50 9.09 8.04 19.4 1.81 4.15 1.77 3.75 1.86 4.27 1.82 3.58 

7.62 8.67 8.08 19.5 8.21 8.82 8.00 19.l 1.88 4.39 1.84 3.75 1.85 4.23 1.82 3.57 

6 6 6 6 6 6 5 6 6 6 6 6 6 6 5 6 

8.26 8.53 8.16 18.8 8.08 8.81 7.77 18.7 1.80 3.96 1.81 4.04 1.83 4.28 1.80 3.49 

0.44 0.29 0.42 1.2 0.34 0.17 0.27 0.8 0.06 0.28 0.06 0.30 0.03 0.04 0.03 0.12 

0.48 0.12 0.44 1.3 0.30 0.14 0.09 0.9 0.03 0.19 0.07 0.25 0.03 0.02 O.ot 0.10 

0.27 0.30 0.28 0.6 0.27 0.14 0.31 0.5 0.06 0.27 0.02 0.25 0.03 0.04 0.03 0.10 

SDmsTx 0.55 0.33 0.52 1.5 0.41 0.20 0.33 1.1 0.07 0.33 0.08 0.36 0.04 0.05 0.03 0.14 

CVNISTx 6.7 3.8 6.4 7.7 5.0 2.3 4.2 5.6 4.1 8.4 4.2 8.8 2.0 1.1 1.8 4.1 

NIST 

12 12 11 12 

8.17 8.67 7.97 18.8 

0.40 0.12 0.33 1.1 

0.24 0.29 0.33 0.5 

0.34 0.34 0.34 0.3 

SDNIST 0.58 0.47 0.58 1.3 

CVNIST 7.1 5.4 7.3 6.9 

RRXXXVIlI 

223 224 225 226 

n, 41 41 41 40 

Median, 7.70 8.28 7.79 19.7 

eso. 0.42 0.50 0.62 3.6 

sollbl 0 0.16 0.23 3.3 

cvllbl 0 2.0 3.0 17 

NAY 7.93 8.47 7.88 19.2 

NAU 0.58 0.50 0.62 3.6 

CV 7.4 5.9 7.9 19 

(38_dll]NISTW 

NIST3=a+b*NIST1 

a:O 

b: 0.99 ±0.02 

R2: 0.338 

<-Current Results -> 

<-Assignments -

12 

1.81 

0.03 

0.05 

0.03 

0.07 

3.7 

223 

20 

1.66 

0.13 

0.11 

6.7 

1.74 

0.13 

7.5 

NIST 

12 11 12 

4.12 1.81 3.76 

0.13 0.05 0.19 

0.20 0.03 0.52 

0.03 0.03 0.03 

0.24 0.07 0.55 

5.9 3.7 15 

RRXXXVIlI 

224 225 226 

20 20 19 

3.89 1.67 3.38 

0.37 0.20 0.59 

0.28 0.19 0.22 

7.1 11 6.4 

4.00 1.74 3.57 

0.37 0.20 0.59 

9.2 11 17 

NIST3=a+b*NIST1 

a: -0.24 ±0.05 

b: 1.14 ±0.02 

R2: 1.000 

Page 217 

J14
 
A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n. 

Mean. 

so. 

SDrepx 

SD11eu 

SDmn. 

CVNISTx 

223 

0 

6 

0.192 

0.005 

n 

Mean 

SD,..p 

SD11e 

SDan1 

I 0.018 

0.007 

Report of ( Meta)Analysis for RR XXXVI// Sera: 223-226 

Table 1 

NIST Data and Calculations 

S-Tocopherol 

NISTl NIST3 

224 

0.840 

0.784 

0.826 

0.798 

0.791 

0.802 

6 

0.807 

0.022 

0.026 

0.009 

0.027 

3.4 

225 

0 

NIST 

12 5 

0.819 0.198 

0.023 0.009 

0.021 0.021 

0.007 0.007 

226 

0 

6 

0.44 

0.02 

0.03 

0.01 

223 224 225 226 

0.203 0.801 0.44 

0.196 0.845 0.223 0.40 

0.168 0.808 0.188 0.41 

0.176 0.824 0.172 0.44 

0.209 0.870 0.212 0.48 

0.202 0.842 0.196 0.47 

6 6 5 6 

0.192 0.832 0.198 0.44 

0.016 0.026 0.020 0.03 

0.005 0.022 0.009 0.02 

O.oI8 0.021 0.021 0.03 

0.018 0.031 0.023 0.04 

9.6 3.7 12 8.2 

NIST3=a+b*Median 

a:O 

b: 1.105 ±0.009 

R2: 0.999 

223 

0.180 

0.179 

0.182 

0.180 

0.180 

0.181 

6 

0.180 

0.001 

0.001 

0.001 

0.001 

0.7 

12 

0.175 

0.002 

0.002 

0.003 

Total ~-Carotene 

NIST! NIST3 

224 225 226 223 224 225 226 

0.59 0.186 0.29 0.174 0.74 0.11 

0.64 0.180 0.30 0.169 0.68 0.164 0.12 

0.67 0.184 0.32 0.168 0.72 0.163 0.10 

0.65 0.181 0.29 0.167 0.70 0.163 0.12 

0.60 0.178 0.27 0.170 0.169 0.09 

0.62 0.175 0.29 0.168 0.69 0.167 0.08 

6 6 6 6 5 5 6 

0.63 0.181 0.29 0.169 0.71 0.165 0.10 

0.03 0.004 0.02 0.003 0.03 0.003 0.02 

0.02 0.003 0.02 0.002 0.03 0.001 0.01 

0.03 0.004 0.01 0.002 O.oI 0.003 0.02 

0.03 0.005 0.02 0.003 0.03 0.003 0.02 

5.5 2.6 6.9 

NIST 

11 11 12 

0.67 0.173 0.20 

0.03 0.002 0.01 

0.02 0.004 0.11 

0.00 0.003 0.00 

1.9 4.2 1.8 18 

NIST3=a+b*NIST1 

a: -0.050 ±0.003 

b: 1.204 ±0.009 

R2: 1.000 

SDNIST 0.020 . 0.033 0.024 0.04 0.004 0.03 0.005 0.11 

CVNIST 10 4.0 12 8.8 2.4 5.1 3.0 57 

RRXXXVIIl RRXXXVill 

223 224 225 226 <- Current Results -> 223 224 225 226 

fin 4 4 4 4 28 28 28 27 

Mediann 0.175 0.755 0.170 0.45 0.166 0.63 0.171 0.24 

. eSDn 0.103 0.098 0.102 0.12 0.019 0.13 0.018 0.08 

SDlab& 0.101 0.093 0.099 0.11 0.019 0.12 0.017 0 

cv •• 58 12 58 25 11 19 10 0 

NAV 0.184 0.787 0.184 0.44 <-Assignments-> 0.170 0.65 0.172 0.22 

NAU 0.103 0.098 0.102 0.12 0.019 0.13 O.oI8 0.11 

CV 56 12 55 27 11 19 10 51 

[38_dat]NISTtxt Page 317 

J15
 
Report of (Meta)Analysisfor RR XXXVll/ Sera: 223-226 

Table 1 

NIST Data and Calculations 

trans-~-Carotene 

NISTl NIST3 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n. 

Mean, 

so. 

SOrepx 

S011e1x 

223 

0.168 

0.172 

0.176 

0.176 

0.172 

0.174 

6 

0.173 

0.003 

0.002 

0.003 

224 

0.504 

0.551 

0.574 

0.584 

0.577 

0.525 

6 

0.553 

0.032 

0.029 

0.026 

225 226 

0.175 0.19 

0.170 0.19 

0.175 0.22 

0.177 0.22 

0.166 0.25 

0.164 0.25 

6 6 

0.171 0.22 

0.005 0.03 

0.002 0.00 

0.006 0.03 

223 224 225 226 

0.174 0.675 0.11 

0.169 0.643 0.164 0.12 

0.168 0.683 0.163 0.10 

0.167 0.674 0.163 0.12 

0.170 0.641 0.169 0.09 

0.168 0.633 0.167 0.08 

6 6 5 6 

0.169 0.658 0.165 0.10 

0.003 0.022 0.003 0.02 

0.002 0.014 0.001 0.01 

0.002 0.021 0.003 0.02 

SONISTx 0.004 0.039 0.006 0.03 0.003 0.025 0.003 0.02 

CV NISTx 2.0 7 .0 3.6 15 1.9 3.8 1.8 18 

n 

Mean 

SO rep 

S011et 

SOan1 

12 

0.171 

0.002 

0.003 

0.001 

NIST 

12 11 12 

0.605 0.168 0.16 

0.023 0.002 0.01 

0.025 0.005 0.07 

0.001 0.001 0.00 

SONIST 0.004 0.034 0.005 0.07 

CVNIST 2.2 5.6 3.2 46 

RRXXXVIlI 

223 224 225 226 

n. 11 11 11 11 

Median. 0.160 0.588 0.163 0.28 

eSO. 0.017 0.091 0.018 0.12 

so, .... 0.016 0.085 0.017 0.09 

cvlabi 10 14 10 32 

NAV 0.166 0.597 0.166 0.22 

NAU 0.017 0.091 0.018 0.12 

CV 10 15 11 53 

[38_dal)NISTtxt 

NIST3=a+b*NIST1 

a: -0.055 ±0.001 

b: 1.291 ±0.004 

R2: 1.000 

<-Current Results -> 

<-Assignments-> 

223 

0 

6 

0.031 

0.001 

0.001 

0.002 

0.003 

8.9 

223 

23 

0.027 

0.009 

0.009 

32 

0.029 

0.009 

32 

Total a-Carotene 

NISTl NIST3 

224 

0.397 

0.454 

0.449 

0.423 

0.395 

0.401 

6 

0.420 

0.027 

0.026 

0.020 

0.032 

7.7 

225 

0 

NIST 

12 4 

0.450 0.037 

0.021 0.007 

0.002 O.ot 1 

0.002 0.002 

0.021 0.013 

4.7 34 

RRXXXVIll 

224 225 

25 23 

0.429 0.030 

226 223 224 225 226 

0.200 0.030 0.496 0.065 

0.188 0.033 0.467 0.051 0.053 

0.192 0.031 0.488 0.037 0.056 

0.186 0.032 0.474 0.025 0.067 

0.180 0.026 0.475 0.051 

0.197 0.033 0.480 0.036 0.050 

6 6 6 4 6 

0.191 0.031 0.480 0.037 0.057 

0.007 0.003 0.010 0.011 0.007 

0.009 0.003 0.013 0.005 0.007 

0.003 0.001 0.002 0.006 

0.009 0.004 0.013 0.009 

4.9 11 2.8 15 

12 

0.124 

0.009 

0.006 

0.002 

0.010 

8.4 

226 

24 

0.164 

NIST3=a+b*Median 

a: 0.002 ±0.002 

b: 1.114 ±0.006 

R2: 1.000 

0.080 0.010 0.068 

0.077 0 0.068 

18 0 41 

0.439 0.034 0.144 

0.080 0.013 0.068 

18 38 48, 

Page4/7 

J16
 
A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n. 

Mean. 

so. 

SOrcpx 

so ..... 

SONISTx 

CVNISTx 

223 

0 

Report of(Meta)Analysisfor RR XXXVIJI Sera: 223-226 

Table 1 

NIST Data and Calculations 

trans-a-Carotene Total Lycopene 

NISTl NIST3 NISTl NIST3 

224 225 226 223 224 225 226 223 224 225 226 223 224 225 226 

0.03 0.5 0.07 0.611 0.497 

0.03 0.5 0.03 0.05 0.573 0.495 0.624 

0.03 0.5 0.02 0.06 0.632 0.543 0.596 

0.03 0.5 0.03 0.07 0.574 0.509 0.535 

0.03 0.5 0.03 0.05 0.569 0.482 0.590 

0.03 0.5 0.03 0.05 0.580 0.494 0.590 

0 0 0 6 6 5 6 0 0 0 0 6 6 5 0 

0.03 0.5 0.03 0.06 0.590 0.503 0.587 

0.00 0.0 0.00 0.01 0.026 0.021 0.032 

0.00 0.0 0.00 0.01 0.029 0.014 0.025 

0.00 0.0 0.00 0.01 0.014 0.020 0.029 

0.00 0.0 0.00 0.01 0.032 0.025 0.038 

11 2.4 17 15 5.4 4.9 6.5 

NIST NIST NIST3=a+b*Median 

n 6 6 5 6 6 6 5 0 

Mean 0.03 0.5 0.03 0.06 0.590 0.503 0.587 a: 0.123 ±0.015 

SO..,p 0.00 0.0 0.00 0.01 0.037 0.019 0.035 b: 1.003 ±0.035 

SObct 0.00 0.0 0.00 0.01 0.014 0.020 0.029 R2: 0.998 

SOan1 0.002 0.002 0.002 

SONIST 0.040 0.028 0.046 

CVNIST 6.7 5.6 7.8 

RRXXXVIII RRXXXVIII 

223 224 225 226 <-Current Results -> 223 224 225 226 

n. 0 0 0 0 26 26 26 22 

Median. 0.467 0.380 0.461 0.03 

eso. 0.082 0.075 0.089 0.02 

S01abo 0.072 0.069 0.076 

cvlabo 15 18 16 

NAVI 0.03 0.5 0.03 0.06 ~-Assignments - 0.528 0.441 0.524 

NAU. ! 0.082 0.075 0.089 

CV 16 17 17 

[38_dal)NISTtxt Page 517 

J17
 
A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n. 

Mean, 

so. 

SD..,P• 

SD11ou 

SOmST. 

CVNIST• 

n 

Mean 

SD"'P 

SD11e1 

SDan1 

SDNIST 

CV NIST 

n. 

Median. 

eSD0 

SDllbo 

cvlabo 

NAV 

NAU 

CV 

223 

0 

6 

0.231 

0.005 

0.003 

0.000 

0.006 

2.6 

223 

7 

0.252 

0.053 

0.052 

21 

0.241 

0.053 

22 

(38_d.r]NISTm 

Report of (Meta)Analysisfor RR XXXVll/ Sera: 223-226 

Table 1 

NIST Data and Calculations 

trans-Lycopene 

NISTl NIST3 

224 225 226 

0 0 0 

NIST 

6 5 0 

0.317 0.230 

0.008 0.003 

0.008 0.007 

0.000 0.000 

O.otl 0.007 

3.5 3.2 

RRXXXVIlI 

224 225 226 

7 7 7 

0.300 0.252 0.04 

0.046 0.039 0.02 

0.045 0.038 

15 15 

0.309 0.241 

0.046 0.039 

15 16 

223 224 225 226 

0.234 0.321 

0.221 0.306 0.221 

0.233 0.330 0.233 

0.233 0.322 0.228 

0.237 0.313 0.239 

0.225 0.310 0.229 

6 6 5 0 

0.231 0.317 0.230 

0.006 0.009 0.007 

0.007 0.007 0.005 

0.003 0.008 0.007 

0.008 0.01 l 0.008 

3.3 3.4 3.6 

NIST3=a+b*Median 

a: -0.225 ±0.003 

b: l .808 ±0.009 

R2: l.000 

<-Current Results -> 

<-Assignments-> 

223 

0 

6 

0.049 

0.000 

0.003 

0.000 

0.003 

5.3 

223 

17 

0.054 

0.016 

0.016 

30 

0.051 

0.016 

32 

~-Cryptoxanthin 

NISTl NIST3 

224 225 226 

0 0 0 

NIST 

6 5 6 

0.050 0.049 0.026 

0.002 0.000 0.003 

0.002 0.001 0.001 

0.000 0.000 0.()()() 

0.003 0.001 0.003 

5.2 2.0 13 

RRXXXVIll 

224 225 226 

17 17 16 

0.060 0.052 0.067 

0.013 0.019 0.020 

0.012 0.019 0.020 

21 36 29 

0.055 0.050 0.046 

0.013 0.019 0.020 

23 37 43 

223 224 225 226 

0.051 0.052 0.028 

0.051 0.048 0.047 0.023 

0.049 0.053 0.049 0.024 

0.048 0.053 0.048 0.029 

0.046 0.049 0.048 0.023 

0.046 0.049 0.050 0.028 

6 6 5 6 

0.049 0.050 0.049 0.026 

0.002 0.002 0.001 0.003 

0.000 0.002 0.001 0.003 

0.003 0.002 0.001 0.001 

0.003 0.003 0.001 0.003 

5.3 5.2 2.0 13 

NIST3=a+b*Median 

a: 0.035 ±0.003 

b: 0.260 ±0.059 

R2: 0.905 

Pqe6/7 

J18
 
Report of(Meta)Analysisfor RR XXXVlll Sera: 223-226 

Table 1 

NIST Data and Calculations 

''Lutein" "Zeaxanthin" 

A:l 

A:2 

B:l 

·B:2 

C:l 

C:2 

n. 

Mean. 

so. 

SOren• 

SObeU 

SI>ms-r. 

CVNim 

n 

Mean 

SOreo 

S011ec 

SOan1 

223 

0 

6 

0.118 

0.004 

0.003 

0.004 

NISTl 

224 225 226 

0 0 0 

. NIST 

6 5 6 

0.136 0.117 0.136 

0.002 0.001 0.002 

0.001 0.001 0.005 

0.004 0.004 0.004 

SONIST 0.006 0.004 0.004 0.006 

CVNJST. 5.0 3.2 3.3 4.5 

RRXXXVill 

223 224 225 226 

n. 13 13 13 12 

Median. 0.125 0.147 0.132 0.135 

eSO. 0.012 0.030 0.014 0.051 

so .... 0.010 0.029 0.014 0.051 

CV1a1111 8.2 20 10 38 

NAV 0.122 0.141 0.124 0.135 

NAU 0.012 0.030 0.014 0.051 

CV 9.8 21 11 38 

(38_dal]NISTttt 

NIST3 

223 224 225 226 

0.117 0.137 0.139 

0.125 0.133 0.118 0.135 

0.117 0.137 0.116 0.131 

0.120 0.137 0.117 0.131 

0.117 0.134 0.117 0.138 

0.115 0.135 0.117 0.141 

6 6 5 6 

0.118 0.136 0.117 0.136 

0.004 0.002 0.001 0.004 

0.004 0.002 0.001 0.002 

0.003 0.001 0.001 0.005 

0.005 0.002 0.001 0.005 

3.8 1.5 0.8 3.7 

NIST3=a+b*Median 

a:O 

b: 0.919 ±0.016 

R2: 0.753 

<- Current Results -> 

<-Assignments-> 

NISTI 

223 224 225 226 

0 0 0 0 

NIST 

6 6 5 6 

0.047 0.092 0.045 0.091 

0.002 0.001 0.001 0.001 

0.003 0.002 0.001 0.001 

0.002 0.002 0.002 0.002 

0.005 0.003 0.003 0.003 

10 3.4 6.2 3.3 

RRXXXVill 

223 224 225 226 

10 10 10 9 

0.028 0.082 0.030 0.080 

0.012 0.009 0.016 0.031 

0.011 0.008 0.015 0.031 

40 10 52 39 

0.037 0.087 0.037 0.086 

0.012 0.009 0.016 0.031 

32 10 42 36 

NIST3 

223 224 225 226 

0.048 0.093 0.092 

0.051 0.092 0.045 0.090 

0.046 0.093 0.045 0.089 

0.049 0.095 0.046 0.091 

0.045 0.090 0.044 0.090 

0.041 0.092 0.044 0.095 

6 6 5 6 

0.047 0.092 0.045 0.091 

0.003 0.002 0.001 0.002 

0.003 0.001 0.001 0.003 

0.003 0.002 0.001 0.001 

0.004 0.002 0.001 0.003 

8.7 2.1 2.1 3.0 

NIST3=a+b*Median 

a: 0.021 ±0.003 

b: 0.878 ±0.058 

R2: 0.991 

Page 111 

J19
 
Analyte 

Retinol 

Retinyl Palmitate 

a-Tocopherol 

y-Tocopherol 

Tocopherol 

Total (}-Carotene 

trans-p-Carotene 

Total a-Carotene 

trans-a-Carotene 

Total Lycopene 

trans-Lycopene 

P-Cryptoxanthin 

"Lutein" 

"Zeaxanthin" 

[38_dlt)SummuyTKI 

Report of ( Meta)Analysis for RR XXXVlll Sera: 223-226 

Table 2 

Summary of NIST Assigned Values and Uncertainties 

Blind Replicates -

223 225 

NAV NAU CV NAV NAU CV 

0.511 0.039 7.7 0.510 0.045 8.8 0.122 0.040 33 0.127 0.036 29 

7.93 0.58 7.4 7.88 0.62 7.9 

1.74 0.13 7.5 1.74 0.20 11 

0.184 0.103 56 0.184 0.102 55 0.170 0.019 11 0.172 0.018 10 0.166 0.017 10 0.166 0.018 11 0.029 0.009 32 0.034 0.013 38 0.03 0.03 0.528 0.082 16 0.524 0.089 17 0.241 0.053 22 0.241 0.039 16 0.051 0.016 32 0.050 0.019 37 

0.122 0.012 9.8 0.124 0.014 11 

0.037 0.012 32 0.037 0.016 42 

224 

NAV NAU CV 

0.675 0.056 8.3 0.275 0.094 34 

8.47 0.50 5.9 

4.00 0.37 9.2 

0.787 0.098 12 

0.65 0.13 19 

0.597 0.091 15 0.439 0.080 18 

0.5 

0.441 0.075 17 0.309 0.046 15 0.055 0.013 23 0.141 0.030 21 0.087 0.009 10 

226 

NAV NAU CV 

0.320 0.059 18 0.23 0.16 71 

19.2 3.6 19 

3.57 0.59 17 

0.44 0.12 27 0.22 0.11 51 0.22 0.12 53 

0.144 0.068 48 

0.06 0.046 0.020 43 

0.135 0.051 38 0.086 0.031 36 

Pagel/I 

J20
 
 

Appendix K. “All-Lab Report” for RR38 

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. 

K1
 
Round Robin XXXVIII Laboratory Results 

Values in μg/mL 

Total Retinol Retinyl Palmitate α-Tocopherol γ-Tocopherol

Lab 

FSV-BA 

FSV-BD 

FSV-BF 

FSV-BG 

FSV-BGa 

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-BZ 

FSV-CA 

FSV-CB 

FSV-CC 

FSV-CF 

FSV-CH 

FSV-CK 

FSV-CL 

FSV-CM 

FSV-CP 

FSV-CQ 

FSV-CR 

FSV-CS 

FSV-CT 

FSV-CU 

FSV-CX 

FSV-DA 

FSV-DJ 

FSV-DK 

FSV-DM 

FSV-DP 

FSV-DR 

FSV-DS 

FSV-DU 

FSV-DX 

FSV-EA 

FSV-EH 

FSV-EI 

FSV-EL 

223 224 225 226 

0.495 0.700 0.494 !0.342 

223 224 225 226 223 224 225 226 223 224 225 226 

0.155 0.24 0.130 !0.169 7.69 8.42 7.64 !19.26 1.93 4.37 1.90 !3.7 

0.490 0.620 0.490 !0.301 8.00 8.10 7.80 !19.8 

0.563 0.766 0.553 !0.332 7.97 8.37 7.80 !17.26 1.68 3.87 1.74 !3.02 

0.537 0.715 0.536 !0.363 0.073 0.24 0.070 !0.218 7.91 8.50 7.79 !23.09 1.72 4.06 1.69 !3.96 

0.517 0.697 0.504 !0.362 0.077 0.27 0.078 !0.244 8.14 8.61 7.94 !23.24 1.64 3.62 1.58 !3.51 

0.439 0.623 0.486 !0.233 0.051 0.22 0.053 !0.322 8.00 8.54 7.85 !20.58 1.76 3.98 1.70 !3.56 

0.526 0.726 0.526 !0.272 0.128 0.36 0.121 !0.299 7.65 8.24 7.51 !16.66 1.67 3.75 1.65 !2.84 

0.501 0.730 0.552 !0.39 0.082 0.20 0.076 !0.166 6.87 8.17 7.70 !25.27 1.57 4.02 1.81 !4.70 

0.545 0.743 0.544 !0.231 8.67 9.54 8.86 !17.73 

0.516 0.687 0.544 !0.345 9.04 9.91 9.91 !22.83 

0.441 0.542 0.469 !0.285 8.10 10.00 8.30 !21.7 

0.550 0.760 0.550 !0.35 0.100 0.33 0.110 !0.49 7.74 8.21 7.70 !21.27 1.62 3.75 1.59 !3.27 

0.533 0.730 0.521 !0.235 8.01 8.27 8.14 !12.10 

0.601 0.838 0.615 !0.407 8.64 9.54 8.85 !24.28 

0.520 0.700 0.540 !0.33 

0.520 0.720 0.530 !0.26 

0.522 0.668 0.589 !0.269 

7.50 7.70 7.10 !16 

0.496 0.728 0.522 !0.640 0.127 0.37 0.119 !0.633 7.64 8.65 8.18 !16.22 1.69 3.92 1.83 !2.84 

0.420 0.523 0.398 !0.232 8.50 8.39 7.34 !20.69 1.74 3.91 1.54 !3.38 

0.470 0.650 0.480 !0.27 0.035 0.13 0.039 !0.066 7.58 8.02 7.14 !17.58 2.05 4.75 2.00 !3.64 

0.560 0.740 0.550 7.91 8.40 7.88 1.58 3.49 1.58 

7.70 8.30 7.34 !21.7 1.50 3.40 1.20 !2.9 

0.489 0.655 0.481 !0.141 7.34 8.01 7.59 !19.56 

0.448 0.607 0.434 !0.268 7.37 7.64 7.07 !22.89 

0.493 0.527 0.500 !0.149 7.24 7.85 7.41 !9.22 

0.470 0.735 0.472 !0.284 8.30 8.90 8.20 !16.9 

0.460 0.690 0.500 !0.3 8.89 9.36 8.77 !19.77 1.75 4.29 1.88 !3.43 

0.407 0.547 0.428 !0.236 0.084 0.15 0.102 !0.073 5.94 6.17 6.00 !14.62 1.52 3.14 1.56 !2.72 

0.304 0.467 0.285 !0.178 3.44 4.20 3.37 !9.645 0.97 2.13 0.99 !1.81 

7.81 8.28 7.89 !21.26 

8.74 9.41 8.95 !18.31 1.89 4.49 1.97 !3.37 

0.438 0.574 0.443 !0.304 7.31 7.94 7.30 !18.82 

0.490 0.690 0.500 !0.31 

0.496 0.720 0.500 !0.311 

7.50 8.30 7.50 !21.6 

0.529 0.692 0.533 !0.131 7.39 7.90 7.12 !17.07 

0.480 0.686 0.482 !0.339 0.129 0.18 0.129 !0.08 7.64 7.90 7.60 !15.28 

0.510 0.700 0.530 !0.45 0.150 0.33 0.130 !0.25 7.97 8.55 8.00 !26.13 1.55 3.46 1.59 !4.05 

0.510 0.670 0.510 !0.31 0.102 0.25 0.106 !0.438 8.00 8.65 8.10 !20.7 1.95 4.43 2.04 !3.75 

0.770 0.890 0.750 !0.39 9.80 11.50 10.60 !28.4 

0.480 0.690 0.480 !0.34 0.040 0.12 0.040 !0.41 7.54 8.20 8.50 !23.9 1.03 2.80 0.96 !2.8 

0.487 0.663 0.495 !0.351 

0.505 0.684 0.507 !0.305 

8.30 8.62 8.42 !20.74 

0.494 0.673 0.533 7.57 7.80 7.91 

0.326 0.432 0.304 !0.322 6.08 6.39 6.26 !16.78 

0.530 0.790 0.550 !0.38 7.44 7.87 7.34 !16.81 

0.505 0.701 0.430 !0.308 7.59 7.89 7.14 !17.95 

0.350 0.522 0.394 !0.192 7.34 8.00 7.35 !18.2 1.37 3.84 1.55 !3.05 

0.440 0.685 0.446 !0.553 0.055 0.10 0.092 !0.087 9.24 8.69 8.99 !20.33 1.71 3.56 1.71 !3.12 

0.450 0.675 0.630 !0.186 

0.500 0.740 0.510 !0.31 

6.74 7.63 9.45 !10.48 1.64 4.14 2.28 !2.00 

n 47 47 47 0 15 15 15 0 45 45 45 0 23 23 23 0 

Min 0.304 0.432 0.285 0.035 0.10 0.039 3.44 4.20 3.37 0.97 2.13 0.96 

Median 0.496 0.690 0.504 0.084 0.24 0.102 7.70 8.28 7.80 1.67 3.87 1.69 

Max 0.770 0.890 0.750 0.155 0.37 0.130 9.80 11.50 10.60 2.05 4.75 2.28 

eSD 0.039 0.057 0.047 0.049 0.13 0.039 0.47 0.55 0.68 0.13 0.46 0.20 

eCV 8 8 9 58 53 38 6 7 9 8 12 12 

NISTa
 

NISTb
 

NAV
 

NAU
 

0.549 0.694 0.527 !0.345 0.150 0.29 0.147 !0.327 8.26 8.53 8.16 !18.79 1.80 3.96 1.81 !4.04 

0.500 0.623 0.503 !0.319 0.153 0.33 0.153 !0.099 8.08 8.81 7.77 !18.72 1.83 4.28 1.80 !3.49 

0.510 0.674 0.510 0.084 0.24 0.102 7.93 8.47 7.87 1.74 4.00 1.75 

0.046 0.062 0.044 0.049 0.13 0.039 0.73 0.73 0.66 0.22 0.46 0.23 

All Lab Report K2 Page 1 / 6 
Round Robin XXXVIII Laboratory Results 

Values in μg/mL 

δ-Tocopherol Total β-Carotene trans-β-Carotene Total cis-β-Carotene

Lab 223 224 225 226 223 224 225 226 223 224 225 226 223 224 225 226 

FSV-BA 0.186 0.619 0.184 !0.894 0.173 0.585 0.172 !0.84 0.013 0.034 0.012 !0.054 

FSV-BD 0.173 0.710 0.178 !0.242
 

FSV-BF
 0.169 0.511 0.156 !0.241
 

FSV-BG
 0.197 0.714 0.194 !0.249 

FSV-BGa 0.193 0.676 0.183 !0.227
 

FSV-BH
 0.170 0.692 0.171 !0.307 0.162 0.677 0.163 !0.299 nd 0.015 nd nd 

FSV-BI 0.175 0.694 0.170 !0.237
 

FSV-BJ
 0.155 0.458 0.173 !0.155 

FSV-BK 

FSV-BL 

FSV-BM 

FSV-BN 0.180 0.750 0.160 !0.44 0.150 0.660 0.150 !0.37 0.140 0.650 0.150 !0.35 0.004 0.014 0.002 !0.021 

FSV-BO 0.117 0.360 0.124 !0.082
 

FSV-BP
 0.166 0.374 0.169 !0.113
 

FSV-BQ
 

FSV-BR
 

FSV-BS
 0.210 0.490 0.210 !0.13 0.160 0.470 0.160 !0.13 0.050 0.020 0.050 nd 

FSV-BT 0.049 0.525 0.019 !0.164 0.156 0.672 0.163 !0.414 0.150 0.662 0.155 !0.402 0.006 0.010 0.007 !0.012 

FSV-BU 0.175 0.693 0.176 !0.253
 

FSV-BV
 0.158 0.612 0.150 !0.256 

FSV-BW 0.220 0.770 0.210 !0.11
 

FSV-BX
 0.160 0.360 0.400
 

FSV-BZ
 >0.180 >0.633 >0.186 0.180 0.633 0.186 !0.265 nd nd 0.015 nd 

FSV-CA 

FSV-CB 

FSV-CC 

FSV-CF 

FSV-CH 0.139 0.645 0.153 !0.247
 

FSV-CK
 0.141 0.510 0.161 !0.083
 

FSV-CL
 0.096 0.339 0.093 !0.092 

FSV-CM 

FSV-CP 0.158 0.651 0.161 !0.203
 

FSV-CQ
 0.087 0.606 0.067 !0.111
 

FSV-CR
 

FSV-CS
 

FSV-CT
 0.166 0.585 0.178 !0.186
 

FSV-CU
 >0.090 >0.287 >0.085 0.090 0.287 0.085 !0.486
 

FSV-CX
 0.230 0.850 0.220 !0.2
 

FSV-DA
 0.170 0.760 0.180 !0.45 0.172 0.656 0.177 !0.288 0.161 0.615 0.165 !0.265 0.011 0.041 0.012 !0.037 

FSV-DJ
 

FSV-DK
 0.157 0.560 0.160 !0.32 

FSV-DM 0.171 0.629 0.167 !0.209
 

FSV-DP
 

FSV-DR
 0.169 0.396 0.163
 

FSV-DS
 0.145 0.469 0.136 !0.142
 

FSV-DU
 >0.190 >0.460 >0.190 0.190 0.460 0.190 !0.28
 

FSV-DX
 >0.155 >0.567 >0.155 0.155 0.567 0.155 !0.173
 

FSV-EA
 0.384 0.830 0.354 !0.526 0.130 0.630 0.170 !0.27
 

FSV-EH
 0.140 0.610 0.140 !0.33 0.228 0.472 0.212 !0.163 0.205 0.432 0.196 !0.15 0.023 0.040 0.016 

FSV-EI 0.146 0.636 0.203 !0.171 0.134 0.588 0.190 !0.165 0.012 0.048 0.013 

FSV-EL 

n 5 5 5 0 32 32 32 0 12 12 12 0 7 8 8 0 

Min 0.049 0.525 0.019 0.087 0.339 0.067 0.090 0.287 0.085 0.004 0.010 0.002 

Median 0.170 0.750 0.160 0.166 0.624 0.170 0.161 0.587 0.164 0.012 0.027 0.013 

Max 0.384 0.830 0.354 0.230 0.850 0.400 0.205 0.677 0.196 0.050 0.048 0.050 

eSD 0.044 0.119 0.030 0.020 0.103 0.020 0.024 0.103 0.017 0.009 0.019 0.004 

eCV 26 16 19 12 16 12 15 18 10 72 71 36 

NISTa 

NISTb 

NAV
 

NAU
 

nd 0.807 nd nd 0.180 0.628 0.181 !0.293 0.173 0.553 0.171 !0.217 0.007 0.076 0.009 

0.192 0.832 0.198 !0.439 >0.169 0.706 >0.165 >0.103 0.169 0.658 0.165 !0.101 nq 0.048 nq 

0.181 0.785 0.181 0.170 0.645 0.171 0.166 0.596 0.166 0.010 0.044 0.011 

0.034 0.122 0.042 0.028 0.142 0.028 0.022 0.127 0.024 0.008 0.043 0.005 

All Lab Report K3 Page 2 / 6 
Round Robin XXXVIII Laboratory Results 

Values in μg/mL 

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

Lab 

FSV-BA 

FSV-BD 

FSV-BF 

FSV-BG 

FSV-BGa 

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-BZ 

FSV-CA 

FSV-CB 

FSV-CC 

FSV-CF 

FSV-CH 

FSV-CK 

FSV-CL 

FSV-CM 

FSV-CP 

FSV-CQ 

FSV-CR 

FSV-CS 

FSV-CT 

FSV-CU 

FSV-CX 

FSV-DA 

FSV-DJ 

FSV-DK 

FSV-DM 

FSV-DP 

FSV-DR 

FSV-DS 

FSV-DU 

FSV-DX 

FSV-EA 

FSV-EH 

FSV-EI 

FSV-EL 

n 26 28 26 0 28 28 28 0 8 8 8 0 20 20 20 0 

Min 0.014 0.180 0.012 0.090 0.190 0.085 0.180 0.240 0.197 0.027 0.030 0.026 

Median 0.026 0.428 0.029 0.462 0.377 0.459 0.251 0.288 0.250 0.055 0.060 0.054 

Max 0.060 0.540 0.060 0.650 0.580 0.674 0.309 0.420 0.330 0.131 0.109 0.118 

eSD 0.009 0.082 0.011 0.089 0.086 0.096 0.053 0.063 0.028 0.016 0.015 0.017 

eCV 34 19 37 19 23 21 21 22 11 30 25 31 

223 224 225 226 223 224 225 226 223 224 225 226 223 224 225 226 

0.032 0.442 0.031 !0.308 0.427 0.386 0.415 !0.063 0.252 0.300 0.248 !0.069 0.068 0.075 0.067 !0.204 

0.033 0.482 0.025 !0.291 

0.400 0.379 0.413 !0.017 

0.460 0.372 0.462 !0.035 

0.052 0.060 0.051 !0.061 

0.040 0.427 0.039 !0.148 

0.055 0.320 0.050 !0.11 

0.565 0.490 0.561 !0.029 

0.533 0.415 0.522 !0.015 

0.273 0.334 0.262 !0.017 0.054 0.055 0.045 !0.047 

0.024 0.527 0.025 !0.214 0.517 0.462 0.534 !0.028 0.071 0.067 0.072 !0.074 

0.026 0.479 0.026 !0.202 

0.033 0.531 0.044 !0.187 

0.481 0.481 0.460 !0.022 

0.220 0.250 0.261 nd 

0.059 0.070 0.059 !0.068 

0.014 0.540 0.027 !0.29 0.650 0.580 0.640 !0.047 0.300 0.420 0.330 !0.04 0.044 0.053 0.051 !0.071 

nd 0.192 nd !0.039 0.474 0.361 0.427 !0.031 0.041 0.047 0.044 !0.049 

0.024 0.244 0.026 !0.077 0.491 0.369 0.535 !0.015 0.131 0.109 0.118 !0.069 

0.060 0.430 0.060 !0.11 0.090 0.190 0.085 !0.01 0.060 0.070 0.070 !0.08 

0.030 0.420 0.033 !0.203 0.392 0.316 0.405 !0.050 0.309 0.275 0.314 !0.039 0.066 0.079 0.072 !0.092 

0.021 0.456 0.021 !0.198 

0.019 0.374 0.018 !0.143 

0.029 0.500 0.029 !0.069 

0.520 0.472 0.524 !0.031 

0.424 0.355 0.400 !0.016 

0.550 0.480 0.590 nd 

0.074 0.084 0.072 !0.079 

0.016 0.180 0.060 

0.038 0.371 0.036 !0.123 

0.370 0.270 0.610 

0.246 0.323 0.256 nd 

0.030 0.030 0.030 

0.017 0.454 0.019 !0.2 0.357 0.361 0.409 !0.014 

0.031 0.350 0.049 !0.081 0.420 0.376 0.415 !0.039 0.200 0.249 0.197 !0.021 0.048 0.050 0.047 !0.048 

0.014 0.269 0.012 !0.065 0.262 0.240 0.261 nd 0.027 0.034 0.027 !0.031 

0.021 0.402 0.022 !0.130 0.338 0.308 0.339 !0.012 0.056 0.061 0.056 !0.065 

0.020 0.520 0.030 !0.08 0.540 0.470 0.530 !0.02 0.040 0.060 0.050 !0.05 

0.025 0.429 0.029 !0.253 

0.020 0.350 0.020 !0.17 

0.033 0.453 0.039 !0.157 

0.479 0.461 0.476 !0.052 

0.409 0.380 0.431 !0.067 

0.231 0.315 0.224 !0.038 0.055 0.055 0.052 !0.065 

0.463 0.373 0.457 !0.024 

nd 0.420 nd !0.183 0.501 0.420 0.500 !0.02 0.028 0.042 0.026 !0.031 

0.026 0.505 0.024 !0.112 0.249 0.240 0.238 nd 0.064 0.066 0.056 !0.06 

0.027 0.408 0.039 !0.135 0.471 0.402 0.674 !0.039 0.180 0.242 0.252 !0.017 0.052 0.057 0.072 !0.038 

NISTa 

NISTb 

NAV
 

NAU
 

nd 0.420 nd !0.191 

0.031 0.480 0.037 !0.057 0.590 0.503 0.587 nd 0.231 0.317 0.230 nd 0.049 0.050 0.049 !0.026 

0.028 0.439 0.034 0.526 0.440 0.526 0.241 0.302 0.239 0.052 0.055 0.051 

0.010 0.114 0.015 0.137 0.124 0.140 0.053 0.063 0.054 0.016 0.017 0.018 

All Lab Report K4 Page 3 / 6 
Round Robin XXXVIII Laboratory Results 

Values in μg/mL 

α-Cryptoxanthin Lutein Zeaxanthin Lutein&Zeaxanthin 

Lab 223 224 225 226 223 224 225 226 223 224 225 226 223 224 225 226 

FSV-BA 0.203 0.315 0.202 !0.112 

FSV-BD 0.125 0.179 0.128 !0.223 0.020 0.086 0.022 !0.117 0.145 0.265 0.150 

FSV-BF 

FSV-BG 

FSV-BGa 

0.134 0.149 0.138 !0.183 0.026 0.075 0.024 !0.097 0.160 0.224 0.162 

FSV-BH 0.102 0.113 0.096 !0.174 0.024 0.082 0.028 !0.08 0.126 0.195 0.124 

FSV-BI 0.124 0.147 0.123 !0.124 0.033 0.081 0.033 !0.067 0.157 0.228 0.156 

FSV-BJ 

FSV-BK 

FSV-BL 

FSV-BM 

FSV-BN 0.011 0.038 0.016 !0.011 0.110 0.120 0.110 !0.14 0.029 0.073 0.031 !0.1 0.130 0.190 0.140 !0.25 

FSV-BO 0.113 0.151 0.113 !0.192 

FSV-BP 

FSV-BQ 

FSV-BR 

FSV-BS 0.140 0.130 0.170 !0.13
 

FSV-BT
 0.027 0.047 0.026 !0.013 0.127 0.218 0.132 !0.429 0.026 0.029 0.027 !0.018 0.153 0.247 0.159 !0.447 

FSV-BU 0.177 0.273 0.199 !0.455 

FSV-BV 0.151 0.201 0.141 !0.237 

FSV-BW 

FSV-BX 0.160 0.170 0.150 0.050 0.090 0.050 0.210 0.260 0.200 

FSV-BZ 0.122 0.211 0.216 !0.259
 

FSV-CA
 

FSV-CB
 

FSV-CC
 

FSV-CF
 

FSV-CH
 

FSV-CK
 0.033 0.046 0.033 !0.015 0.092 0.114 0.094 !0.138 

FSV-CL 0.084 0.114 0.076 !0.113 

FSV-CM 

FSV-CP 0.180 0.272 0.180 !0.352 

FSV-CQ 

FSV-CR 

FSV-CS 

FSV-CT 0.115 0.149 0.117 !0.123
 

FSV-CU
 

FSV-CX
 0.130 0.140 0.130 !0.12 0.020 0.060 0.020 !0.05 0.150 0.200 0.150 

FSV-DA 0.016 0.038 0.017 !0.01 0.131 0.135 0.136 !0.13 0.050 0.094 0.056 !0.09 0.181 0.229 0.192 !0.22 

FSV-DJ 

FSV-DK 

FSV-DM 0.156 0.199 0.142 !0.235 

FSV-DP 

FSV-DR 

FSV-DS 

FSV-DU 

FSV-DX 0.135 0.220 0.138 !0.214 

FSV-EA 

FSV-EH 0.122 0.162 0.118 !0.265 0.034 0.108 0.033 !0.199 0.156 0.270 0.151 

FSV-EI 0.102 0.126 0.142 !0.079 0.043 0.084 0.060 !0.055 0.145 0.210 0.202 

FSV-EL 

n 4 4 4 0 14 14 14 0 11 11 11 0 20 20 20 0 

Min 0.011 0.038 0.016 0.102 0.113 0.096 0.020 0.029 0.020 0.084 0.114 0.076 

Median 0.021 0.042 0.022 0.125 0.148 0.131 0.029 0.082 0.031 0.152 0.222 0.151 

Max 0.033 0.047 0.033 0.160 0.218 0.216 0.050 0.108 0.060 0.210 0.315 0.202 

eSD 0.012 0.006 0.008 0.012 0.030 0.018 0.007 0.012 0.010 0.029 0.044 0.029 

eCV 10 20 14 26 14 33 19 20 19 

NISTa 

NISTb 

NAV
 

NAU
 

0.118 0.136 0.117 !0.136 0.047 0.092 0.045 !0.091 0.165 0.228 0.162 

0.122 0.142 0.124 

0.028 0.034 0.031 

0.038 0.087 0.038 

0.016 0.025 0.015 

0.159 

0.034 

0.225 

0.048 

0.156 

0.033 

All Lab Report K5 Page 4 / 6 
Term 

n 

Min 

Median
 

Max
 

eSD 

eCV 

NAV 

NAU 

nd 

nq 

>x 

! 

italics

Round Robin XXXVIII Laboratory Results 

Analytes Reported By One Laboratory 

Values in μg/mL 

Analyte Code 223 224 225 226 

Coenzyme Q10 FSV-CH 0.190 0.330 0.210 !0.04 

trans-α-Carotene NISTb 0.031 0.463 0.027 !0.057 

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
 

 Estimated standard deviation, calculated from the median absolute deviation

 from the median of the non-NIST results

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

 NIST Assigned Value, our estimate of the "true" analyte concentration

 NIST Assigned Uncertainty, our estimate of the total (serum hetergeniety and

 inter- and intra-laboratory) standard deviation
 

 For details on how we assign these quantities, see the "Report of (Meta)Analysis."

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

 Detected but not quantitatively determined

 Concentration greater than or equal to x

 Discrepant value: heterogeneous serum, damaged sample, malfunction, etc.

 Not explicitly reported but calculated by NIST from reported values

All Lab Report K6 Page 5 / 6 
Round Robin XXXVIII Laboratory Results 
 

Comparability Summary
 

Lab 

FSV-BA
 

FSV-BD
 

FSV-BF
 

FSV-BG
 

FSV-BGa
 

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-BZ
 

FSV-CA
 

FSV-CB
 

FSV-CC
 

FSV-CF
 

FSV-CH
 

FSV-CK
 

FSV-CL
 

FSV-CM
 

FSV-CP
 

FSV-CQ
 

FSV-CR
 

FSV-CS
 

FSV-CT
 

FSV-CU
 

FSV-CX
 

FSV-DA
 

FSV-DJ
 

FSV-DK
 

FSV-DM
 

FSV-DP
 

FSV-DR
 

FSV-DS
 

FSV-DU
 

FSV-DX
 

FSV-EA
 

FSV-EH
 

FSV-EI
 

FSV-EL
 

NISTa
 

NISTb
 

R aT gT bC tbC Label 

Lab

1 1 1 1 

1 1 1 1 

R 

2 1 1 1 aT 

1 1 gT 

1 1 1 bC 

2 1 1 1 tbC 

1 1 4 n 

1 2 1 1 1 

2 2 1 1 1 

1 3 2 2 

3 3 2 4 

2 1 3 1 

Definition

 laboratory number 

 "Standard Score" for Retinol 

 "Standard Score" for α-Tocopherol

 "Standard Score" for γ-Tocopherol

 "Standard Score" for Total β-Carotene

 "Standard Score" for trans-β-Carotene

 number of (non-NIST) laboratories providing data for this analyte 

"Standard Score" 

1 1 Given that our knowledge of the shape, location, and width of the measurement distributions is 

3 2 approximate and that a limited number of labs are involved, we summarize comparability with 

1 2 1 2 the following four-level "Standard Score" (StS)... 

1 

2 3 StS 

1 1 2 1 1 

1 2 2 

3 1 4 3 3 

1 2 1 4 

2 1 2 2 

1 2 3 where: 

1 1 StV 

2 2 2 

3 1 1 1 2 

1 1 3 2 2 NAV 

2 2 2 1 

3 3 1 NAU 

4 4 2 

1 2 

2 1 1 1 t (1-α,n-1)

2 1 

1 1 

1 

1 2 

1 1 

1 1 1 

1 1 4 1 

4 4 1 

1 1 2 1 1 

1 1 

1 

1 1 1 1 

4 3 1 2 2 

2 1 

2 2 2 2 

4 1 

2 2 

3 3 2 

2 2 

1 1 1 1 1 

1 1 1 1 1 

n 47 45 23 32 12
 

StS
 

1
 

2
 

3
 

4
 

All Lab Report 

% Observed Expected 

51 60 52 50 58 68.2 % 

28 24 30 38 33 27.3 % 

13 11 9 6 8 4.3 % 

9 4 9 6 0 0.3 %

Definition

 All StV within ±t (1-0.683,n-1) {i.e., ±1 SD} 

 All StV within ±t (1-0.954,n-1) {i.e., ±2 SD} 

 All StV within ±t (1-0.997,n-1) {i.e., ±3 SD} 

 At least one StV > ±t (1-0.997,n-1) {i.e., >3 SD} 

 Standardized Value, the distance in standard deviation units your

 value is from the "true" concentration: StV = (your value - NAV) / NAU 

 NIST Assigned Value, our estimate of the "true" analyte concentration

 NIST Assigned Uncertainty, our estimate of the total (serum heterogeniety and 

iter- and intra-laboratory) measurement standard deviation.

 Two-tailed Student's t for coverage of ±1, ±2, and ±3 NAU about 

 NAV, assuming a normal population of size n 

For details on the NIST Assigned quantities, see this Round Robin's 

"Report of (Meta)Analysis." 

These are the observed and normal-population-expected proportions of each 

Standard Score (StS), based upon each laboratory's largest StV for the four sera. 

K7 Page 6 / 6
 
 

Appendix L. Representative “Individualized Report” for RR38 

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

results. Each report included a detailed analysis of the results they reported for some or 

all of the following analytes: 

• Retinol 

• Retinol palmitate 

• α-Tocopherol 

• γ-Tocopherol 

• Total β-Carotene 

• trans-β-Carotene 

• Total α-Carotene 

• Total Lycopene 

• β-Cryptoxanthin 

• Lutein 

• Zeaxanthin 

• Lutein & Zeaxanthin 

The following 8 pages are the “Individualized Report” for the analytes evaluated by 

participant FSV-BA. 

L1
 
_, 

.... 

1001196 

Individualized Round Robin XXXVIII Report to: FSV-BA 

Your Data, NIST Assigned Values, and %Differences 

Serum223 Serum224 Serum 225 Serum 226 

Analyte You NAV %A n I You NAV %A n I I You NAV %A n I I You NAV %A nl 

Retinol .50 .51 -3 45 .70 .68 4 45 .49 .51 

Retinyl Palmitate .16 .12 27 15 .24 .28 -12 15 .13 .13 

a-Tocopherol 7.69 7.93 -3 42 8.42 8.47 -1 42 7.64 7.88 

y-Tocopherol 1.93 1.74 11 21 4.37 4.00 9 21 1.90 1.74 

Total P-Carotene .19 .17 9 29 .62 .65 -5 29 .18 

trans-p-Carotene .17 .17 4 12 .59 .60 -2 12 .17 

Total cis-p-Carotene .01 5 .03 6 .01 

Total a-Carotene .03 .03 10 24 .44 .44 1 26 .03 

Total Lycopene .43 .53 -19 26 .39 .44 -12 26 .42 

trans-Lycopene .25 .24 5 8 .30 .31 -3 8 .25 

P-Cryptoxanthin .07 .05 33 18 .08 .06 36 18 .07 

"Lutein&Zeaxanthin" .20 17 .32 17 .20 

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

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

%A : Percent difference between your value and the NA V 

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

Please check our recorded values against your records. 

.17 .17 .03 .52 .24 .05 

-3 45 .34 .32 

2 15 .17 .23 

-3 42 19.26 19.20 

9 21 3.70 3.57 

7 29 .89 .22 

4 12 .84 .22 

6 .05 

-9 24 .31 .14 

-21 26 .06 

3 8 .07 

33 18 .20 .05 

17 .11 

Send corrections to: NNMMQAP 222/B208, NIST, Gaithersburg, MD 20899; fax 301-977-0685; email David.Duewer@NIST.gov 

7 44 

-27 15 

0 41 

4 20 

306 28 

282 12 

4 

114 25 

22 

7 

343 17 

16 

l'l&e I /8 

L2
 
_, 

10/211 

> 

< 

-. 

> 

< z 

I 

j 

..._ 

* 0 

0 

-

<1 

50 

25 

0 

-25 

-50 

Individualized Round Robin XXXVIII Report to: FSV-BA 

Retinol, %il in Round Robin XXIX - XXXVIII 

I I I I I 

8 8 8 8 9 

6 1 8 9 0 

I I I I 

9 9 9 9 

I 2 3 4 

I I I I 

9 9 9 9 

5 6 1 8 

x 

x 

x 

I 

I 

I 2 2 2 

9 0 0 0 

9 0 I 2 

x 

x x 

x x 

I X 

I I 

I V 

tellli)[§Jfu I 

·2 2 2 2 

0 0 0 0 

3 4 5 6 

2 2 2 2 

0 0 0 I 

1 8 9 0 

Serum 

2 2 2 2 

I I I I 

I 2 3 4 

x 

x x 

x x 

x v V I 

I I -.m 

2 2 2 2 

I I I I 

5 6 1 8 

2 2 2 2 

I 2 2 2 

9 0 I 2 

x x x 

v 

I 

I 

2 2 2 2 2 2 2 2 

3 4 5 6 

Po&e2/8 

L3
 
..... 

VI 

> <( > <( 

z 

d 

* 0 

0 

-

<] 

10011116 

50 

25 

Individualized Round Robin XXXVIII Report to: FSV-BA 

Tocopherols, %A in Round Robin XXIX - XXXVIII 

x 

x x 

x x x x 

OL x x X I I I I I --- litllil x x i ibL "'"' 1111': u-u . 

-25 

-50 

I I I I I 

8 8 8 8 9 

6 1 8 9 0 

I I I I 

9 9 9 9 

I 2 3 4 

I I I I 

9 9 9 9 

5 6 1 8 

I 2 2 2 

9 0 0 0 

9 0 I 2 

I 

ill 

• g-Tocopherol El a-Tocopherol 

2 2 2 2 

0 0 0 0 

3 4 5 6 

2 2 2 2 

0 0 0 I 

1 8 9 0 

Serum 

2 2 2 2 

I I I I 

I 2 3 4 

2 2 2 2 

I I I I 

5 6 1 8 

2 2 2 2 

I 2 2 2 

9 0 I 2 

2 2 2 2 

2 2 2 2 

3 4 5 6 

P11&"3/K 

L4
 
..... 

"' 

1001 

> < 

,.-... 

> < z 

I 

j 

'-' 

* 8 

-

<J 

50 

25 

0 

-25 -50 

Individualized Round Robin XXXVIII Report to: FSV-BA 

b-Carotene, in Round Robin XXIX - XXXVIII 

ilil 

'':::/ 

I 

,. 

• trans-b-Carotene !ID Total b-Carotene 

11111 1111 1111 1222 2222 2222 2222 2222 2222 2222 

8 8 8 8 9 9 9 9 9 9 9 9 9 9 0 0 0 0 0 0 0 0 0 0 1 1 I I 1 I 1 1 I I 2 2 2 2 2 2 2 

6 7 8 9 0 1 2 3 4 S 6 7 8 9 0 1 2 3 4 S 6 7 8 9 0 1 2 3 4 S 6 7 8 9 0 1 2 3 4 S 6 

Serum 

..... ,. 

L5
 
.... 

.... 

Individualized Round Robin XXXVIII Report to: FSV-BA 

- ±20% 

-- ±50% 

. 

. 

. 

, 

. 

. 

. 

, 

, 

. 

. 

. 

. 

, 

. 

Retinol 

, .Atlf 

. 

. 

, 

. 

. 

. 

. 

. 

, 

. 

, 

. 

, 

. 

. 

. 

. 

. 

. 

. 

, 

cx-Tocopherol 

- ±20% 

-- ±50% 

111121196 

. 

. 

. 

• .

• 

. 

. 

, 

, 

, 

. 

. 

. 

. 

. 

, 

, 

. 

. 

• 

NIST Assigned Values Vs Laboratory Values 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

, 

. 

. 

. 

. 

, 

A Total 

e trans 

- ±20% 

-- ±50% 

- ±20% 

-- ±50% 

. 

. 

, 

, 

• 

p-Carotene 

,';61" ,,' 

y-Tocopherol 

• , 

. 

. 

. 

, 

, 

. 

, 

, 

. 

, 

. 

. 

, 

• . 

, 

. 

. 

. 

, 

. 

, 

. 

• 

. 

. 

. 

. 

. 

, 

, 

. 

. 

. 

Legend 

Shaded Symbols: RR XXIX-XXXVII 

Black Symbols: RR XXXVIII 

Ordinate (X-axis): NIST Assigned Value 

Abscissa (Y-axis): Your reported value 

Interpretation 

Adequately intercomparable data are within 

±20% lines. If you have data scattered outside 

±50% lines, your measurement system is 

not consistent with those of most participating 

laboratories. If your data are systematically 

higher or lower than the NAV, your system 

may be consistent but your results are biased. 

If your data show increased scatter at low 

concentrations, your "limit of quantification" 

may not be what you think it is. 

If there are one or two "wild" outliers, they 

might be calculation or transcription errors . 

We would appreciate hearing from you about 

any such problems . 

L6
 
..... 

00 

1001 

Individualized Round Robin XXXVIII Report to: FSV-BA 

Accuracy /Precision Summary 

. 

. 

. 

[ 

[ [ 

' 

' 

[ 

[ [ 

XXIX 

xxx 

XXXI 

XX XII 

XX XIII 

XX XIV 

xx xv 

XXXVI 

XXXVII 

xxxvm 

Ret 

vA 

4 4 

9 4 

5 3 

-3 2 -2 2 

4 4 

6 4 

-1 2 

6 2 

-I 4 

a Toe 

vA 

0 3 

4 7 

-2 5 -1 1 

0 2 

-4 I 

-2 14 

2 1 

-4 I 

-2 I 

gToc -

vA 

9 6 

-3 7 

-1 5 

-3 3 

11 11 

3 2 

3 8 

-19 2 

2 2 

10 1 

(Traditional) Performance Criteria 

Total 

vA 

5 4 

9 12 

9 9 

8 4 

12 13 

6 3 

I 4 

10 9 

2 23 

4 8 

The absolute value of %A of every measurement has 

traditionally been evaluated as follows ... 

%A Evaluation 

0-5% Exceptional 

6-10% Acceptable 

11-20% Marginal 

>20% Poor 

More representative criteria need to be established, 

factoring in each serum's analyte level and the 

analyte distribution in adult human populations. 

Stay tuned, we're working on it. . . 

trans 

vA 

3 3 

9 12 9 10 

13 4 12 6 

9 4 

6 3 

11 3 

2 18 2 3 

Legend -

Ret Retinol 

a Toe a-Tocopherol 

gToc ..,... Tocopherol 

Total Total (i-Carotene 

trans trans-(i-Carotene 

Mean difference, the average %A for all sera of a given RR, where 

%A = 1 ()()(Your value - NA V) I NA V 

vA Difference variability, one standard deviation of %A for all sera of a 

NAY NIST Assigned Value, our best estimate of analyte concentration ... 

NA V = (NIST's average-of-averages +Round Robin median)/ 2 

Interpretation 

Accuracy and precision are separate but kindred aspects of measurement 

comparison. We estimate accuracy as mA, the average %A, and precision 

as vL\, the standard deviation of %A, for all sera of a Round Robin. 

It's best to be accurate and precise (small mA, small vA)! 

RR 

Good precision (small vA) with poor accuracy (large is better than the 

converse: at least such values are internally consistent and may be relatable to 

others' values once the relative biases have been determined. 

Poor precision (large vL\) suggests that your measurement system is not in 

adequate control for the analyte levels examined. 

.Pa&c6/I 

L7
 
..... 

'° 

I ,!"'\ , I 

Individualized Round Robin XXXVIII Report to: FSV-BA 

Comparisons 

E!3 

-E!3Q 

0 

c: 

·-

8 

223 22.S 224 226 

·--------------------·---- ------

E ·9 

cu 

Q.. • - D • ! --f]--tl223 22S 

- - --- - -·-- ---- - ·--- - --·--

1001196 

B • 

I 

224 226 

l 

1 

g. 

-Ei3-53 

I I 

223 22S 

. . -a--8-

---. 

223 22S 

EJ 

I 

224 226 

• 

El 8 

224 226 

Q) 

c: 

B 

cb. 

cu 

.... 0 • 

E-< 

I I 

223 22S 

------- - - ------ - -·--·· 

Q) 

I 

u 

I 

ca. 

223 22S 

• 

LJ 

224 226 

B • 

224 226 

------- ··---------·-- ·--·- - ·· -----

Plae71M 

L8
 
00 

0 

Individualized Round Robin XXXVIII Report to: FSV-BA 

Comparisons (Continued) 

,------·--

-

E!3 -E.i:]- - b;J • 

• • Fl n i D l j -8--LI- D LJ 8 x u ;:..... 0 b ....:i a 

cu £:> 

.... • u 0 O I 

-e-0- El 01 

I I I I I I I I I I I I j I I 

223 225 224 226 223 225 224 -- 223 225 -__ - - ---1 I I ----------

, 8 D I • . B II a D J --a--E- t1 J • • El u 

, JJ_fl_ 1l B n Li t1 - --8-

1 I I I I I I I I I I I • 

223 225 m m 223 225 m m 

---

10011 i P.,., 818 

L9
 
 

Appendix M. Shipping Package Inserts for RR09 

The following two items were included in each package shipped to a RR09 participant: 

•	 Cover letter and instructions for preparing the Control Sample 

•	 Report of Analysis datasheets for the preparation of the Control Sample and for 

the analysis of the Control and Serum Samples 

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

samples themselves. 

M1
 
May 20, 1996 

FIELD(Title) FIELD(First) FIELD(Last) 

FIELD( Company) 

FIELD(Address) 

Dear FIELD(Title) FIELD(Last): 

Thank you for agreeing to measure the ascorbic acid in the accompanying samples. Enclosed are 

two sets of samples, one set consisting of four ampules are Test Samples and the second set 

consisting of a vial of solid ascorbic acid is the Control Sample. 

The Control Sample consists of a sample of solid ascorbic acid in an amber vial and should be 

used in the following manner: 

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

2. Weigh out 10-20 mg to 0.1 mg (if possible) and dissolve it in 100 mL of 5% MPA 

using a 100 rnL volumetric flask. This will be referred to as the Stock Solution. 

3. Dilute the Stock Solution by weighing 0.5 rnL of the Stock Solution into a 100 rnL 

volumetric flask. Then add 5% MP A solution to 100 rnL and weigh the amount of 

MP A solution that was added. 

4. Record the ultraviolet spectrum of the diluted solution against 5% MPA solution as 

the blank using paired cuvettes. 

5. Record the Absorbance of the sample at 243 nm and 244 nm. 

6. Measure the concentration of ascorbic acid in the dilute solution in duplicate along 

with the ampuled Test Samples. 

The Test Samples are in sealed ampules and were prepared by adding equal volumes of spiked 

human serum to 10% metaphosphoric acid. All samples have been stored at -70 °C and should 

be kept at this temperature. We have checked them for stability and the ascorbic acid appears 

sufficiently stable. 

Each ampule contains between 20 and 120 μ.mol of ascorbic acid/L of diluted serum. and each 

ampule should be analyzed in duplicate by the method(s) used in your laboratory (preferably one 

measuring total ascorbic acid). 

Dr. Margolis printed a separate cover letter for 

each participant. The “FIELD()” macro 

commands were part of a mail-merge system. 

M2
 
The Test Samples should be defrosted by warming at 20 °C for not more than 10 min 

otherwise some oxidation of ascorbic acid may occur. 

A report form is attached and we would appreciate it if you would make your measurements and 

return your report to me by July 2. 1996 We also request that you send us a representative 

chromatogram for each lot and indicate whether you used the peak area or the peak height for 

calculating the concentration of ascorbic acid in your samples. Your results will be kept 

confidential. We will use these results in a study to demonstrate the comparative accuracy and 

precision of the laboratories currently measuring ascorbic acid. However, values will not be 

assigned to individual labs. If you wish to fax your results to me. The fax number is: (301) 977-

0685. If you have any questions, I can be reached at (301)975-3137. 

Thank you for your assistance. 

Sincerely, 

Sam A. Margolis, Ph. D. 

Research Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosures 

M3
 
REPORT OF ANALYSIS 

NAME: 

ADDRESS: 

Telephone no: _________ _ 

Fax no.: 

Method of Analysis: 

Please attach representative chromatograms. 

Method used for calculating ascorbic acid concentration. 

Peak Height ___ _ Peak Area ----

Manufacturer of ascorbic acid used to make standards. --------

Date of Analysis: ____ _ 

PREPARATION OF STOCK SOLUTION AND DILUTED SOLUTION 

STOCK SOLUTION 

Weight of ascorbic acid in the Stock Solution 

DILUTE SOLUTION 

Weight of added Stock Solution (0.5 mL) 

Weight of 5% MP A added to 100 mL volumetric Flask 

Absorbance of Dilute Solution at 243 nm 

Absorbance of Dilute Solution at 244 nm 

Page 1 of2 

____ mg 

____ mg 

____ g 

M4
 
CONTROL SAMPLE 

REPLICATE 1 

REPLICATE2 

SERUM 688A, VIAL # 

REPLICATE 1 

REPLICATE2 

SERUM 688A, VIAL # 

REPLICATE 1 

REPLICATE2 

SERUM 188A, VIAL # 

REPLICATE 1 

REPLICATE2 

SERUM 188A, VIAL # 

REPLICATE 1 

REPLICATE2 

REPORT OF ANALYSIS 

RESULTS (μmol/L) 

---μmol/L 

---μmol/L 

___ μmol/L 

___ μmol/L 

___ μmol/L 

___ μmol/L 

___ μmol/L 

___ μmol/L 

--- μmol/L 

--- μmol/L 

M5
 
 

 

 

 

Appendix N. Final Report for RR09 

The following seven pages are the final report for RR08 and RR09 as provided to all 

participants. This report contains: 

•	 Cover letter and analysis of results. 

•	 Table 1 “Results of Round Robin RR08 Measurement of Ascorbic Acid in Human 

Serum”. 

•	 Table 2 “Results of Round Robin RR09 Measurement of Ascorbic Acid in Human 

Serum”. 

•	 Table 2 “Results of Round Robin RR09 Measurement of AA using NIST
 

Ascorbic Acid Sample”.
 

•	 Figure 1 “Tukey Box Plot of the Round Robin RR08 Results” 

•	 Figure 2 “Tukey Box Plot of the Round Robin RR09 Results” 

A number of the results reported in the Tables were later revised to correct for 

miscommunication of the reporting units. Since the listed results do not necessarily 

represent measurement performance, the Lab identifiers used by Dr. Margolis have been 

redacted from these Tables rather than re-coded. The reporting unit confusion impacts 

some of the conclusions discussed in the cover letter. However, the results discussed in 

the Dr. Margolis’s text have not been updated or corrected. 

The “All Lab Report” in Appendix O lists the corrected results and provides more 

extensive statistical summaries. 

N1
 
November 12, 1996 

~t,p{Title) ~:i;¢.J;;p(Firstj f:t~t;P{Last) 

*'.~£P.{Company} 

fr.:i'.$.:;ij(Address). 

Dear ~itl%.P{Title) F.tEtP.:{Last}: 

This report describes both the overall-group and your laboratory performance in Round Robin 

VIII and Round Robin IX for the measurement of ascorbic acid in human plasma. The studies 

involve the duplicate analyses of four unknown samples [two from Lots 688a and 682a (RR 

VIII); 688a and l 88a (RR IX)]. RR VIII also included a control sample from Lot 688b and RR 

IX included solid ascorbic acid as a standard. Specifically your data evaluation package contains 

tabular presentations of all of the data submitted for ascorbic acid Round Robins VIII and IX 

Your results are designated as ~ijp):~(Lab No.). in the tables and figures. 

Tables 1 and 2 provide a summary of the data submitted by the participating laboratories (the 

NIST data were not included in the statistical analysis). Two laboratories submitted two sets of 

measurements, each done by a different method. As shown in Tables 1 and 2 the percent 

Relative Standard Deviation (%RSD) for both lots ranged from 4.7 - 13.9. The intralaboratory 

SD varied from 0.3 - 5.8 with the exception of one laboratory in each round robin. These results 

indicate that the intralaboratory variation remains essentially unchanged from the two previous 

round robins (SD = 0.3 - 4.0). However, the interlaboratory %RSD has decreased by 

approximately 50%. This occurred with the improved accuracy of several laboratories in the last 

two round robins and coincides with the introduction of the control material into RR VIII with 

the requirement that the control measurement must be within 10% of the assigned value. The 

Tukey box plots in Figures 1 and 2 graphically summarize the results, the highest and lowest 

10% of the measurements for each lot are plotted as small open circles, the two simple lines each 

span the next 15% intervals, and the center box contains the values from the remaining data sets. 

The NIST mean value for the total ascorbic acid + dehydroascorbic acid is represented by a solid 

circle. The horizontal line in the 50% boxes represents the median interlaboratory values which 

are nearly identical to those of NIST except for Lot 682a which is 8.7% higher and which 

represents the upper end of the range of serum ascorbic acid concentrations. 

Dr. Margolis printed a separate cover letter for 

each participant. The “FIELD()” macro 

commands were part of a mail-merge system. 

N2
 
In RR IX we asked each lab to make up a solution from solid ascorbic acid, measure its UV 

absorbance, and assay the ascorbic acid content. Unfortunately, the concentration was low 

except for several laboratories which increased the concentration 10 fold. The purpose of this 

segment of the study was to try to evaluate the role that your standards might be playing in the 

accuracy and precision of your measurement process. Because of the low ascorbic acid 

concentration, the data (Table 3) are not very meaningful except to indicate that there was a large 

degree of variability that may have been related to the inability to do accurate spectrophotometry 

at the designated analyte concentration. In RR X we will ask you to do the same measurements 

on ascorbic acid solutions that are ten times more concentrated. 

The improvement in the interlaboratory precision of these round robins is encouraging and we 

hope that the next round robin will assess the role of the standards in the measurement accuracy 

and their contribution to the interlaboratory variability. If your results deviated widely from the 

assigned values, we recommend that you reexamine your methods for possible systematic errors. 

The distribution of the results of each laboratory are graphically illustrated in Figures 3-7. 

The next set of samples (RRX) will be shipped around October 28, 1996. If you have any 

questions concerning the previous round robins, please contact me at (301)975-3137. 

Sincerely, 

Sam A Margolis, Ph.D. 

Research Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosures 

N3
 
Results of Round Robin VIII Measurement of Ascorbic Acid in Human Serum. 

Ascorbic Acid (p.mol/L Serum)• 

Lab Method Lot 688b Lot688a Lot 682a 

DNPH 57.8±2.5 28.0±2.5 92.2 ± 2.3 

LC 57.2±2.4 26.7 ± 1.2 90.4 ± 1.3 

LC-EC 

ENZ 60.7±0.9 31.5 ± 0.4 91.7 ± 0.6 

DNPH 62.1±1.4 32.0± 0.2 92.0 ± 0.3 

DCIP 

DCIP 57.8±2.5 28.0± 2.5 92.2 ± 2.3 

LC-EC 61.6± 2.0 34.2± 1.2 98.7 ± 1.3 

LC-EC 56.8± 1.8 26.9± 7.8 99.3 ±10.7 

LC 

LC-EC 57.3 ±0.6 29.4 ± 0.4 89.7 ± 0.9 

LC 

LC-EC 58.3 ± 1.5 25.9 ± 1.2 90.0 ± 1.7 

AUTO AN 58.9± 1.7 28.8 ± 1.3 87.3 ± 2.9 

LC-OPD 54.2± 0.3 27.3 ± 0 84.2 ± 0.7 

LC-EC 67.7± 1.0 32.9±0.2 103.2 ± 1.5 

LC-OPD 56.9±0.7 26.9± 3.3 78.0 ± 1.4 

LC 

LC-EC 51.6 ± 1.2 26.2 ± 1.2 81.8 ± 0.6 

LC-Coul na 32.6± 0.8 65.1 ± 0.5 

MEAN 57.7 28.3 90.5 

SD 2.7 2.5 6.1 

%RSD 4.7 8.7 6.7 

NIST 

AA+DHAA LC-EC 56.8 ± l.6b 27.4 ± 3.2b 83.2 ± 5.Sb 

NIST 

AA LC-EC 43.2 ± 3.3b 6.5 ± 1.4b 70.7 ± l.8b 

• Values represent the mean and SD of replicate measurements on two samples (total of 4 

measurements). 

b Values represent the mean and SD of replicate measurements on five samples (total of 10 

measurements). 

Table 1:
	

N4
 
Results of Round Robin IX Measurement of Ascorbic Acid in Human Serum. 

Ascorbic Acid (μ.mol/L Serum)a 

Lab Method Lot 688a Lot 188a 

LC 28.9 ± 0.6 64.1±0.8 

DNPH 25.5 ± 2.7 56.8±4.6 

LC-EC 26.4 ± 2.1 58.6 ± 5.7 

ENZ 30.5 ± 0.5 62.5 ± 1.3 

DNPH 

DCIP 

DCIP 28.3 ± 3.2 67.7± 5.8 

LC-EC 34.7 ± 0.5 70.9±2.3 

LC-EC 

LC 

LC-EC 24.7 ± 2.7 65.2± 0.8 

LC 

LC-EC 19.2 ± 0.6 52.2± 3.5 

AUTO AN 28.1±1.0 57.8 ± 1.2 

LC-OPD 28.l ± 0.6 61.3 ± 0.7 

LC-EC 

LC-OPD 34.6± 2.6 75:2± 2.8 

LC 28.7 ± 2.2 63.3 ±2.2 

LC-EC 25.9 ± 0.9 51.7 ± 0.6 

LC-Coul 32.3 ±I.I 64.3 ±0.4 

DNPH 51.3 ± 27.4 84.8±24.3 

ENZ 26.2 ± 1.6 56.0 ±I.I 

LC 25.1±1.4 50.2± 3.0 

MEAN 27.7 60.9 

SD 3.8 7.2 

%RSD 13.9 11.8 

NIST 

AA+ DHAA LC-EC 27.4 ± 0.3A 64.2 ± l.8d 

NIST 

AA LC-EC 6.5 ± l.4A 40.2± 6.6d 

a Values represent the mean and SD of replicate measurements on two samples (total of 4 

measurements). 

b These samples were nor included in the mean because of their very large SD. 

c Values represent the mean and SD of replicate measurements on five samples (total of I 0 

measurements). 

Table 2:
	

N5
 
Results of Round Robin IX Measurement of AA using NIST Ascorbic Acid 

Samplea. 

Ascorbic Acid (p.mol/L MPA) 

Lab Method Calculated Measured Et%b AA Source 

LC 2.84 2.84 745 Sigma 

DNPH 

LC-EC 5.14 a Sigma 

ENZ 5.32 15.4 445 Sigma 

DNPH 

DCIP 

DCIP 3.96 8.75 775 Sigma 

LC-EC 5.75 8.0 576 Sigma 

LC-EC 

LC 

LC-EC 5.73 5.6 6l5 Aldrich 

LC 

LC-EC 4.13 2.85 510 Merck 

AUTO AN 4.95 4.80 598 na 

LC-OPD 5.40 5.42 583 na 

LC-EC 5.09 13.0 900 BDH 

LC-OPD 4.72 4.50 791 Sigma 

LC 3.46 3.02 522 BDH 

LC-EC 50.2 48.1 585 Sigma 

DNPH 5.49 3.85 643 Sigma 

ENZ 4.31 4.26 702 Sigma 

LC 20.6 6.05 199 Merck 

NIST (5% MPA) 570 Sigma 

Literature Value. (aqueous) C:- - 560 

NISTb 513 Sigma 

a Used NIST AA to prepare standards for assay. 

btW= Absorbance at 20°C of a solution of lg/lOOmL measured in a cuvette with a path of 1 

cm. 

c Solvent: water : acetonitrile, 1 :3 + DTT 1 mglmL. 

Table 3:
	

N6
 
Round Robin VIII 

120 

110 

100 0 

- 90 E 

::J 

L. 

Q) 80 

en 0 

..J 

- 70 0 0 E 

T ::i 

- 60 

"O ·o 

<( 50 

(.) 

:.0 40 L. 

0 

(.) 

en 

<( 30 

20 

10 

0 

0 1 2 3 4 

688b 688a 682a 

Lot Number 

Figure 1
	

N7
 
80 

-...J 

-0 

E 60 

::i 

-

"C 

·o 

<( 

0 

:c 

'- 40 0 

0 

en 

<( 

20 

0 

0 

Round Robin IX 

0 

~ 0 

1 

688a 

Lot Number. 

0 

2 

188a 

3 

Figure 2
	

N8
 
Appendix O. “All-Lab Report” for VC-RR09 

The following is a single page “All-Lab Report” that contains the same information as 

originally provided to all participants, with the following exceptions: 

•	 the participant identifiers (Lab) have been altered to ensure confidentiality of 

identification codes assigned to laboratories.. 

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

•	 results for the Serum Samples have been corrected and transformed to have units 

of μmol/mL sample. 

•	 results for the Control and Serum Samples have been consolidated. 

•	 additional summary statistics have been included. 

O1
 
Vitamin C Round Robin 09 

[Total Ascorbic Acid], mmol/mL

Lab Method 

VC-MA HPLC-UV 

VC-MB AO-OPD 

VC-MC HPLC-EC 

VC-MD 24DNPH 

VC-ME 24DNPH 

VC-MF HPLC-EC 

VC-MG HPLC-UV 

VC-MO AutoAnal 

VC-MQ HPLC-EC 

VC-MV 24DNPH 

VC-MX HPLC-UV 

VC-MZ 24DNPH 

VC-NA HPLC-UV 

VC-ND HPLC-EC 

VC-NJ AO 

VC-NL HPLC-EC 

VC-NR HPLC-UV 

AA Control 

Av Srep 

1.42 0.00 

7.70 0.00 

2.84 0.00 

2.71 0.02 

2.40 0.02 

1.51 0.04 

3.02 0.10 

4.31 0.00 

4.00 0.00 

1.93 0.11 

2.85 0.06 

1.43 0.04 

4.50 0.28 

2.13 0.20 

24.04 0.00 

688A 

Av Sdup Srep Shet Stot 

13.2 

15.3 

14.4 

12.8 

14.1 

14.1 

14.4 

12.5 

13.4 

17.3 

14.7 

12.6 

9.6 

17.3 

13.1 

13.1 

13.0 

1.9 1.9 

0.2 0.3 

0.3 0.0 

1.3 1.1 

0.0 0.4 

0.4 0.4 

1.4 0.2 

0.3 0.8 

1.0 2.7 

0.2 0.2 

1.0 

1.3 0.5 

0.2 0.3 

1.6 0.2 

0.6 0.8 

0.0 

1.1 0.5 

1.3 

0.0 

0.0 

1.1 

0.0 

0.2 

1.3 

0.0 

0.0 

0.2 

1.3 

0.0 

1.6 

0.3 

1.0 

2.3 

0.3 

0.3 

1.5 

0.3 

0.5 

1.4 

0.6 

2.2 

0.2 

1.4 

0.3 

1.6 

0.8 

1.1 

188A 

Av Sdup Srep Shet Stot 

25.7 

31.2 

31.9 

28.2 

30.7 

28.9 

31.6 

25.1 

33.8 

35.5 

32.6 

32.6 

26.1 

37.6 

28.0 

25.8 

30.6 

0.2 0.3 

0.7 0.4 

0.2 0.0 

2.0 1.9 

0.3 0.3 

0.5 0.5 

1.2 0.7 

1.2 1.3 

2.8 2.1 

1.3 0.5 

0.2 

0.3 0.4 

0.1 2.1 

1.6 0.6 

0.6 0.3 

0.4 

1.0 5.9 

0.0 

0.7 

0.0 

1.5 

0.2 

0.3 

1.1 

0.8 

2.4 

1.3 

0.2 

0.0 

1.6 

0.6 

0.0 

0.3 

0.8 

0.2 

2.4 

0.4 

0.6 

1.3 

1.6 

3.2 

1.4 

0.4 

1.5 

1.7 

0.6 

4.3 

N 15 17 17 

Min 1.4 0.1 9.6 0.0 0.0 0.0 0.2 25.1 0.1 0.0 0.0 0.2 

Median 2.8 13.4 0.6 0.4 0.2 0.8 30.7 0.7 0.5 0.6 1.3 

Max 24.0 17.3 1.9 2.7 1.6 2.3 37.6 2.8 5.9 2.4 4.3 

eSD 1.7 1.2 3.6 

eCV 61 9 12 

AO Ascorbate oxidase 

AutoAnal Auto Analyzer

24DNPH 2,4-Dinitrophenylhydrazine 

EC Electrochemical detector 

HPLC Liquid chromatography

OPD Orthophenlyenediamine

UV Ultraviolet absorbance

All Lab Report Page 1 / 1 

O2