NISTIR 7880-29 

NIST Micronutrients Measurement 

Quality Assurance Program 

Winter, Spring, and Fall 1995 

Comparability Studies 

Results for Round Robins XXXIII, XXXIV, and XXXV 

Fat-Soluble Vitamins and Carotenoids in Human Serum 

and Round Robins 7 and 8 Ascorbic Acid in Human Serum 

David L. Duewer 

Margaret C. Kline 

Sam A. Margolis (Retired) 

Katherine E. Sharpless 

Jeanice B. Thomas 

http://dx.doi.org/10.6028/NIST.IR.7880-29 

 

 

 

 

 

 

 

 

 

 

 

NISTIR 7880-29
 

NIST Micronutrients Measurement 

Quality Assurance Program 

Winter, Spring, and Fall 1995 

Comparability Studies 

Results for Round Robins XXXIII, XXXIV, and XXXV
	

Fat-Soluble Vitamins and Carotenoids in Human Serum
	

and Round Robins 7 and 8 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 

Materials Measurement Laboratory 

http://dx.doi.org/10.6028/NIST.IR.7880-29

 April 2014 

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 1995 MMQAP measurement comparability improvement studies: 1) Round 

Robin XXXIII Fat-Soluble Vitamins and Carotenoids in Human Serum, 2) Round Robin XXXIV 

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

Vitamins and Carotenoids in Human Serum, 4) Round Robin 7 Ascorbic Acid in Human Serum, and 

5) Round Robin 8 Ascorbic Acid in Human Serum. The materials for Round Robin XXXIII were 

shipped to participants in January 1995; participants were requested to provide their measurement 

results by March 20, 1995. The materials for Round Robin XXXIV were shipped to participants in 

April 1995; participants were requested to provide their measurement results by July 24, 1995. The 

materials for Round Robin XXXV were shipped to participants in July 1995; participants were 

requested to provide their measurement results by September 15, 1995. The sample materials for 

Round Robin 7 were distributed in January 1995 with results due by late May 1995. The sample 

materials for Round Robin 8 were distributed in October 1995 with results due by December 18, 

1995. 

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

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

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

Round Robin 7: Vitamin C in Human Serum................................................................................. 3
	

Round Robin 8: Vitamin C in Human Serum................................................................................. 3
	

References ............................................................................................................................................ 4
	

Appendix A. Shipping Package Inserts for RR33........................................................................ A1
	

Appendix B. Final Report for RR33 .............................................................................................. B1 

Appendix C. “All-Lab Report” for RR33 ...................................................................................... C1
	

Appendix D. “Individualized Report” for RR33 ......................................................................... D1 

Appendix E. Shipping Package Inserts for RR34 ......................................................................... E1 

Appendix F. Final Report for RR34............................................................................................... F1 

Appendix G. “All-Lab Report” for RR34...................................................................................... G1 

Appendix H. “Individualized Report” for RR34 .......................................................................... H1 

Appendix I. Shipping Package Inserts for RR35 ........................................................................... I1
	

Appendix J. Final Report for RR35 ................................................................................................ J1
	

Appendix K. “All-Lab Report” for RR35..................................................................................... K1 

Appendix L. “Individualized Report” for RR35........................................................................... L1
	

Appendix M. Shipping Package Inserts for RR07 ....................................................................... M1 

Appendix N. Final Report for RR06 and RR07 ........................................................................... N1 

Appendix O. “All Lab Report” for RR07 ..................................................................................... O1 

Appendix P. Shipping Package Inserts for RR08 ......................................................................... P1 

Appendix Q. “All Lab Report” for RR08 ..................................................................................... Q1 

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 XXXIII: Fat-Soluble Vitamins and Carotenoids in Human Serum 

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

XXXIII comparability study (hereafter referred to as RR33) 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 1995. 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 RR33 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 and a number of 

consensus statistics for analytes reported by more than one participant. 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 XXXIV: Fat-Soluble Vitamins and Carotenoids in Human Serum 

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

XXXIV comparability study (hereafter referred to as RR34) 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 1995. 

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 RR34 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 and a number of 

consensus statistics for analytes reported by more than one participant. 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 XXXV: Fat-Soluble Vitamins and Carotenoids in Human Serum 

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

XXXV comparability study (hereafter referred to as RR35) 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 1995. 

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. 

The final report delivered to every participant in RR35 has three sections: 

2 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

•	 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 and a number of 

consensus statistics for analytes reported by more than one participant. 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 7: Vitamin C in Human Serum 

Participants in the MMQAP Vitamin C in Human Serum Round Robin 7 comparability study 

(hereafter referred to as RR07) received four frozen serum test samples and a frozen serum control 

material for analysis. These materials were shipped on dry ice to participants in January 1995. The 

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

The test and control 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. 

The final report delivered to all participants in RR06 and RR07 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 RR07, 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 RR07. 

Round Robin 8: Vitamin C in Human Serum 

Participants in the MMQAP Vitamin C in Human Serum Round Robin 8 comparability study 

(hereafter referred to as RR08) received four frozen serum test samples and a frozen serum control 

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

1995. The communication materials included in the sample shipment are provided in Appendix P. 

The test and control 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. 

3 
 

 

 

 

 

 

As described in NISTIR 7880-28, the data and results for RR08 were reported November 1996 in 

combination with the data and results for RR09. 

While not distributed to the participants in RR08, Appendix Q 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 RR08. 

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 1995;69(7):1406-1413. 

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

Stability, Intralaboratory Repeatability, and Interlaboratory Reproducibility. Clin Chem 

1995;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 RR33 

The following two items were included in each package shipped to RR33 participants: 

• Cover letter 

• Datasheet 

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

samples themselves. 

A1 
January 17, 1995 

Dear Colleague: 

NI.Sr UNITED STATES DEPARTMENT DF COMMERCE 

National Institute of Standards and Technology 

Gaithersburg, Maryland 20899-0001 

The 1995 Micronutrients Measurement Quality Assurance Program will include three studies 

of fat-soluble vitamins and carotenoids in serum. The core analytes in the program will be: 

retinol, retinyl palmitate, a.-tocopherol, y-tocopherol, and total P-carotene. We will continue 

to encourage you to provide results for other fat-soluble ~alytes and· carotenoids that you 

routinely analyze. · 

Enclosed is the set of samples for the first 1995 Round Robin exercise (Round Robin 

XXXIII). You will find duplicate vials of three lyophilized serum samples and a single vial 

of one sample 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 on the form by using NQ (Not 

Quantified). Results are due to NIST by March 20, 1995. Results received after April 12 

will not be included in the summary report for this round robin study nor in the permanent 

database. Written feedback concerning the study will be mailed to you by April 24. 

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

recommend that dissolution be facilitated with 3 to 5 minutes agitation in an ultrasonic bath 

or at least 30 minutes 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 sinc·e the final volume .-Of the recons:tituted sample 

is greater than 1.0 mL. For consistency, we request that laboratories u~e the following 

absorptivities (E 1 % cm) in ethanol: retinol, 1850 at 325 nm; retinyl palmitate, 97 .5 at 325 

nm; a.-tocopherol, 75.8 at 292 nm; y-tocopherol, 91.4 at 298 nm; a-carotene, 2800 at 444 nm; 

P-carotene, 2560 at 450 nm; lycopene, 3450 at 472 nm. 

Please mail or FAX your results for Round Robin XXXIII to the address below or e-mail 

your results to DLDuewer@enh.nist.gov. A receipt of results will be mailed to you shortly 

thereafter. 

Ms. Donna Sirk 

NIST 

Bldg. 222, Rm. B208 

Gaithersburg, MD 20899 

FAX: (301) 977-0685 

A2
	
If you have questions regarding this round robin exercise, please call me at (301) 975-3120 or 

mail/FAX queries to the above address. 

· ce Brown Thomas 

Research Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

Attachment 

cc: w. May 

S. Wise 

A3
	
 

 

 

 

 

 

 

NIST/NCI 

Micronutrients Measurement Quality Assurance Program 

Round Robin XXXIII Results from Laboratory #_____ 

Serum 

Analyte 203 204 205 206 Units* 

retinol 

retinyl palmitate 

a-tocopherol 

g-tocopherol 

total b-carotene 

trans-b-carotene 

cis-b-carotene 

total a-carotene 

total lycopene 

trans-lycopene 

b-cryptoxanthin 

lutein 

zeaxanthin 

lutein&zeaxanthin 

* We prefer results as microgram/milliliter. 

Comments? 

Mail: Donna Sirk, 222/B208 

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

Gaithersburg, MD 20899 March 20, 1995 Email: DLDuewer@enh.NIST.gov 

A4
	
 

 

 

 

 

Appendix B. Final Report for RR33 

The following 11 pages are the final report for RR33 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 24, 1995 

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 XXXIII (Sera 203-206). Included in 

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

for evaluating your laboratory's performance relative to the other participants'; a summary of your 

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. your 

laboratory value for these analytes. The NIST assigned values are derived from the equally 

weighted values for the combined results from the analyses performed by NIST and the laboratories 

that participated in this round robin exercise (more details are provided in the attached Appendix). 

In this round robin exercise, Serum 205 is a 1: 1 volumetric mix of Serum 203 and stripped serum; 

Serum 204 is a 1 :2 volumetric mix of Serum 203 and the stripped serum. Serum 206 was 

previously distributed in Round Robin XVID as Serum 120 and in Round Robin XXI as Serum 

147. 

The overall laboratory performance for retinol, y- and cx-tocopherol, and !)-carotene for this round 

robin exercise is good and is comparable to that of the last round robin exercise (Round Robin 

XXXII). The average estimated coefficient of variation ( eCV) is about 9% for retinol, 8% for 

cx-tocopherol, and 14% for y-tocopherol. The levels of !)-carotene in this round robin exercise 

were significantly lower (:s:;IOO ng/mL in Sera 203-205) than those in the previous exercise. The 

interlaboratory variation for total !)-carotene is about 32% for this round robin, as compared to 14% 

in Round Robin XXXII. The higher variation is due to the difficulty of making measureinents at 

levels (:s:;IOO ng/mL vs ~:300 ng/mL) which appear to be at or below the limit of quantification for 

most laboratories. Similar findings are reported for retinyl palmitate, which were also at low 

concentrations in this exercise. 

The overall interlaboratory precision for retinol and y- and cx-tocopherol measurements has 

remained at an average eCV of approximately 10% over the past three years. The eCV for 

!)-carotene has averaged around 20% during the same period provided that the levels are above the 

limit of quantification. Interlaboratory precision for 13-cryptoxanthin, total lycopene, lutein, and 

zeaxanthin is continuing to improve. o-Tocopherol was enriched at measurable levels in the 

Round Robin XXXIII samples. However, only one laboratory reported results for this analyte. 

We encourage you to report values for as many quantifiable analytes as possible. 

Data for evaluating your laboratory's performance in Round Robin XXXIII are provided in the 

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

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

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

performance, a rating of 3 (within ± 3 SD of the assigned value) is MARGINAL performance, and 

4 (> 3 SD of the assigned value) indicates POOR performance relative to the current 

state-of-the-practice for these measurements. 

NISI B2
	
As you are probably aware, Standard Reference Material (SRM) 968a (Fat-Soluble Vitamins in 

Human Serum), which we recommend that you use to validate your methods, is sold out. The 

renewal material, SRM 968b, is not yet available for purchase. If your laboratory is out of SRM 

968a, we suggest that you use for method validation control materials that are available in your 

laboratory or previously distributed (~1 year ago) round robin samples. If you do not have access 

to either of these options, please give me a call. 

If you still have some SRM 968a and have concerns regarding your performance, or are a lab whose 

performance would be rated "POOR" based on the convention stated above, we suggest that you 

analyze all three levels of the SRM. If with minor method modifications, your measured values do 

not agree with the certified values, please contact us for consultation. 

Samples for the food round robin (shipped only to those labs that requested these samples) and for 

Round Robin XXXIV were shipped during the last week of April. Results are due June 16 and 

feedback to labs is expected by July 24. We will attempt to follow this schedule as closely as 

possible. 

The methods manual, Methods for Analysis of Cancer Chemopreventive Agents in Human Serum, 

is now available and has been distributed to all QA participants. If you have not received a copy, 

please notify Ms. Donna Sirk at 301/975-3174 or FAX: 301/977-0685. If you have further 

questions or concerns, please contact me at 301/975-3120. 

· ce Brown Thomas 

Research Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

B3
	
"Lies, Damned Lies, and Statistics" 

Mark Twain 

Well, we've done it again ... the attached Round Robin XXXIII Report incorporates a 

major change in the NIST/NCI Micronutrients Measurement Quality Assurance Program 

(NNMMQAP - spreadsheets just don't do N2M2QAP). Most of the Tables look much the 

same, but we now value- and uncertainty-assign many serum analytes. We'll explain how 

this is done in the Appendix, but the bottom line is that we provide you with something 

approaching "true" concentration values - and we make more emphatic statements about 

your measurement performance. 

As before, the Report includes a fairly exhaustive analysis of your results (the 

"Individualized" report) and a complete listing of everyone's results (the "All Lab" report). 

Your "Individualized" has the following elements: 

Pa e Contents 

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

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

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

Note: this replaces the "(Provisional) Performance Summary" page! 

7 Comparison-to-Known-Relationship plots for retinol, total a-carotene, 

total and trans-p-carotene, and a- and y- tocopherol 

8 Comparison-to-Known-Relationship plots for total lycopene, 

p-cryptoxanthin, lutein, zeaxanthin, and lutein & zeaxanthin 

The Comparison-to-Known-Relationship plots on pages 7 and 8 show your individual 

results and a box-plot summary of the group's results, plotted against either historical 

results or known dilution ratios. In detail: 

Serum #206 was #120 in Round Robin XVIII and #147 in Round Robin XXI. The 

"true value" line is the average of the three Round Robin results. 

Sera #203-205 are a dilution series. Serum #205 is a 1: 1 mixture of serum #203 and a 

delipidized serum diluent. Serum #204 is a 1 :2 mixture of serum #203 and the diluent. 

The "true value" has the slope of the designed-in ratios, and is pegged at the average 

(dilution corrected) assigned value over the three sera. 

B4
	
Lies, Damn Lies, and Statistics 

The "All Lab" report has the following elements: 

Pa e Contents 

1-4 A complete listing of all results provided by every laboratory and both NIST 

analysts, plus essential summary statistics. 

5 A Legend for the above. 

6 The "Measurement Comparability Summary" 

Page2 

The "Measurement Comparability Summary" (i,p<;>pularly? known as the "Score Card") 

provides a four-level score for each laboratory for retinol, ex- and y-tocopherol, and total and 

trans-J3-carotene. The score is based upon the worst-case differences between your 

reported values and our assigned values, after scaling the values by the total measurement 

uncertainty for each serum. Details of the calculations are provided along side the scores; 

for those of you who don't want to dig through the details, note the following two points: 

1) The NIST Assigned Value (NAV) is calculated as: 

(the average of all NIST analyses)+ (the median from this Round Robin) 

2 

As the two summary values are equally weighted, our biases (who, us?) don't 

dominate the evaluation. 

2) The NIST Assigned Uncertainty (NAU) is calculated as the maximum of: 

a) 5% of NA V (this experience-based lower bound prevents too-low estimates) 

b) the combined repeatability and material heterogeneity standard deviation 

estimated from NIST replicate analysis of multiple samples 

c) the total estimated standard deviation from this Round Robin, estimated as before: 

eSD = 0.74(IQR), where IQR is the "InterQuartile Range" or central 50% span of 

all non-NIST values 

This insures that NAU is at least as large as the observed interlaboratory estimate 

used last year, and (since we give ourselves worst-case samples) that any sample 

heterogeneity is fully accounted for. 

The attached Appendix details the value and uncertainty assignments for all analytes 

determined by either of the NIST analysts. As patience and time are limited, our promised 

approach to documenting measurement consistency over time will (hopefully!) be part of 

Round Robin XXXIV' s Report. 

B5
	
Lies, Damn Lies, and Staristics 

We do wish to briefly address a data-reporting issue: how many significant digits are 

appropriate for reporting analyte values? There are tWo simple rules-of-thumb 

("R-o-T') and a slightly complex but pretty good answer. 

Page 3 

R-o-T #1: As many as fit readably in the little box on the report form. As far as the 

NNMMQAP Reports are concerned, any excess digits are just invisible. Too few digits, 

and you may introduce an unnecessary bias. Too many digits are data-entry pains, but 

they cause no harm to the analysis. This rule doesn't apply to providing results to your 

customers, though ... too many digits and people get cynical. 

R-o-T #2: Three significant figures, or four if you're compulsive. Experience suggests 

that none of the fat-soluble vitamin-related analytes can reproducibly be measured to 

better than 1-part-in-1000, so three-to-four significant figures will suffice. 

Good Answer: Depends on your measurement repeatability for the particular sample. If 

you could make the measurement many times over the course of a week, what would 

the standard deviation of the repeated measurements be? We would like to see the 

standard deviation stated so that it can read it to about 10% of its calculated value, thus 

two (one is generally too few, three is always too many) significant digits. Report the 

mean to the same number of decimal places. 

What, you don't always know what that standard deviation is? So estimate it from 

previous experience (say, 5% of the measured level?) Using 5%: "9.8765 ... " is 

"9 .88 ±0.49", "0.54321 ... " is "0.543 ±0.027", and"O.O 12345 ... " is 

"0.01234 ±0.00062". 

Two notes on the analytical results: 

We intentionally spiked S-tocopherol into sera #203 - albeit, maybe we spiked a tad 

too much ... While the resulting high levels of this analyte in sera #203-205 caused 

many of you to scratch your heads and mutter, there is no evidence that it interfered 

with the quantitative determination of any reported analyte in any laboratory. 

The carotenoid levels in serum #203 were lower than designed. We'd intended to 

challenge your carotenoid detection limits, but not with all three sera of the dilution 

series! However, the multiple challenges do provide enough information to define your 

true analytical capabilities near your detection limits: if your values for a given analyte 

in the series do not decline monotonically, your real detection limit for this analyte is 

not what you think it is. If they decline but the trend is not parallel to the expected line, 

you probably need to re-examine how you are defining baseline, peak start, and/or peak 

end for both samples and calibrants. 

Once again, your comments and suggestions are welcome. If you discover any errors in 

our recording or interpretation of your data, please let us know! 

.....,__ -, -

L~ ~~ L\--~ 

Dave Duewer 

Research Chemometrician 

DLDuewer@enh.NIST.gov, 301-975-3935 

~~~~ M~~ Kli~e Research Biologist 

B6
	
Lies, Damn Lies, and Statistics Page Al 

Appendix 

Value- and Uncertainty-Assignments for Round Robin XXXIII Sera #203-206 

Four sera were distributed in Round Robin XXXIII (RR33). Serum #203 was prepared 

from stock pools, with effective augmentation of: retinol and a-, y-, and 0-tocopherol. 

Serum 204 and 205 were prepared as 1 :2 and 1: 1 mixtures of serum 203 and delipidized 

serum. Serum 206 was from the archives, having been previously distributed as sera 120 in 

Round Robin XVIII (RR18) and 147 in Round Robin XXI (RR21). 

NIST analysts NISTl and NIST3 extracted and analyzed two aliquots of three vials of each 

of the four sera, providing duplicate results for a total of six samples of each serum. Both 

researchers provided quantitative results for: retinol; a-, y-, and 0-tocopherol; total and 

· trans-13-carotene; and total a-carotene. NIST3 also provided quantitative results for: transa-carotene; total and trans-lycopene; 13-cryptoxanthin; lutein; and zeaxanthin. Retinyl 

palmitate levels in all four sera were too low for either researcher to quantify. 

Table 1 presents the values and measurement uncertainties assigned to sera #203-206 for 

all analytes characterized by either NIST analyst. 

Calculations: The following assumptions and procedures have been used to arrive at the 

various values presented in Tablet: 

1) NIST Assi~ned Values CNAV) 

Anal tes 

trans-a-carotene 

Formula 

NAV=NIST3Av 

0-tocopherol NAV = (NISTlAv + NIST3Av) / 2 

total and trans-lycopene; 13-cryptoxanthin; NAV = (RRMED + NIST3Av) / 2 

lutein, zeaxanthin, lutein & zeaxanthin 

retinol; a- and y-tocopherol; total and 

trans-13-carotene; total a-carotene 

NAV = RRmed +(NISTl~v + NIST3Av) / 2 

where: NISTlAv =mean of 6 analyses by NISTl 

NIST3 Av = mean of 6 analyses by NIST3 

RRMED =median of all RR33 participants' data. 

2) NIST Repeatability Standard Deviation CSDrep) . 

This "within samples" or "repeatability" pooled variance is closely related to the 

· standard deviation of the paired-differences between the replicate extractions I 

measurements of the samples analyzed at NIST. It arises in within-vial differences 

associated with extraction, chromatography. peak area determination, etc. Standard 

analysis-of-variance (anova) calculations were performed as in Eqs. 19.6-4, 19.6-5, and 

19.6-6, Mathematical Handbook for Scientists and Engineers, G. and T. Korn (1968). 

Any proportional systematic bias between results for the two NIST analysts was 

removed prior to anova analysis. 

B7
	
Lies, Damn Lies, and Statistics Page A2 

3) NIST Heterogeneity Standard Deviation CSDhet) 

This "between samples" or "heterogeneity" pooled variance is closely related to the 

standard deviation of the mean values of the unique vials analyzed at NIST. It arises in 

vial-to-vial differences associated with preparing and reconstituting the serum samples. 

Standard anova calculations were performed as in Eqs. 19.6-4, 19.6-5, and 19.6-6, 

Mathematical Handbook for Scientists and Engineers, G. and T. Korn (1968). Any 

proportional systematic bias between results for the two NIST analysts was removed 

prior to anova analysis. 

4) NIST Material Standard Deviation CSDmat) 

This is the combination of SDrep and SDhet as an estimate of the total variation 

observed in the NIST analyses: 

SDmat = -..J SDrep2 + SDhet2 

This value is reported explicitly only for S-tocopherol and trans-a-carotene, as these 

analytes were not well characterized by RR33 participants. This value can, however, be 

directly calculated for all analytes from the provided information. 

5) Interlaboratoty Bias Standard Deviation CSDlab) 

This estimates the residual variance from (non-NIST) laboratory-to-laboratory biases 

after correction for SDmat, assuming that the population of these systematic biases can 

be approximated as a normal distribution centered at the NIST assigned value. 

The observed interlaboratory standard deviation for the results of RR33 is estimated by 

eSD = 0.7421(InterQuartile Range), as previously described ("Lies, Damn Lies, and 

Statistics" report for RR31). This estimate assumes a) that at least 50% of the 

laboratories that report values for a given analyte are "performing" (they basically 

know what they're doing), and b) that "non-performing" labs are about equally likely to 

report low values as high values. 

The variance among single-sample results reported by different laboratories is a 

composite of at least three variation sources: the repeatability of any given method, the 

heterogeneity among supplied samples, and systematic biases among analysts and/or 

methods & materials. As we have NIST-based estimates for the first two sources 

(SDrep and SDhet), we can model laboratory differences as the residual of the observed 

interlaboratory variance (eSD) after subtraction of the measurement and heterogeneity 

components: 

SDlab = "1MAX[0, eSD2 - SDrep2 - SDhet2] = "1MAX[0, eSD2 - SDmat2] 

The ''MAX" function is required if the observed eSD is smaller than the calculated 

SDmat. 

6) NIST Assigned Uncertainty CNAUl 

Using the same assumptions as described above for SDlab, the "total" expected 

interlaboratory variance can be described as: 

NAU= ..Jsorep2 + SDhet2+ SDlab2 = MAX[eSD, SDmat] 

Note that this is constrained to be at least as large as the total observed interlaboratory 

variance, eSD. On the basis of our experience with these analytes in human serum, we 

also force NAU to be at least 5% of NA V. 

B8
	
Lies, Damn Lies, and Statistics Page A3 

7) 95% Material 

This is the 95% confidence range on the "true" analyte concentration: 

NAV±2SDmat 

The value "nq" (for "not quantitated") is used for the lower 95% bound when 2 SDmat 

is greater than or equal to NAV. 

8) 95% Laboratoiy 

This is the 95% confidence range on the RR33 reports of analyte concentration: 

NAU±2NAU 

The value "nq" (for "not quantitated") is used for the lower 95% bound when 2 NAU is 

greater than or equal to NAV. 

B9
	
Table 1 

Value- and Uncertainty Assignments for Round Robin XXXIII 

Sera 

Retinol 203 204 205 206 

NAV 1.26 0.43 0.65 0.26 

SDrep 0.05 0.01 0.02 0.01 

SDhet 0.05 0.02 0.03 0.02 

SD lab 0.09 0.05 0.03 0.02 

NAU 0.12 (9%) 0.06 (12%) 0.05 (8%) 0.03 (10%) 

95% Material 1.11 - 1.41 0.38-0.48 0.56-0.73 0.22-0.30 

95% Laboratory 1.03-1.50 0.33-0.54 0.54-0.75 0.21-0.32 

a-Tocopherol 

NAV 16.5 5.2 8.2 4.7 

SDrep 0.3 0.1 0.2 0.1 

SD bet 1.2 0.7 0.9 0.3 

SD lab 0.9 0.0 0.0 0.3 

NAU 1.6 (9%) 0.8 (14%) 0.9 (11%) 0.5 (9%) 

95% Material 14.0-18.9 3.7-6.7 6.4-10.0 4.1-5.4 

95% Laboratory 13.4-19.5 3.7-6.7 6.4-10.0 3.9-5.6 

g-Tocopherol 

NAV 1.18 0.43 0.65 2.26 

SDrep 0.03 0.02 0.04 0.03 

SDhet 0.12 0.04 0.09 0.11 

SD lab 0.08 0.07 0.03 0.26 

NAU 0.15 (13%) 0.09 (19%) 0.11 (16%) 0.29 (13%) 

95% Material 0.92-1.44 0.34-0.53 0.45 - 0.85 2.02-2.50 

95% Laboratory 0.88-1.48 0.26-0.61 0.44-0.86 1.69-2.83 

Total b-Carotene 

NAV 0.052 0.020 0.031 0.402 

SDrep 0.004 0.003 0.002 0.007 

SDhet 0.010 0.007 0.012 0.040 

SD lab 0.014 0.010 0.000 0.032 

NAU 0.018 (34%) 0.013 (63%) 0.013 (41%) 0.052 (13%) 

95% Material 0.030 - 0.074 0.004 - 0.035 0.005 - 0.056 0.320 - 0.483 

95% Laboratory 0.016 - 0.088 nq-0.045 0.005 - 0.056 0.298 - 0.505 

trans-b-Carotene 

NAV 0.052 0.018 0.030 0.369 

SDrep 0.003 0.003 0.002 0.013 

SDhet 0.011 0.004 0.011 0.035 

SD lab 0.000 0.008 0.000 0.000 

NAU 0.012 (22%) 0.010 (52%) 0.012 (38%) 0.038 (10%) 

95% Material 0.028 - 0.076 0.007 - 0.028 0.006 - 0.053 0.294 - 0.444 

95% Laboratory 0.028 - 0.076 nq-0.037 0.006 - 0.053 0.294 - 0.444 

Lies, Damn Lies, and Statistics: Appendix Page A4 B10
	
Table 1 

Value- and Uncertainty Assignments for Round Robin :xxxm 

Sera 

Total a-Carotene 203 204 205 206 

NAV 0.026 0.010 0.017 0.023 

SDrep 0.002 0.001 0.003 0.003 

SDhet 0.007 0.001 0.004 0.006 

SD lab 0.000 0.005 0.009 0.000 

NAU 0.008 (29%) 0.006 (49%) 0.011 (65%) 0.007 (28%) 

95% Material 0.011-0.042 0.006-0.015 0.006 - 0.027 0.010 - 0.037 

95% Laboratory 0.011 - 0.042 0.000 - 0.021 nq-0.038 0.010 - 0.037 

Total Lycopene 

NAV 0.194 0.047 0.096 0.271 

SDrep 0.008 0.008 0.010 0.011 

SDhet 0.044 0.025 0.038 0.051 

SD lab 0.035 0.000 0.000 0.052 

NAU 0.057 (29%) 0.027 (56%) 0.040 (41 %) 0.075 (27%) 

95% Material 0.105 - 0.283 nq-0.101 0.016-0.175 0.166 - 0.377 

95% Laboratory 0.081 - 0.307 nq-0.101 0.016-0.175 0.123 - 0.420 

trans-Lycopene 

NAV 0.113 0.027 0.053 0.149 

SDrep 0.006 0.002 0.000 0.002 

SD bet 0.025 0.008 0.021 0.018 

SD lab 0.039 0.000 0.000 0.022 

NAU 0.047 (41%) 0.009 (30%) 0.021 (39%) 0.029 (19%) 

95% Material 0.062 - 0.165 0.010 - 0.044 0.011 - 0.096 0.112-0.187 

95% Laboratory 0.019 - 0.208 0.010- 0.044 0.011 - 0.096 0.092 - 0.207 

b-Cryptoxanthin 

NAV 0.052 0.017 0.027 0.040 

SDrep 0.002 0.001 0.001 0.001 

SDhet 0.008 0.004 0.008 0.005 

SD lab 0.010 0.004 0.005 0.013 

NAU 0.013 (25%) 0.006 (36%) 0.010 (36%) 0.014 (35%) 

95% Material 0.035 - 0.069 0.007 - 0.026 0.011 - 0.044 0.030 - 0.050 

95% Laboratory 0.026 - 0.078 0.004 - 0.029 0.007 - 0.047 0.012 - 0.068 

Lute in 

NAV 0.078 0.026 0.042 0.051 

SDrep 0.001 0.001 0.002 0.002 

SD bet 0.003 0.001 0.001 0.004 

SD lab 0.009 0.004 0.005 0.006 

NAU 0.010 (13%) 0.005 (16%) 0.006 (13%) 0.008 (15%) 

95% Material 0.071 - 0.084 0.022 - 0.030 0.036 - 0.047 0.041 - 0.060 

95% Laboratory 0.058 - 0.097 0.018 - 0.035 0.031 - 0.053 0.035 - 0.066 

Lies, Damn Lies, and Statistics: Appendix Page A5 

B11
	
Table 1 

Value- and Uncertainty Assignments for Round Robin XXXIII 

Sera 

Zeaxanthin 203 204 205 206 

NAV 0.039 0.013 0.022 0.015 

SDrep 0.001 0.001 0.002 0.002 

SDhet 0.002 0.002 0.003 0.003 

SD lab 0.007 0.006 0.002 0.004 

NAU 0.007 (18%) 0.007 (48%) 0.004 (17%) 0.006 (38%) 

95% Material 0.034 - 0.043 0.009 - 0.017 0.016 - 0.028 0.006 - 0.023 

95% Laboratory 0.025 - 0.053 0.000 - 0.026 0.014- 0.030 0.003 - 0.027 

1tein&Zeaxanthin 

NAV 0.120 0.040 0.063 0.065 

SDrep 0.002 0.001 0.004 0.004 

SDhet 0.001 0.004 0.004 0.009 

SD lab 0.011 0.009 0.007 0.009 

NAU 0.012 (9%) 0.010 (24%) 0.010 (14%) 0.014 (21%) 

95% Material 0.115-0.125 0.032 - 0.047 0.052 - 0.074 0.044 - 0.086 

i95% Laboratory 0.097-0.143 0.020 - 0.059 0.044 - 0.082 0.038 - 0.093 

d-Tocopherol 

NAV 3.25 1.08 1.66 0.18 

SDrep 0.04 0.06 0.03 0.03 

SDhet 0.03 0.02 0.09 0.04 

NAU= SDrnat 0.06 (2%) 0.07 (6%) 0.10 (6%) 0.05 (28%) 

95% Material 3.13-3.36 0.94-1.22 1.46-1.85 0.07-0.28 

trans-a-Carotene 

NAV 0.022 0.007 0.012 0.014 

SDrep 0.003 0.002 0.004 0.001 

SDhet 0.008 0.001 0.005 0.004 

NAU = SDrnat 0.009 (37%) 0.003 (35%) 0.007 (53%) 0.004 (27%) 

95% Material 0.006 - 0.039 0.002 - 0.012 nq - 0.024 0.006 - 0.022 

Lies, Damn Lies, and Statistics: Appendix Page A6 

B12
	
 

 

 

 

 

 

Appendix C. “All-Lab Report” for RR33 

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 XXXIII Laboratory Results 

Values in μg/mL 

Retinol Retinyl Palmitate α-Tocopherol γ-Tocopherol 

Lab 203 204 205 206

FSV-BA 

FSV-BD 

FSV-BE 

FSV-BG 

FSV-BH 

FSV-BI 

FSV-BJ 

FSV-BK 

FSV-BM 

FSV-BN 

FSV-BO 

FSV-BP 

FSV-BQ 

FSV-BR 

FSV-BS 

FSV-BT 

FSV-BU 

FSV-BV 

FSV-BX 

FSV-BY 

FSV-CA 

FSV-CB 

FSV-CD 

FSV-CH 

FSV-CJ 

FSV-CK 

FSV-CL 

FSV-CM 

FSV-CN 

FSV-CP 

FSV-CR 

FSV-CT 

FSV-CU 

FSV-CV 

FSV-CX 

FSV-CY 

FSV-DA 

FSV-DB 

FSV-DJ 

FSV-DK 

FSV-DL 

FSV-DM 

FSV-DP 

FSV-DX 

FSV-EC 

FSV-EH 

FSV-EJ 

FSV-EK 

FSV-EL 

FSV-FD 

FSV-FP 

1.23 0.414 0.632 0.267 

1.31 0.426 0.636 0.270 

1.29 0.512 0.632 0.275 

1.20 0.400 0.590 0.250 

1.19 0.415 0.617 0.261 

1.05 0.352 0.492 0.186 

1.27 0.418 0.610 0.269 

1.34 0.423 0.636 0.263 

1.25 0.425 0.645 0.266 

1.34 0.455 0.654 0.329 

1.18 0.352 0.550 0.227 

1.35 0.478 0.716 0.308 

1.29 0.450 0.650 0.270 

1.29 0.445 0.674 0.283 

1.19 0.725 0.653 0.271 

1.36 0.434 0.652 0.286 

1.25 0.405 0.706 0.228 

1.36 0.456 0.654 0.283 

1.20 0.404 0.623 0.269 

1.20 0.380 0.620 0.260 

1.57 0.518 0.770 0.327 

1.37 0.461 0.684 0.259 

1.33 0.428 0.608 0.249 

1.40 0.435 0.611 0.254 

1.15 0.353 0.586 0.244 

1.14 0.431 0.586 0.310 

1.19 0.388 0.613 0.276 

0.99 0.321 0.519 0.209 

1.48 0.480 0.730 0.300 

1.28 0.426 0.642 0.246 

1.18 0.416 0.611 0.259 

1.24 0.443 0.661 0.263 

1.22 0.470 0.660 0.270 

1.27 0.375 0.649 0.270 

1.21 0.470 0.680 0.280 

1.29 0.511 0.667 0.648 

1.24 0.440 0.730 0.290 

1.17 0.300 0.440 0.196 

1.29 0.318 0.695 0.299 

1.13 0.367 0.493 0.248 

1.19 0.404 0.586 0.242 

1.03 0.398 0.563 0.258 

1.32 0.491 0.701 0.299 

1.44 0.558 0.756 0.303 

1.31 0.553 0.718 0.253 

1.50 0.653 0.909 0.454 

1.32 0.410 0.640 0.290 

1.71 0.507 0.713 0.291 

0.81 0.446 0.829 0.272 

203 204 205 206 

0.129 0.073 0.118 0.059 

0.066 0.045 0.080 nq 

nq nq nq nq 

0.114 0.042 0.123 nd 

0.131 0.086 0.117 nq 

0.068 0.072 0.066 

0.084 0.079 0.091 nd 

nq nq nq nq 

0.172 0.049 0.085 nd 

nq 0.027 0.022 0.035 

0.137 0.018 0.028 0.080 

0.170 0.040 0.030 0.030 

nd nd nd nd 

203 204 205 206 

16.2 5.37 8.16 4.76 

16.0 5.43 8.27 4.84 

17.6 6.36 8.56 5.03 

16.7 5.48 8.25 4.74 

18.1 6.22 9.18 5.28 

18.3 6.02 9.25 4.88 

17.5 6.98 9.70 5.16 

16.7 5.47 8.04 4.31 

18.2 5.80 8.80 5.30 

18.0 5.16 8.95 4.57 

17.7 5.87 8.00 4.92 

19.4 7.14 10.67 6.08 

18.1 4.10 9.30 5.40 

15.5 5.35 8.02 4.43 

16.1 4.73 8.05 4.15 

17.5 6.07 10.14 5.25 

17.3 5.55 8.47 4.91 

16.8 4.83 8.38 4.84 

17.1 5.74 8.75 4.64 

20.0 7.28 10.19 6.38 

21.7 7.02 10.35 5.58 

19.4 5.90 8.54 4.81 

16.8 5.76 7.80 5.66 

14.7 5.25 7.79 4.60 

15.3 6.27 8.36 5.89 

17.1 5.60 8.90 5.10 

17.4 5.48 9.50 4.78 

11.7 3.81 5.98 3.28 

16.8 5.90 8.80 5.10 

17.0 5.69 8.32 5.32 

15.5 4.87 7.51 4.72 

17.2 5.32 8.80 4.75 

15.5 5.96 8.49 4.81 

22.1 5.30 8.84 4.82 

16.6 5.71 8.87 4.75 

15.6 5.59 8.42 4.99 

17.0 6.60 8.80 5.20 

18.3 6.72 9.20 5.30 

17.1 5.10 8.66 5.16 

18.7 5.56 8.30 5.20 

15.2 5.17 8.10 4.60 

13.5 5.04 7.20 4.12 

19.6 6.63 10.02 5.49 

18.8 5.80 9.18 5.17 

19.0 5.34 9.14 4.40 

16.4 5.95 9.22 4.49 

17.3 6.77 8.61 5.26 

203 204 205 206 

1.26 0.54 0.73 2.23 

1.22 0.49 0.63 2.48 

1.04 0.37 0.55 1.95 

1.34 0.52 0.69 2.47 

1.45 0.62 0.80 2.61 

0.96 0.18 0.52 2.13 

1.17 0.45 0.59 2.06 

1.09 0.32 0.50 2.06 

1.31 0.50 0.77 2.53 

1.21 0.48 0.62 2.27 

1.54 0.45 0.74 2.30 

1.07 0.37 0.54 2.03 

1.23 0.41 0.55 2.29 

1.11 0.48 0.66 2.49 

1.09 0.22 0.43 2.02 

1.19 0.26 1.26 

1.05 0.62 0.57 2.83 

1.13 0.39 0.61 2.39 

1.23 0.45 0.67 2.22 

1.52 0.45 0.66 2.45 

1.45 0.65 0.93 2.68 

1.33 0.46 0.67 2.33 

n 49 49 49 49 9 9 10 5 47 47 47 47 22 21 22 22 

Min 0.81 0.300 0.440 0.186 0.066 0.018 0.022 0.030 11.7 3.81 5.98 3.28 0.96 0.18 0.26 1.26 

Median 1.27 0.428 0.645 0.270 0.129 0.045 0.083 0.059 17.1 5.69 8.66 4.91 1.22 0.45 0.63 2.30 

Max 1.71 0.725 0.909 0.648 0.172 0.086 0.123 0.080 22.1 7.28 10.67 6.38 1.54 0.65 0.93 2.83 

eSD 0.11 0.044 0.052 0.025 0.061 0.027 0.052 0.031 1.5 0.55 0.74 0.43 0.17 0.09 0.11 0.28 

eCV 8 10 8 9 47 59 63 53 9 10 9 9 14 20 18 12 

1.22 0.415 0.611 0.254 nq nq nq nq 16.4 4.94 8.08 4.77 1.08 0.42 0.70 2.21 

1.29 0.460 0.688 0.265 nq nd nd nd 15.2 4.63 7.62 4.50 1.23 0.40 0.63 2.25 

1.26 0.433 0.647 0.265 16.5 5.24 8.26 4.77 1.19 0.43 0.65 2.26 

0.12 0.049 0.059 0.029 1.6 0.87 0.92 0.51 0.17 0.11 0.11 0.30 

NISTa
	

NISTb
	

NAV
	

NAU
	

C2
	

All Lab Report Page 1 / 6 
 

 

Round Robin XXXIII Laboratory Results 

Values in μg/mL 

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

Lab 203 204 205 206 

FSV-BA 

FSV-BD 

FSV-BE 

FSV-BG 

FSV-BH 

FSV-BI 

FSV-BJ 

FSV-BK 

FSV-BM 

FSV-BN 

FSV-BO 

FSV-BP 

FSV-BQ 

FSV-BR 

FSV-BS 

FSV-BT 

FSV-BU 

FSV-BV 

FSV-BX 

FSV-BY 

FSV-CA 

FSV-CB 

FSV-CD 

FSV-CH 

FSV-CJ 

FSV-CK 

FSV-CL 

FSV-CM 

FSV-CN 

FSV-CP 

FSV-CR 

FSV-CT 

FSV-CU 

FSV-CV 

FSV-CX 

FSV-CY 

FSV-DA 2.70 0.910 1.400 0.130 

FSV-DB 

FSV-DJ
	

FSV-DK
	

FSV-DL
	

FSV-DM
	

FSV-DP
	

FSV-DX
	

FSV-EC
	

FSV-EH
	

FSV-EJ
	

FSV-EK
	

FSV-EL
	

FSV-FD
	

FSV-FP
	

203 204 205 206 

0.067 0.019 0.035 0.425 

0.040 0.013 0.027 0.383 

0.055 0.024 0.030 0.398 

0.060 0.021 0.033 0.405 

0.062 0.022 0.033 0.408 

0.075 0.031 0.037 0.432 

0.095 0.043 0.042 0.455 

0.050 0.017 0.026 0.352 

0.044 0.025 0.037 0.325 

0.140 0.070 0.070 0.450 

0.068 0.027 0.037 0.420 

0.059 0.019 0.031 0.362 

0.069 0.099 0.037 0.400 

>0.044 >0.018 >0.031 >0.377 

0.037 0.018 0.029 0.358 

0.058 nd 0.028 0.411 

0.040 0.010 0.018 

0.045 0.016 0.027 0.336 

0.055 0.016 0.024 0.345 

0.049 0.022 0.031 0.427 

0.069 0.035 0.042 0.360 

>0.030 nd nd >0.321 

0.043 0.013 0.019 0.268 

0.063 0.019 0.027 0.341 

0.110 0.037 0.048 0.497 

0.066 0.010 0.020 0.380 

0.050 0.020 0.030 0.410 

0.042 0.117 0.138 0.339 

0.068 0.032 0.038 0.441 

0.021 nq nq 0.426 

0.061 0.013 0.030 0.412 

0.042 0.009 0.024 0.314 

>0.046 >0.008 >0.025 >0.309 

0.045 0.022 0.033 0.413 

0.056 0.025 0.031 0.403 

0.162 0.121 0.126 3.016 

nd 0.120 0.398 

0.047 0.018 0.029 0.440 

0.042 0.031 0.057 0.415 

203 204 205 206 

0.061 0.019 0.035 0.392 

0.060 0.021 0.033 0.379 

0.077 0.026 0.042 0.410 

0.056 0.018 0.029 0.338 

nq 0.083 nq 0.384 

0.044 0.018 0.031 0.377 

0.030 nd nd 0.321 

0.098 0.037 0.038 0.394 

0.064 0.030 0.034 0.396 

0.055 0.011 0.026 0.390 

0.046 0.008 0.025 0.309 

0.056 0.025 0.031 0.366 

203 204 205 206 

0.006 nd nd 0.033 

nq nq nq 0.026 

0.037 0.017 0.020 0.081 

0.003 0.001 0.001 0.025 

nq 0.018 nq 0.016 

0.012 0.000 0.010 0.103 

0.004 0.002 0.004 0.045 

0.006 0.002 0.004 0.022 

nq nq nq 0.014 

nd nd nd nd 

n 

Min 

Median 

Max 

eSD 

eCV 

NISTa 

NISTb 

NAV 

NAU 

1 

3.24 

3.26 

1 

1.07 

1.09 

1 

1.63 

1.69 

1 

0.18 

0.17 

35 

0.021 

0.056 

0.162 

0.017 

31 

0.047 

0.044 

0.051 

0.018 

33 

0.009 

0.022 

0.121 

0.009 

40 

0.023 

0.012 

0.020 

0.011 

35 

0.018 

0.031 

0.138 

0.009 

29 

0.038 

0.018 

0.030 

0.016 

35 

0.268 

0.405 

3.016 

0.040 

10 

0.450 

0.351 

0.403 

0.076 

11 11 10 12 

0.030 0.008 0.025 0.309 

0.056 0.021 0.032 0.382 

0.098 0.083 0.042 0.410 

0.012 0.007 0.004 0.020 

21 35 14 5 

0.043 0.017 0.035 0.384 

0.044 0.012 0.018 0.313 

0.050 0.018 0.029 0.365 

0.013 0.009 0.014 0.063 

6 

0.003 

0.006 

0.037 

0.004 

59 

0.004 

0.000 

0.004 

0.005 

6 

0.000 

0.002 

0.018 

0.002 

100 

0.006 

0.000 

0.002 

0.009 

5 

0.001 

0.004 

0.020 

0.004 

96 

0.004 

0.000 

0.003 

0.005 

9 

0.014 

0.026 

0.103 

0.015 

59 

0.066 

0.039 

0.039 

0.029 

C3 

All Lab Report Page 2 / 6 
 

 

Lab 

FSV-BA 

FSV-BD 

FSV-BE 

FSV-BG 

FSV-BH 

FSV-BI 

FSV-BJ 

FSV-BK 

FSV-BM 

FSV-BN 

FSV-BO 

FSV-BP 

FSV-BQ 

FSV-BR 

FSV-BS 

FSV-BT 

FSV-BU 

FSV-BV 

FSV-BX 

FSV-BY 

FSV-CA 

FSV-CB 

FSV-CD 

FSV-CH 

FSV-CJ 

FSV-CK 

FSV-CL 

FSV-CM 

FSV-CN 

FSV-CP 

FSV-CR 

FSV-CT 

FSV-CU 

FSV-CV 

FSV-CX 

FSV-CY 

FSV-DA 

FSV-DB 

FSV-DJ 

FSV-DK 

FSV-DL 

FSV-DM 

FSV-DP 

FSV-DX 

FSV-EC 

FSV-EH 

FSV-EJ 

FSV-EK 

FSV-EL 

FSV-FD 

FSV-FP 

n 

Min 

Median 

Max 

eSD 

eCV 

NISTa 

NISTb 

Round Robin XXXIII Laboratory Results 

Values in μg/mL 

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

203 204 205 206 

0.031 0.010 0.014 0.023 

0.028 0.013 0.014 0.023 

203 204 205 206 203 204 205 206 203 204 205 206 

0.234 0.082 0.106 0.326 

0.114 0.042 0.057 0.159 0.071 0.033 0.040 0.050 

0.029 0.010 0.015 0.020 0.203 0.064 0.102 0.293 0.083 0.027 0.041 0.052 

0.028 0.009 0.018 0.019 

0.052 0.025 0.033 0.034 

0.144 0.037 0.074 0.190 

0.132 0.038 0.065 0.184 

0.077 0.026 0.040 0.045 

0.046 0.017 0.029 0.024 0.262 0.062 0.151 0.415 0.232 0.030 0.103 0.227 0.050 0.023 0.046 0.055 

0.026 0.009 0.013 0.015 0.197 0.060 0.088 0.279 0.059 0.021 0.030 0.036 

0.024 0.011 0.017 0.020 0.086 0.038 0.063 0.150 0.051 0.022 0.031 0.035 

0.024 0.012 0.017 0.016 0.120 0.040 0.010 0.140 0.042 0.020 0.051 0.074 

0.030 0.014 0.019 0.021 0.167 0.051 0.094 0.232 0.135 0.044 0.077 0.187 0.069 0.027 0.034 0.040 

0.025 0.016 0.016 0.016 0.219 0.055 0.092 0.263 nq nq nq nq 0.055 0.012 0.029 0.038 

0.036 0.014 0.024 0.028 0.314 0.102 0.184 0.450 0.038 0.016 0.025 0.029 

0.082 0.019 0.031 0.033 0.172 0.052 0.079 0.207 0.110 0.043 0.059 0.058 

0.024 nd 0.013 0.018 0.139 0.043 0.071 0.310 0.060 0.018 0.031 0.043 

0.019 0.005 0.008 0.095 0.013 0.033 0.041 0.013 0.021 

0.020 0.008 0.012 0.014 

0.028 0.010 0.012 0.013 

0.161 0.053 0.078 0.223 

0.199 0.037 0.076 0.234 

0.043 0.015 0.020 0.025 

0.030 0.014 0.018 0.017 0.209 0.032 0.105 0.304 0.064 0.016 0.033 0.045 

0.033 0.012 0.019 0.026 0.225 0.063 0.106 0.368 0.067 0.022 0.032 0.067 

0.047 0.033 0.036 0.038 

nd nd nd nd 

0.330 0.178 0.209 0.392 

0.205 nd nd 0.182 

0.119 0.069 0.082 0.088 

0.022 0.009 0.014 0.015 0.172 0.052 0.077 0.214 0.063 0.022 0.034 0.036 

0.215 0.046 0.095 0.271 

0.030 0.010 0.020 0.020 0.230 0.070 0.120 0.350 0.060 0.020 0.030 0.040 

0.027 0.013 0.018 0.024 0.168 0.042 0.070 0.255 0.088 0.023 0.040 0.139 0.039 0.014 0.022 0.032 

0.032 0.007 0.015 0.021 

0.014 0.003 0.009 0.013 

0.208 0.040 0.090 0.304 

0.151 0.043 0.075 0.246 

0.104 0.027 0.046 0.062 

0.020 0.012 0.012 0.015 

0.105 0.054 0.064 0.091 

0.020 0.015 0.028 0.014 

0.191 0.063 0.100 0.267 

0.262 0.163 0.175 0.394 

0.504 

0.093 0.061 0.087 0.193 

0.102 0.037 0.055 0.145 0.054 0.015 0.023 0.033 

28 27 28 27 29 28 28 29 5 5 5 5 22 22 22 21 

0.014 0.003 0.008 0.013 0.086 0.013 0.010 0.140 0.088 0.023 0.040 0.139 0.038 0.012 0.020 0.025 

0.028 0.012 0.017 0.020 0.197 0.052 0.089 0.267 0.114 0.037 0.057 0.159 0.060 0.021 0.033 0.043 

0.105 0.054 0.064 0.091 0.330 0.178 0.209 0.504 0.232 0.044 0.103 0.227 0.119 0.069 0.082 0.088 

0.006 0.004 0.005 0.006		 0.050 0.017 0.023 0.087 0.031 0.010 0.025 0.030 0.016 0.008 0.011 0.013 

21 37 31 30 25 32 26 33 27 27 44 19 26 38 34 31 

NAV 

NAU 

C4 

0.025 0.010 0.019 0.030 

0.022 0.007 0.012 0.022 0.192 0.043 0.104 0.272 0.084 0.020 0.037 0.121 0.041 0.011 0.021 0.032 

0.026 0.010 0.016 0.023 0.194 0.048 0.096 0.269 0.099 0.028 0.047 0.140 0.050 0.016 0.027 0.038 

0.009 0.005 0.006 0.009 0.052 0.021 0.031 0.083 0.039 0.017 0.023 0.051 0.021 0.011 0.013 0.016 

All Lab Report		 Page 3 / 6 
 

 

Round Robin XXXIII Laboratory Results 

Values in μg/mL 

Lutein Zeaxanthin Lutein&Zeaxanthin 

Lab 203 204 205 206 203 204 205 206 203 204 205 206 

FSV-BA 0.148 0.074 0.092 0.088 

FSV-BD 

FSV-BE 

FSV-BG 

FSV-BH 0.079 0.031 0.042 0.052 0.038 nq 0.028 0.011 0.117 0.031 0.070 0.063 

FSV-BI 0.078 0.027 0.038 0.045 0.042 0.012 0.020 0.015 0.122 0.039 0.056 0.057 

FSV-BJ 

FSV-BK 

FSV-BM 

FSV-BN 0.054 0.014 0.022 0.038 0.036 0.007 0.016 0.008 0.090 0.021 0.038 0.046 

FSV-BO 0.090 0.032 0.047 0.056 

FSV-BP 

FSV-BQ 

FSV-BR 

FSV-BS 

FSV-BT 0.089 0.056 0.050 0.054 0.023 0.019 0.020 0.010 0.113 0.075 0.070 0.064 

FSV-BU nq nq nq nq nq nq nq nq 0.126 0.032 0.055 0.064 

FSV-BV 0.096 0.035 0.061 0.061 

FSV-BX 0.084 0.033 0.044 0.045 0.032 0.013 0.017 0.012 0.116 0.033 0.061 0.057 

FSV-BY 0.090 0.027 0.045 0.057 0.024 0.008 0.012 0.020 0.114 0.035 0.057 0.077 

FSV-CA 

FSV-CB 0.120 0.044 0.061 

FSV-CD 0.167 0.057 0.080 0.089 

FSV-CH 

FSV-CJ 0.148 0.049 0.064 0.073 

FSV-CK 0.133 0.042 0.066 0.081 

FSV-CL 0.129 0.047 0.064 0.088 

FSV-CM 

FSV-CN 

FSV-CP 0.113 0.047 0.068 0.060 

FSV-CR 

FSV-CT 

FSV-CU 

FSV-CV 

FSV-CX 0.120 0.040 0.060 0.070 

FSV-CY 

FSV-DA 0.069 0.026 0.038 0.053 0.033 0.019 0.022 0.023 0.102 0.045 0.060 0.076 

FSV-DB 

FSV-DJ 

FSV-DK 

FSV-DL 0.139 0.034 0.071 0.080 

FSV-DM 

FSV-DP 

FSV-DX 0.099 0.035 0.052 0.061 

FSV-EC 

FSV-EH 0.069 0.026 0.037 0.047 0.046 0.017 0.023 0.021 0.115 0.042 0.060 0.068 

FSV-EJ 

FSV-EK 0.092 

FSV-EL 

FSV-FD 

FSV-FP 

n 8 8 8 9 8 7 8 8 21 21 21 20 

Min 0.054 0.014 0.022 0.038 0.023 0.007 0.012 0.008 0.090 0.021 0.038 0.046 

Median 0.079 0.027 0.040 0.052 0.035 0.013 0.020 0.014 0.117 0.040 0.061 0.066 

Max 0.090 0.056 0.050 0.092 0.046 0.019 0.028 0.023 0.167 0.075 0.092 0.089 

eSD 0.014 0.004 0.006 0.007 0.008 0.007 0.004 0.007 0.018 0.010 0.007 0.013 

eCV 18 15 14 14 24 57 22 49 15 25 12 20 

NISTa 

NISTb 0.076 0.026 0.042 0.049 0.044 0.014 0.024 0.018 0.120 0.040 0.065 0.067 

0.077 0.026 0.041 0.051 

0.020 0.009 0.012 0.014 

0.039 0.013 0.022 0.016 

0.012 0.006 0.007 0.008 

0.119 

0.027 

0.040 

0.012 

0.063 

0.016 

0.066 

0.017 

NAV 

NAU 

C5 

All Lab Report Page 4 / 6 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Term
	

n 

Min 

Median 

Max 

eSD 

eCV 

NAV 

NAU 

nd 

nq 

>x 

italics 

Round Robin XXXIII Laboratory Results 

Analytes Reported By One Laboratory
	

Values in μg/mL
	

Analyte 

trans-α-Carotene

Code 203 204 205 206 

NISTb 0.022 0.007 0.012 0.014 

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 "Analysis of Results." 

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

Detected but not quantitatively determined 

Concentration greater than or equal to x 

Not explicitly reported but calculated by NIST from reported values 

C6
	

All Lab Report Page 5 / 6 
 

 

 

 

 

 

 

 

 

Lab 

FSV-BA 

FSV-BD 

FSV-BE 

FSV-BG 

FSV-BH 

FSV-BI 

FSV-BJ 

FSV-BK 

FSV-BM 

FSV-BN 

FSV-BO 

FSV-BP 

FSV-BQ 

FSV-BR 

FSV-BS 

FSV-BT 

FSV-BU 

FSV-BV 

FSV-BX 

FSV-BY 

FSV-CA 

FSV-CB 

FSV-CD 

FSV-CH 

FSV-CJ 

FSV-CK 

FSV-CL 

FSV-CM 

FSV-CN 

FSV-CP 

FSV-CR 

FSV-CT 

FSV-CU 

FSV-CV 

FSV-CX 

FSV-CY 

FSV-DA 

FSV-DB 

FSV-DJ
	

FSV-DK
	

FSV-DL
	

FSV-DM
	

FSV-DP
	

FSV-DX
	

FSV-EC
	

FSV-EH
	

FSV-EJ
	

FSV-EK
	

FSV-EL
	

FSV-FD
	

FSV-FP
	

NISTa 

NISTb 

n 49 47 22 36 12 

StS % Observed Expected 

1 43 40 50 58 50 68.2 % 

2 29 45 36 22 33 27.3 % 

3 16 11 14 6 8 4.3 % 

4 12 4 0 14 8 0.3 %

Round Robin XXXIII Laboratory Results
	

R aT gT bC tbC Label 

Lab

1 1 1 1 

1 1 2 1 

R 

2 2 1 aT 

1 1 gT 

1 2 bC 

3 2 tbC 

1 2 1 1 n 

1 1 1 1 1 

1 2 2 1 1 

3 1 1 1 

Comparability Summary 

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" 

2 1 1 1 Given that our knowledge of the shape, location, and width of the measurement distributions is 

2 3 4 approximate and that a limited number of labs are involved, we summarize comparability with the 

1 2 following four-level "Standard Score" (StS)... 

1 2 2 

StS 

4 1 2 1 1 

1 2 3 3 2 

2 3 3 2 3 

1 1 1 1 4 

1 1 1 1 

2 1 4 where: 

3 3 2 StV 

1 4 2 

1 2 1 1 

2 2 1 NAV 

2 2 2 

2 3 3 3 2 NAU 

1 1 

1 2 1 

3 3 1 t (1-α,n-1)

2 1 1 1 1 

1 2 1 

1 1 

1 1 4 

1 1 

2 4 

1 1 

4 1 2 

2 2 3 4 

4 2 1 1 

3 1 

3 2 1 

2 2 

2 1 2 4 4 

2 2 1 2 

3 2 1 2 2 

3 2 

4 2 

1 2 1 

4 2 2 1 1 

4 2 2 2 

1 1 1 1 1 

1 1 1 1 1 

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. 

C7 

All Lab Report Page 6 / 6 
Appendix D. Representative “Individualized Report” for RR33 

Each participant in RR33 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 
20/4195 

Individualized Round Robin XXXIII Report to: FSV-BA 

Your Data, NIST Assigned Values, and %Differences 

Serum203 Serum 204 Serum 205 Serum 206 

Analyte You NAV %L\ n I You NAV %L\ n II You NAV %L\ n II You NAV %L\ n I 

Retinol 1.23 1.26 -3 44 .41 .43 -4 44 .63 .65 -2 44 .27 .26 1 44 

Retinyl Palmitate .129 9 .073 8 .118 9 .059 4 

a-Tocopherol 16.23 16.47 -1 42 5.37 5.19 3 42 8.16 8.20 0 42 4.76 4.75 0 42 

g-Tocopherol 1.26 1.18 7 19 .54 .43 24 17 .73 .65 13 18 2.23 2.26 -1 19 

Total b-Carotene .067 .052 29 32 .019 .020 -3 31 .035 .031 14 33 .425 .402 6 32 

trans-b-Carotene .061 .052 17 8 .019 .018 8 9 .035 .030 17 8 .392 .369 6 9 

Total cis-b-Carotene .006 4 nd 3 nd 3 .033 7 

Total a-Carotene .031 .026 18 25 .010 .010 -4 24 .014 .017 -15 25 .023 .023 -1 24 

trans-Lycopene .114 .113 1 4 .042 .027 55 4 .057 .053 7 4 .159 .149 6 4 

b-Cryptoxanthin .071 .052 37 19 .033 .017 99 19 .040 .027 47 19 .050 .040 26 18 

Lutein & Zeaxanthin .148 .120 23 18 .074 .040 87 18 .092 .063 

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 

nd : Not detected 

Please check our recorded values against your records. 

46 18 .088 

Send corrections to: NNMMQAP, 222/B208, NIST, Gaithersburg, MD 20899 fax: 301-977-0685 

.065 35 17 

1/8 

D2
 
50 

> 25 

< 

...-

> 

< z 

I 

0 

d 

* 0 

0 

-

<I 

-25 -50 

20/4195 

x x 

I 

Individualized Round Robin XXXIII Report to: FSV-BA 

Retinol, in Round Robin XXIV - XXXIII 

x x 

x x x x 

x x v x x x x 

x x v I x I 

x v I I 

,,. .. 1,) I ii _ mroV I I 11 WM"""'_x ill®I ., . I mrnm= ...•.. Rl'm I I 

1111 1111 11111 11111 11111 

6 6 6 6 6 6 6 6 6 6 7 7 7 7 7 7 7 7 8 8 8 8 8 

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

Serum 

11111 1111 1111 

8 8 8 8 9 9 9 9 9 9 9 9 9 

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

I 2 2 2 2 2 2 2 

9 0 0 0 0 0 0 0 9 0 1 2 3 4 5 6 

RR33. Plge 2 / 8 

D3
 
50 

> 25 < 

,..... 

> < z 

I 

Individualized Round Robin XXXIII Report to:. FSV-BA 

Tocopherols, in Round Robin XXIV - XXXIIl 

0 I 1!1!h-.•'"'..I»' • 111/!,iillr•·w •m mJ!!ia"'.i."iiii" 

"""lliii7 us;- .iii" •w'-.• • '!'!'!. •na1ii"urnii' a d __,,,__ .. '!'!' iii'w II/! •m• 8 . •·• ,,, .. , 

* 8 

-

<l 

-25 -50 

., , / 

• g-Tocopherol IJ a-Tocopherol 

1111 1111 11111 11111 11111 11111 1111 1111 1222 2222 

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

Serum 

ni 

_,.,. 

( )Page3/8 

,! 

D4
 
50 

> 25 

< 

,.-.,. 

> < z 

I 

0 

8 

* 8 

-

-<I 

-25 -50 

20/4195 

Individualized Round Robin XXXIII Report to: FSV-BA 

b-Carotene, %A in Round Robin XXIV - XXXIII 

• all-trans-b-Carotene ml Total b-Carotene 

1111 1111 11111 11111 11111 11111 1111 1111 1222 2222 

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

Serum 

RR33. Page 4 / 8 

D5
 
-±20% 

±50% 

-±20% 

- - ±50% 

Individualized Round Robin XXXIII Report to: FSV-BA 

Retinol 

a-Tocopherol,,

NIST 

, 

Assigned Values Vs Laboratory 

A.Total 

®trans 

- ±50% 

-±20% 

±50% 

b-Carotene 

g-Tocopherol 

.... r.,...,_""' 

Values 

Legend 

Shaded Symbols: Round Robin XXIV-XXXII 

Black Symbols: Round Robin XXXIII 

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. 

/ 

RP ··,age 5 / 8 

D6
 
2&419S 

Individualized Round Robin XXXIII Report to: FSV-BA 

Accuracy /Precision Summary 

Ret a Toe gToc Total 

mA vll. mA vll. mA vll. mA vll. 

3 1 1 2 4 3 4 4 

-2 3 2 4 -2 8 3 8 

-7 2 6 3 -2 5 -7 4 

-1 3 0 3 -6 1 6 3 

0 4 1 2 1 4 1 7 

4 4 0 3 9 6 5 4 

XXIV 

xxv 

XXVI 

XXVII 

XXVIII 

XXIX 

xxx 

XXXI 

XXXII 

XXXIII 

9 4 4 7 -3 7 9 12 

5 3 -2 5 -1 5 9 9 

-4 1 0 1 -2 4 10 2 

-2 2 0 2 11 11 12 13 

(Traditional) Performance Criteria 

The absolute value of %fl. of every measurement has 

traditionally been evaluated as follows ... 

%fl. 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 vll. 

7 5 

1 6 

-5 5 

5 3 

0 3 

3 3 

9 12 9 10 

14 3 12 6 

Legend 

Ret Retinol 

a Toe a-Tocopherol 

gToc g-Tocopherol 

Total Total b-Carotene 

trans all-trans-b-Carotene 

mA Mean difference, the average %fl. for all sera of a given RR, where 

%fl. = 1 OO(Your value - NA V) I NA V 

vll. Difference variability, one standard deviation of %fl. for all sera of a R 

NAY 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 %fl., and precision 

as vA, the standard deviation of %fl., for all sera of a Round Robin. 

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

Good precision (small vll.) 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 determined. 

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

adequate control for the analyte levels examined. 

R 

RR33. Page 6 / 8 

D7
 
RRl8 RR21 RR33 

Individualized Round Robin XXXIII Report to: FSV-BA 

Comparisons to Known Relationships 

-

c: 

·.o 

--,--

203 

E1i::3 

205 204 

E!:JQ) 

c 

B 

--,- -,--- 1 .---

- -• - -- - - +- -

't!I 

El 

RRl8 RR21 RR33 203 205 204 

0 

EE 

]._ 

$ 

l t-:iJ i;;;:i. EiJ 

i-.--- 1--r · ···- - -,-----r 

_i;;i _6 __ 

Q) ' 

RRl8 RR21 RR33 203 205 204 

()Plge 7/8 

-

........ _ 

·' 

D8
 
Individualized Round Robin XXXIII Report to: FSV-BA 

Comparisons to Known Relationships (Continued) 

,-, 

·a 

B 

I I 

t;i 

c::I --

• :s \ --

___ 

' . 

- "B u I ,0 

r-· - r I-, 1 1 

RR18 RR21 RR33 203 20S 204 

21W419S 

- ------El1-·-----,---, 

c:: 

' tl 

' ' 

8'" 

'E3 

'O 

-·1 

fa 

-u 

r------

RR18 RR21 RR33 203 205 204 

• .5 

-s 

cld 

.s. 

...:l 

,. 

8 

• 

'El • 

[,I_ 

,-,- ·--··--·-,---

RR18 RR21 RR33 203 205 204 

RR33_ Page 8 / 8 

D9
 
 

 

Appendix E. Shipping Package Inserts for RR34 

The following two items were included in each package shipped to RR34 participants: 

• Cover letter 

• Datasheet 

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

samples themselves. 

E1 
UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standards and Technology 

Gaithersburg, Maryland 20899-

April 13, 1995 

Dear Colleague: 

Enclosed is the set of samples for the second round robin exercise (Round Robin XXXIV). You 

will find one vial of four lyophilized sera 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 the detection limit, please indicate this result on the 

form by using ND (Not Detected). For values not obtained, please leave a blank for the given 

analyte. Results will be due to NIST by June 16, 1995. 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 to you by July 24, 1994. 

Samples should be reconstituted with LO mL ofHPLC-Grade water or equivalent. We 

rec_ommend that dissolution be facilitated with 3 to 5 minutes 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; a:-tocopherol, 75.8 at 292 

nm; y-tocopherol, 91.4 at 298 nm; a:-carotene, 2800 at 444 nm; 

j3-carotene, 2560 at 450 nm; lycopene, 3450 at 472 nm. 

Please mail or FAX your results for Round Robin XXXIV 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 or 

mail/FAX queries to the above address. 

( 

-~~n· Ct_ 

ice Brown Tho 

esearch Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

Attachment 

cc: W.May 

S. Wise N•Si E2
	
 

 

 

 

 

 

NIST/NCI 

Micronutrients Measurement Quality Assurance Program 

Round Robin XXXIV Results from Laboratory #_____ 

Serum 

Analyte 207 208 209 210 Units* 

retinol 

retinyl palmitate 

a-tocopherol 

g-tocopherol 

total b-carotene 

trans-b-carotene 

total cis-b-carotene 

total a-carotene 

total lycopene 

trans-lycopene 

b-cryptoxanthin 

lutein 

zeaxanthin 

lutein&zeaxanthin 

Other Analytes?
	

* We prefer results as microgram/milliliter. 

Comments? 

Mail: NNMMQAP, 222/B208 

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

Gaithersburg, MD 20899 June 16, 1995 Email: DLDuewer@enh.NIST.gov 

E3
	
 

 

 

 

 

Appendix F. Final Report for RR34 

The following 13 pages are the final report for RR34 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 28, 1995 

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 XXXIV (Sera 207-210). Included 

in this report are: a summary of data for all laboratories; a summary of your 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 y-tocopherol, and 

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

analytes; and the measurement comparability summary for evaluating your laboratory's 

performance relative to the other participants'. The NIST assigned values (described in the 

attached Appendix) are derived from the equally weighted values for the combined results from 

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

In this round robin exercise, Serum 207, 209, and 210 were previously distributed in Round 

Robin XXXII as sera 200, 201, and 202, respectively. These serum samples are also the low, 

medium, and high levels of SRM 968b. Serum 208 (identified as "Control B" during the initial 

stages of the QA program), was previously distributed as serum 81 in Round Robin XII, serum 

94 in Round Robin XIII, and serum 112 in Round Robin XVI. 

The overall interlaboratory performance for retinol, y- and a-tocopherol, and B-carotene for 

Round Robin XXXIV is comparable to that of Round Robin XXXII. The average estimated 

coefficient of variation (eCV) is about 8.5% for retinol, 10% for a-tocopherol, 9% for 

y-tocopherol, and about 17% for B-carotene. The eCV for B-carotene was about 14% in round 

robin XXXII. The median values obtained in this round robin exercise are also in agreement 

with those from the previous round robin exercises and the NIST-assigned values. The results 

for retinol, retinyl palmitate, y- and a-tocopherol, total and trans-B-carotene, total a-carotene, and 

lutein in this round robin exercise are comparable to the proposed certified values in SRM 968b 

(See Figure 1 in Appendix). 

The overall interlaboratory measurement comparability for B-cryptoxanthin, total lycopene, and 

zeaxanthin continues to improve. Laboratories are beginning to report additional values for new 

analyte(s) of interest (i.e., one laboratory has reported values for co-enzyme QlO). We encourage 

you to continue to report values for as many quantifiable analytes as possible. 

Data for evaluating your laboratory's performance in Round Robin XXXIV 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 of the assigned value) indicates POOR performance relative to the current state-ofthe-practice for these measurements. 

N•Si F2
	
SRM 968b: Fat-Soluble Vitamins and Cholesterol in Human Serum, the renewal material for 

SRM 968a, which we recommend that you use to validate your methods, will be available for 

purchase in August. If your laboratory is out of SRM 968a, we suggest that you use for method 

validation control materials that are available in your laboratory or previously distributed (~1 year 

ago) round robin samples. If neither of these options is available, please give me a call. 

If you have concerns regarding your performance, or are a lab whose performance would be rated 

"POOR" based on the convention stated above, we suggest that you validate your method using 

SRM 968a or available control materials. If with minor method modifications your measured 

values do not agree with the assigned values, please contact us for consultation. 

Samples for Round Robin :XXXV were shipped during the last week of July. Results are due 

September 15 and feedback to labs is expected by October 20. Feedback for the food round 

robin (shipped only to those labs that requested these samples) will be mailed within two weeks. 

As was discussed at the QA workshop last fall, future workshops will be held on a bi-annual 

basis. The next workshop will be held in April as a pre-meeting in conjunction with 

Experimental Biology '96 in Washington, DC. You will be provided with updated information 

regarding the QA workshop as plans for this meeting are finalized. 

We will hold our annual tutorial session at NIST this fall, provided there is sufficient interest. 

As usual, this session will include a discussion of calibration, sample preparation, and 

chromatographic techniques for measuring fat-soluble vitamins and carotenoids in serum. We 

will ask you to indicate. your plans for attending this tutorial in a future mailing. If you have 

further questions or concerns, please contact me at 301/975-3120; fax: 301/977-0685; or e-mail: 

jbthomas@enh.nist.gov. 

Sincerely, 

· ce Brown Thomas 

Research Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

cc: W. May 

F3
	
Lies, Damn Lies, and Statistics 

"Lies, Damned Lies, and Statistics" 

Mark Twain 

Page I 

The attached NNMMQAP Round Robin XXXIV Report is (ta da!) essentially unchanged 

from RR XXXIII's. It includes a fairly exhaustive analysis of your results (the 

"Individualized" report) and a complete listing of everyone's results (the "All Lab" report). 

Your "Individualized" has the following elements: 

Pa e Contents 

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

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

3 %Bias barchart for ex- and y-tocof)lferol for your last 3 years' results 

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

S Our assigned value vs. your value scatterplots for retinol, ex- and ytocopherol, total and trans-~-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, ex- and 

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

8 Comparison-to-Prior-Analyses plots for total ex-carotene, total lycopene, 

~-cryptoxanthin, 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. In detail: 

Serum #208 is "Control B." It was distributed as #81 in Round Robin XII, #94 in 

Round Robin Xill, and #112 in Round Robin XVI. The "true value" lines are averages 

of the four Round Robin results. 

Seruin #207, 209, and 210 were distributed as #200, 201, and 202 in Round Robin 

XXXII. These sera are the "low", "medium'', and "high" components of the candidate 

SRM 968b ! The "true value" lines are the proposed certified or informational values 

for the SRM. 

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" 

F4
	
Lies. Damn Lies. and Statistics Page 2 

The "Measurement Comparability Summary" (the "score card") provides a four-level score 

for each laboratory for: retinal, a- and y-tocopherol, and total and trans-j3-carotene. The 

score is based upon the worst-case differences between your reported values and our 

assigned values, after scaling the values by the total measurement uncertainty. The 

attached Appendix details our value and uncertainty assignment methods. 

If you dig through the Appendix, you may note that we intend to certify values for retinal, 

retinyl palmitate, a- and y-tocopherol, total and trans-13-carotene, total a-carotene, and 

lutein (also cholesterol, 9-cis-, 15-cis-, and 13- & 15-cis-13-carotene) in SRM 968b. We 

will also provide non-certified values for: o-tocopherol, trans-a-carotene, total and translycopene, 13-cryptoxanthin, and zeaxanthin_ What's the difference between "certified" and 

"non-certified" analytes? Well ... 

In addition to your Round Robin results, we analyze SRM-to-be samples using three 

separate and distinct methodologies. We believe that our "normal method" results for total 

and trans-lycopen~. zeaxanthin, and probably 13-cryptoxanthin are confounded with one-ormore co-eluting compounds. (Results for o-tocopherol and trans-a-carotene are mostly 

detector-sensitivity limited.) Judging from the high-bias discord between the Round Robin 

and our best-guess non-certified values, many of you who report these analytes also are 

plagued with co-eluting compounds ... 

We recognize that the levels of these and other analytes in the lyophilized sera are too low 

to be reliably measured. Resources permitting (it's not so much the$ cost, but the -0.3L 

plasma/sample set that's the hassle), we still hope to eventually obtain more interesting 

"natural" sera. But to really nail down what's going on, we need methods for augmenting 

plasma with known analytes and their potential co-eluters. Ideas? 

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 

DLDuewer@enh.NIST.gov 

-

~~Margaret 77~ Kline 

Research Biologist 

Kline@enh.NIST.gov 

F5
	
Reportof(Meta)Analysisfor RR XXXIV Sera: 207-210 

From: David Duewer Date: July 22, 1995 

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

cc: Laurie Locascio, Dennis J. Reeder, Stephen A. Wise 

Re: Value Assignment and Analysis of Variance for RR XXXIV Sera: 207 -210 

Purpose: We now compare individual laboratory values to a NIST value-assigned analyte 

concentration rather than to the interlaboratory median. Analysts NISTl and NIST3 provide 

replicate measurements on sufficient samples to permit confident value-assignment. This reports 

the statistical I chemometrical analysis of their analytical results for the sera distributed in Round 

Robin XXXIV (RR34 ). 

Background: Four sera were distributed in &R34. Sera 207, 209, and 210 were distributed as 

sera 200, 201, and 202, respectively, in RR32 (i.e., the low, medium, and high components of 

SRM 968b). Serum 208 is "Control B" from the archives, having been previously distributed as 

sera 81 (RR12), 94 (RR13), and 112 (RR16). 

NIST I and NIST3 analyzed all sera using their normal procedures. Both researchers extracted 

and analyzed two aliquots of three vials, providing dllplicate results for a total of six samples of each serum. NISTl provided quantitative results for: retinol, a-, and y-tocopherol, total and 

trans-~-carotene, and total a-carotene. NIST3 provided quantitative results for these analytes, 

plus: retinyl palmitate, 0-tocopherol, trans-a-carotene, total and trans-Iycopene, ~-cryptoxanthin, 

lutein, and zeaxanthin. 

Results: Table 1 presents the values and uncertainties assigned to sera 207 - 210. Table 2 

compares average results for the two NIST analysts in RR34, the median results from RR34, and 

the median results from previous RRs. Table 3 lists the linear bias models between the NISTl 

and NIST3 data. 

The following assumptions and definitions have been used in calculating the various statistics: 

1) NIST Assigned Value (NAV): (RR+ (Nl + N3) / 2) / 2 

(RR+ N3) / 2 

(N3) 

where: NI= mean of NISTl 's data, 

N3 =mean ofNIST3's data, and 

RR = median of all RR34 participants' data. 

(Both NIST analysts, ~2 RR labs) 

(One NIST analyst, ~ RR labs) 

(One· NIST analyst) 

2) NIST Repeatability Standard Deviation (SDrep): "measurement" standard deviation (sd), 

within-vial differences associated with extraction, chromatography, peak area determination, 

etc. This "within samples" pooled sd is closely related to the sd of the paired-differences 

between the replicate extractions I measurements of the samples analyzed at NIST. For the 

analytes reported by both NIST analyt'es, any proportional systematic bias between results for 

the two analysts was removed as part of the combined-data ANOV A. These bias models are 

listed in Table 3. 

3) NIST Heterogeneity Standard Deviation (SDhet): "heterogeneity" sd, vial-to-vial differences 

associated with preparing and reconstituting the serum samples. This "between samples" 

pooled sd is closely related to the sd of the mean values of the unique vials analyzed at NIST. 

F6
	
Report of (Meta)AMlysisfor RR XXXIV Sera: 207-210 

For the analytes reported by both NIST analysts, any systematic proportional bias between 

results for the two analysts was removed as part of the combined-data ANOV A. These bias 

models are listed in Table 3. See Eqs. 19.6-4, 19.6-5, and 19.6-6, Mathematical Handbook 

for Scientists and Engineers, G. and T. Korn ( 1968), for details of the ANOV A calculations. 

4) Interlaboratory Bias Standard Deviation (SDlab): "Laboratory bias" sd, the residual sd from 

(non-NIST) laboratory-to-laboratory biases after correction for SDrep and SDhet. This 

assumes that the population of these systematic biases can be approximated as a normal 

distribution centered at the NAV. 

The observed interlaboratory sd for the results of RR34 is estimated as 

eSD = MAX(0.7421 *InterQuartile Range, 0.05*NAV), 

as previously described ("Lies, Damn Lies, and Statistics" report for RR3 l ). This estimate 

assumes a) that at least 50% of the laboratories that report values for a given analyte are 

"performing" (they basically know what they're doing), b) that "non-performing" labs are 

about equally likely to report low values as-high values, and c) that standard deviations less 

than 5 % of NA V are unrealistically low. 

The sd among single-sample results reported by different laboratories is a composite of at 

least three variation sources: the repeatability of any given method, the heterogeneity among 

supplied samples, and systematic biases among analysts and/or methods and materials. As 

we have NIST-based estimates for the first two sources (SDrep and SDhet), we can model 

laboratory differences as the residual of the observed interlaboratory sd (eSD) after 

subtraction of the measurement and heterogeneity components: 

SDlab = MAX(VeSD2 - SDrep2 - SDhet2 , 0). 

The "MAX" function is required if eSD is smaller than ~.-S-D-re_p__+_S_D-he_t_2 • 

5) NIST Assigned Uncertainty (NAU) 

Using the same assumptions as described above for SDlab, the "total" expected 

interlaboratory sd can be described as: 

NAU = 4t/.-S-D-re_p_2 _+_S_D-he-t2_+_S_D_l-ab-2 . 

Note that this is constrained to be at least as large as the observed interlaboratory sd, eSD. 

6) 95% Material, the 95% confidence range on the "true" analyte concentration: 

NA V ±2 ~SDrep2 + SDhet2 • 

The value "nq" (for "not quantitative") is used if the uncertainty is large relative to the value. 

7) 95% Laboratory, the 95% confidence range on the RR34 reports of analyte concentration: 

NAV±2NAU. 

The value "nq" (for "not quantitative") is used if the uncertainty is large relative to the value. 

Conclusions: The RR34 median values agree well with the NIST-analyst values and with the 

median values from recent Round Robin exercises (Table 2). The retinol, a-tocopherol, total and 

trans-~-carotene RR 34 values for serum 208 ("Control B") are remarkably unchanged from the 

RR12, RR13, and RR16 (1988- 1989) results. 

F7
	
Report of ( Meta)Analysis for RR XXXIV Sera: 207-2 IO 

Figure 1 compares the NA Vs and NAUs for sera 207, 209, and 210 to the proposed values for 

SRM 968b. RR34 results for analytes with certified values in SRM 968b agree very well with 

the proposed certified values and material uncertainty regions (top segment of Figure 1). For all 

levels of all these analytes: 1) the RR34 NA Vs are within the certified 95% confidence region 

and 2) the RR34 95% interlaboratory uncertainty region is slightly larger than the (NISTanalysis-based) certified 95% confidence region. 

Note: The two 95% confidence region definitions reflect philosophical differences between the 

SRM and QA programs. SRM value/uncertainty statements reflect NIST's state-ofknowledge of the composition of the "stuff in the vials". The NAV/NAU in this report 

reflect the QA community's ability to measure the "stuff in the vials". 

RR34 results for analytes with non-certified values in SRM 968b are biased and generally have 

large NAUs (bottom segment of Figure 1). While there is qualitative agreement between the 

"informational" SRM and RR-assigned values, the putative 95% confidence ranges for 8-

tocopherol, trans-a-carotene, and zeaxanthin do not overlap for some/all levels. The current 

routine methods for these analytes do not yet provide adequately quantitative information. 

The systematic biases between the Nl and N3 data (Table 3) continue to be intriguing. As we 

now have at least three data sets to intercompare, it may be possible to separate intrinsic 

differences between the two methods from "accidental" differences between the analyses. 

Should we invest the resources? 

This rnemo will be attached as the Appendix to RR34's "Lies, Damn Lies, and Statistics" report. 

David Lee Duewer 

Research Chemist 

F8
	
Table l 

RR XXXIV Analyte Value and Uncertainty Assignments 

NAV 

SDrep 

SDhet 

SDI ab 

NAU 

95% Material 

95% Laboratory 

NAV 

SD rep 

SDhet 

NAU 

95% Material 

95% Laboratory 

NAV 

SDrep 

SDhet 

SDI ab 

I 

NAU 

95% Materia 

95% Laboratory 

NAV 

SDrep 

SDhe 

SD lab 

t 

I 

NAU 

95% Materia 

95% Laboratory 

NAV 

SDrep 

SDhet 

NAU 

95% Material 

Sera 

207 208 209 

Retinal 

0.28 0.43 I 0.52 ----~----·-- T ---- 0.01 0.01 0.01 

0.02 0.02 0.02 

0.02 0.04 0.04 >---------r--------··---- 0.03 (10%) --~Q? (I 0_%) 0.05 (8%) 

0.24-0.32 0.38-0.47 0.47-0.56 

0.22-0.34 0.34-0.52 0.43-0.61 

R . I I . etiny pa m1tate 

0.088 - 0.030 0.177 -----·---1-- -- - - ~- ---- --·-- ·----

0.016 0.003 

0.021 0.018 0.014 ~-

0.027 (30%) 0.018 (59%) 0.015 (8%) 

0.050 - 0.120 0.160-0.190 

0.030 - 0.150 nq-0.070 0.140-0.210 

a-T h ocop ero 

7.0 6.0 IO.I t---·-- ---

0.2 0.2 0.2 

0.2 0.1 0.3 

0.9 0.9 0.7 ----t-- -------t---

1.0 (13%) __ O.~J!~~J- - - 0.8 (8%) 

6.5-7.6 5.6-6.4 9.3-10.8 

5.1-9.0 4.2-7.8 8.5-11.7 

g-T h ocop ero 

1.67 2.93 2.38 ----1----

0.08 0.12 0.11 

0.07 0.21 0.14 

0.21 0.22 0.17 

0.24 (14%) 0.33 (11%) 0.25 (10%) 

1.45-1.89 2.44-3.42 2.02-2.74 

1.18-2.15 2.27-3.59 1.88-2.87 

dT - ocop h I ero 

0.130 0.181 0.181 

0.009 0.011 0.018 

0.004 0.018 0.014 

0.011 (8%) 0.022 (12%) 0.023 (13%) 

0.100-0.150 0.130 - 0.230 0.130 - 0.230 

210 

0.88 

0.02 

0.01 

0.07 

0.08 (8%) 

0.83-0.94 

0.74-1.03 

0.263 f----

0.001 

0.024 

0.024 (9%) 

0.260 - 0.270 

0.210 - 0.320 

17.7 

0.3 

0.2 

0.9 

1.0 (6%) 

17.0-18.5 

15.7-19.7 

3.76 

0.15 

0.15 

0.15 

0.26 (7%) 

3.33-4.19 

3.24-4.28 

0.186 

0.008 

0.013 

0.016 (8%) 

0.150- 0.220 

RR34_Va1Ass (19/0711995) I/ 3 F9
	
Table l 

RR XXXIV Analyte Value and Uncertainty Assignments 

NAV 

SDrep 

SDhet 

SD lab 

NAU 

95% Material 

95% Laboratory 

NAY 

SDrep 

SDhet 

SD lab 

NAU 

95% Material 

· 95% Laboratory 

NAY 

SDrep 

SDhet 

SD lab 

NAU 

95% Material 

95% Laboratory 

NAV 

SDrep 

SDhet 

NAU 

95% Material 

NAY 

SDrep 

SDhet 

SD lab 

NAU 

95% Material 

95% Laboratory 

Sera 

207 208 I 209 

Total b-Carotene 

0.252 0.194 0.635 -- - --- 0.013 0.017 I 0.024 

0.015 0.018 0.011 

0.050 0.033 0.099 -·-- --- ·-· -- ---- 0.054 (21%) 0.042 (2 J_~) 0.103 ( 16%) 

0.213 - o.~92 0.144 - 0.244 0.582 - 0.687 

0.145 - 0.360 0.111-0.277 0.430 - 0.840 

trans-b-Carotene 

0.241 - 0. 175 0.584 -- -- .. - ---- --.. ···---

0.012 0.018 0.023 

O.Dl5 0.015 0.012 

0.009 0.014 0.045 ----- -------·--- ·-· - -

0.022 (9%) 0.028 (16%) 0.052 (9%) -- ---··- ··· ··------ 0.202 - 0.279 0. 127 - 0.222 0.532 - 0.636 

0.197 - 0.284 0.120 - 0.230 0.479 - 0.688 

Total a-Carotene 

0.022 0.017 0.034 --------- 0.003 0.005 0.003 

0.005 0.006 0.006 

0.000 0.000 0.009 

0.006 (26%) Q_'.008 (43%) 0.012 (34%) 

0.010-0.034 0.002 - 0.033 0.020 - 0.049 

0.0 I 0 - 0.034 0.002 - 0.033 0.011 - 0.058 

trans-a-Carotene 

0.022 0.017 0.040 ----·- 0.003 0.002 0.003 

0.002 0.002 0.002 

0.004 (15%) 0.003 (17%) 0.004 (8%) 

0.0 I 5 - 0.030 0.0 I 0 - 0.023 0.033 - 0.048 

T Ola IL .ycopene 

0.201 0.229 0.301 

0.034 0.017 0.012 

0.018 0.017 0:026 

0.033 0.042 0.052 

0.05 I (25%) ' 0.049 (21%) 0.060 (20%) 

0.124 - 0.278 0.181-0.278 0.243 - 0.359 

0.100 - 0.302 0.131 - 0.327 0.182 - 0.420 

210 

1.239 

0.058 

0.038 

0.147 

0.163 (13%) 

1.099 - 1.378 

0.913 - 1.564 

1.165 

0.039 

0.034 

0.048 

0.071 (6%) 

1.061 -1.268 

1.023 - 1.306 

0.047 

0.006 

0.002 

0.012 

0.014 (29%) 

0.034 - 0.059 

0.019 - 0.075 

0.039 

0.003 

0.002 

0.004 (8%) 

0.032 - 0.046 

0.345 

0.027 

0.008 

0.078 

0.084 (24%) 

0.287 - 0.402 

0.178-0.511 

RR34_ Va1Ass (19~7/1995) 213 

F10
	
Table 1 

RR XXXIV Analyte Value and Uncertainty Assignments 

NAV 

SD rep 

SDhet 

SDI ab 

NAU 

95% Material 

95% Laboratory 

NAV 

SD rep 

SDhet 

SDI ab 

NAU 

95% Material 

95% Laboratory 

NAV 

SDrep 

SDhet 

SDI ab 

NAU 

95% Material 

95% Laboratory 

NAV 

SDrep 

SDhet 

SDI ab 

NAU 

95% Material 

95% Laboratory 

NAV 

SD rep 

SDhet 

SD lab 

NAU 

95% Material 

95% Laboratory 

Sera 

207 208 209 

trans-L .ycopene 

0.138 0.178 0.196 -· . ---·- - - - ·--· 0.006 0.004 0.002 

0.005 0.003 0.003 - -- - - ···-- - - - -- 0.129 0.156 0. 151 ·- --- ----- - ---- 0.130(94%) .. . -9.:~.?J8~%) 0.152 (77%) 

0.123-0.153 0.167-0.189 0.189 - 0.204 

nq-,.0.398 nq-0.492 nq-0.500 

b -c :ryptoxant h" m 

0.029 - 0.040 0.040 ---- -- - - -- 0.002 0.003 0.002 

0.002 0.003 0.001 - r-- ·- --·- -- ----- -- r--

0.012 0.014 0.009 ---- - -- - --·-- ··- ---- -- 0.012 (41%) 0.015 (36%) 0.009 (23%) ··-- ,__ ___ - -- · -- 0.023 - 0.035 0.031 - 0.048 0.036 - 0.044 

0.005 - 0.054 0.011 - 0.069 0.021 - 0.058 

Lutein 

0.061 0.074 0.064 --- - -·--- - - - --· 

0.002 0.004 0.000 

0.002 0.002 0.001 - - -· 

0.011 0.011 0.011 .. 

0.011 (18%) ~_:_0_12 (15%_L _ Q.011 (17%) 

0.054 - 0.067 0.066 - 0.082 0.061 - 0.067 

0.038 - 0.083 0.051 - 0.097 0.042 - 0.086 

Zeaxanthin 

0.023 0.041 0.030 ----·---- ·-

0.002 0.001 0.001 

0.001 0.002 0.001 

0.002 0.008 0.003 

0.004 (14%) 0.009 (22%) 0.003 (10%) 

0.018 - 0.028 0.035 - 0.046 0.026 - 0.033 

0.016-0.030 0.023 - 0.059 0.023 - 0.036 

Lutein&Zeaxanthin 

0.083 0.124 0.092 

0.004 0.002 0.001 

' 0.002 0.004 0.001 

0.015 0.023 0.02J 

0.016 (19%) 0.024 (19%) 0.022 (23%) 

0.074 - 0.092 0.114-0. 133 0.089 - 0.095 

0.050-0.115 0.077-0.171 0.049 - 0.135 

210 

0.215 

0.006 

0.002 

0.152 -- 0.152 (71%) 

0.203 - 0.227 

nq-0.519 

0.039 

0.002 

0.001 

0.010 

0.010 (25%) 

0.034 - 0.044 

0.019 - 0.059 

0.037 

0.001 

0.002 

0.008 

0.009 (22%) 

0.032 - 0.042 

0.020 - 0.054 

0.019 

0.002 

0.004 

0.000 

0.005 (24%) 

0.009 - 0.029 

0.009 - 0.029 

0.056 

0.003 

0.005 

0.010 

0.012 (20%) 

0.044 - 0.068 

0.033 - 0.079 

RR:l4_ ValAs& (19/07/199') 3 / 3 F11
	
Retinol 

Retinyl palmitate 

a-Tocopherol 

g-Tocopherol 

d-Tocopherol 

Total b-Carotene 

trans-b-Carotene 

Total a-Carotene 

trans-a-Carotene 

Total Lycopene 

trans-Lycopene 

b-Cryptoxanthin 

Lutein 

Zeaxanthin 

Lutein&Zeaxanthin 

Retinol 

Retinyl palmitate 

a-Tocopherol 

g-Tocopherol 

d-Tocopherol 

Total b-Carotene 

trans-b-Carotene 

Total a-Carotene 

trans-a-Carotene 

Total Lycopene 

trans-Lycopene 

b-Cryptoxanthin 

Lutein 

Zeaxanthin 

Lutein&Zeaxanthin 

NI 

0.22 

7.27 

1.65 

0.264 

0.222 

0.023 

Nl 

0.41 

6.28 

2.53 

0.208 

0.155 

nd 

Table 2 

Summary of Data Used in Assigning Values 

207 209 

N3 RR34 RR32 NI N3 RR34 RR32 

0.30 0.30 0.30 0.51 0.51 0.52 0.51 

0.08 0.09 0.IO O.I6 0.20 0.18 

6.92 7.00 7.15 10.60 9.97 9.83 10.00 

1.68 1.67 1.69 2.34 2.39 2.39 2.41 

O. I I 0.15 0.15 0.2I 

0.263 0.241 0.248 0.631 Q.658 0.625 0.619 

0.230 0.255 0.231 0.535 0.594 0.603 0.565 

0.027 0.019 0.020 0.035 0.044 0.029 0.031 

0.018 0.026 0.030 0.051 

0.221 0.181 0.179 - 0.325 0.277 0.268 

0.084 0.193 0.139 0.254. 

0.026 0.033 0.041 0.033 0.047 0.053 

0.055 0.066 0.064 0.060 0.068 0.064 

0.024 0.023 0.020 0.032 0.027 0.028 

0.079 0.087 0.094 0.092 0.093 0.099 

208 

N3 RR34 RRI6 RR13 RR12 

0.42 0.44 0.43 0.43 0.44 

nq 0.03 

5.91 5.87 6.02 5.90 5.98 

3.06 3.06 

0.17 0.20 

0.198 0.185 0.205 0.20 0.207 

0.173 0.185 0.196 0.203 

0.022 0.013 

0.014 0.019 

0.242 0.216 

0.112 0.245 

0.032 0.047 

0.075 0.073 

0.048 0.034 

0.123 0.125 

210 

NI N3 RR34 RR32 

0.88 0.88 0.89 0.88 

0.24 0.28 0.26 

18.07 17.56 17.67 I7.80 

3.60 3.80 3.83 3.76 

0.23 O.I4 

1.204 I.270 1.240 1.232 

1.066 1.150 1.221 1.117 

0.059 0.056 0.036 0.039 

0.033 0.045 

0.358 0.331 0.314 

0.148 0.282 

0.033 0.045 0.049 

0.037 0.037 0.036 

0.019 0.020 0.014 

0~056 0.056 0.061 

RR34_ Va1As.s (19/0711995) U I 

F12
	
Table 3 

Summary of Linear Calibration of N l to N3 Average Values 

Bias Models 

N l = Intercept + Slope.*N3 ± SDreg 

Retinol 

a-Tocopherol 

g-Tocopherol 

Total b-Carotene 

trans-b-Carotene 

Total a-Carotene 

Slope 

0.92 (0.06) 0.99 (0.01) 

l.08 (0.04) 

1.07 (0.00) 

l.08 (0.01) 

0.76 (0.24) 

Inter 

0.06 (0.04) 

-0.3 (0.2) 

0 

-0.023 (0.002) 

0 

0.012 (0.010) 

Legend 

SDreg 

0.03 

0.1 0.2 0.003 0.011 

0.006 

Slope: Estimate of slope ("standard error" of estimate) 

Inter: Estimate of intercept ("standard error" of estimate) 

CV reg R2 

3-10% 0.990 

1-2% l.000 

6-13% 0.942 

0-1% 1.000 

1-7% 0.999 

11 -29% 0.912 

SDreg: "Standard error" (sd of residuals) of N l regression onto N3 values 

CVreg: lOO*SDreg/(maximum N3 value)- lOO*SDreg/{minimum N3 value) 

R2: Square of the correlation between NI and N3 

F 

207 

4604 

49 

104034 

4636 

10 

F: F statistic (=variance accounted for by the model I variance not accounted for) 

df: Degrees of freedom ( = number of data - number of parameters in model) 

df 

2 

2 

3 

2 

3 

l 

F13
	
c:: 

·-..c 

~ 

] 

= 

~ 

10 

1 

0.1 

0.01 

Figure 1 

Comparison of SRM 968b to RR34 Results 

SRM 968b Certified Values 

R retinol 

r retinyl palmitate 

a cx-tocopherol 

y y-tocopherol 

~ total ~-carotene 

B · trans-~-carotene 

a total a-carotene 

I lutein 

/ 95%RR34 

-f '\ 95% SRM 968b 

0.1 1 

SRM 968b Information Values 

5 5-tocopherol 

ex trans-a-carotene 

L total lycopene 

I trans-lycopene 

~ ~-cryptoxanthin 

z zeaxanthin 

' ' 

' ' 

0.01 0.1 

Proposed SRM 968b Values 

10 

F14
	
 

 

 

 

 

Appendix G. “All-Lab Report” for RR34 

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 XXXIV Laboratory Results 

Values in μg/mL 

Retinol Retinyl Palmitate α-Tocopherol γ-Tocopherol δ-Tocopherol 

Lab 207 208 209 210

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-BV 

FSV-BY 

FSV-BZ 

FSV-CB 

FSV-CD 

FSV-CH 

FSV-CJ 

FSV-CK 

FSV-CM 

FSV-CN 

FSV-CQ 

FSV-CR 

FSV-CT 

FSV-CU 

FSV-CV 

FSV-CX 

FSV-CY 

FSV-DA 

FSV-DB 

FSV-DJ 

FSV-DK 

FSV-DL 

FSV-DM 

FSV-DP 

FSV-DS 

FSV-DX 

FSV-EA 

FSV-EH 

FSV-EK 

FSV-EL 

FSV-FC 

FSV-FD 

FSV-FP 

0.299 0.459 0.517 0.891 

0.264 0.416 0.467 0.832 

0.266 0.417 0.489 0.838 

0.290 0.420 0.540 0.920 

0.299 0.385 0.499 0.847 

0.283 0.432 0.481 0.839 

0.296 0.451 0.547 0.936 

0.318 0.489 0.567 0.900 

0.401 0.573 0.659 1.003 

0.306 0.395 0.532 0.895 

0.358 0.454 0.617 1.103 

0.273 0.367 0.493 0.854 

0.322 0.484 0.565 0.939 

0.302 0.429 0.540 0.822 

0.294 0.458 0.503 0.812 

0.378 0.501 0.496 0.856 

0.277 0.408 0.478 0.844 

0.283 0.453 0.802 

0.302 0.420 0.515 0.872 

0.461 0.620 0.657 1.191 

0.299 0.445 0.511 0.929 

0.284 0.433 0.504 0.851 

0.357 0.465 0.531 0.910 

0.358 0.498 0.566 1.024 

0.299 0.540 0.799 

0.278 0.464 0.492 0.886 

0.330 0.560 0.630 0.980 

0.272 0.407 0.480 0.889 

0.280 0.439 0.496 0.822 

0.289 0.439 0.551 0.903 

0.280 0.410 0.490 0.850 

0.280 0.450 0.530 0.900 

0.309 0.451 0.513 0.934 

0.320 0.500 0.560 0.930 

0.320 0.460 0.550 0.930 

0.315 0.475 0.575 1.030 

0.312 0.365 0.396 0.832 

0.309 0.485 0.548 0.934 

0.300 0.441 0.535 0.900 

0.250 0.360 0.420 0.700 

0.383 0.541 0.642 1.109 

0.283 0.374 0.455 0.789 

0.310 0.550 0.940 

0.417 0.578 0.730 1.060 

0.280 0.430 0.540 0.840 

0.304 0.438 0.519 0.863 

0.270 0.500 0.480 1.030 

0.420 0.652 0.864 1.652 

207 208 209 210 

0.110 0.032 0.199 0.275 

0.074 0.021 0.181 0.276 

0.041 nd 0.196 0.287 

0.112 nd 0.207 0.304 

0.091 0.056 0.191 0.253 

0.085 nd 0.224 0.377 

0.108 0.019 0.186 0.269 

0.093 nd 0.175 0.279 

0.086 0.040 0.168 0.275 

0.143 0.056 0.194 0.318 

0.120 0.030 0.210 0.310 

0.092 0.018 0.203 0.288 

0.026 nd 0.072 0.089 

207 208 209 210 

6.80 5.75 9.53 17.3 

5.60 4.97 8.68 16.5 

6.81 5.72 9.83 17.5 

6.23 5.29 9.24 16.3 

7.18 6.21 10.30 18.1 

7.00 6.12 10.07 17.0 

7.68 6.49 10.22 17.8 

7.41 6.44 9.88 17.9 

8.18 6.85 11.41 20.7 

7.45 6.53 10.16 18.1 

7.57 6.81 10.79 20.7 

6.55 5.94 9.48 17.5 

8.09 6.34 10.18 17.6 

5.80 5.70 9.30 14.9 

7.52 7.42 10.66 17.7 

6.28 5.56 9.40 16.2 

6.81 9.86 16.9 

7.04 5.53 9.87 17.8 

5.61 4.32 8.98 19.7 

7.72 5.74 8.96 17.1 

8.50 6.93 11.18 21.0 

5.84 4.84 8.04 14.4 

7.77 6.45 10.00 17.5 

8.52 6.62 10.91 19.6 

6.86 5.87 9.99 18.6 

6.85 10.62 17.5 

6.08 5.21 9.39 18.2 

7.50 6.30 9.70 15.0 

6.96 5.93 9.35 16.9 

6.97 6.16 10.48 18.1 

7.04 5.20 10.50 17.9 

6.67 5.77 9.69 17.3 

7.23 5.98 9.31 19.2 

7.22 6.52 10.10 17.7 

6.18 4.97 9.11 15.8 

7.16 5.68 11.39 20.2 

7.90 7.50 10.10 17.0 

6.85 5.31 8.39 18.0 

6.83 5.76 9.56 16.9 

6.01 4.76 7.47 13.4 

9.62 7.89 12.97 23.1 

8.10 6.80 11.30 19.2 

7.70 10.90 18.7 

9.29 7.98 11.70 23.3 

7.33 6.31 10.64 18.1 

6.43 5.26 9.81 17.4 

5.13 4.02 6.85 13.2 

207 208 209 210 

1.75 3.09 2.39 3.87 

1.74 3.09 2.45 3.97 

1.77 3.21 2.46 3.95 

1.65 3.04 2.35 3.74 

1.96 3.37 2.56 4.02 

1.41 2.68 2.03 3.60 

1.66 3.08 2.44 3.83 

1.45 3.03 2.26 3.66 

1.44 2.26 3.77 

1.69 2.66 2.34 3.83 

2.21 3.43 2.92 4.45 

1.57 2.74 2.09 3.38 

1.45 2.80 2.18 3.32 

2.13 3.56 2.74 4.23 

1.46 2.25 3.89 

1.58 2.90 2.39 3.83 

1.73 3.31 2.50 3.71 

1.34 2.03 1.70 2.91 

1.50 2.80 2.10 3.70 

1.77 2.58 3.92 

2.65 2.02 2.48 4.50 

1.78 3.21 2.54 3.94 

1.12 2.02 1.55 2.68 

207 208 209 210 

0.203 

0.100 

nd 

0.271 0.297 0.178 

0.120 0.120 0.110 

0.150 0.182 

n 48 45 48 48 

Min 0.250 0.360 0.396 0.700 

Median 0.300 0.450 0.531 0.898 

Max 0.461 0.652 0.864 1.652 

eSD 0.029 0.050 0.052 0.073 

eCV 10 11 10 8 

13 8 13 13 

0.026 0.018 0.072 0.089 

0.092 0.031 0.194 0.279 

0.143 0.056 0.224 0.377 

0.027 0.016 0.019 0.014 

29 52 10 5 

47 44 47 47 23 20 23 23 

5.13 4.02 6.85 13.2 1.12 2.02 1.55 2.68 

7.04 5.94 9.88 17.7 1.66 3.03 2.39 3.83 

9.62 7.98 12.97 23.3 2.65 3.56 2.92 4.50 

0.79 0.84 0.86 1.1 0.24 0.38 0.20 0.19 

11 14 9 6 14 13 8 5 

2 

0.10 

0.15 

0.20 

2 

0.12 

0.20 

0.27 

3 

0.12 

0.15 

0.30 

3 

0.11 

0.18 

0.18 

NISTa 

NISTb 

0.224 0.407 0.511 0.876 

0.295 0.423 0.506 0.885 0.083 nd 0.158 0.242 

7.27 6.28 10.60 18.1 

6.92 5.91 9.97 17.6 

1.65 2.53 2.34 3.60 

1.68 3.06 2.39 3.80 0.108 0.167 0.154 0.228 

NAV 

NAU 

0.280 0.432 0.519 0.890 

0.059 0.054 0.052 0.077 

0.092 0.031 0.194 0.279 

0.027 0.016 0.019 0.014 

7.07 6.02 10.08 17.7 1.67 2.92 2.38 3.76 

0.80 0.77 0.89 1.4 0.21 0.43 0.25 0.38 

G2
	

All Lab Report Page 1 / 6 
 

 

Round Robin XXXIV Laboratory Results 

Values in μg/mL 

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

Lab 207 208 209 210 207 208 209 210 207 208 209 210 

FSV-BA 0.267 0.213 0.66 1.29 0.252 0.200 0.634 1.24 0.015 0.013 0.025 0.050 

FSV-BD 

FSV-BE 0.243 0.194 0.70 1.42 

FSV-BG 0.226 0.164 0.57 1.17 

FSV-BH 0.234 0.194 0.65 1.31 0.221 0.183 0.606 1.22 0.013 0.011 0.041 0.082 

FSV-BI 0.232 0.182 0.61 1.15 

FSV-BJ 0.291 0.206 0.72 1.31 

FSV-BK 

FSV-BL 

FSV-BM 

FSV-BN 0.279 0.190 0.63 1.16 0.239 0.175 0.540 1.03 0.101 0.077 0.142 0.186 

FSV-BO 0.222 0.154 0.50 0.97 

FSV-BP 0.168 0.115 0.46 0.90 

FSV-BQ 0.316 0.254 0.77 1.51 

FSV-BR 

FSV-BS 0.291 0.187 0.64 1.29 0.258 0.169 0.582 1.22 0.032 0.018 0.057 0.069 

FSV-BT 0.259 0.196 0.64 1.25 0.242 0.185 0.599 1.16 0.017 0.011 0.041 0.090 

FSV-BU 0.212 0.155 0.70 1.06 

FSV-BV >0.22 >0.66 >1.077 0.220 0.660 1.08 

FSV-BY 0.264 0.172 0.62 1.21 

FSV-BZ 0.241 0.146 0.24 0.42 

FSV-CB 

FSV-CD 0.234 0.170 0.55 1.17 

FSV-CH 0.193 0.161 0.54 1.03 

FSV-CJ 0.189 0.161 0.56 1.12 

FSV-CK 0.203 0.233 0.74 1.49 

FSV-CM 

FSV-CN >0.238 >0.636 >1.164 0.238 0.636 1.16 

FSV-CQ 0.338 0.262 0.85 1.48 

FSV-CR 

FSV-CT 0.232 0.165 0.61 1.22 

FSV-CU 0.314 0.222 0.65 1.29 0.263 0.185 0.599 1.22 0.051 0.037 0.046 0.069 

FSV-CV 0.226 0.131 0.57 1.05 

FSV-CX 0.230 0.160 0.52 1.04 

FSV-CY 0.220 0.180 0.61 1.24 

FSV-DA 0.292 0.251 0.79 1.54 0.272 0.233 0.727 1.41 0.020 0.018 0.058 0.130 

FSV-DB 0.140 0.130 0.55 1.24 

FSV-DJ 

FSV-DK 0.326 0.144 0.44 

FSV-DL 0.193 0.125 0.44 1.04 

FSV-DM 0.320 0.232 0.85 1.60 

FSV-DP 

FSV-DS 0.216 0.209 0.57 1.14 

FSV-DX >0.337 >0.24 >0.869 >1.714 0.337 0.240 0.869 1.71 

FSV-EA 0.262 0.178 0.61 1.20 0.237 0.166 0.581 1.16 0.025 0.012 0.029 0.041 

FSV-EH 0.262 0.64 1.21 0.236 0.573 1.09 

FSV-EK 0.248 0.179 0.68 1.43 

FSV-EL 

FSV-FC 0.236 0.185 0.70 1.34 

FSV-FD 0.210 0.140 0.59 1.06 

FSV-FP 0.342 0.234 0.82 1.80 

n 37 36 37 36 12 9 12 12 8 8 8 8 

Min 0.140 0.115 0.24 0.42 0.220 0.166 0.540 1.03 0.013 0.011 0.025 0.041 

Median 0.236 0.180 0.62 1.22 0.241 0.185 0.603 1.19 0.023 0.016 0.044 0.076 

Max 0.342 0.262 0.85 1.80 0.337 0.240 0.869 1.71 0.101 0.077 0.142 0.186 

eSD 0.039 0.037 0.10 0.16 0.022 0.022 0.045 0.06 0.013 0.006 0.021 0.030 

eCV 16 20 16 13 9 12 8 5 56 38 48 39 

NISTa 

NISTb 

0.264 0.208 

0.263 0.198 

0.63 

0.66 

1.20 

1.27 

0.222 

0.230 

0.155 

0.173 

0.535 

0.594 

1.07 

1.15 

0.042 

0.033 

0.053 

0.025 

0.097 

0.064 

0.138 

0.120 

0.249 0.191 

0.051 0.039 

0.63 

0.11 

1.23 

0.17 

0.239 

0.034 

0.175 

0.029 

0.582 

0.067 

1.16 

0.14 

0.030 

0.019 

0.027 

0.026 

0.062 

0.039 

0.103 

0.046 

NAV 

NAU 

G3 

All Lab Report 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-BV 

FSV-BY 

FSV-BZ 

FSV-CB 

FSV-CD 

FSV-CH 

FSV-CJ 

FSV-CK 

FSV-CM 

FSV-CN 

FSV-CQ 

FSV-CR 

FSV-CT 

FSV-CU 

FSV-CV 

FSV-CX 

FSV-CY 

FSV-DA 

FSV-DB 

FSV-DJ 

FSV-DK 

FSV-DL 

FSV-DM 

FSV-DP 

FSV-DS 

FSV-DX 

FSV-EA 

FSV-EH 

FSV-EK 

FSV-EL 

FSV-FC 

FSV-FD 

FSV-FP 

n 

Min 

Median 

Max 

eSD 

eCV 

NISTa 

NISTb 

NAV 

NAU 

Total α-Carotene 

207 208 209 210 

0.025 0.013 0.036 0.047 

0.015 0.010 0.025 0.034 

0.018 0.011 0.032 0.048 

0.022 0.013 0.030 0.035 

0.034 0.026 0.057 0.079 

0.047 0.019 0.050 0.059 

0.017 0.009 0.022 0.032 

0.155 0.157 0.160 0.130 

0.020 0.015 0.030 0.037 

0.013 0.009 0.026 0.035 

0.029 0.046 0.051 

0.019 0.010 0.043 0.044 

0.020 0.030 0.020 0.017 

0.020 0.009 0.026 0.039 

0.011 0.011 0.021 0.032 

0.016 0.012 0.029 0.035 

0.021 0.023 0.054 0.073 

nd nd nd 

0.020 0.010 0.010 0.020 

0.018 0.006 0.018 0.042 

0.010 0.003 0.020 

0.027 0.013 0.035 0.057 

0.015 0.016 0.027 0.035 

0.017 0.015 0.021 0.026 

23 22 23 22 

0.010 0.003 0.010 0.017 

0.020 0.013 0.029 0.038 

0.155 0.157 0.160 0.130 

0.006 0.004 0.012 0.011 

30 35 41 30 

0.023 nd 0.035 0.059 

0.027 0.022 0.044 0.056 

0.022 0.017 0.034 0.047 

0.008 0.010 0.014 0.018 

Round Robin XXXIV Laboratory Results 

Values in μg/mL 

trans-α-Carotene Total Lycopene trans-Lycopene 

207 208 209 210 

0.026 0.019 0.051 0.045 

0.018 0.029 0.038 

207 208 209 210 

0.200 0.213 0.294 0.357 

0.181 0.252 0.304 0.344 

0.117 0.163 0.191 0.208 

0.141 0.190 0.232 0.240 

0.217 0.246 0.314 0.348 

0.190 0.252 0.336 0.432 

0.143 0.088 0.149 0.153 

0.623 0.788 0.906 1.355 

0.186 0.216 0.277 0.308 

0.166 0.214 0.265 0.280 

0.280 nd 0.347 

0.180 0.185 0.276 0.311 

0.160 0.200 0.239 0.286 

0.118 0.183 0.215 0.231 

0.168 0.231 0.299 0.345 

0.191 0.349 0.460 0.587 

0.160 nd 0.337 

0.150 0.190 0.240 0.260 

0.183 0.224 0.215 0.331 

0.166 0.156 0.238 0.319 

0.145 0.199 0.252 0.267 

0.214 0.246 0.344 0.378 

0.219 0.255 0.316 0.373 

0.195 0.282 0.303 

0.240 0.330 0.430 0.470 

0.111 0.115 0.159 0.188 

207 208 209 210 

0.113 0.159 0.177 0.188 

0.108 0.139 0.152 0.171 

0.504 0.620 0.613 0.644 

0.144 0.178 0.216 0.241 

0.096 0.127 0.113 0.168 

0.099 0.148 0.160 

2 1 2 2 26 23 24 26 6 5 6 6 

0.02 0.03 0.04 0.111 0.088 0.149 0.153 0.096 0.127 0.113 0.160 

0.02 0.02 0.04 0.04 0.181 0.214 0.276 0.325 0.111 0.159 0.165 0.180 

0.03 0.05 0.05 0.623 0.788 0.906 1.355 0.504 0.620 0.613 0.644 

0.038 0.047 0.058 0.069		 0.019 0.030 0.050 0.023 

21 22 21 21 17 19 30 13 

0.018 0.014 0.030 0.033 0.221 0.242 0.325 0.358 0.084 0.112 0.139 0.148 

0.201 0.228 0.301 0.339 0.098 0.136 0.158 0.168 

0.055 0.058 0.075 0.080 0.034 0.046 0.054 0.059 

G4 

β-Cryptoxanthin 

207 208 209 210 

0.040 0.054 0.049 0.048 

0.038 0.052 0.052 0.050 

0.032 0.047 0.040 0.038 

0.047 0.060 0.050 0.056 

0.024 0.033 0.034 0.031 

0.010 0.023 0.019 0.016 

nd nd nd nd 

0.034 0.044 0.043 0.043 

0.021 0.028 0.038 0.022 

0.018 0.038 0.021 

0.041 0.050 0.050 0.051 

0.017 0.022 0.022 0.022 

0.033 0.047 0.051 0.057 

0.043 0.065 0.065 0.078 

0.020 0.030 0.030 0.040 

0.030 0.036 0.047 0.045 

0.024 0.026 0.028 0.032 

0.026 0.033 0.028 

17 15 17 17 

0.010 0.022 0.019 0.016 

0.030 0.044 0.040 0.040 

0.047 0.065 0.065 0.078 

0.013 0.015 0.015 0.016 

43 35 37 41 

0.026 0.032 0.033 0.033 

0.029 0.038 0.038 0.038 

0.013 0.018 0.015 0.016 

All Lab Report		 Page 3 / 6 
 

 

Round Robin XXXIV Laboratory Results 

Values in μg/mL 

Lutein Zeaxanthin Lutein&Zeaxanthin 

Lab 207 208 209 210 207 208 209 210 207 208 209 210 

FSV-BA 0.112 0.162 0.111 0.064 

FSV-BD 

FSV-BE 

FSV-BG 

FSV-BH 0.057 0.058 0.054 0.030 nd 0.029 nd nd 0.057 0.087 0.054 0.030 

FSV-BI 0.053 0.070 0.056 0.031 0.020 0.042 0.029 0.020 0.083 0.126 0.086 0.052 

FSV-BJ 

FSV-BK 

FSV-BL 

FSV-BM 

FSV-BN 0.048 0.065 0.056 0.034 0.029 0.035 0.027 0.015 0.080 0.103 0.089 0.051 

FSV-BO 

FSV-BP 

FSV-BQ 

FSV-BR 

FSV-BS 0.068 0.061 0.095 0.171 

FSV-BT 0.075 0.103 0.069 0.037 0.023 0.034 0.022 0.020 0.098 0.137 0.092 0.057 

FSV-BU 0.080 0.110 0.046 0.026 

FSV-BV 0.060 0.083 0.042 

FSV-BY 0.065 0.083 0.067 0.037 0.022 0.019 0.027 0.022 0.087 0.102 0.094 0.059 

FSV-BZ 0.090 0.075 0.070 0.040 

FSV-CB 

FSV-CD 0.120 0.158 0.135 0.071 

FSV-CH 

FSV-CJ 0.105 0.124 0.096 0.056 

FSV-CK 0.114 0.146 0.112 0.071 

FSV-CM 

FSV-CN 

FSV-CQ 

FSV-CR 

FSV-CT 0.058 0.075 0.061 0.036 

FSV-CU 

FSV-CV 

FSV-CX 0.060 0.090 0.070 0.040 

FSV-CY 

FSV-DA 0.069 0.077 0.072 0.057 0.025 0.054 0.033 0.020 0.094 0.131 0.105 0.077 

FSV-DB 

FSV-DJ 

FSV-DK 

FSV-DL 0.080 0.089 0.065 0.067 

FSV-DM 0.087 0.130 0.107 0.055 

FSV-DP 

FSV-DS 

FSV-DX 0.102 0.134 0.096 0.070 

FSV-EA 

FSV-EH 0.053 0.055 0.029 0.027 0.025 0.010 0.084 0.081 0.042 

FSV-EK 

FSV-EL 

FSV-FC 

FSV-FD 

FSV-FP 

n 10 9 10 10 6 6 6 6 17 15 17 17 

Min 0.048 0.058 0.054 0.029 0.020 0.019 0.022 0.010 0.057 0.087 0.046 0.026 

Median 0.062 0.075 0.064 0.037 0.024 0.034 0.027 0.020 0.087 0.126 0.092 0.056 

Max 0.090 0.103 0.095 0.171 0.029 0.054 0.033 0.022 0.120 0.162 0.135 0.077 

eSD 0.012 0.012 0.012 0.007 0.004 0.010 0.003 0.002 0.016 0.030 0.020 0.021 

eCV 19 16 19 18 16 28 11 9 18 24 22 37 

NISTa 

NISTb 0.055 0.075 0.060 0.037 0.024 0.048 0.032 0.019 0.079 0.123 0.092 0.056 

0.060 0.075 0.063 0.037 

0.016 0.017 0.016 0.008 

0.023 0.041 0.030 0.019 

0.007 0.014 0.009 0.006 

0.083 

0.020 

0.124 

0.027 

0.093 

0.021 

0.056 

0.013 

NAV 

NAU 

G5 

All Lab Report Page 4 / 6 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Term
	

n 

Min 

Median 

Max 

eSD 

eCV 

NAV 

NAU 

nd 

>x 

italics 

Round Robin XXXIV Laboratory Results 

Analytes Reported By One Laboratory
	

Values in μg/mL
	

Analyte 

cis-Lutein&Zeaxanthin 

Coenzyme Q10 

Total Carotenoids 

α-Cryptoxanthin

Code 207 208 209 210 

FSV-BT 0.053 0.058 0.072 0.066 

FSV-CH 0.751 1.718 1.243 0.682 

FSV-BT 0.748 0.767 1.252 1.852 

FSV-BT 0.020 0.032 0.023 0.016 

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 "Analysis of Results." 

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

Concentration greater than or equal to x 

Not explicitly reported but calculated by NIST from reported values 

G6
	

All Lab Report Page 5 / 6 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Round Robin XXXIV 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-BV
	

FSV-BY
	

FSV-BZ
	

FSV-CB
	

FSV-CD
	

FSV-CH
	

FSV-CJ 

FSV-CK 

FSV-CM 

FSV-CN 

FSV-CQ 

FSV-CR 

FSV-CT 

FSV-CU 

FSV-CV 

FSV-CX 

FSV-CY 

FSV-DA 

FSV-DB 

FSV-DJ 

FSV-DK 

FSV-DL 

FSV-DM 

FSV-DP 

FSV-DS 

FSV-DX 

FSV-EA 

FSV-EH 

FSV-EK 

FSV-EL 

FSV-FC 

FSV-FD 

FSV-FP 

NISTa 

NISTb 

R aT gT bC tbC 

1 1 1 1 

1 2 1 1 

1 1 1 

1 2 2 

1 1 

1 1 3 

1 1 1 2 

2 1 1 1 1 

3 3 1 1 1 

1 1 3 2 

3 3 3 4 

2 1 1 

1 2 

1 2 

1 2 1 

2 2 2 

1 2 2 1 

2 1 3 2 

1 1 2 2 

3 3 

4 2 2 1 1 

1 3 1 2 

1 3 

2 1 2 

2 2 2 1 1 

1 1 1 

2 1 1 

1 2 2 

3 2 1 

1 1 1 1 1 

1 1 1 1 

1 2 

1 1 2 

1 2 

1 1 

2 2 

1 2 4 

2 2 4 2 

3 2 2 1 

1 1 2 

1 2 

3 3 3 

3 4 2 1 

2 2 3 4 

1 1 1 2 2 

4 4 

1 

1 1 2 2 

2 1 1 1 1 

4 4 1 1 

1 1 1 1 1 

1 1 1 1 1 

n 48 47 23 37 12 

StS 

1 58 45 48 46 75 

2 23 36 30 41 17 

3 13 13 17 8 0 

4 6 6 4 5 8 

% 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 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 

All Lab Report Page 6 / 6 
Appendix H. Representative “Individualized Report” for RR34 

Each participant in RR34 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 
2CW7/1995 

Individualized Round Robin XXXIV Report to: FSV-BA 

Your Data, NIST Assigned Values, and %Differences 

Serum 207 Serum 208 Serum 209 

Anal te You NAV %A n I You NA V %A n I I You NAV %A n I 

Retinal .30 .28 7 38 .46 .43 7 38 .52 .52 0 38 

Retinyl Palmitate .110 .088 26 12 .032 .030 7 7 .199 .177 13 12 

a-T ocopherol 6.80 7.05 -4 37 5.75 5.98 -4 37 9.53 10.06 -5 37 

g-Tocopherol 1.75 1.67 5 18 3.09 2.93 5 18 2.39 2.38 0 18 

Total b-Carotene .267 .252 6 31 .213 .194 10 31 .659 .635 4 31 

trans-b-Carotene .252 .241 5 8 .200 .175 15 8 .634 .584 9 8 

Total cis-b-Carotene .015 7 .013 7 .025 7 

Total a-Carotene .025 .022 14 21 .013 .017 -25 21 .036 .034 5 21 

trans-Lycopene .113 .138 -18 5 .159 .178 -11 5 .177 .196 -10 5 

b-Cryptoxanthin .040 .029 37 13 .054 .040 36 13 .049 .040 23 13 

Lutein&Zeaxanthin .112 .083 35 14 .162 .124 31 14 .ll l .092 20 14 

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

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

%.d : 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 210 

I You NAV %A nl 

.89 .88 1 38 

.275 .263 5 12 

17.28 17.74 -3 37 

3.87 3.76 3 18 

1.290 1.239 4 30 1.240 1.165 6 8 

.050 7 .047 .047 0 20 .188 .215 -13 5 

.048 .039 23 13 

.064 .056 14 14 

Send corrections to: NNMMQAP 222/B208, NIST, Gaithersburg, MD 20899; fax 301-977-0685; email DLDuewer@enh.NIST.gov 

RR34; Pose 1/8 

H2
	
50 

25 

> 

< 

-. 

> x 

< x z v 

0 

d 

* 0 

0 

-

<I 

-25 -50 

Individualized Round Robin XXXIV Report to: FSV-BA 

Retinol, %Li in Round Robin XXV - XXXIV 

I I I I 

6 6 6 6 

4 5 6 7 

x x 

v 

I 

I I I I I 

6 6 7 7 7 

8 9 0 I 2 

x 

x 

v 

I I 

I I I I I 

7 7 7 7 7 

3 4 5 6 7 

·::f!.S· 

--

I I I I I 

8 8 8 8 8 

I 2 3 4 5 

x 

I I I I I 

8 8 8 8 9 

6 7 8 9 0 

Serum 

0 

I I I I 

9 9 9 9 

I 2 3 4 

x x 

x 

I 

I I I I 

9 9 9 9 

5 6 7 8 

x 

x x 

I I 

I 2 2 2 

9 0 0 0 

9 0 I 2 

x 

x x 

I I 

I 

2 2 2 2 

0 0 0 0 

3 4 5 6 

x x x 

Ir 11 

.vl ·· l1 

2 2 2 2 

0 0 0 I 

7 8 9 0 

, 6. Paacl/ 8 

G,.,, C

.. . / 

H3
	
50 -

25 

> 

< 

.......... 

> 

< z v 

.0 

cd 

0 

d 

* 0 

0 

-

<J 

-25 

-50 J 

2tw7/1!195 

Individualized Round Robin XXXIV Report to:: FSV-BA 

Tocopherols, %.1 in Round Robin XXV - XXXIV 

x 

x x x x 

x x x x x 

x v x I x 

v I I I I 

I I I I 

L..J 

• g-Tocopherol ml a-Tocopherol 

I I I I I I I I I I I I I I 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 

6 6 6 6 6 6 7 7 7 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 I 

4 5 6 7 8 9 0 I 2 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 

Serum 

RR:W_ Pqe ) /I 

H4
	
50 

25 

> < 

-.. 

> < z 

..c 0 

c:s 

d 

* 0 

0 

-

<I 

-25 -50 j 

2Mnl(,_) 

'\, 

Individualized Round Robin XXXIV Report to: FSV-BA 

b-Carotene, %A in Round Robin XXV - XXXIV 

x 

x x x v 

v I 

I I 

• all-trans-b-Camtene mi Total b-Carotene 

I I I I I I I I I I I I I I 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 

6 6 6 6 6 6 7 7 7 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 I 

4 5 6 7 8 9 0 I 2 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 

Serum 

0 Plp:4/8 

H5
	
- ±20% 

-- ±50% 

. 

. 

. 

. 

. 

. 

- ±20% 

-- ±50% 

21W7/199S 

Individualized Round Robin XXXIV Report to: FSV-BA 

NIST Assigned Values Vs Laboratory Values 

Retinol 

. 

• • • . 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

• 

• • • . 

. 

a-Tocopherol. • , 

. 

. 

. 

. 

. 

. 

. 

. 

. 

• • .

. 

. 

. 

, 

. 

• .

, 

. 

. 

. 

. 

• . 

• .

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

, 

• , 

A Total 

e trans 

-- ±50% 

- ±20% 

-- ±50% 

. 

. 

. 

. 

. 

. 

. 

b-Carotene 

g-Tocopherol • • . 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

. 

• , 

• .

. 

. 

. 

. 

. 

. 

• .

. 

. 

. 

. 

. 

, 

. 

. 

• • .

. 

. 

. 

. 

, 

Legend 

Shaded Symbols: Round Robin XXV-XXXIII 

Black Symbols: Round Robin XXXIV 

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 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 . 

RR34_ PaacS/& 

H6
	
2!W7/(¢") 

·

. ) 

Individualized Round Robin XXXIV Report to: FSV-BA 

Accuracy /Precision Summary 

Rel a Toe gToc Total -

l1ll\ vll l1ll\ vll l1ll\ vll rn.ll vll 

-1 3 0 3 -6 1 6 3 

0 4 I 2 I 4 I 7 

4 4 0 3 9 6 5 4 

xxv 

XXVI 

XXVII 

XXVIII 

XXIX 

xxx 

XXXI 

XXXII 

XXXIII 

XXXIV 

9 4 4 7 -3 7 9 12 

5 3 -2 5 -1 5 9 9 

-3 2 -1 I -3 3 8 4 -2 2 0 2 11 11 12 13 

4 4 -4 1 3 2 6 3 

(Traditional) Performance Criteria 

1lle absolute value of %/l. 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 lo 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 

l1ll\ vll 

5 3 

0 3 

3 3 

9 12 

9 10 

13 4 

12 6 

9 4 

Legend -

Rel Retinol 

a Toe a-Tocopherol 

gToc g-Tocopherol 

Total Total b-Carotene 

trans al 1-trans-b-Carotene 

l1ll\ Mean difference, Jhe average %A for all sera of a given RR, where 

%!l = 1 OO(Your value - NA V) I NA V 

v!l. Difference variability, one standard deviation of %ll for all sera of a RR 

NAV 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 llll\, the average %ll, and precision 

as v!l., the standard deviation of %A, for all sera of a Round Robin. 

It's best to be accurate and precise (small rn.ll, small v!l.)! 

Good precision (small vll) with poor accuracy (large rn.ll) 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. 

() ' · -· Paac6/I 

H7
	
]l 

81 94 112 208 

----

81 94 112 208 

2CW7/19'.IS 

Individualized Round Robin XXXIV Report to: FSV-BA 

Comparisons to Prior Analyses 

iiJ!J c:::::::ca:I I 

Q) 

- c: 

e Q) 

Q) 

0 fit&J u 8 I ..0 

E- ca , . ....... 

tU 

fI{!l 

0 

EEl 

ltEl 

II r--. ,---·1 r r r - . I I "1 I - 1 I I I I I I I I I I I I 

200 207 201 2()1) 202 210 81 94 112 208 200 207 201 209 202 210 81 94 112 208 200 207 201 209 202 210 

_ 

1 

I - _ 

gl •• -e---- Q) 

.ru 

....... 

u 

I 

1 -Bij 

II r--1 r--1 I 81 94 112 208 r--1 ,---, r-1 t r-.-.--, ,--- , ,----, r--. 200 207 201 2119 202 210 200 207 201 209 202 210 81 94 112 208 200 207 201 2119 202 210 

RR34 l'a&C 7 I 8 

H8
	
Individualized Round Robin XXXIV Report to: FSV-BA 

Comparisons to Prior Analyses (Continued) 

• 

i --------[j -§a . 

D 

BB BB 

11 r - 1 r-· -- 1 , - -r l · ·-1 ,- l r-- I I I 

81 94 112 208 200 1.(J/ 201 2()1) 202 210 81 94 112 208 200 207 201 2()1) 202 210 

_gB- --------8- D c: ·-'5 

------ a -

- - --

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

81 94 112 208 200 1.(JJ 20 I 200 202 210 81 94 112 208 200 207 201 209 202 210 

200.() 

"-··-'"--··"''/ 

n 

, _____ / 

c: 

:s 

c: 

ell 

>< 

• 

0 - - - - - - - _._ 

-

u 

I 

,D 

------

I ;4 1:2 I I I I I I 200 207 201 209 202 2IO 

• ' 

c: 

-------ft B. g. ..c: ·- - fl ---t} -§ >< ell. 

ad 

c: 

"i) 

::s 

-

...l 

.----i- ---r-·1 r ·--i r--i r - 1 

81 94 112 208 200 207 201 20') 202 210 

( ) ··8/8 

,_ 

H9
	
 

 

 

Appendix I. Shipping Package Inserts for RR35 

The following two items were included in each package shipped to RR35 participants: 

• Cover letter 

• Datasheet 

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

samples themselves. 

I1
	
July 14, 1995 

UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standards and Technology 

Gaithersburg, Maryland 20899-

Dear Colleague: 

Enclosed is the set of samples for the third round robin exercise (Round Robin XXXV). You 

will find one vial each of four lyophilized sera 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 the detection limit, please indicate 

this result on the form by using ND (Not Detected). For values not ob~ained, please leave a 

blank for the given analyte. Results will be due to NIST by September 15. 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 to you by October 20. 

Samples should be reconstituted with 1.0 mL of HPLC-Grade water or equivalent. We 

recommend that dissolution be facilitated with 3 to 5 minutes agitation in an ultrasonic bath 

or at least 30 minutes 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 retinal 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, 97 5 at 

325 nm; a-tocopherol, 75.8 at 292 nm; y-tocopherol, 91.4 at 298 nm; a-carotene, 2800 at 

444 rim; f3-carotene, 2560 at 450 nm; lycopene, 3450 at 472 nm. 

Please mail or FAX your results for Round Robin XXXV 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 

or mail/FAX queries to the above address. 

\~~ ~incerely, . ~: · ·. ' 

·.\ t>A>. .: -- :· :.Jb'~IAll. ( _ ~ / 

~\Je~~~ce Brown T~mas ~search Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosures 

cc: W. May 

S. Wise N•Si I2
	
 

 

 

 

 

 

NIST/NCI 

Micronutrients Measurement Quality Assurance Program 

Round Robin XXXV Results from Laboratory #_____ 

Serum 

Analyte 211 212 213 214 Units* 

retinol 

retinyl palmitate 

a-tocopherol 

g-tocopherol 

total b-carotene 

trans-b-carotene 

total cis-b-carotene 

total a-carotene 

total lycopene 

trans-lycopene 

b-cryptoxanthin 

lutein 

zeaxanthin 

lutein&zeaxanthin 

Other Analytes?
	

* We prefer results as microgram/milliliter. 

Comments? 

Mail: NNMMQAP, 222/B208 

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

Gaithersburg, MD 20899 September 15, 1995 Email: DLDuewer@enh.NIST.gov 

I3
	
 

 

 

 

 

Appendix J. Final Report for RR35 

The following 19 pages are the final report for RR35 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 3, 1995 

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 XXXV. This report 

summarizes both overall and individual laboratory performance for the three round robin 

exercises conducted during 1995. Included in this report are: tabular summaries of data for 

Round Robins XXXIII, XXXIV, and XXXV; a graphical summary of the interlaboratory 

median vs. individualized laboratory data for retinol, a.- and y-tocopherol, and total and transP-carotene; percent bias charts for retinol, a.- and y-tocopherol, and trans- and total Pcarotene; 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. 

The overall interlaboratory precision of retinol and a.-tocopherol measurements has remained 

at an average estimated coefficient of variation ( eCV) of approximately 10% over the past 

three years, and around 21 % for P-carotene during the same period of time. The eCV for ytocopherol has remained at about 10% over the past 18 months. 

Round Robin XXXIII (Sera 203-206) consisted of a dilution series where Serum 205 was a 

1: 1 volumetric mix of Serum 203 and stripped serum; Serum 204 was a 1 :2 volumetric mix of 

Serum 203 and the stripped serum. Serum 206 was previously distributed in Round Robin 

XVIII as Serum 120 and in Round Robin XXI as Serum 147. The results from this exercise 

indicate that the measurement capability for retinol, a.- and y-tocopherol, and P-carotene is 

adequate. 

Round Robin XXXIV consisted of Sera 207-210 where Sera 207, 209, and 210 were 

previously distributed as Sera 200, 201, and 202 , respectively in Round Robin XXXII and 

are the three concentration levels of SRM 968b. Serum 208 (also identified as Control B in 

earlier studies) was previously distributed as Serum 81 in Round Robin XII, Serum 94 in 

Round Robin XIII, and Serum 112 in Round Robin XVI. In this study, the average eCV for 

retinol and a.- and y-tocopherol was 9-10% and 17% for P-carotene. Results from this study 

demonstrated that the interlaboratory measurement reproducibility over the past 18 months has 

improved. 

Round Robin XXXV (Sera 211-214) consisted of a replicate dilution series. Sera 211, 212, 

and 214 were previously distributed in Round Robin XXXI as Sera 197, 198, and 195, 

respectively. Serum 213 was distributed in Round Robin XXX as Serum 191. Sera 195, 197, 

and 198 are a dilution series. Serum 198 was blended from native sera that was high in Pcarotene. Serum 195 is a 1: 1 blend of Serum 198 and stripped serum. Serum 197 is a 1 :3 

blend of Serum 198 and stripped serum. Serum 191 is a blend of native serum that was 

supplemented with a high level of retinol. 

N•Si 

The tabular summaries for Round Robins XXXIII and XXXIV mentioned below 

are provided in previous Appendices of this document and are not repeated here.
	

J2
	
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 of 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 last year, the fees for non-NCI funded laboratories will be $300 for US labs and $600 for 

non-US labs. An invoice to that effect will be mailed in January. 

The 1996 QA Program will consist of three round robin exercises for the analysis of fat-soluble 

vitamins and carotenoids in serum, two studies for the analysis of ascorbic acid in serum, and 

two exercises for the analysis of fat-soluble vitamins and carotenoids in food. The FY96 program 

thrusts will continue to include methods development for the measurement of 

difluoromethylomithine, 4-hydroxyphenylretinamide, and selenomethionine in serum. Attention 

will also be focused on agents that are currently in preclinical efficacy and toxicity trials 

( e.g.,epigallocatechin gallate, phenethyl isothiocyanate, indole-3-carbinol, dimethyl fumarate, 

and curcumin). 

The first set of samples for the fat-soluble vitamins in serum analysis will be distributed the week 

of January 22. Results are due by March 15; written feedback will be provided to labs by April 

12. The second set of samples will be shipped the week of April 29 with results due by June 14 

and feedback to labs by July 26. The third set of samples will be shipped the week of July 29. 

Results will be due by September 20. Feedback will be provided to the laboratories by October 

25. 

The round robin studies for the analysis 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). 

The first set of samples for the analysis of ascorbic acid in serum will be distributed in February. 

The second set will be distributed in May. These round robin studies are being coordinated by 

Dr. Sam Margolis (301/975-3137). 

The next QA workshop will be held Saturday, April 13 as a pre-meeting in conjunction with 

Experimental Biology '96 in Washington, DC. Details of the workshop will be provided as 

plans are finalized. 

J3
	
( 

Certificates of participation in the FY95 QA Program will be distributed again in January. If 

you have suggestions regarding improvements to the certificates, please contact us. We are 

also in the process of developing a home page through the Internet for the QA program. You 

will be updated as to when it becomes available. 

Sincerely, 

anice Brown Thomas 

Research Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

cc: W. May 

J4
	
Lies, Damn Lies, and Statistics 

"Lies, Damned Lies, and Statistics" 

Marie Twain 

Page 1 

The attached N2M2QAP Round Robin XXXV Report is identical (!)in form to RR XXXIV's. It 

includes an exhaustive analysis of your results (the "Individualized" report), a complete listing of 

everyone's results (the "All Lab" report), and the details of the NIST value and uncertainty 

assignments (the "Report of (Meta)Analysis for RR XXXV Sera: 211-214"). 

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-~-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, 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-~-carotene 

8 Comparison-to-Prior-Analyses plots for cis-~-carotene, total a-carotene, total 

lycopene, ~-cryptoxanthin, lutein, 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 #213 was distributed as #191 in Round Robin XXX. This serum was prepared to 

have high levels of the retinoids, tocopherols, and trans-~-carotene. (It has a very high level 

of retinol, one representative of extreme retinol poisoning.) The "true value" line is the 

average of the assigned values for the two Round Robins. 

Serum #211, 212, and 214 were distributed as #197, 198, and 195, respectively, in Round 

Robin XXXI. These sera were prepared as a concentration series by dilution of a blended 

native serum with delipidized serum. The level of analytes in serum 214 is 50% of that in 

serum 212 and the level in serum 211is25% of that in 212. There are thus two sets of "true 

value" lines: the horizontal lines are the average of the assigned values for the two Round 

Robins. The sloping lines represent the expected dilution relationship. 

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. 

5a A list ofresults 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") 

J5
	
Lies, Damn Lies, and Statistics Page2 

The Legend for the data summary lists all the "flag codes" we currently use. Two new codes 

have been added: "?" and "*". The "?" indicates non-quantitative values resulting from the 

analyte level being above the limit of quantification of the routine calibration curve. The "*" 

indicates non-quantitative values resulting from a miscellany of causes: broken vial, instrument 

malfunction, etc. These codes have been introduced to insure that values you report as somehow 

suspect are not included in the statistical and "Score card" calculations. We want to keep as 

accurate a record of measurement results as possible, but do not wish to in any way "punish" 

anyone for honest reporting of results recognized as non-quantitative. 

The "?" code for non-quantitative high values was suggested by Laboratory 70. They recognized 

that the value from the routine analysis was beyond the range of their calibration, but were 

unable to rerun a properly diluted sample. We believe that "?" is a better code for such 

extrapolated values than is the upper-limit of quantification code ''>x". We believe that 

differentiating extrapolation-related from other sources of non-quantitative values is important, 

as the recognition of "toxic high level!" is the critical aspect of the retinol in serum 213. 

Note that the dilution series ( [212], [214] = [212]/2, [211] = [212]/4) enables you to estimate 

your effective limits of quantification ("LOQ"s) for some of the analytes in these lyophilized 

sera. For example, as described in the "Report of (Meta)Analysis", the NIST LOQs are below 

the serum 211 levels for retinol, a- and y-tocopherol, total and trans-~-carotene, and lutein. The 

LOQs are between the serum 212 and 211 levels for retinyl palmitate, total and trans-a-carotene, 

total and trans-lycopene, ~-cryptoxanthin, and zeaxanthin. The LOQ for 0.tocopherol is at least 

as high as the serum 214 level. The Comparison-to-Prior-Analyses plots present all the values 

required for you to make your own LOQ determinations. We encourage you to report "<X" 

(where x is your LOQ) for values below your LOQ; "nq" is acceptable, but is less informative. 

Please reserve "ntf' (or "0") for situations where you find no evidence forthe analyte's presence 

in the sample. 

The interlaboratory medians for nearly all analytes reported in this Round Robin are very similar 

to those reported previously, and the observed distribution of values among reporting 

laboratories is generally tighter. Thus, we believe that interlaboratory measurement performance 

for most analytes is again improving. (We're still working on methods to more quantitatively 

document such trends ... ) However, the lutein and especially the zeaxanthin values are suspect. 

The poorer performance for lutein and zeaxanthin is not surprising, as some of you measure a 

combined "lutein and zeaxanthin" peak, others measure lutein and zeaxanthin independently, 

some just estimate lutein, and a few laboratories differentiate all-trans- and cis-isomers. Our 

separation system may provide resolved peaks for trans-lutein and trans-zeaxanthin, but we have 

J6
	
Lies, Damn Lies, and Statistics Page3 

thus far not determined whether any of the cis-isomers are included under these dominant peaks. 

There are many peaks eluting in this region; most of them remain to be i~ntified. 

The retinol level in serum 213, while about that of an actual polar-bear-liver poisoning case, 

represents an extreme "Challenge Sample." We promise not to distribute it again for a few 

years ... As we should have freeze-dryer capability again soon, we anticipate introducing a 

number of new and "more interesting" samples in '96. We intend to explore the expected high 

levels for many of the carotenoids. The attached Table summarizes the analyte distributions we 

have gleaned from recent literature. 

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 

DLDuewer@enh.NIST.gov 

Margaret Kline 

Research Biologist 

Kline@enh.NIST.gov 

J7
	
Lies, Damn Lies, and Statistics Page4 

Recent Literature Statistics0 for Selected Analytes 

Stud n -Carotene a-Carotene 13-C toxanthin 

Bieri { 1} 5 0.28±.13 [0.13 0.33 0.46] 0.071±.032 [0.029 0.082 0.11] 0.15±.09 [0.07 0.13 0.30] 

Stacewicz { 2} 110 0.20±.19 [0.02 0.69] 0.034±.023 [0.0 0.12] 0.09±.06 [0.020 0.27] 

,Cavina {3} 14 0.31±.17 [0.08 0.26 0.58] 0.022±.017 [0.005 0.023 0.06] 0.20±.17 [0.051 0.15 0.70] 

'Cantilena {4} 33 0.14±.08 0.045±.034 0.10±.04 

Olmedilla {5} 307 0.29±.18 0.062±.054 

IAscherio {6} 43 0.18±.08 [0.05 0.17 0.44] 0.043±.023 [0.007 0.039 0.12] 0.28±.23 [0.052 0.21 1.1 1 

Stacewicz { 7} 160 0.19±.14 [0.02 0.80] 0.048±.037 [0.003 0.24] 0.10±.07 [0.0 0.47] 

Sowell {8} 3480 0.18 [0.04 0.37]c 0.043 [0.011 0.12]c 0.12 [0.03 0.29]c 

Sharoless f 91 1402 0.17±.19 0.02 0.13 0.43 c 0.036±.036 0.006 0.026 0.09 c 0.09±.11 0.001 0.053 0.29lc 

L co ne Lute in Zeaxanthin 

Bieri 0.32±.17 [0.20 0.29 0.62] 0.28±.10 [0.17 0.32 0.41] b 

Stacewicz 0.20±.12 [0.015 0.71] 0.18±.09 [0.044 0.45] b 

Cavina 0.40±.18 [0.010 0.37 0.81] 0.28±.09 [0.13 0.27 0.46] b 

'Cantilena 0.14±.05 0.20±.08 b 

Olmedilla 0.42±.19 0.16±.06 0.036±.017 

Ascherio 0.31±.15 [0.068 0.28 0.65] 0.15±.07 [0.063 0.14 0.43] 0.045±.022 [0.015 0.041 0.10] 

Stacewicz 0.29±.16 [0.009 0.80] 0.12±.06 [0.020 0.38] 0.030±.017 [0.0 0.11] 

Sowell 0.21 [0.06 0.43]c 0.20 [0.08 0.42]c b 

Sharoless 0.13±.08 ro.025 0.11 0.49 c 0.13±.06 0.053 0.12 0.25 c 0.037±.018 0.014 0.035 0.071c 

a-Tocopherol y-Tocooherol Retinol ' Bieri 

Stacewicz ,0.70±.19 [0.38 1.3 1 

Cavina 13±3 [7.0 13 19] 0.65±.22 [0.35 0.58 1.21 

Cantilena 

Olmedilla 11±4 0.6±0.3 

Ascherio 15±3 [9.0 15 25] 0.57±.14 [0.31 0.54 0.86] 

Stacewicz 14±5 [6.3 34] 3.1±1.6 [0.3 10 1 0.64±.18 (0.30 1.21 

Sowell 11 [6.0 21]c 0.55 [0.30 0.85]c 

Sharoless 11±6 5.8 9.8 110 c 1.8±1.1 0.47 1.6 3.9 c 0.56±.17 0.33 0.54 0.87 c 

a Mean±SD and [minimum median maximum], expressed in μg/mL. Values recalculated from literature data as necessary. 

b The corresponding lutein values report lutein + zeaxanthin. 

c [5% median 95%] range reported rather than [minimum median maximum). 

J8
	
Lies, Damn Lies, and Statistics 

References 

1 Bieri JG, Brown ED, Smith JC Jr. 1985. Determination of Individual Carotenoids in 

Human Plasma by High Performance Liquid Chromatography. Journal of Liquid 

Chromatography 8(3) 473-484. 

2 Stacewicz-Sapuntzakis M, Bowen PE, Kikendall JW, Burgess M. 1987. 

Simultaneous Determination of Serum Retinol and Various Carotenoids: Their 

Distribution in Middle-aged Men and Women. Journal of Micronutrient Analysis 3 

27-45. 

3 Cavina G, Gallinella B, Pomi R, Pecora P, Suraci C. 1988. Carotenoids, Retinoids, 

and alpha-Tocopherol in Human Serum: Identification and Determination by 

Reversed-phase HPLC. Journal of Pharmaceutical and Biomedical Analysis 6 

259-269. 

4 Cantilena LR, Nierenberg DW. 1989. Simultaneous Analysis of Five Carotenoids in 

Human Plasma by Isocratic High Performance Liquid Chromatography. Journal of 

Micronutrient Analysis 6 127-145. 

5 Olmedilla B, Granado F, Blanco I, Rojas-Hidalgo E. 1992. Determination of Nine 

Carotenoids, Retinol, Retinyl Palmitate, and cx-Tocopherol in Control Human Serum 

Using Two Internal Standards. Food Chemistry 45 205-213. 

6 Ascherio A, Stampfer MI, Colditz GA, Rimm EB, Litin L, Willett WC. 1992. 

Correlations of Vitamin A and E Intakes with the Plasma Concentrations of 

Carotenoids and Tocopherols among American Men and Women. Journal of 

Nutrition 122 1792-1801. 

7 Stacewicz-Sapuntzakis M, Bowen PE, Mares-Perlman, IA. 1993. Serum Reference 

Values for Lutein and Zeaxanthin Using a Rapid Separation Technique. Carotenoids in 

Human Health. Eds: Canfield LM, Krinsky NI, Olson IA. Annals of the New York 

Academy of Sciences, Vol. 691: 207-209. 

8 Sowell AL, Huff DL, Yeager PR, Caudill SP, Gunter EW. 1994. Retinol, 

cx-Tocopherol, Lutein/Zeaxanthin, 13-Cryptoxanthin, Lycopene, ex-Carotene, 

trans-j3-Carotene, and Four Retinyl Esters in Serum Determined Simultaneously by 

Reversed-Phase HPLC with Multiwavelength Detection. Clinical Chemistry 40 

411-416. 

9 Sharpless KS, Duewer DL. 1995. Population Distributions and lntralaboratory 

Reproducibility for Fat-Soluble Vitamin-related Compounds in Human Serum. 

Analytical Chemistry, scheduled for publication Dec 1, 1995. 

Page 5 

J9
	
Report of (Meta)Analysisfor RR XXXV Sera: 211-214 Page I 

From: David L. Duewer Pate: October 31, 1995 

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 XXXV (RR35) Sera: #211to214. 

Background: Four sera were distributed in RR35. Sera 211, 212, and 214 had been distributed 

as sera 197, 198, and 195, respectively, in Round Robin XXXI (RR31); serum 213 had been 

distributed as serum 191 in Round Robin XXX (RR30). Seta 212, 214, and 211 are a dilution 

series: serum 212-stock was blended from native sera high in J3-carotene, serum 214 is a 50:50 

blend of 212-stock and delipidized serum, and serum 211 is a 25:75 blend of 212-stock and 

delipidized serum. Serum 213 is a blend of native sera augmented to a very high retinol level. 

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, aand y -tocopherol, total and trans-J3-carotene, and total a-carotene. In addition, analyst NIST3 

reported results for retinyl palmitate, S-tocopherol, trans-a-carotene, total and trans-lycopene, 13-

cryptoxanthin, "lutein", and "zeaxanthin". (NIST3 is uncertain about the isomeric composition 

of the single peaks observed for lutein and zeaxanthin: while mostly the respective all-trans 

isomers, they may include some as yet unknown proportion of the cis isomers.) 

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

interlaboratory results for serum 191 in RR30 and sera 195, 197, and 198 in RR31, summary 

interlaboratory results for sera 211 - 214 in RR35, 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 sera are listed in order of decreasing retinol concentration, facilitating 

interpretation of the dilution series: [212], [214] = [212]/2, [211] = [212]/4. 

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. 

°x 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. 

SD1ie111 among-sample standard deviation, reflecting heterogeneity in preparing and 

reconstituting the serum samples 

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

replicates reduce the true degrees of freedom. 

CV NISTx 1 OO*SD Nisr/Meanx 

J10
	
Report of (Meta)Analysisfor RR XXXV Sera: 211-214 

• NIST Summary Statistics 

n number of quantitative values for this analyte for this serum 

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

SDrep within-vial pooled standard deviation 

SD1ie1 among-sample standard deviation 

Page2 

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

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

analytes that NISTl did not report, SD8111 is estimated from the regression of the 

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

regression model used to determine SDan1 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~1 + SD~1 • total standard deviation for NIST analyses. 

CV NIST 100*SDN1s/Mean 

• 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 0.7421 *InterQuartile Range (IQR). The IQR is a robust dispersion estimate. 

The scale factor 0.7421 is the expected ratio between SD and IQR for normal 

distributions. 

• Round Robin XXXV Summary Statistics 

~ 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 0.7421 *InterQuartile Range (IQR) 

( !Median0 - MedianPl~.--n_+_n_P ___ 2 . ) 

P(n=p) TDIST , ~+n -2, 2 tail 

{ (n0 -1 )eSD~ + (nP -1 )eSD! )(_!_ + _!_] 

nn 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 = 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. 

P( ) FDIST( eSD~ n -1 n -1) n<p eSD! • ";! ' -,, 

This represents the approximate probability that the interlaboratory variance in 

RR35 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. 

SD1abs ~eSD~ -SD~ST, the residual non-NIST interlaboratory biases after correction 

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

When SDNIST is greater than eSD0 , SDlabs = 0. 

CV1abs 100*SD ab/Medi~ 

J11
	
Report of (Meta)Analysisfor RR XXXV Sera: 211-214 

• NIST Assigned Values and Uncertainties 

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

NAU Maximum( 0.05*NA V, ~SD~+ SD~ ), our best guess for the "true" 

interlaboratory standard deviation characterizing measurement, sample 

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

SDJabs could not be determined, NAU is estimated as 

Max.imum(O.lO*NAV, ~2 SD~T ). 

CV lOO*NAU/NAV 

Page 3 

Conclusions: The retinol, ex- and y-tocopherol, total and trans-j3-carotene, and "lutein" values 

are fully compatible with the known dilution series ((214] = (212]/2, (211] = [212]/4); NIST's 

limits of quantification (LOQ) for these analytes are below the levels of serum 211. The retinyl 

palmitate, total and trans-ex-carotene, total and trans-lycopene, j3-cryptoxanthin, and 

"zeaxanthin" values are compatible with the dilution series for sera 214 and 212, but the serum 

211 values are higher than expected; NIST's LOQ for these analytes are therefore somewhere 

between the levels of sera 214 and 211. The 5-tocopherol values are not compatible with the 

dilution series; NIST's LOQ for this analyte is at least as high as the level in serum 212. 

All median values from RR35 (Media:I\i) are statistically indistinguishable at the 95% confidence 

level from the corresponding values (Media.I\,) determined in RR30 and RR3 l. Nearly all of the 

interlaboratory standard deviations from RR35 (eSD0 ) are smaller than the corresponding 

previous values ( eSDp). Most of the few increases can be accounted for by insufficient or 

contradictory data in me earlier RR: only the ex- and y-tocopherol eSD0 values for serum 212 may 

have actually increased (9.9 vs. 7.0% and 8.5 vs. 5.3%, respectively). Therefore: 1) none of the 

sera degraded during storage and 2) the interlaboratory reproducibility has improved somewhat 

over the past 12 to 18 months. 

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. 

To better account for the NIST versus non-NIST sources of variation, the standard estimate of 

error for the regression has been included into the total NIST standard deviation. In general, this 

"analyst" or "method" component is greater than or equal to the analytical repeatability and 

sample heterogeneity components. For low levels of all analytes, it is the dominant component. 

For total ex-carotene and r -tocopherol in these sera, the NIST analyses are now revealed as being 

at least as variable as the interlaboratory values. For ex-carotene, this probably just reflects the 

quantification limit: we need sera with higher native "minor" carotenoid levels and/or methods 

for selectively augmenting their levels. For y-tocopherol, it is another indication that we need to 

re-evaluate our methodologies. This modification of the analysis of variance does NOT affect 

either the NIST assigned value (NAV) or the NIST assigned uncertainty (NAU); it only 

redistributes part of what was previously attributed to interlaboratory biases onto NIST. The 

SDNIST can be interpreted as defining NIST's "true" measurement uncertainty. 

This memo will be attached as the Appendix to RR35' s "Lies, Damn Lies, and Statistics" report. 

J12
	
Report of (Meta)Analysis for RR XXXV Sera: 211-214 

Table 1 

NIST Data and Calculations 

Retinol Retinyl Palmitate 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n, 

Mean, 

so. 

SDreox 

SDbetx 

NISTl 

211 212 213 214 

0.210 0.734 6.63 0.353 

0.191 0.712 6.86 0.369 

0.192 0.687 6.63 0.369 

0.179 0.733 6.42 0.353 

0.198 0.723 6.57 0.380 

0.190 0.684 6.45 0.381 

6 6 6 6 

0.193 0.712 6.59 0.368 

0.010 0.022 0.16 0.012 

0.010 0.026 0.14 0.010 

0.008 0.010 0.13 0.011 

NIST3 

211 212 213 214 

0.195 0.736 7.71 0.363 

0.180 0.725 6.98 0.373 

0.172 0.684 6.71 0.339 

0.176 0.683 6.79 0.346 

0.169 0.702 6.96 0.365 

0.174 0.711 6.96 0.376 

6 6 6 6 

0.178 0.707 7.02 0.360 

0.009 0.022 0.36 O.D15 

0.006 0.006 0.30 0.007 

0.009 0.024 0.30 0.016 

SDmsr. 0.013 0.028 0.19 O.oI5 0.011 0.024 0.42 0.017 

CYmsrx 6.5 3.9 2.9 4.0 6.1 3.4 6.0 4.7 

n 

Mean 

SDrcn 

SD bet 

SDan1 

NIST 

12 12 12 

0.185 0.709 6.81 

0.008 0.019 0.23 

0.009 0.019 0.21 

0.014 0.014 O.Ql 

12 

0.364 

0.008 

0.013 

0.014 

SDNIST 0.019 0.030 0.32 0.021 

CVNIST 10 4.2 4.6 5.7 

RR XXXI XXXI XXX XXXI 

Serum 

Do 

Median0 

eSD0 

n. 

Median. 

eSD0 

P(n=p) 

P(n<p) 

197 198 191 195 

38 39 41 38 

0.195 0.725 6.84 0.378 

0.024 0.067 0.87 0.039 

RRXXXV 

211 212 213 214 

42 42 40 42 

0.196 0.737 6.93 0.383 

0.021 0.068 0.77 0.035 

1.00 0.97 0.98 0.97 

0.81 0.46 0.79 0.77 

SDlabs 0.008 0.061 0.70 0.028 

cv1abs 4.2 8.3 10 7.3 

NIST3=a+b*NIST1 

a: -0.039 ±0.009 

b: 1.070 ±0.003 

R2: 1.000 

<- Previous Results -> 

<-Current Results -> 

NAY 0.190 0.723 6.87 0.374 <-Assignments-> 

NAU 0.021 0.068 0.77 0.035 

CV 11 9.4 11 9.3 

13S_dalJNISTtxt 

NISTl 

211 212 213 214 

0 0 0 0 

NIST 

1 6 6 6 

0.01 0.205 0.113 0.082 

0.021 0.014 0.009 

0.019 0.011 0.011 

0.02 O.D19 0.019 0.019 

0.034 0.026 0.024 

17 23 29 

XXXI XXXI XXX XXXI 

197 198 191 195 

6 8 10 7 

0.06 0.262 0.156 0.106 

0.01 0.069 0.031 0.025 

RRXXXV 

211 212 213 214 

10 11 11 11 

0.05 0.297 0.135 0.126 

0.02 0.036 0.022 0.022 

0.92 

0.26 

0.76 

0.97 

0.012 

4.1 

0.73 

0.87 

0 

0 

0.68 

0.66 

0 

0 

0.251 0.124 0.104 

0.036 0.026 0.024 

14 21 23 

NIST3 

211 212 213 214 

0.01 0.213 0.139 0.074 

0.237 0.113 0.091 

0.203 0.114 0.088 

0.172 0.099 0.097 

0.194 0.106 0.079 

0.209 0.109 0.061 

1 6 6 6 

0.01 0.205 0.113 0.082 

0.022 0.014 0.013 

0.017 0.012 0.011 

0.019 0.011 0.011 

0.026 0.016 0.016 

13 14 19 

NIST3=a+b*Median 

a:O 

b: 0.696 ±0.054 

R2: 0.892 

Paae I /7 J13
	
A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

Dx 

Meanx 

so. 

SDr.ox 

SD11e1x 

211 

3.83 

3.67 

3.61 

3.52 

3.58 

4.09 

6 

3.72 

0.21 

0.22 

0.14 

Report of(Meta)Analysisfor RR XXXV Sera: 211-214 

Table 1 

NIST Data and Calculations 

a-Tocopherol y-Tocopherol 

NISTl NIST3 NISTl 

212 213 214 211 212 213 214 211 212 213 214 211 

14.8 23.8 7.35 3.27 13.5 22.6 6.63 0.67 2.70 2.97 1.25 0.61 

14.8 23.8 7.25 2.86 13.7 22.1 6.64 0.70 2.78 3.68 1.51 0.60 

14.5 23.5 7.68 2.71 12.8 21.6 6.41 0.69 2.75 3.36 1.38 0.55 

14.1 24.2 7.28 2.88 12.7 21.9 6.49 0.63 2.50 3.21 1.41 0.56 

14.5 24.7 7.18 3.05 13.1 25.3 7.20 0.66 2.64 3.53 1.36 0.57 

13.7 22.7 7.03 2.77 13.1 24.4 7.07 0.79 2.87 3.21 1.41 0.56 

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

14.4 23.8 7.29 2.92 13.2 23.0 6.74 0.69 2.71 3.33 1.39 0.58 

0.5 0.7 0.22 0.21 0.4 1.5 0.32 0.06 0.13 0.25 0.08 0.02 

0.4 0.9 0.18 0.21 0.1 0.4 0.06 0.06 0.15 0.32 0.11 0.01 

0.4 0.1 0.19 0.14 0.4 1.6 0.35 0.03 0.07 0.04 0.01 0.03 

NIST3 

212 213 214 

2.38 3.23 1.24 

2.37 3.19 1.21 

2.30 3.05 1.18 

2.30 3.11 1.20 

2.33 3.33 1.20 

2.32 3.23 1.18 

6 6 6 

2.33 3.19 1.20 

0.04 0.10 0.02 

0.01 0.05 0.02 

0.04 0.10 0.02 

SDNJsrx 0.26 0.5 0.9 0.26 0.25 0.4 1.7 0.36 0.07 0.16 0.33 0.11 0.03 0.04 0.11 0.02 

CVNJsrx 7.0 3.8 3.7 3.6 8.7 3.2 7.3 5.3 10 6.0 9.8 7.8 4.8 1.8 3.5 2.0 

n 

Mean 

SD'"" 

SDi,.. 

SDID I 

12 

3.32 

0.21 

0.12 

0.34 

NIST 

12 12 12 

13.8 23.4 7.02 

0.3 0.6 0.13 

0.4 1.0 0.29 

0.3 0.3 0.34 

SDNIST 0.42 0.6 1.3 0.47 

CV NIST 13 4.4 5.4 6.6 

RR XXXI XXXI XXX XXXI 

Serum 

Do 

Median0 

eSD0 

n. 

Median. 

eSD0 

P(n=p) 

P(n<p) 

197 

39 

3.63 

0.53 

211 

43 

3.62 

0.58 

1.00 

0.29 

198 191 195 

40 43 39 

14.2 24.0 7.18 

1.0 2.9 0.83 

RRXXXV 

212 213 214 

42 43 43 

14.1 24.4 7.10 

1.4 2.4 0.83 

0.99 0.97 0.98 

0.03* 0.89 0.51 

SDlabs 0.40 1.3 2.0 0.69 

cvlabs 11 9.o 8.2 9.7 

NIST3=a+b*NIST1 

a: -0.73 ±0.32 

b: 0.99 ±0.02 

R2: 0.998 

<-Previous Results -> 

<-Current Results -> 

NA V 3.47 13.9 

NAU 0.58 1.4 

23.9 7.06 <-Assignments-> 

2.4 0.83 

CV 17 IO 9.9 12 

J3S_dalJNISTtxt 

NIST 

12 12 12 12 

0.63 2.52 3.26 1.29 

0.04 0.10 0.23 0.08 

0.04 0.09 0.11 0.04 

0.13 0.13 0.13 0.13 

0.14 0.19 0.29 0.16 

22 7.5 8.8 12 

XXXI XXXI XXX XXXI 

197 198 191 

15 16 20 

0.71 2.62 3.58 

0.15 0.14 0.27 

RRXXXV 

211 212 

20 19 

0.74 2.72 

0.14 0.23 

0.95 0.85 

0.62 0.03* 

0 0.13 

0 4.6 

213 

19 

3.62 

0.27 

0.96 

0.50 

0 

0 

195 

15 

1.35 

0.18 

214 

19 

1.34 

0.10 

0.98 

0.99 

0 

0 

0.68 2.62 3.44 1.32 

0.14 0.23 0.29 0.16 

21 8.6 8.3 12 

NIST3=a+b*NIST1 

a:O 

b: 0.91 ±0.03 

R2: 0.976 

Page2/7 J14
	
Report of(Meta)Analysisfor RR XX.XV Sera: 211-214 

Table 1 

NIST Data and Calculations 

0-Tocopherol Total 13-Carotene 

NISTl NIST3 NIST! NIST3 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n, 

Mean, 

so. 

SDreox 

SDbcu 

SDNISTx 

CVNis-rx 

n 

Mean 

SD"'1> 

SDbet 

SDan1 

SD NIST 

CVNIST 

211 212 213 214 

0 0 0 0 

NIST 

5 6 6 6 

0.05 0.159 0.219 0.08 

0.01 0.006 0.005 0.01 

0.00 0.010 0.005 0.00 

0.07 0.071 0.071 0.07 

0.07 0.072 0.071 0.07 

150 45 32 86 

RR XXXI XXXI XXX XXXI 

Serum 

Do 

Median0 

eSD0 

Dn 

Median. 

eSD. 

P(n=p) 

P(n<p) 

SD!abs 

cvlabs 

197 

0 

211 

1 

0.05 

198 191 195 

0 0 0 

RRXXXV 

212 213 214 

1 1 1 

0.330 0.170 0.01 

211 212 213 214 211 212 213 214 

0.04 0.162 0.218 0.07 0.177 0.717 1.65 0.355 

0.175 0.230 0.09 0.175 0.710 1.64 0.384 

0.06 0.161 0.213 0.09 0.175 0.729 1.64 0.416 

0.04 0.156 0.216 0.08 0.177 0.749 1.77 0.383 

0.06 0.153 0.212 0.08 0.175 0.785 1.74 0.392 

0.04 0.146 0.223 0.09 0.148 0.753 1.64 0.404 

5 6 6 6 6 6 6 6 

0.05 0.159 0.219 0.08 0.171 0.741 1.68 0.389 

O.ot 0.010 0.007 0.01 0.011 0.028 0.06 0.021 

0.01 0.006 0.007 0.01 0.011 0.016 0.07 0.019 

0.00 0.010 0.005 0.00 0.008 0.028 0.03 0.017 

O.Ql 0.011 0.008 0.01 0.014 0.032 0.08 0.025 

21 7.2 3.8 16 8.1 4.3 4.5 6.5 

NIST3=a+b*Median NIST 

6 12 10 11 

a: 0.078 ±0.053 0.171 0.715 1.69 0.363 

b: 0.351 ±0.285 0.011 0.012 0.06 O.Q15 

R2: 0.187 0.009 0.022 0.14 0.025 

0.013 0.013 0.01 0.013 

0.019 0.029 0.15 0.032 

11 4.0 8.7 8.8 

XXXI XXXI XXX XXXI 

<-Previous Results -> 197 198 191 195 

30 31 35 30 

0.150 0.678 1.65 0.338 

0.029 0.076 0.21 0.047 

RRXXXV 

<-Current Results -> 211 212 213 214 

32 32 33 33 

0.166 0.704 1.69 0.360 

0.037 0.057 0.08 0.035 

0.90 0.92 0.96 0.89 

0.09 0.95 1.00 0.95 

0.032 0.049 0 0.014 

19 6.9 0 3.8 

NAVI I <-Assignments-> 

NAU ""'-~~~ ~~~ 

0.169 

0.037 

0.710 1.69 0.361 

0.057 0.15 0.035 

CV 22 8.0 8.7 9.7 

(lS_dat)NISnxt 

211 212 213 214 

0.705 1.97 0.374 

0.713 

0.681 1.57 0.337 

0.693 1.63 0.357 

0.671 0.308 

0.676 1.61 0.307 

0 6 4 5 

0.690 1.69 0.337 

0.017 0.18 0.029 

0.006 0.03 0.008 

0.018 0.21 0.033 

0.019 0.21 0.034 

2.7 12 10 

NIST3=a+b*NIST1 

a: -0.082 ±0.015 

b: 1.056 ±0.014 

R2: 1.000 

Plael/7 J15
	
Report of (Meta)Analysisfor RR XXXV Sera: 211-214 

Table I 

NIST Data and Calculations 

trans-~-Carotene 

NISTI NIST3 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n, 

Mean, 

so. 

SDreox 

SDbcU 

211 

0.154 

0.152 

0.152 

0.154 

0.149 

0.134 

6 

0.149 

0.008 

0.006 

0.007 

212 

0.65 

0.65 

0.65 

0.65 

0.65 

0.63 

6 

0.65 

0.01 

0.01 

0.00 

213 214 

1.57 0.302 

1.47 0.335 

1.44 0.343 

1.59 0.364 

1.42 0.328 

1.47 0.356 

6 6 

1.49 0.338 

0.07 0.022 

0.07 0.020 

0.04 O.Ql8 

SI>msr, 0.009 0.01 0.08 0.027 

CVNISTx 6.1 1.3 5.5 7.9 

NIST 

n 

Mean 

SDreo 

SDbet 

SDan1 

6 

0.149 

0.006 

0.007 

0.010 

12 

0.63 

0.01 

0.01 

0.01 

12 12 

1.52 0.318 

0.09 0.016 

0.08 0.018 

0.01 0.010 

SDNIST 0.014 0.02 0.12 0.026 

CVNIST 9.4 2.9 8.0 8.3 

RR XXXI XXXI XXX XXXI 

Serum 197 198 191 195 

Op 7 7 10 7 

Median0 0.160 0.63 1.44 0.332 

eSD0 0.021 O.ot 0.17 0.026 

RRXXXV 

n. 

Median0 

eSD0 

P(n=p) 

P(n<p) 

211 

11 

0.159 

0.022 

0.99 

0.47 

212 

11 

0.64 

0.12 

0.95 

0.00* 

SDlabs 0.017 0.12 

CV1abs 11 19 

213 214 

11 11 

1.59 0.335 

0.06 0.041 

0.59 0.97 

1.00 0.14 

0 0.032 

0 9.5 

211 212 213 214 

0.64 1.82 0.325 

0.64 1.57 0.308 

0.61 1.47 0.295 

0.62 1.51 0.309 

0.60 1.47 0.275 

0.61 1.48 0.276 

0 6 6 6 

0.62 1.55 0.298 

0.02 0.14 0.020 

0.00 0.11 0.009 

0.02 0.12 0.021 

0.02 0.16 0.022 

3.3 10 7.5 

NIST3=a+b*NIST1 

a: -0.077 ±0.012 

b: 1.091 ±0.012 

R2: 1.000 

<-Previous Results-> 

<-Current Results - > 

NAY 0.154 0.64 1.56 0.326 <-Assignments - > 

NAU 0.022 0.12 0.12 0.041 

CV 14 19 7.9 13 

(3S_dalJNISTlxt 

Total a-Carotene 

NISTl NIST3 

211 212 213 214 211 212 213 214 

0.043 0.046 0.022 0.065 0.020 

0.042 0.046 O.ot8 0.038 0.064 0.018 

0.046 0.048 0.016 0.042 0.041 0.022 

0.042 0.048 0.016 0.043 0.058 0.023 

0.045 0.050 0.019 0.041 0.049 0.017 

0.042 0.040 0.023 0.042 0.049 0.020 

0 6 6 6 0 5 6 6 

0.043 0.046 0.019 0.041 0.054 0.020 

0.002 0.004 0.003 0.002 0.010 0.002 

0.002 0.004 0.002 0.000 0.007 0.002 

0.001 0.001 0.003 0.002 0.009 0.002 

0.002 0.005 0.003 0.002 0.011 0.003 

4.6 9.7 18 5.6 21 14 

NIST NIST3=a+b*NIST1 

0 11 12 12 

0.042 0.050 0.020 a:O 

0.001 0.007 0.002 b: 1.064 ±0.074 

0.003 0.006 0.002 R2: 0.843 

0.005 0.005 0.005 

0.006 0.011 0.006 

15 22 29 

XXXI XXXI XXX XXXI 

197 198 191 195 

18 22 21 21 

0.010 0.037 0.026 0.017 

0.006 0.011 O.ot5 0.004 

RRXXXV 

211 212 213 214 

22 25 25 25 

0.010 0.036 0.033 0.018 

0.003 0.008 0.010 0.004 

0.97 0.98 0.87 0.95 

1.00 0.90 0.98 0.53 

0.005 0 0 

14 0 0 

0.039 0.042 0.019 

0.008 0.01 1 0.006 

21 26 30 

Page4/7 

J16
	
Report of (Meta)Analysis for RR XXXV Sera: 211-214 

Table 1 

NIST Data and Calculations 

trans-a-Carotene 

NISTl NIST3 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n, 

Mean1 

so. 

SDm>x 

SD11etx 

SDmsrx 

CVmsrx 

n 

211 

0 

0 

212 213 214 

0 0 0 

NIST 

5 6 6 

Mean 0.03 0.02 0.012 1-----------l SDICP 0.00 0.00 0.001 

SD11e1 0.00 0.00 0.001 

SDw.__ _______ _, 

SDNIST 

CVNIST 

RR XXXI XXXI XXX XXXI 

211 212 213 214 

0.03 O.Qll 

0.02 0.02 0.013 

0.02 0.02 0.012 

0.02 0.02 0.014 

0.03 0.02 0.011 

0.03 0.02 0.011 

0 5 6 6 

0.03 0.02 0.012 

0.00 0.00 0.001 

0.00 0.00 0.001 

0.00 0.00 0.001 

0.00 0.00 0.001 

4.8 14 12 

Serum 197 198 191 

0 0 0 0 0 

195 <-Previous Results -> 

0 

Median0 

eSD0 .__ _______ _, 

n. 

Median. 

eSD0 

P(n=p) 

P(n<p) 

SD1abs 

cvlabs 

211 

0 

RRXXXV 

212 213 214 

0 0 0 

<-Current Results -> 

~~~l .... _______ __.I <-Assignments-> 

CV 

J3S_dallNISTtxt 

211 

0 

0 

Total Lycopene 

NISTl NIST3 

212 213 214 

0 0 0 

NIST 

6 6 5 

0.157 0.189 0.085 

0.008 O.Q18 0.003 

0.004 O.Q15 0.005 

0.002 0.002 0.002 

0.010 0.024 0.006 

6.1 13 7.4 

211 212 213 214 

0.155 0.206 

0.159 0.206 0.087 

0.154 0.163 0.088 

0.169 0.194 0.092 

0.158 0.171 0.071 

0.149 0.191 0.089 

0 6 6 5 

0.157 0.189 0.085 

0.007 O.ot8 0.008 

0.007 O.Q15 0.007 

0.004 0.015 0.005 

0.008 0.021 0.009 

5.3 11 11 

NIST3=a+b*Median 

a: 0.017 ±0.004 

b: 0.948 ±0.031 

R2: 0.998 

XXXI XXXI XXX XXXI 

197 

19 

0.02 

O.Ql 

211 

22 

0.03 

O.Ql 

0.82 

0.16 

198 191 195 

22 23 20 

0.118 0.167 0.062 

0.049 0.045 O.Q18 

RRXXXV 

212 213 214 

22 22 22 

0.146 0.183 0.073 

0.054 0.062 0.027 

0.87 0.93 0.88 

0.33 0.07 0.03* 

0.053 0.058 0.027 

36 32 37 

0.152 0.186 0.079 

0.054 0.062 0.027 

35 34 35 

PageS/7 

J17
	
Report of (Meta)Analysis for RR XXXV Sera: 211-214 

Table 1 

NIST Data and Calculations 

trans-Lycopene 

NISTl NIST3 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n, 

Mean. 

so. 

SD..,px 

SD11etx 

SDNISTx 

CVNISTx 

n 

Mean 

SD..,p 

SD11et 

SD1111 

SDNJST 

CVNJST 

211 

0 

0 

212 213 214 

0 0 0 

NIST 

6 6 5 

0.061 0.082 0.030 

0.002 0.004 0.000 

0.002 0.004 0.001 

0.004 0.004 0.004 

0.004 0.007 0.004 

7.2 8.3 13 

RR XXXI XXXI XXX XXXI 

Serum 

np 

Medianp 

eSDP 

n. 

Median. 

eSD0 

P(n=p) 

P(n<p) 

SDlabs 

cvlabs 

NAV 

NAU 

197 

1 

0.02 

211 

6 

0.02 

0.01 

198 191 195 

1 1 

0.070 0.041 

RRXXXV 

212 213 214 

6 6 6 

0.087 0.107 0.046 

0.017 0.013 0.004 

0.016 O.otl 0.002 

19 11 4.6 

0.074 0.094 0.038 

'--~~~~~~~ 

0.017 0.013 0.004 ....... CV 23 14 12 

f3S_dal]NISTtxt 

211 212 213 214 

0.060 0.091 

0.064 0.081 0.031 

0.061 0.077 0.031 

0.062 0.080 0.031 

0.058 0.082 0.027 

0.060 0.081 0.031 

0 6 6 5 

0.061 0.082 0.030 

0.002 0.005 0.002 

0.002 0.004 0.002 

0.002 0.004 0.001 

0.002 0.006 0.002 

4.0 6.9 7.5 

NIST3=a+b*Median 

a: -0.009 ±0.007 

b: 0.838 ±0.083 

R2: 0.981 

<-Previous Results -> 

<-Current Results -> 

<--Assignments--> 

~-Cryptoxanthin 

NISTl NIST3 

211 212 213 214 

0 0 0 0 

NIST 

0 6 6 5 

0.016 0.039 0.007 

0.001 0.002 0.000 

0.002 0.005 0.002 

0.001 0.001 0.001 

0.002 0.006 0.002 

15 15 31 

XXXI XXXI XXX XXXI 

197 198 191 195 

12 15 18 13 

0.008 0.024 0.050 0.013 

0.003 0.008 0.008 0.007 

RRXXXV 

211 212 213 214 

11 15 15 14 

0.010 0.026 0.053 0.014 

0.004 0.007 0.008 0.005 

0.77 0.92 0.91 0.95 

0.32 0.65 0.42 0.94 

0.007 0.005 0.004 

26 10 30 

0.021 0.046 0.011 

0.007 0.008 0.005 

34 18 44 

211 212 213 214 

0.019 0.047 

0.018 0.041 0.010 

0.017 0.038 0.006 

0.017 0.039 0.007 

0.014 0.033 0.007 

0.013 0.034 0.006 

0 6 6 5 

0.016 0.039 0.007 

0.002 0.005 0.002 

0.001 0.002 0.000 

0.002 0.005 0.002 

0.002 0.006 0.002 

15 15 30 

NIST3=a+b*Median 

a: -0.005 ±0.001 

b: 0.817 ±0.024 

R2: 0.998 

Paac6/7 

J18
	
Report of (Meta)Analysisfor RR XXXV Sera: 211-214 

Table 1 

NIST Data and Calculations 

''Lutein" "Zeaxanthin" 

A:l 

A:2 

B:l 

B:2 

C:l 

C:2 

n, 

Mean, 

SD, 

SDreox 

SDbeu 

SDNISl"x 

CVmSTx 

n 

Mean 

SDreo 

SDbcl 

SDan1 

211 

0 

6 

O.Qll 

0.001 

0.001 

0.001 

NISTl 

212 213 214 

0 0 0 

NIST 

6 6 5 

0.050 0.022 0.024 

0.001 0.003 0.001 

0.001 0.000 0.004 

0.001 0.001 0.001 

SDNIST 0.002 

CVNIST 18 

0.002 0.003 0.004 

3.2 12 16 

RR XXXI XXXI XXX XXXI 

Serum 

Do 

Median0 

eSD0 

n. 

Median. 

eSD0 

P(n=p) 

P(n<p) 

SD labs 

cvlabs 

197 198 191 195 

6 8 13 7 

0.011 0.057 0.035 0.020 

0.002 0.019 0.018 0.003 

RRXXXV 

211 212 213 214 

9 10 10 10 

0.016 0.054 0.026 0.030 

0.005 0.007 0.007 0.004 

0.53 0.92 0.79 0.21 

0.03* 1.00 1.00 0.24 

0.005 0.007 0.006 0.001 

29 12 24 3.1 

NIST3 

211 212 213 214 

0.010 0.048 0.020 

0.009 0.051 0.024 0.020 

0.013 0.050 0.024 0.025 

0.010 0.050 0.020 0.023 

0.011 0.051 0.023 0.027 

0.011 0.049 0.021 0.026 

6 6 6 5 

O.Qll 0.050 0.022 0.024 

0.001 0.001 0.002 0.003 

0.001 0.001 0.002 0.001 

0.001 0.001 0.000 0.004 

0.001 0.001 0.002 0.004 

13 3.0 11 15 

NIST3=a+b*Median 

a: -0.006 ±0.001 

b: 1.034 ±0.029 

R2: 0.997 

<-Previous Results-> 

<-Current Results - > 

NA V 0.013 0.052 0.024 0.027 <--Assignments-> 

NAU 0.005 0.007 0.007 0.004 

CV 37 13 28 15 

13S_dal)NISTuu 

NISTl 

211 212 213 214 

0 0 0 0 

NIST 

0 6 6 5 

0.019 0.009 0.010 

0.002 0.001 0.001 

0.001 0.003 0.003 

0.000 0.000 0.000 

0.002 0.003 0.003 

12 33 27 

XXXI XXXI XXX XXXI 

197 

4 

0.009 

211 

6 

0.006 

0.003 

198 191 195 

4 6 4 

0.025 0.011 0.017 

0.006 

RRXXXV 

212 213 214 

6 6 6 

0.019 0.012 0.012 

0.004 0.004 0.002 

0.85 

0.88 

0.003 0.002 

17 16 

0 

0 

0.019 0.011 0.011 

0.004 0.004 0.003 

21 34 24 

NIST3 

211 212 213 214 

0.017 0.013 

0.021 0.012 0.006 

0.016 0.008 0.010 

0.018 0.007 0.010 

0.022 0.009 0.012 

0.018 0.006 0.011 

0 6 6 5 

0.019 0.009 0.010 

0.002 0.003 0.002 

0.002 0.001 0.001 

0.001 0.003 0.003 

0.003 0.003 0.003 

14 35 27 

NIST3=a+b*Median 

a: -0.007 ±0.001 

b: 1.324 ±0.082 

R2: 0.992 

Paae 717 

J19
	
Report of (Meta)Analysisfor RR XXXV Sera: 211-214 

Table 2 

Summary of NIST Assigned Values and Uncertainties 

213 212 214 211 

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

Retinol 6.87 0.77 11 0.723 0.068 9.4 0.374 0.035 9.3 0.190 0.021 11 

Retinyl Palmitate 0.124 0.025 20 0.251 0.036 14 0.102 0.027 26 0.03 

a-Tocopherol 23.9 2.4 9.9 13.9 1.4 10 7.06 0 83 . 12 3.47 0.58 17 

y-Tocopherol 3.44 0.29 8.3 2.62 0.23 8.6 1.32 0.16 12 0.68 0.14 21 

a-Tocopherol 0.194 0.100 52 0.245 0.101 41 0.05 0.10 210 0.05 0.10 210 

Total (}-Carotene 1.69 0.15 8.7 0.710 0.057 8.0 0.361 0.035 9.7 0.169 0.037 22 

trans-p-Carotene 1.56 0.12 7.9 0.64 0.12 19 0.326 0.041 13 0.154 0.022 14 

Total a-Carotene 0.042 0.011 26 0.039 0.008 21 0.019 0.006 30 

trans-a-Carotene 0.02 0.03 0.012 

Total Lycopene 0.186 0.062 34 0.152 0.054 35 0.079 0.027 35 

trans-Lycopene 0.094 0.013 14 0.074 0.017 23 0.038 0.004 12 

p-Cryptoxanthin 0.046 0.008 18 0.021 0.007 34 0.011 0.005 44 

"Lutein" 0.024 0.007 28 0.052 0.007 13 0.027 0.004 15 0.013 0.005 37 

"Zeaxanthin" 0.011 0.004 34 0.019 0.004 21 0.011 0.003 24 

f)S_dal)SummuyTxt Page I II 

J20
	
 

 

 

 

 

Appendix K. “All-Lab Report” for RR35 

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 XXXV Laboratory Results 

Values in μg/mL 

Retinol Retinyl Palmitate α-Tocopherol γ-Tocopherol δ-Tocopherol 

Lab 211 212 213 214

FSV-BA 

FSV-BD 

FSV-BE 

FSV-BF 

FSV-BG 

FSV-BH 

FSV-BI 

FSV-BJ 

FSV-BK 

FSV-BM 

FSV-BN 

FSV-BO 

FSV-BP 

FSV-BQ 

FSV-BR 

FSV-BS 

FSV-BT 

FSV-BU 

FSV-BV 

FSV-BY 

FSV-BZ 

FSV-CA 

FSV-CB 

FSV-CD 

FSV-CH 

FSV-CK 

FSV-CM 

FSV-CN 

FSV-CP 

FSV-CQ 

FSV-CR 

FSV-CT 

FSV-CU 

FSV-CV 

FSV-CX 

FSV-CY 

FSV-DA 

FSV-DB 

FSV-DJ 

FSV-DK 

FSV-DM 

FSV-DP 

FSV-DS 

FSV-DX 

FSV-EC 

FSV-EH 

FSV-EK 

FSV-EL 

FSV-FC 

FSV-FD 

0.213 0.740 7.21 0.390 

0.182 0.733 5.74 0.375 

0.183 0.718 2.49 0.354 

0.200 0.780 6.87 0.430 

0.200 0.780 7.80 0.370 

0.156 0.680 6.96 0.364 

0.183 0.796 8.14 0.395 

0.197 0.739 5.92 0.419 

0.180 0.750 7.30 0.388 

0.184 0.689 7.61 0.363 

0.200 0.938 9.31 0.459 

0.094 0.622 5.29 0.316 

0.248 0.811 0.455 

0.180 0.760 6.54 0.400 

0.194 0.761 6.99 0.388 

!0.34 0.718 7.06 !0.41 

0.223 0.783 7.78 0.385 

0.187 0.734 6.94 0.369 

0.149 0.580 5.96 0.309 

0.279 0.844 8.01 0.468 

0.201 0.832 8.09 0.391 

0.172 0.662 6.55 0.340 

0.238 0.717 6.94 0.356 

0.223 0.754 6.65 0.403 

0.169 5.95 0.328 

0.220 0.820 7.88 0.420 

0.170 0.735 8.28 0.336 

0.193 0.679 6.21 0.366 

0.191 0.690 7.23 0.375 

0.210 0.690 6.47 0.460 

0.170 0.770 5.2? 0.380 

0.198 0.730 6.89 0.396 

0.240 0.930 7.09 0.330 

0.200 0.840 Hi? 0.420 

0.190 0.800 6.92 0.410 

0.125 0.477 4.77 0.263 

0.188 0.729 7.29 0.389 

0.340 0.510 4.72 0.410 

0.207 0.692 6.54 0.382 

0.193 0.757 6.37 0.377 

0.210 0.788 7.75 0.386 

0.228 0.845 7.77 0.430 

0.210 0.680 6.26 0.350 

0.218 0.707 6.60 0.382 

0.210 0.771 6.85 0.420 

211 212 213 214 

0.016 0.143 0.079 0.063 

0.043 0.282 0.146 0.113 

0.053 0.303 0.133 0.117 

0.050 0.337 0.199 0.148 

nd 0.241 0.133 0.126 

0.059 0.372 0.188 0.187 

!0.07 0.297 0.135 !0.13 

0.064 0.256 0.126 0.128 

0.049 0.260 0.114 0.111 

0.032 0.299 0.164 0.164 

0.030 0.300 0.080 0.100 

0.062 0.250 0.153 0.105 

211 212 213 214 

2.67 14.0 25.8 7.41 

3.70 12.8 22.5 6.60 

3.24 13.3 23.6 6.61 

3.50 15.3 28.7 7.30 

3.36 13.3 21.6 6.01 

4.05 14.6 24.9 7.80 

3.81 15.7 27.3 6.59 

4.81 15.0 22.5 8.19 

2.66 14.3 25.4 7.50 

3.40 14.7 25.1 6.70 

4.18 15.3 27.1 7.58 

3.06 14.0 25.2 7.55 

4.40 15.8 27.9 8.54 

2.80 10.1 21.5 6.00 

3.57 12.9 23.0 6.85 

2.88 13.8 24.4 6.07 

4.16 19.5 17.1 9.24 

3.49 14.2 24.1 7.14 

5.30 16.1 26.0 9.80 

3.76 15.2 27.2 8.00 

6.69 15.2 22.9 9.05 

4.38 17.1 28.2 8.06 

3.15 12.2 24.5 7.04 

4.40 13.4 19.6 6.44 

<4.0 14.6 26.7 7.50 

3.48 15.0 22.8 7.27 

3.29 10.3 17.1 5.36 

3.65 26.4 6.93 

3.70 13.4 25.8 7.30 

3.45 13.5 27.1 6.91 

3.40 14.9 25.0 7.08 

3.38 15.1 24.3 7.10 

3.89 14.0 25.3 7.90 

3.89 15.0 25.0 7.59 

3.73 13.5 24.2 7.05 

3.54 16.9 22.9 5.73 

3.80 15.3 22.9 7.80 

3.62 13.9 24.3 6.89 

2.86 13.1 22.5 6.69 

5.07 12.7 21.4 8.27 

3.19 13.5 21.4 6.66 

3.44 12.7 21.4 6.73 

4.38 17.1 28.8 8.39 

4.30 15.2 24.0 8.32 

4.58 

3.24 13.0 18.1 6.61 

211 212 213 214 

0.64 2.79 3.85 1.34 

0.69 2.54 3.51 1.29 

0.60 2.70 3.80 1.30 

0.82 2.90 3.84 1.48 

0.73 2.85 3.85 1.38 

1.16 2.93 3.62 1.75 

0.55 2.21 3.29 1.08 

0.63 2.72 3.54 1.29 

0.57 2.43 3.67 1.30 

0.86 3.43 4.21 1.87 

0.68 2.68 3.55 1.34 

4.00 3.00 3.50 3.00 

0.65 2.52 3.17 1.22 

0.65 2.62 3.85 1.28 

0.82 2.76 3.38 1.31 

0.65 2.60 3.16 1.19 

1.79 1.79 2.78 0.93 

0.83 2.74 3.71 1.64 

0.74 2.60 3.43 1.33 

0.66 2.91 3.83 1.36 

0.83 2.33 3.04 1.37 

0.74 

211 212 213 214 

0.047 0.330 0.170 0.015 

n 44 44 42 44 10 12 12 11 45 44 45 45 22 21 21 21 1 1 1 1 

Min 0.094 0.477 2.49 0.263 0.016 0.143 0.079 0.063 2.66 10.1 17.1 5.36 0.55 1.79 2.78 0.93 

Median 0.198 0.740 6.93 0.385 0.050 0.289 0.134 0.117 3.62 14.2 24.3 7.14 0.71 2.70 3.55 1.33 0.05 0.33 0.17 0.01 

Max 0.340 0.938 9.31 0.468 0.064 0.372 0.199 0.187 6.69 19.5 28.8 9.80 4.00 3.43 4.21 3.00 

eSD 0.022 0.071 0.91 0.035 0.016 0.047 0.029 0.018 0.56 1.4 2.5 0.78 0.14 0.24 0.38 0.07 

eCV 11 10 13 9 33 16 22 15 15 10 10 11 20 9 11 6 

NISTa 0.193 0.712 6.59 0.368 3.72 14.4 23.8 7.30 0.69 2.71 3.33 1.39
	

NISTb
	0.178 0.707 7.02 0.360 0.010 0.205 0.113 0.082 2.92 13.2 23.0 6.74 0.58 2.33 3.19 1.20 0.05 0.16 0.22 0.08 

NAV 0.192 0.725 6.87 0.375 0.050 0.289 0.134 0.117 3.47 14.0 23.8 7.08 0.67 2.61 3.40 1.31
	

NAU
	0.022 0.072 0.85 0.038 0.016 0.047 0.029 0.018 0.65 1.4 2.5 0.83 0.15 0.32 0.40 0.16 

K2 

All Lab Report Page 1 / 6 
 

 

Round Robin XXXV Laboratory Results 

Values in μg/mL 

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

Lab 211 212 213 214 211 212 213 214 211 212 213 214 

FSV-BA 0.168 0.704 1.69 0.386 0.159 0.671 1.62 0.361 0.009 0.033 0.068 0.025 

FSV-BD 

FSV-BE 0.129 0.759 1.88 0.361 

FSV-BF 0.237 0.672 1.70 0.399 

FSV-BG 0.212 0.712 1.67 0.374 

FSV-BH 0.150 0.689 1.60 0.341 0.140 0.642 1.50 0.315 0.010 0.047 0.097 0.026 

FSV-BI 0.147 0.740 1.75 0.360 

FSV-BJ 0.176 0.746 1.72 0.385 

FSV-BK 

FSV-BM 

FSV-BN 0.213 0.818 1.68 0.411 0.159 0.690 1.53 0.335 0.054 0.124 0.150 0.076 

FSV-BO 0.131 0.656 1.69 0.358 

FSV-BP 0.120 0.518 1.29 0.377 

FSV-BQ 0.190 1.120 2.63 0.500 

FSV-BR 

FSV-BS 0.225 0.477 2.04 0.284 0.203 0.451 2.02 0.264 0.022 0.026 0.022 0.020 

FSV-BT 0.167 0.686 1.70 0.356 0.153 0.641 1.59 0.333 0.013 0.045 0.108 0.024 

FSV-BU 0.132 0.681 1.41 0.298 

FSV-BV >0.179 >0.779 >1.639 >0.409 0.179 0.779 1.64 0.409 

FSV-BY 0.159 0.655 1.63 0.330 

FSV-BZ >0.225 >0.423 >1.78 >0.466 0.225 0.423 1.78 0.466 0.034 0.073 0.140 0.060 

FSV-CA 

FSV-CB 

FSV-CD 0.177 0.634 1.36 0.360 

FSV-CH 0.118 0.606 1.41 0.270 

FSV-CK 0.070 0.663 1.53 0.334 

FSV-CM 

FSV-CN >0.152 >0.603 >1.698 >0.342 0.152 0.603 1.70 0.342 

FSV-CP 0.155 0.572 1.67 0.373 

FSV-CQ 0.060 3.11 0.294 

FSV-CR 

FSV-CT 0.155 0.692 1.72 0.334 

FSV-CU 0.195 0.704 1.62 0.365 0.182 0.660 1.57 0.339 0.013 0.044 0.045 0.026 

FSV-CV 0.181 0.730 1.63 0.369 

FSV-CX 0.180 0.920 2.15 0.440 

FSV-CY 0.790 1.80 0.250 

FSV-DA 0.176 0.662 1.74 0.288 0.148 0.597 1.61 0.249 0.028 0.065 0.130 0.039 

FSV-DB 0.150 0.850 1.86 0.340 

FSV-DJ 

FSV-DK 0.198 0.722 1.73 0.381 

FSV-DM 0.099 0.647 1.52 0.317 

FSV-DP 

FSV-DS 0.206 0.671 0.15 0.360 

FSV-DX >0.126 >0.546 >1.046 >0.286 0.126 0.546 1.05 0.286 

FSV-EC 0.166 0.745 1.63 0.328 

FSV-EH 0.202 0.756 1.72 0.395 0.177 0.680 1.58 0.351 0.025 0.076 0.143 0.044 

FSV-EK 0.196 0.682 1.67 0.369 

FSV-EL 

FSV-FC 0.144 0.724 1.73 0.369 

FSV-FD 0.170 0.720 1.68 0.330 

n 34 34 35 35 12 12 12 12 9 9 9 9 

Min 0.060 0.477 0.15 0.250 0.126 0.423 1.05 0.249 0.009 0.026 0.022 0.020 

Median 0.167 0.698 1.69 0.360 0.159 0.642 1.60 0.337 0.022 0.047 0.108 0.026 

Max 0.237 1.120 3.11 0.500 0.225 0.779 2.02 0.466 0.054 0.124 0.150 0.076 

eSD 0.038 0.062 0.09 0.039 0.027 0.062 0.08 0.034 0.013 0.027 0.052 0.009 

eCV 23 9 5 11 17 10 5 10 61 57 48 33 

NISTa 

NISTb 

0.171 

nq 

0.741 

0.690 

1.68 

1.70 

0.389 

0.337 

0.149 0.646 1.49 0.338 

nq 0.620 1.56 0.298 

0.022 

nq 

0.095 

0.070 

0.186 

0.140 

0.051 

0.039 

0.169 

0.036 

0.707 

0.095 

1.69 

0.21 

0.363 

0.053 

0.154 0.637 1.56 0.328 

0.022 0.066 0.16 0.040 

0.022 

0.011 

0.064 

0.039 

0.133 

0.087 

0.036 

0.024 

NAV 

NAU 

K3 

All Lab Report Page 2 / 6 
 

 

Round Robin XXXV Laboratory Results 

Values in μg/mL 

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

Lab 

FSV-BA 

FSV-BD 

FSV-BE 

FSV-BF 

FSV-BG 

FSV-BH 

FSV-BI 

FSV-BJ 

FSV-BK 

FSV-BM 

FSV-BN 

FSV-BO 

FSV-BP 

FSV-BQ 

FSV-BR 

FSV-BS 

FSV-BT 

FSV-BU 

FSV-BV 

FSV-BY 

FSV-BZ 

FSV-CA 

FSV-CB 

FSV-CD 

FSV-CH 

FSV-CK 

FSV-CM 

FSV-CN 

FSV-CP 

FSV-CQ 

FSV-CR 

FSV-CT 

FSV-CU 

FSV-CV 

FSV-CX 

FSV-CY 

FSV-DA 

FSV-DB 

FSV-DJ 

FSV-DK 

FSV-DM 

FSV-DP 

FSV-DS 

FSV-DX 

FSV-EC 

FSV-EH 

FSV-EK 

FSV-EL 

FSV-FC 

FSV-FD 

n 23 26 26 26 23 24 24 23 6 6 6 6 12 16 16 15 

Min 0.004 0.013 0.016 0.010 0.016 0.014 0.087 0.042 0.015 0.066 0.096 0.025 0.003 0.012 0.018 0.006 

Median 0.009 0.036 0.032 0.018 0.030 0.142 0.176 0.073 0.024 0.087 0.107 0.046 0.009 0.026 0.052 0.014 

Max 0.032 0.060 0.088 0.047 0.079 0.292 0.378 0.201 0.044 0.138 0.125 0.083 0.075 0.039 0.617 0.051 

eSD 0.003 0.007 0.010 0.005 0.009 0.043 0.062 0.028 0.012 0.017 0.013 0.005 0.005 0.008 0.011 0.006 

eCV 33 19 33 27 30 30 35 39 49 20 12 12 54 32 21 42 

211 212 213 214 211 212 213 214 211 212 213 214 211 212 213 214 

0.009 0.040 0.036 0.019 0.015 0.074 0.100 0.045 0.075 0.031 0.073 0.051 

0.015 0.049 0.040 0.020 0.029 0.203 0.253 0.092 

0.014 0.036 0.038 0.018 0.033 0.164 0.174 0.072 

0.007 0.038 0.029 0.018 0.029 0.144 0.172 0.070 nd 0.024 0.052 nd 

0.007 0.039 0.035 0.018 0.021 0.096 0.120 0.048 0.008 0.025 0.052 0.011 

0.032 0.059 0.048 0.038 0.068 0.228 0.264 0.124 

0.011 0.060 0.048 0.047 0.066 0.229 0.218 0.104 0.031 0.097 0.096 0.047 0.032 0.055 0.032 

0.006 0.031 0.033 0.014 0.029 0.148 0.214 0.074 nd 0.015 0.033 0.009 

0.010 0.036 0.034 0.025 0.041 0.200 0.228 0.116 0.003 0.029 0.061 0.014 

0.026 0.045 0.088 0.029 0.073 0.051 0.087 0.042 0.057 0.027 0.063 0.027 

0.007 0.027 0.030 0.013 0.028 0.140 0.154 0.073 0.021 0.098 0.123 0.051 0.011 0.033 0.057 0.019 

0.016 0.120 0.150 0.050 

0.009 0.039 0.026 0.020 0.079 0.292 0.303 0.142 0.013 0.020 0.018 0.018 

0.010 0.039 0.040 0.019 0.028 0.124 0.168 0.062 0.007 0.026 0.038 0.013 

0.022 0.013 0.033 0.034 0.026 0.014 0.323 0.201 

0.007 0.033 0.020 0.017 0.032 0.122 0.134 0.066 0.003 0.012 0.030 0.006 

nd 0.026 0.024 0.012 0.019 0.099 0.120 0.053 

0.005 0.049 0.050 0.023 0.022 0.250 0.378 0.131 0.003 0.039 0.053 0.016 

nd nd nd nd nd 0.106 0.177 nd 

0.008 0.028 0.026 0.018 0.039 0.122 0.173 0.073 0.006 0.021 0.046 0.013 

<0.01 0.020 0.020 0.010 0.030 0.150 0.170 0.070 0.010 0.020 0.050 0.010 

0.011 0.037 0.037 0.017 0.031 0.137 0.356 0.051 0.015 0.066 0.107 0.025 0.010 0.017 0.617 0.014 

nd 0.032 0.020 0.018 

0.004 0.020 0.020 0.011 0.027 0.138 0.161 0.070 

0.010 0.025 0.016 0.012 0.044 0.138 0.125 0.083 

0.007 0.034 0.027 0.016 0.049 0.153 0.191 0.083 0.027 0.077 0.106 0.044 nd 0.028 0.054 0.012 

0.005 0.032 0.025 0.015 0.036 0.180 0.223 0.091 

0.010 0.038 0.016 0.014 

NISTa 

NISTb 

nd 

nq 

0.043 0.046 0.019 

0.041 0.054 0.020 nq 0.157 0.189 0.085 nq 0.061 0.082 0.030 nq 0.016 0.039 0.007 

0.039 0.041 0.019 0.150 0.182 0.079 0.074 0.094 0.038 0.021 0.046 0.011 

0.012 0.017 0.006 0.048 0.056 0.027 0.026 0.028 0.015 0.010 0.017 0.007 

NAV 

NAU 

K4 

All Lab Report Page 3 / 6 
 

 

Round Robin XXXV Laboratory Results 

Values in μg/mL 

Lutein Zeaxanthin Lutein&Zeaxanthin 

Lab 211 212 213 214 211 212 213 214 211 212 213 214 

FSV-BA 

FSV-BD 

FSV-BE 

FSV-BF 

FSV-BG 

FSV-BH nd 0.035 0.025 0.031 nd nd nd nd nd 0.035 0.025 0.031 

FSV-BI 0.014 0.054 0.026 0.026 0.004 0.023 0.017 0.014 0.021 0.077 0.046 0.040 

FSV-BJ 

FSV-BK 

FSV-BM 

FSV-BN 0.017 0.048 0.026 0.028 0.013 0.031 0.013 0.010 0.030 0.078 0.039 0.038 

FSV-BO 0.014 0.048 0.025 0.027 

FSV-BP 

FSV-BQ 

FSV-BR 

FSV-BS 0.078 0.053 0.186 0.222 

FSV-BT 0.022 0.059 0.029 0.031 0.009 0.017 0.030 0.012 0.030 0.076 0.059 0.043 

FSV-BU 

FSV-BV 0.020 0.086 0.016 0.044 

FSV-BY 0.011 0.045 0.026 0.023 0.005 0.017 0.011 0.009 0.016 0.062 0.037 0.032 

FSV-BZ 0.032 0.055 0.040 0.040 

FSV-CA 

FSV-CB 

FSV-CD 0.028 0.101 0.056 0.056 

FSV-CH 

FSV-CK 0.028 0.087 0.045 0.047 

FSV-CM 

FSV-CN 

FSV-CP 0.021 0.072 0.046 0.046 

FSV-CQ 

FSV-CR 

FSV-CT 0.015 0.048 0.037 0.025 

FSV-CU 

FSV-CV 

FSV-CX 0.020 0.070 0.040 0.040 

FSV-CY 

FSV-DA 0.016 0.064 0.024 0.032 0.007 0.021 0.011 0.013 0.023 0.085 0.035 0.045 

FSV-DB 

FSV-DJ 

FSV-DK 

FSV-DM 0.018 0.063 0.034 0.037 

FSV-DP 

FSV-DS 

FSV-DX 0.014 0.054 0.015 0.026 

FSV-EC 

FSV-EH 0.015 0.058 0.026 0.028 0.004 0.018 0.012 0.039 0.019 0.076 0.037 0.067 

FSV-EK 

FSV-EL 

FSV-FC 

FSV-FD 0.016 0.064 0.034 0.033 

n 9 10 10 10 6 6 6 6 15 16 16 16 

Min 0.011 0.035 0.024 0.023 0.004 0.017 0.011 0.009 0.014 0.035 0.015 0.026 

Median 0.016 0.054 0.026 0.030 0.006 0.019 0.012 0.012 0.020 0.074 0.037 0.040 

Max 0.078 0.064 0.186 0.222 0.013 0.031 0.030 0.039 0.030 0.101 0.059 0.067 

eSD 0.003 0.008 0.002 0.004 0.003 0.004 0.002 0.003 0.006 0.016 0.012 0.009 

eCV 19 15 9 15 52 18 15 24 30 22 33 23 

NISTa 

NISTb 0.011 0.050 0.022 0.024 nq 0.019 0.009 0.010 >0.011 0.069 0.031 0.034 

0.013 0.052 0.024 0.027 

0.006 0.012 0.007 0.008 

0.019 0.011 0.011 

0.006 0.005 0.005 

0.016 

0.009 

0.071 

0.016 

0.034 

0.011 

0.036 

0.011 

NAV 

NAU 

K5 

All Lab Report Page 4 / 6 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Term
	

n 

Min 

Median
	

Max
	

eSD 

eCV 

NAV 

NAU 

nd 

nq 

>x 

! 

italics 

Round Robin XXXV Laboratory Results 

Analytes Reported By One Laboratory
	

Values in μg/mL
	

Analyte 

cis-Lutein&Zeaxanthin 

Total Carotenoids 

α-Cryptoxanthin
 

trans-α-Carotene
 

Code 

FSV-BT 

FSV-BT 

FSV-BT 

NISTb 

211 212 213 214 

0.018 0.052 0.021 0.029 

0.284 1.084 2.080 0.571 

0.006 0.013 0.012 0.007 

nq 0.02 0.02 0.01 

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 "Analysis of Results."
	

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
	

K6
	

All Lab Report Page 5 / 6 
 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Round Robin XXXV Laboratory Results
	

Comparability Summary
	

Lab 

FSV-BA 

FSV-BD 

FSV-BE 

FSV-BF 

FSV-BG 

FSV-BH 

FSV-BI 

FSV-BJ 

FSV-BK 

FSV-BM 

FSV-BN 

FSV-BO 

FSV-BP 

FSV-BQ 

FSV-BR 

FSV-BS 

FSV-BT 

FSV-BU 

FSV-BV 

FSV-BY 

FSV-BZ 

FSV-CA 

FSV-CB 

FSV-CD 

FSV-CH 

FSV-CK 

FSV-CM
	

FSV-CN
	

FSV-CP
	

FSV-CQ
	

FSV-CR
	

FSV-CT
	

FSV-CU
	

FSV-CV
	

FSV-CX
	

FSV-CY
	

FSV-DA
	

FSV-DB
	

FSV-DJ
	

FSV-DK
	

FSV-DM
	

FSV-DP
	

FSV-DS
	

FSV-DX
	

FSV-EC
	

FSV-EH
	

FSV-EK
	

FSV-EL
	

FSV-FC
	

FSV-FD
	

NISTa
	

NISTb
	

R aT gT bC tbC 

1 2 1 1 

2 1 2 1 

4 1 2 

2 2 

2 2 

2 1 1 2 

2 2 4 

2 2 1 2 

1 2 2 1 1 

1 1 2 1 1 

3 2 2 3 

4 1 4 3 

3 2 3 

1 3 

1 3 1 

1 1 1 

2 2 1 2 

4 4 2 

1 1 2 2 

4 2 

2 2 2 3 

4 4 

2 3 2 

1 2 2 2 1 

3 2 3 3 

2 1 

2 1 2 

3 4 

2 2 1 1 1 

2 1 1 

2 2 1 1 

1 1 

1 1 4 

3 1 

1 1 

1 1 

3 2 3 

2 1 2 1 

2 1 1 2 

4 1 1 

1 1 

4 3 2 

1 1 1 2 

1 1 1 2 2 

2 3 

2 2 

1 3 2 

2 2 2 1 1 

2 3 1 1 

1 1 1 1 1 

1 1 1 1 1 

n 45 46 22 35 12 

StS 

1 36 41 41 43 50 

2 42 39 41 37 25 

3 11 13 9 11 25 

4 11 7 9 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 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 

All Lab Report Page 6 / 6 
Appendix L. Representative “Individualized Report” for RR35 

Each participant in RR35 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
	
10/31195 

Individualized Round Robin :XXXV Report to: FSV-BA 

Your Data, NIST Assigned Values, and %Differences 

Serum 211 Serum 212 Serum 213 

Analyte You NAV %Li n I You NAV %Li n I I You NAV %Li n I 

Retinol .21 .19 12 42 .74 .72 2 42 7.21 6.87 5 40 

Retinyl Palmitate .016 9 .143 .251 -43 11 .079 .124 -36 11 

a-Tocopherol 2.67 3.47 -23 43 14.01 13.90 1 42 25.76 23.90 8 43 

g-Tocopherol .64 .68 -6 20 2.79 2.62 6 19 3.85 3.44 12 19 

Total b-Carotene .168 .169 -1 32 .704 .710 -1 32 1.686 1.690 0 33 

trans-b-Carotene .159 .154 3 11 .671 .640 5 11 1.618 1.560 4 11 

Total cis-b-Carotene .009 7 .033 7 .068 7 

Total a-Carotene .009 22 .040 .039 3 25 .036 .042 -14 25 

trans-Lycopene .015 6 .074 .074 0 6 .100 .094 6 6 

b-Cryptoxanthin .075 11 .031 .021 48 15 .073 .046 59 15 

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. 

Serum 214 I You NA V %Li n I 

.39 .37 . 4 42 

.063 .104 -39 10 

7.41 7.05 5 43 

1.34 1.32 1 19 

.386 .361 7 33 .361 .326 11 11 

.025 7 .019 .019 0 25 

.045 .038 18 6 

.051 .011 364 14 

Send corrections to: NNMMQAP 222/B208, NIST, Gaithersburg, MD 20899; fax 301-977-0685; email DLDuewer@enh.NIST.gov 

RRJ5_ Page I/ 8 

L2
	
50 

25 

> < 

,-... 

> < z 

0 

8 

* 8 

-

<l 

-25 

-50 

llll31/9n 

· ..../ 

x x 

v 

I 

Individualized Round Robin XXXV Report to: FSV-BA 

Retinol, %L\ in Round Robin XXVI - XXXV 

x x 

v 

I I &$ill 

I I I I I I I I I I 

6 6 7 7 7 7 7 7 7 7 

8 9 0 I 2 3 4 5 6 7 

x 

x 

v 

I I ll I 

I I I I I 

8 8 8 8 8 

I 2 3 4 5 

x x 

I 

x 

x I x I x 

I I I I I I I I I 

8 8 8 8 9 9 9 9 9 

6 7 8 9 0 I 2 3 4 

Serum 

0 

x 

x x 

x x x 

x I x I 

WllrEl 

I 

I 

I I I I I 2 2 2 2 2 2 2 2 2 2 2 2 2 2 2 

9 9 9 9 9 0 0 0 0000 0001 1111 

5 6 7 8 9 0 I 2 3456 7890 1234 

RRO ge2/8 

L3
	
50 

25 

> < 

...-... 

> 

I 

,.0 0 

c.;s 

8 

* 0 

0 

-

<l 1 

-25 -50 J 

llW31/95 

Individualized Round Robin XXXV Report to: FSV-BA 

Tocopherols, %L\ in Round Robin XXVI - XXXV 

• g-Tocopherol E3 a-Tocopherol 

I I I I I I I I I I 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 

6 6 7 7 7 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 I I I I I 

8 9 0 I 2 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 

Serum 

RR35 Page 3 / 8 

L4
	
50 

Individualized Round Robin XXXV Report to: FSV-BA 

b-Carotene, %1'.\ in Round Robin XXVI - XXXV 

25 

> x x 

< x x xi x x v . x x x x 

Z 1 I 1.s;.·.I 1 J. x lrx n 1 R 1 ,11I,, !!! 1 > V I X 2#( X X . I I I I i·'> ''"' X X • I w I - - -•iht!B II. "' % .JI • % 4 

..0 0 

d 

* 0 

0 

....... 

<I 

-25 

-50 

10/31/9r\ 

____ ) 

I I I I I 

6 6 7 7 7 

8 9 0 I 2 

I I I I I 

7 7 7 7 7 

3 4 5 6 7 

I I I I I 

8 8 8 8 8 

I 2 3 4 5 

• trans-b-Carotene till Total b-Carotene 

I I I I I 

8 8 8 8 9 

6 7 8 9 0 

I I I I 

9 9 9 9 

I 2 3 4 

Serum 

0 

I I I I 

9 9 9 9 

5 6 7 8 

I 2 2 2 

9 0 0 0 

9 0 I 2 

2 2 2 2 

0 0 0 0 

3 4 5 6 

2 2 2 2 

0 0 0 I 

7 8 9 0 

2 2 2 2 

I I I 

2 3 4 

RRO e4/8 

L5
	
Individualized Round Robin XXXV Report to: FSV-BA 

NIST Assigned Values Vs Laboratory Values 

Retinol 

- ±20% 

-- ±50% 

. 

• .

, 

, 

, 

, 

, 

• , 

. 

• • . 

• , 

, 

, 

, 

, 

. 

. 

, 

, 

, 

. 

, 

• . 

, 

, 

, 

, 

, 

, 

, 

. 

, 

, 

• , 

, 

, 

, 

. 

. 

, 

a-Tocopherol / 

- ±20% 

-- ±50% 

, 

10/31/95 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

A Total 

8 trans 

-- ±50% 

- ±20% 

-- ±50% 

, 

, 

, 

, 

, 

, 

, 

b-Carotene 

g-Tocopherol ,· 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

. 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

, 

Legend 

Shaded Symbols: Round Robin XXVI-XXXIV 

Black Symbols: Round Robin XXXV 

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 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. 

RR35. Pagd / 8 

L6
	
ltl/Jl/9n 

Individualized Round :Robin XXXV Report to: FSV-BA 

Accuracy/Precision Summary 

Ret a Toe gToc Total -

ml v!:J. ml v!:J. ml v!:J. ml v!:J. 

-7 2 6 3 -2 5 -7 4 

-1 3 0 3 -6 1 6 3 

0 4 1 2 1 4 1 7 

4 4 0 3 9 6 5 4 

XXVI 

XXVII 

xxvm 

XXIX 

xxx 

XXXI 

XXXII 

XXXIII 

XXXN 

xxxv 

9 4 4 7 -3 7 9 12 

5 3 -2 5 -1 5 9 9 

-3 2 -1 1 -3 3 8 4 

-2 2 0 2 11 11 12 13 

4 4 -4 1 3 2 6 3 

6 4 -2 14 3 8 1 4 

(Traditional) Performance Criteria 

The absolute value of %/:J. of every measurement has 

traditionally been evaluated as follows ... 

%/:J. 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 

ml v!:J. 

-5 5 

5 3 

0 3 

3 3 

9 12 

9 10 

13 4 

12 6 

9 4 

6 3 

Legend 

Ret Retinol 

a Toe a-Tocopherol 

gToc g-Tocopherol 

Total Total b-Carotene 

trans all-trans-b-Carotene 

ml IMean difference, the average %/:J. for all sera of a given RR, where 

%/:J. = 1 OO(Y our value - NA V) I NA V 

v!:J. I Difference variability, one standard deviation of %a for all sera of a RR 

NA V INIST 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 ml, the average %.:1, and precision 

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

It's best to be accurate and precise (small ml, small v!:J.)! 

Good precision (small v.:1) with poor accuracy (large ml) 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 v!:J.) suggests that your measurement system is not in 

adequate control for the analyte levels examined. 

0 RRo gc6/H 

L7
	
,---------, 

0 

c:: ·..:i 

-S--a- ·I 

ti. 

• > 

c 

,---------, 

191 213 

llWJJ/95 

Individualized Round Robin :XXXV Report to: FSV-BA 

Comparisons to Prior Analyses 

' ' ' ' 

' ' ' ' ' ' ' ' -EEQ3 

' ' ' ' ' ' ' ' 

' ' ' 

\ ' 

' \ ' " ... 

" '@ 

-- .-

' ' ' ' ' ' ' 

--W. LJ . 

198 195\212 197\214 211 

.--. 

,

- -

, 

191 213 

e 

i 

els 

' ' 

' 

' ' 

' ' ' 

' ' " . " 

' \ ' \ ' ' ' 

\ ' 

\ ' ' ' ' ' ' ' ' ' _!i::J __ 

' 

' ' ' ' ' ' -15--e-

• ' ' 

198 195\212 197\214 211 

,----, 

.--·-··-. 

191 213 

Q) c:: 

i 

u 

I 

.0 

....... 

0 

E-< 

Q) 

c 

B 

u 

I 

.0 

I 

VJ 

c:: 

' ' 

' ' ' ' \ 

' 

' ' 

.----,--

-.---, 

' ' 

' Li. 

' ' ' --¥--t!i-

' ' \ ' 

' ' ' ' 

--1!1- -ftil -

' ' ' ' 

,

---

- -,----,----· -. 

198 195\212 197\214 211 

RR35. Puge 11 K 

L8
	
Individualized Round Robin XXXV Report to: FSV-BA 

Comparisons to Prior Analyses (Continued) 

------B-

. 

,---------, 

(.( 

-9 

VJ 

..... 

u 

r---.-

8 [3 ' LJ, ------ c: ' ' - ' ' 

... B .. 3 .. 0 -

E-< '. ' 

' ' 

,---------, I 

191 213 198 195\212 197\214 211 

... 

_

/ 

-9-bJ6. 

.----i 

.-----. 

191 213 

....J 

';! 

..... 

u 

I 

.0 

' ' 

-l-1-- < 

' ' ·. ·o ' ' ' . . 

. ' ' 

-LJ' 

t(g· :.. . . --

__ g_ '. .. §- .. - . • 

• • . . 

. ' ' ' 

.----.-- ---.----. 

198 195\212 197\214 21 I 

0 

. . ·g .. -.. --e-

• • 

. 

.5 " " . . 

'E " '-i::::i 

....J " l!.J 

- --8- --a.:--\ 

.----. 

c: 

..... 

'5 

i 

....J 

E-< 

.----. 

191 213 

. 

• 

• • • • • • . 

• 

__ _g '!,. _ - - -·, - - • . . . 

r -----,- • • • 

. 

. LJ. 

• • "o .. - - fc- .. - - r ' 

. LJ, • 

.-------i--..-----• 

198 195\212 197\2)4 211 

RR(}gc8/8 

.. .... 

L9
	
 

 

 

 

 

 

 

Appendix M. Shipping Package Inserts for RR07 

Three items were included in each package shipped to a RR07 participant: 

• Cover letter 

• Methodology questionnaire 

• Report of Analysis datasheet for the analysis of the Control and Serum Samples 

The cover letter, questionnaire, and datasheet were enclosed in a sealed waterproof bag 

along with the samples themselves. 

Dr. Margolis’s records did not preserve these materials. By inference, the cover letter 

was similar to that for RR08 (see Appendix Q) with the addition of information and 

instructions relating to the questionnaire. The questionnaire and Report of Analysis have 

been recreated from the preserved participant responses. 

M1 
 

 

 

 

Survey of Methods used in the Round Robin Studies 

on Ascorbic Acid in Plasma 

Please complete the sections in the following list which apply to the method(s) you are using in the 

Round robin study and return it to with the attached report of analysis form. 

I. Method of preparing calibration standards: 

A. Solvent: 

B. Source of standard:
	

C. Ascorbic acid concentration in stock solution; in working solution:
	

II. Method for preparing quality conrol standards:
	

III. Method for preparing plasma sample for analysis:
	

IV. Method of analysis:
	

A. Calorimetric: 

1. Dinitrophenylhydrazine 

Reference for method: 

2. Dichlorophenol 

Reference for method: 

B. Enzymatic: 

M2
	
 

C. HPLC:
	

1. Column brand size:
	

2. Solvent(s) composition: 

3. Method of detection: 

a. UV-wavelength: 

b. Electrochemical-voltage: 

4. Method of sample introduction: 

5. Literature reference for method (if published): 

D. Other: 

M3
	
 

 

 

 

 

REPORT OF ANALYSIS 

Name and mailing address specified on sheet set to each participant 

LAB NO.: Assigned code number 

PHONE NO.: specified 

FAX NO.: specified 

Method of Analysis: 

Date of Analysis: 

SERUM 179, VIAL# 

REPLICATE 1 

REPLICATE 2 

RESULTS (μmol/L) 

________ μmol/L 

________ μmol/L 

SERUM 688b, VIAL# 

REPLICATE 1 

REPLICATE 2 

________ μmol/L 

________ μmol/L 

SERUM 688b, VIAL# 

REPLICATE 1 

REPLICATE 2 

________ μmol/L 

________ μmol/L 

SERUM 682b, VIAL# 

REPLICATE 1 

REPLICATE 2 

________ μmol/L 

________ μmol/L 

SERUM 682b, VIAL# 

REPLICATE 1 

REPLICATE 2 

________ μmol/L 

________ μmol/L 

M4 
 

 

 

 

 

 

 

 

 

 

Appendix N. Final Report for RR07 

The following 13 pages are the final report for RR07 and for Round Robin 6 (RR06); the 

samples for RR06 were distributed in August 1994 and are described in NISTIR 7880-30. 

This report was provided to all participants in either study. 

This report contains: 

•	 Cover letter and analysis of results. 

•	 Table 1 “Results of Round Robin RR06 Measurement of Ascorbic Acid in Human 

Plasma”. 

•	 Table 2 “Results of Round Robin RR07 Measurement of Ascorbic Acid in Human 

Plasma”. 

•	 Table 3 “NIST Results of Measurement AA in Human Plasma”. 

•	 Figure 1 “Box Plot of the Round Robin RR06 Results” 

•	 Figure 2 “Box Plot of the Round Robin RR07 Results” 

•	 Figure 3. “Box Plot Comparing the Results of Round Robins RR04, RR05 and 

RR06”. 

•	 Figure 4. “Distribution of Round Robin RR06 Results for Lot 179”. 

•	 Figure 5. “Distribution of Round Robin RR06 Results for Lot 180”. 

•	 Figure 6. “Distribution of Round Robin RR07 Results for Lots 179 and 688b”. 

•	 Figure 7. “Distribution of Round Robin RR07 Results for Lot 682b”. 

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 
August 22, 1995 

Title- First- LastCompanyAddressDear Title- Last-: 

This report describes both the overall-group and your laboratory's performance in Round 

Robin VI and Round Robin VII for the measurement of ascorbic acid in human plasma. The 

studies involve the duplicate analysis of four unknown samples (two each from lots 179 and 

180 and two each from lots 688b and 682b ). Round Robin VII also contained two vials of 

lot 179 which served as a control material. Specifically, your package contains tabular 

presentations of all data submitted for ascorbic acid for Round Robins VI and VIL Your 

results are designated 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 18.0 - 24.8. The intralaboratory %RSD ranged from 0.3 - 4.0 with three exception in Round robin VII indicating 

that the major source of variation was the interlaboratory variation. The 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 ascorbic acid (AA) + dehydro-AA is represented by a solid circle and the 

NIST mean for reduced AA is represented by a solid square. The horizontal line in the 50% 

boxes represents the median interlaboratory values which are slightly different from the NIST 

values. Finally, the results of the previous round robins are compared to the results of this 

round robin and show a similar distribution of results (Figure 3). 

The basis of the distribution of the majority of the LC measurements below the NIST mean 

requires further evaluation along with the large variation in the results (%RSD = 18-24.8%). 

In Round Robin VII we added in a control material to help you evaluate the capability of 

your method to measure the AA in a sample of known concentration. Three laboratories were 

between 12.5 and 14% lower and one 11 % higher than the stated value of the control sample. 

The results of remaining laboratories were in agreement with the stated value. The assay 

done by the DNPH method was also high as would be expected from the previous round 

robin studies. Further examination of the data indicates that three laboratories, which were 

N2
	
able to measure AA in the control material, varied quite widely from the values established 

for the unknown samples. The fact that all of the gravimetrically added AA was accounted 

for (Table 3) also supports the need to continue these round robins in order to reduce the 

measurement variation. We would appreciate it if each of you, whose results deviated widely 

from the assigned values, would reexamine your methods for possible systematic errors. The 

distribution of the results of each laboratory are graphically illustrated in figures 4-7. 

The next set of samples, Round Robin VIII, will be shipped around September 25, 1995. If 

you have any questions concerning Round Robin VI and VII please indicate it on the enclose 

sheet and return it to us via mail (Donna Sirk, NIST, Chemistry B208, Gaithersburg, MD 

20899) or FAX (301/977-0685), or contact me at 301/975-3137. 

Sincerely, 

Sam A Margolis, Ph.D. 

Research Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosures 

N3
	
Table 1. Results of the Round Robin VI Measurement of Ascorbic Acid in Human Plasma. 

Ascorbic Acid (μmol/L Plasma)a 

Lab Data Seth Method Lot 179 Lot 180 

2 DNPH 54.8 ± 1.1 52.8 ± 1.5 

6 LC 48.6 ± 1.9 47.4 ± 1.9 

12 LC-EC 45.4 ± 2.9 44.3 ± 2.8 

3 DNPH 

5 ENZ 40.9 ± 4.0 40.6 ± 1.4 

4 DNPH 

1 DCIP 47.0 ± 1.3 47.3 ± 1.2 

13 LC-EC 71.3 ± 1.0 79.2 ± 3.0 

14 LC-EC 39.6 ± 1.2 39.9 ± 1.7 

15 LC-EC 45.6 ± 0.5 44.0 ± 0.3 

11 LC 39.3 ± 0.3 38.3 ± 0.7 

8 LC-EC 39.2 ± 0.5 38.1±0.5 

18 LC 39.2 ± 1.3 37.6 ± 0.9 

19 LC 28.2 ± 0.9 38.0 ± 1.3 

20 LC-UV 58.l ± 4.7 40.7 ± 2.7 

21 AUTO AN 41.5 ± 0.8 39.2 ± 1.8 

17 LC-EC 42.2 ± 0.3 40.3 ± 1.2 

MEAN 45.4 43.8 

SD 10.1 11.3 

%RSD 22.2 24.8 

NIST 

AA+DHAA LC-EC 43.5 ± l.5c 42.7 ± 1.53 

NIST 

AA LC-EC 12.l ± 0.3c 15.1 ± 0.43 

a Values represent the mean and SD of replicate measurements on two samples (total of 4 

measurements). 

b The Data Set numbers correspond to those in the figures 2-4. 

c Values represent the mean and SD of replicate measurements on five samples (total of 10 

measurements). 

N4
	
Table 2. Results of the Round Robin VII Measurement of Ascorbic Acid in Human Plasma. 

Ascorbic Acid (μmol/L Plasmat 

Lab Data Seth Method Lot 179 Lot 688b Lot 682b 

2 DNPH 50.3 ± 0.1 ~5.5 ± 0.9 122.2 ± 4.0 

6 LC 48.6 ± 0.7 6.0 ± 3.7 122.5 ± 5.2 

12 LC-EC 41.7 ± 2.1 63.1 ± 19.8 111.8 ± 6.2 

3 LC-UV 37.7 ± 0.9 31.3 ± 3.5 105.9 ± 3.3 

5 ENZ 41.0 ± 1.4 55.5 ± 6.2 127.3 ± 12.0 

4 DNPH 54.D 60.5 ± 0.6 124.3 ± 0.5 

13 46.7 ± 5.2 72.2 ± 0.6 141.2 ± 1.5 

14 LC-EC 42.5 ± 0.7 55.0 ± 2.0 122.8 ± 3.1 

11 LC 40.1 ± 0.4 50.4 ± 1.0 110.5 ± 1.8 

8 LC-EC 41.8 ± 1.7 56.5 ± 3.1 122.4 ± 2.4 

18 LC 37.9 ± 0.1 52.9 ± 0.3 128.9 ± 16.1 

19 LC 46.0 ± 2.3 52.2 ± 1.8 119.3 ± 5.0 

20 LC-UV 41.4 ± 7.5 33.1 ± 2.0 55.7 ± 29.l 

21 AUTO AN 42.0 ± 0.2 54.7 ± 0.3 118.1 ± 0.9 

22 LC-EC 40.9 ± 0.2 55.7 ± 0.5 118.7 ± 1.3 

23 LC-EC 42.7 ± 1.1 50.1 ± 0.5 105.2 ± 0.2 

24 LC-OPD 38.5 ± 0.7 39.3 ± 1.2 74.7 ± 2.1 

MEAN 43.2 53.2 113.6 

SD 4.5 10.6 20.5 

%RSD 10.4 19.9 18.0 

NIST 

AA+DHAA LC-EC 43.5 ± 1.5c 56.4 ± l.6a 115.4 ± 2.7 

NIST 

AA LC-EC 12.1 ± 0.3c 43.2 ± 3.3a 100.1 ± 1.4 

a Values represent the mean and SD of replicate measurements on two samples (total of 4 

measurements). 

b The Data Set numbers correspond to those in the figures 2-4. 

c Values represent the mean and SD of replicate measurements on five samples (total of 10 

measurements). 

N5
	
Table 3. NIST Results of Measurement of AA in Human Plasma. 

Ascorbic Acid (μmol/L) 

without DTT with DTT Supplemented 

Lot No. (AA) (AA+DHAA) Amount 

Plasma 1 5.1 ± I.I (4t 11.5 ± 0.2 (4) 

178 10.2 ± 0.4 (4) 27.0 ± 0.5 (4) 15.8 

179 12.1 ± 3.9 (10) 43.5 ± 1.5 (10) 32.1 

180 15.1 ± 0.4 (4) 42.7 ± 0.3 (4) 31.6 

Plasma 2 18.9 ± 6.5 (4) 52.2 ± 1.6 (4) 

179B 67 .2 ± 26.4 (5) 154.4 ± 1.1 (10) 101.3 

a The value in parentheses is the number of measurements made. 

N6
	
Figure 1. Box Plot of the Round Robin VI Results. 

Figure 2. Box Plot of the Round Robin VII Results. 

Figure 3. Box Plot Comparing the Results of Round Robins IV, V and VI. 

Figure 4. Distribution of Round Robin VI Results for Lot 179. 

Figure 5. Distribution of Round Robin VI Results for Lot 180. 

Figure 6. Distribution of Round Robin VII Results for Lots 179 and 688b. 

Figure 7. Distribution of Round Robin VII Results for Lot 682b. 

Key for Figures 1 and 2: 

The small open circles represent the highest and low.est 10% of the measurements, 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 ascorbic acid (AA) + dehydro-AA is 

represented by a solid circle and the NIST mean for reduced AA is represented by a solid 

square. The horizontal line in the 50% boxes represents the median interlaboratory values 

which are slightly different from the NIST values. 

Key for Figure 3: 

The highest and lowest 10% of the measurements are not represented in this figure, the two 

simple lines each span the next 15% intervals and the center box contains the values from the 

remaining data sets. The horizontal line in the 50% boxes represents the median 

interlaboratory values. The dashed lines represent the 95% confidence range of the NIST 

values for total AA. 

Key for Figures 4, 5 and 7: 

• First Vial; First Measurement 

+ Second Vial; First Measurement 

D First Vial; Second Measurement 

0 Second Vial; Second Measurement 

Key for Figure 6: 

• First Vial; First Measurement Lot 179 

D First Vial; Second Measurement Lot 179 

+ First Vial; First Measurement Lot 688b 

0 First Vial; Second Measurement Lot 688b 

• Second Vial; First Measurement Lot 688b 

0 Second Vial; Second Measurement Lot 688b 

N7
	
Round Robin VI 

80 0 

- 0 ro 

E 70 

CJ) 

ro 

c.. 

~ 

:::::: 60 0 

E 

::::i.. 

-

"O ·5 50 <( 

(.) 

.c 

I.... • 0 

(.) 40 CJ) 

<( 

• 

30 

0 

Lot179 Lot 180 

Lot No. 

Fig . 1 

N8
	
Round Robin VII 

140 0 

130 

120 ......... • ro 

E 

CJ) 110 

ro 

a. 

...J 100 

::::::: 

0 

E 90 ::l. 

"C -

·u 80 

<( 

0 .2 0 .c 70 L.-

0 

(.) 

CJ) 60 <( 

0 0 

50 

40 

~ 0 30 

Lot 179 Lot 688b Lot 682b 

Lot No. 

Fi8. 2 

N9
	
,,_ 

~ 100 

-0 90 

8 80 ::i. 

'-' 

'"O 70 . -(.) 

< 60 

(.) 

-Q 

·--€ 50 

0 

(.) 

r.I) --~-- -- < 40 ---- -- -

-Cd 

...... 

0 

~ 30 --- - -

20 

Round Robin IV V All IV VI All V VI All IV 

Lot 178 180 179 179b 

Fig. 3 

N10
	
en 

"" ""'" -0 

..J 

0 

co 

Ill ~ 

a 

cm 

<>• 

• 

I • 

1-.:i 

• 

a 

41 <>a 

a<>• 

•<> • 

• <> a • 

• +a<> 

D•+ 

0 0 0 

<.O I.!) """'" 

(111owrl) P!!>V' :>!qJO!>SV' 

Fig. 4 

e::a 

a 

~ 

--

--

-

0 

N 

I.!) 

N 

0 

N 

I.!) 

....-

0 

....-

I.!) 

0 

0 

z 

~ 

0 

-e 

0 

.c 

n:s 

..J 

N11
	
0 

CIO 

..... 

-0 

...J 

0 

(J') 

• IJ 

0 

ro 

• 

m • • •<> 

a• • 

Ill+ 

19 

-

Ill 

• <> 

<>• 

<>m a 

• a • o~ 

cm+<> 

0 0 0 0 

I'-- <D L{) "<;f" 

(111owrl ) P!=>'V :>!qJo:>s'Q' 

Fig. 5 

•• ,... 

-

--

-

0 

N 

L{) 

N 

0 

N 

L{) 

..--

0 

..--

L{) 

0 

0 

z 

~ 0 -C'IS 

.... 

0 

.c 

C'IS 

...J 

N12
	
.c 

co 

co 

CD 

"O 

c 

ca 

en 

,.... 

"'"" !? 

0 

...J 

> 

c 

:c 

0 

a:= 

"O 

c 

::l 

0 

a:= 

0 

ci 

CJ) 

• 

0 

0 

co 

" 

0 

I+:! t 1:> • 

... lnl 

IDJ •a 

eo • <• Ill 

a • 

II • • b 

• • 

094 ~ • Cl 

41 • ID 

• ~ CJm 

[ • 

•• • 

• ~ CJm 

a• 

4 <l I 

0 <Ii.. e I 

41111 E 

0 0 0 0 

ci ci ci ci 

I'- <D I.{) ~ 

(111owri) P!=>'V =>!qJo:>s-v 

Fip; . 6 

•• <C 

~ • 

0 

ci 

{"') 

--

-~ 

~ 

._ 

-~ 

0 

0 

N 

0 

{"') 

I.{) 

N 

0 

N 

0 

z 

~ 

~ .s 

~ 

I.{) 

0 

0 

.c 

ca 

...J 

N13
	
150.0 

140.0 

130.0 • • <> 

_. 

-

:::: 

120.0 

:l. 

I ca a 

• 

- $ -

• 

-

'"rj "'C t-'· 

(JQ 110.0 . a • '-I (.) • .c • i... 8 100.0 

ti) 

<( 

90.0 

80.0 

70.0 

- "T 

0 5 

. • 

. 

<> 

a 

• 

-

T 

10 

Round Robin VII - Lot 682b 

• 

a 

• 

• 

I 

15 

Laboratory No. 

• • 

a 

<> 

I 

20 

• a 

3 

• 

n 

• <> • i 

' 

T 

25 30 

N14
	
 

 

 

 

Appendix O. “All-Lab Report” for VC-RR07 

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 7 

Control 

688B, [AA] mmol/mL 682B, [AA] mmol/mL 

Lab Method 

VC-MA 

VC-MB 

VC-MC 

VC-MD 

VC-ME 

VC-MF 

VC-ML 

VC-MQ 

VC-MV 

VC-MX 

VC-MZ 

VC-NA 

VC-NB 

VC-NC 

VC-ND 

VC-NR 

VC-NU 

NIST 

24DNPH 

AO 

AO-OPD 

HPLC-EC 

HPLC-EC 

HPLC-EC 

HPLC-EC 

HPLC-UV 

24DNPH 

24DNPH 

HPLC-UV 

HPLC-EC 

HPLC-EC 

HPLC-EC 

HPLC-UV 

HPLC-UV 

AutoAnal 

HPLC-EC 

Min 

Median 

Max 

eSD 

eCV 

N 17 

18.8 

20.9 

27.0 

1.3 

6 

0.1 

0.7 

2.8 

0.0 

0.4 

3.8 

0.0 

0.7 

2.8 

0.0 

0.6 

3.8 

17 

15.7 

27.2 

31.6 

3.0 

11 

0.0 

0.7 

11.9 

0.0 

0.4 

2.6 

0.0 

0.4 

11.8 

0.0 

0.9 

12.0 

17 

27.8 

59.3 

64.4 

6.1 

10 

0.0 

0.9 

16.6 

0.0 

0.6 

6.4 

0.0 

1.1 

16.0 

0.0 

1.6 

17.2 

AO 

AutoAnal 

24DNPH 

EC 

HPLC 

OPD 

UV 

 Ascorbate oxidase 

Auto Analyzer

 2,4-Dinitrophenylhydrazine

 Electrochemical detector

 Liquid chromatography

 Orthophenlyenediamine

 Ultraviolet absorbance 

179, [AA] mmol/mL 

Av Sdup Srep Shet Stot 

20.0 

20.5 

22.3 

24.3 

21.1 

20.6 

20.7 

23.3 

21.3 

18.9 

20.9 

23.0 

21.4 

27.0 

19.3 

20.9 

18.8 

2.8 

1.1 

0.2 

0.1 

0.2 

0.7 

0.4 

0.1 

0.1 

0.4 

3.8 

2.6 

0.4 

0.0 

0.8 

1.1 

0.6 

0.0 

0.4 

1.1 

0.5 

2.8 

1.1 

0.2 

0.0 

0.2 

0.7 

2.8 

1.1 

0.2 

0.4 

3.8 

2.6 

0.4 

0.0 

0.8 

1.1 

0.6 

0.0 

0.4 

1.1 

0.5 

21.8 0.1 

Av Sdup Srep Shet Stot 

25.2 

27.8 

31.4 

27.2 

27.3 

27.8 

16.6 

18.1 

27.5 

26.4 

28.2 

26.1 

25.1 

30.3 

19.6 

31.6 

15.7 

0.5 

2.8 

2.0 

1.0 

0.1 

0.0 

0.4 

0.1 

0.7 

0.2 

1.5 

0.7 

0.1 

0.0 

0.7 

11.9 

1.8 

0.4 

2.6 

0.6 

1.7 

0.1 

0.3 

1.2 

0.0 

1.0 

0.1 

1.1 

0.9 

0.3 

0.4 

0.3 

2.2 

0.0 

0.4 

2.2 

2.0 

0.5 

0.0 

0.0 

0.0 

0.0 

0.2 

1.3 

0.3 

0.0 

0.6 

11.8 

1.8 

0.5 

3.4 

2.0 

1.8 

0.1 

0.3 

1.2 

0.0 

1.0 

0.2 

1.7 

0.9 

0.3 

0.4 

0.7 

12.0 

1.8 

28.2 0.1 

Av Sdup Srep Shet Stot 

55.2 

63.6 

62.2 

63.6 

59.1 

59.3 

27.8 

35.3 

61.4 

64.4 

61.2 

59.6 

52.6 

62.1 

37.3 

55.9 

53.0 

0.9 

5.1 

2.2 

4.4 

0.0 

0.6 

16.6 

0.4 

0.5 

9.9 

0.7 

0.0 

0.1 

0.2 

1.2 

2.7 

1.6 

0.5 

5.3 

0.8 

4.7 

0.6 

0.5 

6.4 

0.0 

1.8 

0.1 

1.3 

3.0 

0.0 

0.3 

0.6 

2.7 

0.0 

0.8 

3.5 

2.2 

3.7 

0.0 

0.5 

16.0 

0.0 

9.9 

0.0 

0.0 

0.0 

1.1 

1.8 

1.6 

1.0 

6.3 

2.3 

5.9 

0.6 

0.7 

17.2 

0.0 

1.8 

9.9 

1.3 

3.0 

0.0 

0.3 

1.2 

3.3 

1.6 

57.7 1.4 

8/13/2013 O2 1 / 1 
 

 

Appendix M. Shipping Package Inserts for RR08 

The following two items were included in each package shipped to a RR08 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. 

P1 
UNITED STATES DEPARTMENT OF COMMERCE 

National Institute of Standards and Technology 

Gaithersburg, Maryland 20899-0001 

Dear 

Thank you for agreeing to measure the ascorbic acid in the accompanying samples. Enclosed are 

two sets of samples, one set consisting of two ampules is a Control Sample, and the second set 

consisting of four ampules, is the Test Samples. 

The control materials consist of two ampules (57 μmol ascorbic acid/L). 

We ask that you use this control material to test your method before you analyze the Round 

Robin (RR) samples. We request that the following testing pattern be used. 

• Analyze a single vial of the Control Sample. If these results are within 10% of the 

assigned values, proceed with the analysis of the unknown samples. 

• If the results of your Control Sample is biased by 10-20%, we suggest that you review 

your method, make adjustments as necessary, then analyze the second Control Sample. 

• If your results for the Control Sample exceeds 20%, we ask that you thoroughly examine 

your procedures and make necessary adjustments, and then analyze the second Control. 

If your data remains significantly biased, feel free to contact us to discuss possible 

solutions to your measurement problems. 

The samples are in sealed ampules and were prepared by adding equal volumes of spiked human 

serum to 10% metaphosphoric acid (MP A). 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 ampul contains between 20 and 120 μ,mol of ascorbic acid/L of diluted serum and each 

ampul should be analyzed in duplicate by the method(s) used in your laboratory (preferably one 

measuring total ascorbic acid). 

NISI 

Dr. Margolis sent individual letters to invited study participants. 

His original form letter is no longer available. This has been 

redacted from a letter that was prepared but never sent. 

P2
	
The 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 December 18, 1995. 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 participation is this exercise. 

Sincerely, 

Sam A. Margolis, Ph. D. 

Research Chemist 

Analytical Chemistry Division 

Chemical Science and Technology Laboratory 

Enclosures 

P3
	
 

 

 

 

 

 

 

 

 

REPORT OF ANALYSIS 

Name: specified on sheet set to each participant 

Address: specified on sheet set to each participant 

Telephone no: 

Fax no: 

Method of Analysis: 

- Please attach representative chromatograms. 

- Method used for calculating ascorbic acid concentration 

Peak Height Peak Area 

Date of Analysis: 

RESULTS (mg/dL) 

TEST SAMPLE, VIAL# 

REPLICATE 1 ________ μmol/L 

REPLICATE 2 ________ μmol/L 

TEST SAMPLE, VIAL# 

REPLICATE 1 ________ μmol/L 

REPLICATE 2 ________ μmol/L 

SERUM 688A, VIAL# 

REPLICATE 1 ________ μmol/L 

REPLICATE 2 ________ μmol/L 

SERUM 688A, VIAL# 

REPLICATE 1 ________ μmol/L 

REPLICATE 2 ________ μmol/L 

SERUM 688A, VIAL# 

REPLICATE 1 ________ μmol/L 

REPLICATE 2 ________ μmol/L 

SERUM 682A, VIAL# 

REPLICATE 1 ________ μmol/L 

REPLICATE 2 ________ μmol/L 

P4 
 

 

 

 

Appendix Q. “All-Lab Report” for VC-RR08 

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. 

Q1 
Vitamin C Round Robin 8 

Control 

688A, [AA] mmol/mL 682A, [AA] mmol/mL

Lab Method 

VC-MB 

VC-MC 

VC-MD 

VC-ME 

VC-MF 

VC-MQ 

VC-MV 

VC-MX 

VC-MZ 

VC-NA 

VC-NB 

VC-NC 

VC-ND 

VC-NG 

VC-NL 

NIST 

AO 

AO-OPD 

HPLC-EC 

24DNPH 

HPLC-EC 

HPLC-EC 

24DNPH 

24DNPH 

HPLC-UV 

HPLC-UV 

HPLC-EC 

HPLC-UV 

AutoAnal 

HPLC-UV 

HPLC-EC 

HPLC-EC 

N 

Min 

Median 

Max 

eSD 

eCV 

15 

16.9 

28.7 

31.1 

1.2 

4 

0.1 

0.5 

1.4 

0.0 

0.4 

1.3 

0.0 

0.3 

1.4 

0.1 

0.8 

1.4 

15 

6.7 

13.6 

17.1 

1.2 

8 

0.0 

0.6 

2.3 

0.0 

0.3 

1.4 

0.0 

0.4 

2.3 

0.0 

0.6 

2.4 

15 

24.8 

44.8 

49.3 

3.7 

8 

0.1 

0.4 

3.2 

0.1 

0.6 

4.1 

0.0 

0.3 

3.2 

0.2 

0.8 

4.1 

AO 

AutoAnal 

24DNPH 

EC 

HPLC 

OPD 

UV 

 Ascorbate oxidase 

Auto Analyzer

 2,4-Dinitrophenylhydrazine

 Electrochemical detector

 Liquid chromatography

 Orthophenlyenediamine

 Ultraviolet absorbance 

688B, [AA] mmol/mL 

Av Sdup Srep Shet Stot 

30.4 

28.6 

28.9 

29.5 

27.1 

28.7 

30.8 

26.6 

28.7 

29.1 

16.9 

31.1 

28.5 

28.4 

25.8 

0.4 

1.4 

0.8 

0.1 

0.2 

1.1 

0.2 

0.1 

0.3 

0.9 

0.2 

0.8 

0.9 

0.6 

0.4 

0.3 

1.3 

1.0 

0.0 

1.2 

0.0 

0.2 

0.4 

0.0 

0.4 

0.7 

0.3 

1.4 

0.0 

0.0 

0.2 

1.1 

0.0 

0.1 

0.3 

0.8 

0.2 

0.8 

0.7 

0.6 

0.5 

1.4 

1.3 

1.0 

0.2 

1.1 

1.2 

0.1 

0.3 

0.9 

0.2 

0.8 

0.5 

1.0 

0.6 

27.7 0.8 

Av Sdup Srep Shet Stot 

15.8 

13.4 

14.0 

14.4 

13.6 

17.1 

17.1 

13.3 

14.7 

12.9 

10.9 

16.0 

13.5 

6.7 

13.1 

0.2 

0.4 

0.6 

0.7 

0.0 

1.0 

0.7 

0.0 

0.1 

0.6 

0.1 

1.4 

2.3 

0.6 

0.0 

0.4 

1.2 

0.3 

0.0 

0.8 

0.2 

0.0 

0.3 

0.4 

0.1 

1.4 

0.4 

0.2 

0.3 

0.1 

0.7 

0.0 

0.8 

0.7 

0.0 

0.0 

0.5 

0.1 

1.0 

2.3 

0.6 

0.2 

0.5 

1.2 

0.7 

0.0 

1.1 

0.7 

0.0 

0.3 

0.7 

0.1 

1.8 

2.4 

0.6 

14.0 1.6 

Av Sdup Srep Shet Stot 

45.9 

45.9 

46.4 

43.7 

42.1 

47.3 

49.3 

41.2 

44.8 

45.0 

34.1 

46.0 

39.0 

24.8 

40.9 

0.2 

0.8 

0.8 

1.5 

0.1 

2.3 

0.3 

0.5 

0.4 

0.8 

0.1 

0.2 

3.2 

0.3 

0.3 

0.8 

0.8 

1.0 

0.4 

4.1 

0.8 

0.1 

0.4 

0.6 

0.1 

0.8 

0.5 

0.0 

0.7 

0.6 

1.3 

0.0 

0.0 

0.0 

0.5 

0.2 

0.7 

0.1 

0.0 

3.2 

0.3 

0.3 

1.0 

1.0 

1.6 

0.4 

4.1 

0.8 

0.5 

0.5 

1.0 

0.2 

0.8 

3.3 

0.3 

41.6 2.8 

Q2
	 8/13/2013 1 / 1