NISTIR 7880-34 

NIST Micronutrients Measurement

Quality Assurance Program

Winter, Spring, and Fall 1990 

Comparability Studies

Results for Round Robins XVIII, XIX, and XX

Fat-Soluble Vitamins and Carotenoids in Human Serum

Neal E. Craft (Former Employee)

David L. Duewer

Margaret C. Kline

Sam A. Margolis (Retired)

Willie E. May

Katherine E. Sharpless

Jeanice B. Thomas

This publication is available free of charge from

http://dx.doi.org/10.6028/NIST.IR.7880-34
NISTIR 7880-34

NIST Micronutrients Measurement

Quality Assurance Program

Winter, Spring, and Fall 1990 

Comparability Studies

Results for Round Robins XVIII, XIX, and XX

Fat-Soluble Vitamins and Carotenoids in Human Serum

Neal E. Craft (Former Employee)

David L. Duewer

Sam A. Margolis (Retired)

Jeanice B. Thomas

Chemical Sciences Division, Materials Measurement Laboratory 

Margaret C. Kline

Biomolecular Measurement Division, Materials Measurement Laboratory 

Katherine E. Sharpless 

Office of Special Programs 

Wille E. May

Under Secretary of Commerce for Standards and Technology and Director 

This publication is available free of charge from

http://dx.doi.org/10.6028/NIST.IR.7880-34 

June 2015 

U.S. Department of Commerce 

Penny Pritzker, Secretary

National Institute of Standards and Technology

Willie E. May, 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 1990 MMQAP measurement comparability improvement studies: 1) Round 

Robin XVIII Fat-Soluble Vitamins and Carotenoids in Human Serum, 2) Round Robin XIX FatSoluble Vitamins and Carotenoids in Human Serum, and 3) Round Robin XX Fat-Soluble Vitamins 

and Carotenoids in Human Serum. The materials for Round Robin XVIII were shipped to 

participants in January 1990; participants were requested to provide their measurement results by 

March 5, 1990. The materials for Round Robin XIX were shipped to participants in May 1990; 

participants were requested to provide their measurement results by July 6, 1990. The materials for 

Round Robin XX were shipped to participants in August 1990; participants were requested to 

provide their measurement results by October 22, 1990. 

Keywords

Human Serum 

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

iii
Table of Contents 

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

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

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

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

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

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

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

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

Appendix A. Shipping Package Inserts for RR18 ........................................................................ A1

Appendix B. Final Report for RR18 .............................................................................................. B1 

Appendix C. Revised “All-Lab Report” for RR18 ....................................................................... C1 

Appendix D. Shipping Package Inserts for RR19 ........................................................................ D1 

Appendix E. Final Report for RR19 .............................................................................................. E1 

Appendix F. Revised “All-Lab Report” for RR19 ........................................................................ F1 

Appendix G. Shipping Package Inserts for RR20........................................................................ G1 

Appendix H. Final Report for RR20 ............................................................................................. H1 

Appendix I. Revised “All-Lab Report” for RR20 .......................................................................... I1 

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] 

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

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

XVIII comparability study (hereafter referred to as RR18) received three 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 1990. The 

communication materials included in the sample shipment are described 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 some 

participants report values for non-target analytes.

The final report delivered to every participant in RR18 is reproduced as Appendix B. This report 

included: 

• Our analysis of the participants’ results. 

• Tabular presentations of all participant results. 

• Graphical presentations of interlaboratory precision over time. These Figures are no longer 

available. 

Each participant also received an “Individualized Report” that graphed their results for selected 

analytes. These figures are no longer available. 

Appendix C lists all of the measurement results reported for RR18 in a more accessible format. 

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

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

XIX comparability study (hereafter referred to as RR19) received three 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 May 1990. 

The communication materials included in the sample shipment are described in Appendix D. 

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 some 

participants report values for non-target analytes.

The final report delivered to every participant in RR19 is reproduced as Appendix E. This report 

included: 

• Our analysis of the participants’ results.

• Tabular presentations of all participant results. 

• Graphical presentations of interlaboratory precision over time.

Each participant also received an “Individualized Report” that graphed their results for selected 

analytes. These figures are no longer available.

Appendix F lists all of the measurement results reported for RR19 in a more accessible format. 

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

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

XX comparability study (hereafter referred to as RR20) received two liquid-frozen and three 

lyophilized human sera. Unless multiple vials were previously requested, participants received one 

vial of each material. These sample materials were shipped on dry ice to participants in August

1990. The communication materials included in the sample shipment are described in Appendix G. 

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 some 

participants report values for non-target analytes.

It is probable that a preliminary report for RR20 was mailed to all participants shortly before the 

NIST/NCI Micronutrients Analysis Workshop held on November 15, 1990. However, no version of 

either the letter or the preliminary report is available. Likewise, only the tabular parts of the Final 

Report for RR20 are available; these tables are reproduced as Appendix H. 

It is probable that each participant also received an “Individualized Report” that graphically analyzes 

their results for selected analytes. These figures are no longer available.

Appendix I lists all of the measurement results reported for RR20 in a more accessible format. 

2 
References

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

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

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

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

3 
Appendix A. Shipping Package Inserts for RR18 

Two items were included in each package shipped to an RR18 participant:

• Cover letter. The original letter has been lost. It would have described the three

lyophilized sample materials (sera 120 to 122), ethanolic solution (sample 123), and three 

ethanolic calibration solutions distributed for the study, given guidance on reconstituting 

the serum samples and use of the calibration solutions, stated that results were due March 

5, 1990 and to whom they should be sent, and who to contact with technical questions. 

While there is no record of the cover letter, page A2 reproduces a letter sent at the same 

time as the Final Report for Round Robin XVII (RR17) that describes the RR18 

materials. This notification letter was sent to laboratories that had not reported results for 

RR17; similar descriptions were included in the RR17 Final Reports provided to 

laboratories that had participated in RR17. These letters were sent about two weeks 

before the packages were to be shipped.

• Datasheets. Pages A3 and A4 reproduce the form. The first page of the form is for 

reporting the primary-focus analytes: retinol, α-tocopherol, and total and trans-βcarotene. The second page is for reporting three “optional” analytes: retinyl palmitate, 

γ-tocopherol, and lycopene. In the absence of other information, the lycopene results are 

assumed to report total lycopene. 

These items were attached to the shipping box. 

A1 
January 4, 1990

^F1^

^F2^

HAPPY NEW YEAR! 

Samples for analysis of ROUND ROBIN XVIII will be shipped to you on 

January 16, 1990, and will include three serum samples and an ethanol 

solution of retinol, α-tocopherol, and β-carotene. Analyze the serum 

samples as you normally do. We also invite you to provide us with data on 

retinol palmitate, lycopene, and γ-tocopherol in these samples.

Please complete your serum analyses before you analyze the unknown 

solution. For analysis of the unknown solution, we ask that you calibrate 

your system with the set of solution standards provided. Quantitation 

should be accomplished by comparing the response from the unknown with 

that from the calibration solutions. No extractions, additions of 

internal standards, or solvent exchanges should be required for labs using 

reversed-phase systems. The assigned values for the target analytes in 

calibration solutions to be used for analysis of the unknown solution 

follows:

(μg/mL)

RETINOL α-TOCOPHEROL TRANS β-CAROTENE

Solution 10 0.195 2.22 0.135

Solution 11 0.977 11.1 0.945

Solution 12 1.95 22.2 1.62

These solutions should be allowed to equilibrate at room temperature for 

at least 4 hours, but no more than 24 hours prior to use.

Results from the analysis of RR-XVIII are due by March 5, 1990. 

Sincerely,

Willie E. May, Ph.D.

Chief

Organic Analytical Research Division

Center for Analytical Chemistry

cc: Robert Schaffer

Winfred Malone

Individualized letters were sent to study participants. The “^F1^” and “^F2^” 

were mail-merge commands for inserting a participant’s name and address.

A2 
REPORT ON NIST/NCI SAMPLES FROM LABORATORY # _________ 

DATE OF ANALYSIS _____________ 

RESULTS IN μg/mL

SAMPLE # ANALYTE

SERUM 120 RETINOL

VIAL # ___ B-CAROTENE

Trans Total

A-TOCOPHEROL

SERUM 121 RETINOL

VIAL # ___ B-CAROTENE

Trans Total

A-TOCOPHEROL

SERUM 122 RETINOL

VIAL # ___ B-CAROTENE

Trans Total

A-TOCOPHEROL

SERUM 123

(EtOH Sol) RETINOL

VIAL # ___ B-CAROTENE

Trans Total

A-TOCOPHEROL

 Add 1.0 mL of Distilled water to the Serum Samples.

A3 
REPORT ON NIST/NCI SAMPLES FROM LABORATORY # _________

OPTIONAL ANALYTES

DATE OF ANALYSIS _____________ 

RESULTS IN μg/mL

SAMPLE # ANALYTE

SERUM 120 RETINYL PALMITATE

VIAL # ___ LYCOPENE

GAMMA-TOCOPHEROL

SERUM 121 RETINYL PALMITATE

VIAL # ___ LYCOPENE

GAMMA-TOCOPHEROL

SERUM 122 RETINYL PALMITATE

VIAL # ___ LYCOPENE

GAMMA-TOCOPHEROL

A4 
Appendix B. Final Report for RR18 

The following six pages are the available components of the final report for RR18 as 

provided to all participants. The original report consisted of:

• A cover letter and discussion.

• Tables 1 to 3 that list results and various summary values for retinol,

α-tocopherol, and total β-carotene.

• Four unnumbered tables that list results and simple summary statistics for retinyl

palmitate, lycopene, γ-tocopherol, and trans-β-carotene. Note: the cover letter

states that the first three of these analytes constitute “Table 5”; the

trans-β-carotene values were doubtless intended to be “Table 4.”

• Graphical presentations of interlaboratory precision over time for retinol,

α-tocopherol, and total β-carotene.

When the isomeric form of an analyte is not specified, it is likely that most participants 

reported “total” (the sum of all isomers.) Since resolution of γ-tocopherol and 

β-tocopherol is challenging, the results reported as γ-tocopherol can be confidently 

assumed to be γ/β-tocopherol. 

The graphical presentations for RR18 are no longer available; however, they would have 

been very similar to the graphs in the Final Report for RR19 in Appendix E. 

Due to the complex formatting used in the Tables, the originally listed laboratory codes 

have been deleted without replacement. However, Appendix C provides a complete 

listing of the RR18 results where the original codes have been altered to ensure 

confidentiality. Appendix C also provides more relevant summary statistics.

B1 
B2
B3
Table 1. Round Robin XVIII Results 

Retinal Solution # Retinal % Bias from Grand Average Serum g 1 Serum Serum g Serum 1 Serum Solution Lab.# 12 12 12 123 12 12 12 123 

0.240 0.493 0.897 0.525 -7.2 1. 7 5.7 2.3 0.240 0.470 0.812 0.568 -7.2 -3.0 -4.3 10.7 0.270 0.508 0.954 0.561 4.4 4.8 12.4 9.4 

0.216 0.503 0.904 0.514 -16.5 3.8 6.5 0.2 0.223 0.420 0.778 0.570 -13.8 -13.3 -8.3 11.1 0.255 0.467 0.780 -1.6 -3.7 -8.1 0.270 0.520 0.849 0.488 4.4 7.3 0.1 -4.9 0.314 0.477 0.819 21.4 -1.6 -3.5 0.260 0.476 0.818 0.444 0.5 -1.8 -3.6 -13.5 0.252 0.462 0.852 0.517 -2.6 -4.7 0.4 0.8 

0.259 0.421 0.689 0.497 0.1 -13.1 -18.8 -3.l 0.270 0.499 0.753 0.544 4.4 3.0 -11.3 6.0 0.270 0.500 0.840 0.390 4.4 3.2 -1.0 -24.0 0.282 0.524 0.896 0.593 9.0 8.1 5.6 15.6 0.278 0.514 0.856 0.445 7.5 6.1 0.9 -13.3 0.339 0.699 0.866 0.562 31.1 44.2 2.1 9.6 0.258 0.510 0.852 0.440 -0.3 5.2 0.4 -14.2 

*0.327 *0.823 * 1. 092 *0.574 26.4 69.8 28.7 11.9 

0.220 0.450 0.770 0.560 -15.0 -7.2 -9.2 9.2 0.281 0.498 0.854 0.380 8.6 2.7 0.7 -25.9 0.230 0.570 1.850 0.600 -11.1 17.6 118.0 17.0 0.230 0.419 0.767 0.474 -11.1 -13.6 -9.6 -7.6 

0.265 0.437 0.804 0.557 2.4 -9.8 -5.2 8.6 

0.248 0.494 0.867 0.505 -4.1 1.9 2.2 -1.6 

0.243 0.501 0.815 0.512 -6.l 3.4 -3.9 -0.2 

0.260 0.490 0.848 0.620 0.5 1.1 -0.1 20.9 0.290 0.520 1.030 0.520 12.1 7.3 21.4 1.4 0.244 0.504 1.030 0.463 -5.7 4.0 21.4 -9.7 0.269 0.473 0.879 0.530 4.0 -2.4 3.6 3.3 

NIST 0.275 0.521 0.905 0.501 

Avg 0.259 0.485 0.848 0.513 SD 0.023 0.030 0.080 0.062 

RSD 9.0 6.2 9.5 12.1 

* = Value not includ,ed in statistical analysis. 

L = Late, Results not included in Statistical Analysis. 

NIST value not included in statistical Analysis. 

B4
Table 2. Round Ronin xviii 

Solution # 

% Bias from Grand Average 

erum g 1 Serum Serum g erum 1 Serum Solution Lab # 12 12 12 123 12 12 12 123 

4.71 6.53 9.99 7.98 -2.4 -2.3 3.8 -13.2 4.48 6.27 8.66 11.19 -7.3 -6.2 -10.0 21. 7 

4.69 6.58 10.65 9.68 -2.9 -1.5 10.7 5.3 

5.09 7.45 10.11 8.66 5.4 11.5 5.1 -5.8 

4.56 6.07 8.78 11.28 -5.6 -9.2 -8.8 22.7 4.75 6.57 9.14 7.19 -1.8 -1. 7 -5.0 -21.8 4.90 7.60 10.10 8.50 1.4 13.7 4.9 -7.5 

5.23 6.72 8.76 8.3 0.6 -9.0 

4.72 6.36 9.53 8.12 -2.3 -4.8 -1.0 -11.6 

7.00 9.50 9.28 4.8 -1. 3 1. 0 

4.98 6.23 9.10 8.52 3.1 -6.7 -5.5 -7.3 4.88 6.68 9.34 11.28 1.0 o.o -2.9 22.7 

5.00 6.50 9.20 9.00 3.5 -2.7 -4.4 -2.1 

4.39 7.05 9.08 10.04 -9.1 5.5 -5.7 9.2 

5.22 7.09 9.24 8.06 8.0 6.1 -4.0 -12.3 

4.42 6.81 9.73 -8.5 -29.2 5.9 4.51 6.63 9.31 8.03 -6.6 -a.a -3.3 -12.6 

*5.10 * 10. 49 *11.97 * 11. 40 5.6 57.0 24.4 24.0 

5.49 6.69 9.42 7.40 13.5 0.1 -2.1 -19.5 5.17 6.82 9.04 10.40 7.0 2.1 -6.1 13.1 

4.63 6.60 9.20 8.40 -4.3 -1.3 -4.4 -8.6 4.71 6.68 9.74 9.80 -2.5 o.o 1.2 6.6 4.02 5.12 7.69 8.37 -16.8 -23.4 -20.1 -8.9 

4.72 5.86 8.64 7.39 -2.3 -12.3 -10.2 -19.6 

4.90 7.10 10.50 10.10 1.4 6.3 9.1 9.9 

4.75 7.00 10.85 10.43 -1.7 4.8 12.7 13.5 4.90 6.45 12.03 10.90 1.4 -3.5 25.0 18.6 

4.85 6.00 9.70 8.71 0.4 -10.2 0.8 -5.2 

4.24 7.14 10.30 8.30 -12.2 6.9 7.0 -9.7 

NIST 4.99 7.17 9.21 8.48 

Avg 4.83 6.68 9.62 9.19 SD 0.28 0.43 0.80 1.29 

RSD 5.9 6.5 8.3 14.0 

* = Value not includ19d in statistical analysis. 

L = Late, Results not included in Statistical Analysis. 

NIST value not included in Statistical Analysis. 

B5
Table 3. Round Robin XVIII Results 

Total Beta-Carotene % Bias from 

Total Beta-Carotene 

Solution # 

Grand Average Serum g Serum 1 Serum Serum g Serum 1 Serum Solution Lab # 12 12 12 123 12 12 12 123 

0.386 0.990 1.950 -5.5 -4.6 -1.3 0.357 0.874 1.539 1.363 -12.6 -15.8 -22.1 28.0 0.417 1.049 2.145 1.102 2.0 1.1 8.6 3.5 0.392 1.071 2.100 1.213 -4.1 3.2 6.3 13.9 0.457 1.126 2.155 0.630 11. 7 8.5 9.0 -40.9 0.357 1.042 1.332 0.925 -12.6 0.4 -32.6 -13.2 0.470 1.092 2.446 0.566 15.0 5.2 23.8 -46.9 

0.292 0.847 1.651 1.367 -28.5 -18.4 -16.4 28.3 0.440 1.130 1.690 0.930 7.7 8.9 -14.5 -12.7 

0.345 0.948 1.942 1.629 -15.6 -8.7 -1.7 52.9 0.455 1.170 2.280 0.649 11. 3 12.7 15.4 -39.l 

0.384 1.056 1.802 0.420 -6.0 1.7 -8.8 -60.6 

*0.472 *0.437 *1.644 * 1. 390 15.4 -57.9 -16.8 30.5 

0.390 1.020 1.930 1.200 -4.6 -1.7 -2.3 12.7 

0.365 1.430 2.700 -10.7 37.8 36.6 0.407 0.831 1.940 0.660 -0.4 -19.9 -1.8 -38.0 0.457 1.010 2.150 11.8 -2.7 8.8 

0.450 1.120 2.060 1.570 10.1 7.9 4.3 47.4 

0.480 1.069 2.485 1.210 17.5 3.0 25.8 13.6 0.394 1.050 1.760 0.558 -3.6 1.2 -10.9 -47.6 0.447 0.664 1.420 0.534 9.4 -36.0 -28.1 -49.9 0.487 0.626 1.600 0.499 

Avg 0.409 1.038 1.976 1.065 SD 0.053 0.090 0.319 0.364 

RSD 13.l 8.6 16.2 34.2 

* = Value not included in statistical analysis. 

L = Late, Results not included in Statistical Analysis. 

NIST value not included in Statistical Analysis. 

B6
Round Robin XVIII 

Retinyl Palmitate Gamma Tocopherol 

Serum # Serum # Serum # Serum # Serum 1 Serum # Lab # 120 121 122 Lab # 120 12 122 

ND ND ND 2.12 0.95 0.69 ND ND ND 2.20 0.93 0.82 

ND ND ND 1.12 *3.57 

0.051 0.136 0.268 2.32 1.13 0.85 

0.025 0.030 0.037 3.47 1.53 *9.50 0.002 0.002 0.005 2.24 0.92 0.72 

NIST ND ND ND 2.56 1.62 0.99 

*1. 34 *0.47 *0.24 

1.67 0.77 0.62 

2.59 1.55 1.02 2.52 1.13 1.06 

NIST 2.24 0.89 0.70 

Avg 2.410 1.164 0.846 SD 0.488 0.300 0.164 

RSD 20 26 19 

* = Value not used in statistical analysis. Lycopene NIST Value not used in statistical analysis. 

Lab # Serum # 120 Serum # 121 Serum # 122 

0.383 0.495 0.166 

0.210 0.270 0.110 

1.861 2.352 0.689 

0.239 0.305 0.114 

0.060 0.077 0.037 0.186 0.241 0.088 Trans Beta-Carotene 0.267 0.106 0.054 Serum 8 Serum f Serum Solution # 0.180 0.200 0.050 Lab # 12 12 12 123 0.456 0.505 0.176 

0.260 0.340 0.110 0.413 1.090 2.140 0.274 

0.361 1.005 1.696 0.227 0.463 0.407 1.536 0.410 Avg 0.273 0.308 0.108 0.231 SD 0.098 0.138 0.046 NIST 0.409 0.526 1.380 0.199 RSD 36 45 42 

Avg 0.412 0.834 1.791 0.286 

* = Value not used in statistical analysis. 

SD 0.051 0.372 0.313 0.086 RSD 12.4 44.6 17.5 30.0 

B7
Appendix C. Updated “All-Lab Report” for RR18 

The following four pages are a revised version of an “All-Lab” report for RR18. This 

report has three parts: 

• pages 1 and 2 list results for all analytes reported at least twice, counting both

participants and NIST analysts.

• page 3 provides a legend for pages 1 and 2.

• page 4 summarizes each participants’ performance for retinol, α-tocopherol, and

total β-carotene. These summaries are compatible with the percent bias

evaluation advice given in the RR18 Report. However, the current bias

summaries are estimated relative to the median of all reported values for each

analyte in each serum rather than to the “Trimmed Average” used in the original

and detailed in Appendix B. These original reference values were estimated from

on-time results, with subjective exclusion of results deemed non-representative.

To ensure confidentiality, the laboratory identifiers used in this “All-Lab Report” have 

been altered from those used in RR18. 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. 

Note: The results designated NISTa in this updated All-Lab report are designated as 

NIST in the Tables of Appendix B. 

C1 
Round Robin XVIII Laboratory Results

All Lab Report Page 1 / 4

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

Lab 120 121 122 123 120 121 122 123 120 121 122 123 120 121 122 123

FSV-BA 0.278 0.514 0.856 0.445 0.025 0.030 0.037 5.22 7.09 9.24 8.1

FSV-BD 0.270 0.520 0.849 0.488 4.90 7.60 10.10 8.5

FSV-BE 0.270 0.499 0.753 0.544 5.00 6.50 9.20 9.0

FSV-BF 0.260 0.476 0.818 0.444 4.72 6.36 9.53 8.1 2.3 1.13 0.85

FSV-BG 0.270 0.508 0.954 4.69 6.58 10.65 9.7

FSV-BH 0.258 0.510 0.852 0.440 <0.02 <0.02 <0.02 4.51 6.63 9.31 8.0 2.2 0.95 0.72

FSV-BI 0.240 0.470 0.812 0.546 nd nd nd 4.48 6.27 8.66 9.9 2.2 0.93 0.82

FSV-BJ 0.243 0.501 0.815 0.512 4.75 7.00 10.85 10.4 2.5 1.13 1.06

FSV-BL 0.267 0.482 0.798 0.505 4.96 6.38 8.71 9.1

FSV-BM 0.248 0.494 0.867 0.505 4.90 7.10 10.50 10.1

FSV-BY 0.240 0.493 0.897 0.525 nd nd nd 4.71 6.53 9.99 8.0 2.1 0.95 0.69

FSV-BZ 5.50 6.69 9.42 7.4

FSV-CA 0.223 0.420 0.778 0.570 4.56 6.07 8.78 11.3

FSV-CJ 0.216 0.503 0.904 0.514 5.09 7.45 10.11 8.7

FSV-CK 0.327 0.823 1.092 0.574 5.10 10.49 11.97 11.4 2.6 1.62 0.99

FSV-CM 0.480 4.71 6.68 9.74 9.8

FSV-CN 0.314 0.477 0.819 5.23 6.72 8.76

FSV-CO 0.255 0.467 0.780 nd nd nd 4.75 6.57 9.14

FSV-CQ 0.252 0.462 0.852 0.517 0.051 0.136 0.268 na 7.00 9.50 9.3 3.5 1.53 9.50

FSV-CV 0.260 0.490 0.848 0.620 4.90 6.45 12.03 10.9

FSV-CY 0.220 0.450 0.770 0.560 5.17 6.82 9.04 10.4 1.3 0.47 0.24

FSV-DC 0.282 0.544 0.896 0.593

FSV-DE 4.88 6.68 9.34 9.5 2.2 0.92 0.72 nd

FSV-DG 0.270 0.500 0.840 0.390 4.39 7.05 9.08 10.0

FSV-DH 0.230 0.419 0.767 0.474 0.058 0.108 0.226 4.02 5.12 7.69 8.4 2.0 0.73 0.74

FSV-DL 0.279 0.493 0.825 0.530

FSV-DT 0.259 0.421 0.689 0.497 4.98 6.23 9.10 8.5

FSV-DY 0.230 0.570 1.850 0.600

FSV-DZ 0.339 0.699 0.866 0.562 4.42 6.81 9.7

FSV-EB 0.244 0.504 1.020 0.463 4.24 7.14 10.30 8.3

FSV-EF 0.281 0.498 0.854 0.380 4.63 6.60 9.20 8.4 1.7 0.77 0.62

FSV-EV 0.290 0.520 1.030 0.520 4.85 6.00 9.70 8.7

FSV-FA 0.265 0.437 0.804 0.557 0.002 0.002 0.005 4.72 5.86 8.64 7.4 2.6 1.55 1.02

n 30 30 30 28 4 4 4 0 29 29 30 28 12 12 12 0

Min 0.216 0.419 0.689 0.380 0.002 0.002 0.005 4.02 5.12 6.81 7.39 1.34 0.47 0.24

Mean 0.263 0.505 0.885 0.513 0.034 0.069 0.134 4.79 6.75 9.50 9.18 2.26 1.06 1.50

Max 0.339 0.823 1.850 0.620 0.058 0.136 0.268 5.50 10.49 12.03 11.40 3.47 1.62 9.50

SD 0.029 0.079 0.201 0.059 0.026 0.063 0.132 0.32 0.87 1.07 1.11 0.53 0.35 2.53

CV 11 16 23 12 75 92 99 7 13 11 12 23 34 169

NISTa 0.275 0.521 0.905 nd nd nd 4.99 7.16 9.21 2.2 0.89 0.70

NISTc 0.244 0.433 0.726 4.47 6.18 8.27 2.5 1.43 1.25

Median 0.260 0.496 0.849 0.516 4.75 6.63 9.33 9.05 2.22 0.95 0.78

eSD 0.026 0.029 0.068 0.062 0.31 0.53 0.82 1.22 0.39 0.27 0.18

eCV 10 6 8 12 7 8 9 13 18 28 24

C2
Round Robin XVIII Laboratory Results

All Lab Report Page 2 / 4

Lab

FSV-BA

FSV-BD

FSV-BE

FSV-BF

FSV-BG

FSV-BH

FSV-BI

FSV-BJ

FSV-BL

FSV-BM

FSV-BY

FSV-BZ

FSV-CA

FSV-CJ

FSV-CK

FSV-CM

FSV-CN

FSV-CO

FSV-CQ

FSV-CV

FSV-CY

FSV-DC

FSV-DE

FSV-DG

FSV-DH

FSV-DL

FSV-DT

FSV-DY

FSV-DZ

FSV-EB

FSV-EF

FSV-EV

FSV-FA

n

Min

Mean

Max

SD

CV

NISTa

NISTc

Median

eSD

eCV

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

120 121 122 123 120 121 122 123 120 121 122 123 120 121 122 123

0.455 1.17 2.28 0.65 0.413 1.090 2.140 0.274 0.042 0.080 0.140 0.375 0.19 0.24 0.088

0.470 1.09 2.45 0.57 0.24 0.31 0.114

0.417 1.05 2.15 1.10

0.384 1.06 1.80 0.42 0.361 1.005 1.696 0.227 0.023 0.051 0.106 0.193 0.39 0.55 0.154

0.357 0.87 1.54 1.14 0.21 0.27 0.110

0.450 1.12 2.06 1.57 0.26 0.34 0.110

0.386 0.99 1.95 0.38 0.50 0.166

0.392 1.07 2.10 1.21

0.472 0.44 1.64 1.39 0.463 0.407 1.536 0.410 0.009 0.029 0.109 0.980 0.27 0.11 0.054

0.357 1.04 1.33 0.93

0.457 1.13 2.15 0.63

0.292 0.85 1.65 0.06 0.08 0.037

0.480 1.07 2.49 1.21

0.390 1.02 1.93 1.20 0.18 0.20 0.050

0.345 0.95 1.95 1.63

0.440 1.13 1.69 0.93

0.407 0.83 1.94 0.66 0.37 0.40 0.177

0.451 1.50 1.49

0.365 1.43 2.70

0.394 1.05 1.76 0.56

0.457 1.01 2.15 0.231 0.46 0.51 0.176

21 21 21 16 3 3 3 4 3 3 3 3 11 11 11 0

0.292 0.437 1.332 0.420 0.361 0.407 1.536 0.227 0.009 0.029 0.106 0.193 0.060 0.077 0.037

0.410 1.041 1.962 0.987 0.412 0.834 1.791 0.286 0.025 0.053 0.118 0.516 0.273 0.317 0.112

0.480 1.495 2.700 1.629 0.463 1.090 2.140 0.410 0.042 0.080 0.140 0.980 0.456 0.548 0.177

0.050 0.211 0.348 0.377 0.051 0.372 0.313 0.086 0.017 0.025 0.019 0.412 0.117 0.159 0.051

12 20 18 38 12 45 17 30 69 48 16 80 43 50 46

0.487 0.63 1.60 0.409 0.526 1.383 0.078 0.100 0.213

0.448 0.98 1.71 0.369 0.853 1.530 0.080 0.124 0.175 0.21 0.22 0.127

0.407 1.050 1.950 1.016 0.260 0.305 0.110

0.065 0.104 0.303 0.536 0.119 0.156 0.083

16 10 16 53 46 51 75

C3
Round Robin XVIII Laboratory Results

All Lab Report Page 3 / 4

Symbol

na 

nd 

italics Value calculated from reported results

n 

Min

Mean Average over all non-NIST reported values.

Max

SD

CV

Median 

eSD

eCV 

Table Legend

Interpretation

Not available (not reported by participant)

Not detected (not reported or reported as '0', 'not determined', etc.)

Number of non-NIST laboratories reporting quantitative results

Minimum non-NIST reported value.

Maximum non-NIST reported value.

Standard deviation over all non-NIST values.

Coefficient of Variation (% relative standard deviation): 100*SD/Mean

Median over all non-NIST reported values

Robust estimate of SD based on the adjusted median absolute difference from the median (MADe)

Robust estimate of CV, 100*eSD/Median

C4
Round Robin XVIII Laboratory Results

All Lab Report Page 4 / 4

Lab TR aT bC Label Definition

FSV-BA 4±3 5±6 13±3 Lab Participant code

FSV-BD 3±3 9±6 TR Total Retinol

FSV-BE -2±8 1±4 aT a-Tocopherol

FSV-BF -3±2 -1±3 15±11 bC Total b-Carotene

FSV-BG 6±5 4±9 4±5 % Bias (Mean ± SD) of individual serum biases

FSV-BH 1±2 -2±3 -4±4

FSV-BI -6±2 -6±1 -17±4 Mean Average of (xi

-Mediani)/Mediani

FSV-BJ -3±4 7±8 8±3 SD Standard deviation of (xi

-Mediani)/Mediani

FSV-BL -2±4 -2±6 xi Result for analyte in serumi

FSV-BM -1±3 8±5 Mediani Median of non-NIST results in serumi

FSV-BY -1±7 2±5 -4±3

FSV-BZ 6±9

FSV-CA -13±4 -6±2

FSV-CJ -3±12 9±3 2±6

FSV-CK 40±22 31±26 -19±37

FSV-CM 1±3

FSV-CN 4±14 2±8 -15±16

FSV-CO -5±3 -1±1 10±3

FSV-CQ -3±4 4±3 -21±7

FSV-CV 0±1 10±17 16±13

FSV-CY -11±4 3±6 -3±2

FSV-DC 8±2 -8±8

FSV-DE 1±1

FSV-DG 1±2 -1±7 1±12

FSV-DH -12±3 -19±4 -7±12

FSV-DL 1±5 10±33

FSV-DT -11±10 -1±6

FSV-DY 40±68 21±28

FSV-DZ 24±20 -17±14

FSV-EB 5±14 2±12 -4±5

FSV-EF 3±4 -1±1

FSV-EV 13±8 -1±7

FSV-FA -5±7 -7±6 6±9

NISTa 6±1 4±5 -13±30

NISTc -11±4 -8±3 -3±12

The results for the calibration solution 123 do not 

necessarily reflect a participant's measurement 

performance for serum samples. Therefore, these 

summary values are calculated using only results for the 

four serum samples: 120, 121, and 122.

The original analysis listed % Bias for each result for 

each serum calculated relative to the "Trimmed Core 

Lab Average" of that analyte in the serum. The 

summary values reported here are the (arithmetic mean 

± standard deviation) of each laboratory's reported 

results for the analyte estimated relative to each serum's 

median value.

C5
Appendix D. Shipping Package Inserts for RR19 

Two items were included in each package shipped to an RR19 participant:

• Cover letter. The original letter has been lost. It would have described the four 

lyophilized sample materials (sera 130 to 133) distributed for the study, given guidance 

on reconstituting these samples, stated that results were due July 6, 1990 and to whom 

they should be sent, and who to contact with technical questions. 

• Datasheets. The following two pages reproduce the form. The first page of the form is 

for reporting the primary-focus analytes: retinol, α-tocopherol, and total and trans-βcarotene. The second page is for reporting three “optional” analytes: retinyl palmitate, 

γ-tocopherol, and lycopene. In the absence of other information, the lycopene results are 

assumed to report total lycopene. 

These items were attached to the shipping box. 

D1 
REPORT ON NIST/NCI SAMPLES FROM LABORATORY # _________ 

DATE OF ANALYSIS _____________ 

RESULTS IN μg/mL

SAMPLE # ANALYTE

SERUM 130

RETINOL

VIAL # ___

B-CAROTENE

Trans Total

A-TOCOPHEROL

SERUM 131

RETINOL

VIAL # ___

B-CAROTENE

Trans Total

A-TOCOPHEROL

SERUM 132

RETINOL

VIAL # ___

B-CAROTENE

Trans Total

A-TOCOPHEROL

SERUM 133

RETINOL

VIAL # ___

B-CAROTENE

Trans Total

A-TOCOPHEROL

 Add 1.0 mL of Distilled water to the Serum Samples.

D2 
REPORT ON NIST/NCI SAMPLES FROM LABORATORY # _________

OPTIONAL ANALYTES

DATE OF ANALYSIS _____________ 

RESULTS IN μg/mL

SAMPLE # ANALYTE

SERUM 130

RETINYL PALMITATE

VIAL # ___

LYCOPENE

GAMMA-TOCOPHEROL

SERUM 131

RETINYL PALMITATE

VIAL # ___

LYCOPENE

GAMMA-TOCOPHEROL

SERUM 132

RETINYL PALMITATE

VIAL # ___

LYCOPENE

GAMMA-TOCOPHEROL

SERUM 133

RETINYL PALMITATE

VIAL # ___

LYCOPENE

GAMMA-TOCOPHEROL

D3 
Appendix E. Final Report for RR19 

The following eight pages are the final report for RR19 as provided to all participants: 

• A cover letter and discussion. 

• Tables 1 to 3 that list the results and various summary values for retinol, 

α-tocopherol, and total β-carotene. 

• Table 4 that lists the results and simple summary statistics for trans-β-carotene, 

retinyl palmitate, lycopene, and γ-tocopherol. 

• Figures 1 to 3 that present interlaboratory precision over time for retinol, 

α-tocopherol, and total β-carotene.

It is likely that most participants reported “total lycopene” (the sum of all isomers.) Since 

resolution of γ-tocopherol and β-tocopherol is challenging, the results reported as 

γ-tocopherol can be confidently assumed to be γ/β-tocopherol. 

Due to the complex formatting used in the Tables, the originally listed laboratory codes 

have been deleted without replacement. However, Appendix F provides a complete 

listing of the RR19 results where the original codes have been altered to ensure 

confidentiality. Appendix F also provides more relevant summary statistics.

E1 
Personalized letters were sent to participants.

This block contained their formal name and address.

(Personal name),

E2
Table 1. 

Round Robin XIX . Percent Bias from the Average • Retinol Results 

I.ab # Serum 13 Serum ! 13 Serum 13 Serum 13 Serum #Serum #Serum #Serum # 130 131 132 133 

0.188 0.425 0.244 0.745 -16.6 -17.4 -16.2 0.9 0.230 0.488 0.273 0.729 2.0 -5.2 -6.3 -1.2 0.243 0.569 0.292 0.847 7.8 10.6 0.3 14.8 0.196 0.359 0.216 0.522 -13.l -30.2 -25.8 -29.3 0.192 0.478 0.309 0.754 -14.9 -7.1 6.1 2.2 0.222 0.523 

0 . 290 0.731 -1.8 1.6 -0.6 -1.0 

0.231 0.514 0.282 0.756 2.4 -0.1 -3.2 2.4 0.420 0.990 0.540 1.350 86.2 92.4 85.4 82.9 

0.484 0.315 0.657 -5.9 8.2 -11.0 

0.264 0.455 

0 . 299 0.801 17.1 -11.6 2.7 8.5 

0.236 0.482 0.292 0.748 4.6 -6.3 0.3 1.3 0.247 0.571 0.301 0.800 9.5 11.0 3.4 8.4 0.208 0.504 0.274 0.724 -7.8 -2.0 -5.9 -1.9 0.177 0.402 0.234 0.601 -21.5 -21.9 -19.6 -18.6 0.248 0.686 0.311 0.695 10.0 33.3 6.8 -5.8 0.222 0.527 0.285 0.757 -1.6 2.4 -2.1 2.6 

0.211 0.499 0.281 0.730 -6.4 -3.0 -3.5 -1.1 0.230 0.510 

0 . 290 0.780 2.0 -0.9 -0.4 5.7 

0.250 0.550 0.330 0.840 10.9 6.9 13.3 13.8 0.424 0.442 0.248 0.614 88.0 -14.1 -14.8 -16.8 0.204 0.451 0.270 0.695 -9.5 -12.3 -7.3 -5.8 0.235 0.578 0.332 0.875 4.2 12.3 14.0 18.6 0.257 0.482 0.318 0.674 14.0 -6.3 9.2 -8.7 0.279 0.560 0.318 0.867 23.7 8.8 9.2 17.5 0.252 0.452 0.303 0.668 11.7 -12.2 4.0 -9.5 0.238 0.529 0.303 0.745 5.7 2.8 3.9 0.9 0.205 0.526 0.291 0.748 -9.1 2.2 -0.1 1.3 0.218 0.518 0.288 0.712 -3.3 0.7 -1.1 -3.5 0.215 0.506 0.276 0.750 -4.6 -1.7 -5.3 1.6 0.223 0.556 0.321 0.719 -1.1 8.1 10.2 -2.6 0.233 0.526 0.292 0.775 3.3 2.2 0.3 5.0 0.238 0.661 0.363 0.926 5.5 28.5 24.6 25.5 0.235 0.530 0.292 0.775 4.2 3.0 0.3 5.0 0.255 0.610 0.290 0.765 13.1 18.6 -0.4 3.6 0.188 0.229 0.263 0.575 -16.6 -55.5 -9.7 -22.1 

NIST 0.212 0.524 

0 . 307 0.820 

Avg 0.226 0.515 

0 . 291 0.738 

SD 0.023 0.067 0.028 0.081 

RSD 10.1 13.1 9.8 11.0 

* = Value not included in staistical analysis. 

L = Late, Results not included in statistical analysis. 

NIST value not included in statistical analysis. 

E3
Table 2. 

Round Robin XIX Percent Bias from the Average Alpha-Tocopherol Results 

Lab # Serum 13 Serum j 13 serum 13 Serum 13 Serum #Serum #Serum #Serum # 130 131 132 133 

3.73 6.55 

4 . 43 11.48 -0.4 -1.4 -4.2 -3.4 

3.82 6.57 

4 . 55 11.91 2.0 -1.1 -1.6 0.2 

4.17 7.12 

4 . 99 12.69 11.4 7.1 7.9 6.8 

13.04 7.41 

7 . 21 7.31 248.3 11.4 55.9 -38.5 

3.84 6.89 5.02 13.09 2.6 3.7 8.6 10.2 3.66 6.73 

4 . 55 11.71 -2.4 1.3 -1.7 -1.5 

3.65 6.43 4.66 11.90 -2.5 -3.2 0.8 0.2 

1.60 2.80 1 . 90 4.60 -57.3 -57.9 -58.9 -61.3 

3.55 6.73 4.38 12.14 -5.2 1.3 -5.3 2.2 3.57 6.53 

4 . 63 12.70 -4.7 -1.7 0.1 6.9 

3.75 6.62 

4 . 52 11.93 0.2 -0.4 -2.3 0.4 

3.84 6.28 

4 . 67 11.12 2.6 -5.5 1.0 -6.4 

4.01 6.46 

4 . 37 12.45 7.1 -2.9 -5.4 4.8 

3.91 4.52 3 . 96 9.61 4.4 -31.9 -14.4 -19.1 3.79 6.90 

4 . 63 11.81 1.2 3.8 0.1 -0.6 

3.88 6.82 

4 . 54 11.41. 3.6 2.6 -1.9 -3.9 

6.26 7.65 

4 . 84 11.65 67.1 15.0 4.7 -2.0 

3.83 6.51 

4 . 65 11.95 2.3 -2.0 0.6 0.6 

3.20 6.30 4.20 11.60 -14.5 -5.2 -9.2 -2.4 3.40 7.20 

4 . 60 13.60 -9.2 8.3 -0.5 14.5 

4.57 7.88 

5 . 39 14.31 22.1 18.6 16.6 20.4 

3.26 6.47 

4 . 33 12.96 -13.0 -2.6 -6.4 9.1 

2.58 5.17 

2 . 06 9.67 -31.2 -22.2 -55.4 -18.6 

2.81 4.84 3.52 9.12 -24.9 -27.1 -23.9 -23.2 

3.80 7.30 4.90 12.40 1.5 9.8 6.0 4.4 

3.83 7.02 4.75 12.21 2.3 5.6 2.8 2.8 

3.74 6.63 4.46 12.12 -0.l -0.3 -3.7 2.0 

3.58 6.85 

4 . 89 11.23 -4.4 3.1 5.7 -5.5 

4.47 6.37 4.85 10.10 19.4 -4.2 4.9 -15.0 

3.80 7.40 

4 . 80 12.80 1.5 11.3 3.8 7.7 

3.75 6.18 4.21 11.08 0.2 -7.0 -9.0 -6.7 

4.81 7.70 

5 . 84 13.70 28.3 15.9 26.2 15.3 

1.59 0.18 1.12 2.95 -57.6 -97.4 -75.7 -75.2 

NIST 3.32 6.75 

4 . 43 11.46 

Avg 3.74 6.65 4.62 11.88 SD 0.46 0.76 0.43 1.21 

RSD 12.3 11.4 9.3 10.2 

* = Value not included in staistical analysis. 

L = Late, Results not included in statistical analysis. 

NIST value not included in statistical analysis. 

E4
Table 3. 

Round Robin XIX Percent Bias from the Average Total Beta-carotene Results 

Lab # Serum g 13 Serum 1 13 Serum 13 Serum 13 Serum #Serum #Serum #Serum # 130 131 132 133 

0.993 0.181 1.153 0.526 1.9 -4.3 0.7 0.3 0.864 0.176 0.994 0.439 -11.3 -7.0 -13.2 -16.3 0.950 0.182 1.083 0.484 -2.5 -3.8 -5.4 -7.7 

1.134 0.244 1.219 0.695 16.4 29.0 6.5 32.5 

0.958 0.205 1.135 0.534 -1.7 8.4 -0.9 1.8 

1.800 

0 . 410 

2 . 360 1.100 84.7 116.7 106.1 109.8 

1.015 0.195 1.092 0.494 4.2 3.1 -4.6 -5.8 1.210 0.000 0.621 0.415 24.2 -100 . 0 -45.8 -20.9 1.047 0.212 1.183 0.582 7.4 12 . 1 3.3 11.0 

0.964 0.198 1.096 0.532 -1.1 4.7 -4.3 1.4 0.947 0.194 1.241 0.522 -2.8 2.6 8.4 -0.5 0.823 0.190 1.034 0.487 -15.5 0.4 -9.7 -7.1 0.962 0.178 1.112 0.463 -1.3 -5 . 9 -2.9 -11.7 0.910 0.160 1.140 0.560 -6.6 -15 . 4 -0.4 6.8 0.290 0.053 0.354 0.182 -70.2 -72.0 -69.l -65.3 0.874 0.185 1.053 0.554 -10.3 -2.2 -8.0 5.6 0.801 0.157 0.926 0.535 -17.8 -17 . 0 -19.1 2.0 0.974 0.223 1.156 0.521 o.o 17.9 1.0 -0.6 

1.025 0.180 1.226 0.535 5.2 -4.8 7.1 2.0 1.163 0.186 1.111 0.590 19.3 -1 . 7 -3.0 12.5 

0.902 0.159 1.110 0.524 -7.4 -15.9 -3.1 -0 . 1 

1.415 0.450 1.465 0.935 45.2 137.9 28.0 78.3 

0.974 0.849 1.370 0.496 o.o 348 . 8 19.7 -5.4 

NIST 0.984 0.208 1.110 0.502 

Avg 0.974 0.189 1.145 0.524 SD 0.106 0.022 0.121 0.059 

RSD 10.9 11.7 10.6 11.3 

* = Value not included in staistical analysis. 

L = Late, Results not included in statistical analysis. 

NIST value not included in statistical analysis. 

E5
Table 4. 

RR XIX Results 

Trans-Beta carotene Lycopene 

Serum g Serum #Serum #Serum Serum # Serum 1 Serum Serum Lab # 130 131 132 133 Lab# 13 13 13 13 0.135 0.312 0.254 0.297 

0.916 0.168 1.058 0.441 0.084 0.182 0.149 0.172 

0.770 0.1.67 0.944 0.492 0.170 0.480 0.380 0.460 

NIST 0.864 0.184 1.020 0.432 0.097 0.218 0.179 0.192 0.091 0.204 0.171 0.196 

Avg 0.843 0.168 1.001 0.467 0.112 0.241 0.204 0.216 0.130 0.210 0.210 0.240 

0.117 0.266 0.219 0.263 

0.080 0.213 0.165 0.192 

Retinyl Palmitate 0.068 0.134 0.112 0.156 0.750 0.200 0.173 0.203 

Serum # Serum # Serum # Serum i 0.489 0.263 0.723 0.452 

Lab # 130 131 132 13 Avg 0.194 0.244 0.245 0.253 0.008 ND ND ND 

ND ND ND ND ND ND ND ND Gamma-Tocopherol ND ND ND ND 

0.056 0.020 0.069 0.051 Serum #Serum #Serum Serum # 0.025 0.026 

0 . 068 0.046 Lab # 130 131 132 133 

0.037 ND ND 0.058 0.010 0.012 

0 . 014 0.016 0.696 2.601 1.522 2.234 

0.108 0.830 2.810 1.770 2.530 0.730 2.750 1.730 2.590 

Avg 0.041 0.019 0.050 0.043 0.220 0.710 0.420 0.600 0.770 2.810 1.620 2.350 

0.700 2.540 1.500 2.210 0.850 2.780 1.640 2.540 0.731 2.555 1.547 2.220 0.570 2.050 1.410 0.750 3.000 1.800 3.000 

1.290 5.130 3.150 4.570 

0.532 2.139 1.292 2.052 0.648 2.305 1.450 2.130 0.860 3.127 1.923 2.735 0.750 2.590 1.780 2.050 

NIST 0.867 3.030 1.510 2.530 

Avg 0.728 2.660 1.637 2.254 

E6
30 

20 

10 

0 

20 

10 

lnterlaboratory Precision vs Time 

Retinal 

Percent 

3/88 10/884/87 7/87 1/88 7188 9/88 1/89 4/89 

Date 

• - % SD Retinal 

Percent 

8/89 1/90 5/90 

Controls Avallabfe 

---------1 

+ + + 

+ 

+ 

+ - -t---- + + 

+ + + 

o .................. ..._._ .......... _._._..._.__ ........... _._._ ...................... _._._ .................................. ~ .................................................................... _._._ .................... ............. 3186 10/66 4 /87 7 /87 1/88 7 /88 9/88 1/89 4/89 8/89 1/90 5/90 

Date 

--·~· Controls Available 

+ % SD Retlnol 

FIGURE 1 

E7
30 

20 

10 

0 

lnterlaboratory Precision vs Time 

Alpha-Tocopherol 

Percent 

3/88 10/884/87 7/87 1/ 88 7188 9/88 1189 4 / 89 8/89 1/90 6/90 

Date 

--··-- Controls Available - % SD Tocopherol 

Percent 

* 

--*""--- * * 

* 

* * * * * * * 

I I I I I I I I I I I I I I I I I I I I I II 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 II I I I I I I I 

3/86 10/86 4/87 7 /87 1/88 7 /88 9/88 1/89 4/89 8/89 1/90 5/90 

Date 

--··-- Controls Aval lable * % SD Tocopherol 

FIGURE 2 

E8
30 

20 

10 

0 

30 

20 

lnterlaboratory Precision vs Time 

Beta -Carotene 

Percent 

---------t 

3/86 10/8&•187 7/87 1/88 7/88 9/88 1/ 89 4 / 89 8 / 89 1/90 6/90 

Date 

--··~ Controls Availabl e - % SD Beta- Carotene 

Percent 

x 

x x 

x 

x 

10 ---------~-----,.--------~x x 

x 

o._._.._._._._._..._._.._._._._._ ............................... ...__._ ......................................................... ...__._.._._.._._. ........... ..._._ ........... _._..........._ ......... ....._.__. 

3/86 10/86 4/87 7187 1188 7 /88 9/88 1/89 4/89 8/89 1/90 5/90 

Date 

---·~ Controls Available 

x % so Beta-Carotene 

FIGURE 3 

E9
Appendix F. Updated “All-Lab Report” for RR19 

The following four pages are an updated version of an “All-Lab” report for RR19. This 

report has three parts: 

• pages 1 and 2 list results for all analytes reported at least twice, counting both

participants and NIST analysts.

• page 3 provides a legend for pages 1 and 2.

• page 4 summarizes each participants’ performance for retinol, α-tocopherol, and

total β-carotene. These summaries are compatible with the percent bias

evaluation advice given in the RR19 Report. However, the current bias

summaries are estimated relative to the median of all reported values for each

analyte in each serum rather than to the trimmed average (“Avg”) used in the

original and detailed in Appendix E. The original reference values were

estimated from on-time results, with subjective exclusion of results deemed nonrepresentative.

To ensure confidentiality, the laboratory identifiers used in this “All-Lab Report” have 

been altered from those used in RR19. 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. 

Note: The results designated NISTa in this updated All-Lab report are designated NIST 

in the Tables of Appendix E. 

F1 
Round Robin XIX Laboratory Results

All Lab Report Page 1 / 4

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

Lab 130 131 132 133 130 131 132 133 130 131 132 133 130 131 132 133

FSV-BA 0.234 0.536 0.297 0.786 3.76 6.48 4.53 11.09

FSV-BD 0.231 0.514 0.282 0.756 3.65 6.43 4.66 11.90 0.73 2.75 1.73 2.59

FSV-BE 0.236 0.482 0.292 0.748 3.84 6.28 4.67 11.12 0.85 2.78 1.64 2.54

FSV-BH 0.211 0.499 0.281 0.730 nd nd nd nd 3.88 6.82 4.54 11.41 0.73 2.56 1.55 2.22

FSV-BI 0.230 0.488 0.273 0.729 nd nd nd nd 3.82 6.57 4.55 11.91 0.83 2.81 1.77 2.53

FSV-BJ 0.218 0.518 0.288 0.712 3.83 7.02 4.75 12.21 0.86 3.13 1.92 2.74

FSV-BK 0.215 0.506 0.276 0.750 3.74 6.63 4.46 12.12

FSV-BL 0.204 0.451 0.270 0.695 4.57 7.88 5.39 14.31 1.29 5.13 3.15 4.57

FSV-BM 0.205 0.526 0.291 0.748 3.80 7.30 4.90 12.40

FSV-BY 0.188 0.425 0.244 0.745 0.008 nd nd nd 3.73 6.55 4.43 11.48 0.70 2.60 1.52 2.23

FSV-BZ 6.26 7.65 4.84 11.65

FSV-CA 0.192 0.478 0.309 0.754 3.84 6.89 5.02 13.09

FSV-CH 0.255 0.610 0.290 0.765 4.81 7.70 5.84 13.70

FSV-CJ 0.243 0.569 0.292 0.847 4.17 7.12 4.99 12.69

FSV-CM 3.40 7.20 4.60 13.60

FSV-CN na 0.484 0.315 0.657 3.55 6.73 4.38 12.14 0.77 2.81 1.62 2.35

FSV-CO 0.222 0.523 0.290 0.731 3.66 6.73 4.55 11.71

FSV-CQ 0.264 0.455 0.299 0.801 3.57 6.53 4.63 12.70

FSV-CS 0.238 0.529 0.303 0.745 2.81 4.84 3.52 9.12

FSV-CV 0.233 0.526 0.292 0.775 4.47 6.37 4.85 10.10 0.75 2.59 1.78 2.05

FSV-CY 0.230 0.510 0.290 0.780 3.83 6.51 4.65 11.95 0.57 2.05 1.41 1.88

FSV-DC 0.208 0.504 0.274 0.724 nd nd nd nd

FSV-DE 3.75 6.62 4.52 11.93 0.70 2.54 1.50 2.21

FSV-DG 0.247 0.571 0.301 0.800 4.01 6.46 4.37 12.45

FSV-DH 0.235 0.578 0.332 0.875 0.056 0.020 0.069 0.051 3.26 6.47 4.33 12.96 0.53 2.14 1.29 2.05

FSV-DL 0.260 0.489 0.288 0.739

FSV-DN 0.420 0.990 0.540 1.350 1.60 2.80 1.90 4.60 0.22 0.71 0.42 0.60

FSV-DO 0.196 0.359 0.216 0.522 13.04 7.41 7.21 7.31

FSV-DY 0.424 0.442 0.248 0.614

FSV-DZ 0.248 0.686 0.311 0.695 3.91 4.52 3.96 9.61

FSV-EB 0.235 0.530 0.292 0.775 3.75 6.18 4.21 11.08

FSV-ED 0.222 0.527 0.285 0.757 3.79 6.90 4.63 11.81

FSV-EF 0.250 0.550 0.330 0.840 3.20 6.30 4.20 11.60 0.75 3.00 1.80 3.00

FSV-EJ 0.188 0.229 0.263 0.575 1.92 2.05 1.12 2.95

FSV-EO 0.177 0.402 0.234 0.601

FSV-EV 0.238 0.661 0.363 0.926 3.80 7.40 4.80 12.80

FSV-EY 0.223 0.556 0.321 0.719 3.58 6.85 4.89 11.23

FSV-FA 0.252 0.452 0.303 0.668 <0.01 0.012 0.014 0.016 2.58 5.17 2.06 9.67 0.65 2.31 1.45 2.13

FSV-FQ 0.257 0.482 0.318 0.674 0.025 0.026 0.068 0.046

FSV-FV 0.279 0.560 0.318 0.867 0.037 nq nq 0.058

n 36 37 37 37 4 3 3 4 34 34 34 34 15 15 15 15

Min 0.177 0.229 0.216 0.522 0.008 0.012 0.014 0.016 1.60 2.05 1.12 2.95 0.22 0.71 0.42 0.60

Mean 0.239 0.519 0.298 0.756 0.032 0.019 0.050 0.043 3.98 6.39 4.44 11.25 0.73 2.66 1.64 2.38

Max 0.424 0.990 0.540 1.350 0.056 0.026 0.069 0.058 13.04 7.88 7.21 14.31 1.29 5.13 3.15 4.57

SD 0.051 0.112 0.049 0.129 0.020 0.007 0.031 0.019 1.78 1.24 1.05 2.34 0.22 0.89 0.55 0.81

CV 21 22 17 17 64 36 63 43 45 19 24 21 30 33 33 34

NISTa 0.212 0.524 0.307 0.820 3.32 6.75 4.43 11.46 0.87 3.03 1.51 2.53

Median 0.234 0.514 0.292 0.748 3.78 6.60 4.58 11.86 0.73 2.60 1.62 2.23

eSD 0.026 0.053 0.024 0.053 0.24 0.44 0.35 1.11 0.12 0.31 0.24 0.44

eCV 11 10 8 7 6 7 8 9 17 12 15 20

F2
Round Robin XIX Laboratory Results

All Lab Report Page 2 / 4

Lab

FSV-BA

FSV-BD

FSV-BE

FSV-BH

FSV-BI

FSV-BJ

FSV-BK

FSV-BL

FSV-BM

FSV-BY

FSV-BZ

FSV-CA

FSV-CH

FSV-CJ

FSV-CM

FSV-CN

FSV-CO

FSV-CQ

FSV-CS

FSV-CV

FSV-CY

FSV-DC

FSV-DE

FSV-DG

FSV-DH

FSV-DL

FSV-DN

FSV-DO

FSV-DY

FSV-DZ

FSV-EB

FSV-ED

FSV-EF

FSV-EJ

FSV-EO

FSV-EV

FSV-EY

FSV-FA

FSV-FQ

FSV-FV

n

Min

Mean

Max

SD

CV

NISTa

Median

eSD

eCV

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

130 131 132 133 130 131 132 133 130 131 132 133 130 131 132 133

0.909 0.201 1.086 0.522

0.962 0.178 1.112 0.463 0.916 0.168 1.058 0.441 0.046 0.010 0.054 0.022 0.112 0.241 0.204 0.216

0.864 0.176 0.994 0.439 0.084 0.182 0.149 0.172

1.025 0.180 1.226 0.535 0.068 0.134 0.112 0.156

0.993 0.181 1.153 0.526 0.135 0.312 0.254 0.297

1.415 0.450 1.465 0.935

0.950 0.182 1.083 0.484

1.015 0.195 1.092 0.494 0.097 0.218 0.179 0.192

0.958 0.205 1.135 0.534

1.210 nd 0.621 0.415

1.163 0.186 1.111 0.590 0.108 0.200 0.173 0.203

0.910 0.160 1.140 0.560 0.130 0.210 0.210 0.240

0.964 0.198 1.096 0.532 0.091 0.204 0.171 0.196

1.047 0.212 1.183 0.582

0.874 0.185 1.053 0.554 0.770 0.167 0.944 0.492 0.104 0.018 0.109 0.062 0.117 0.266 0.219 0.263

1.067 0.166 1.138 0.527

1.800 0.410 2.360 1.100 0.170 0.480 0.380 0.460

1.134 0.244 1.219 0.695

0.290 0.053 0.354 0.182

0.902 0.159 1.110 0.524

0.823 0.190 1.034 0.487

1.586 0.176 1.370 0.496 0.489 0.263 0.723 0.452

0.947 0.194 1.241 0.522

0.974 0.223 1.156 0.521 0.080 0.213 0.165 0.192

0.801 0.157 0.926 0.535

25 24 25 25 2 2 2 2 2 2 2 2 12 12 12 12

0.290 0.053 0.354 0.182 0.770 0.167 0.944 0.441 0.046 0.010 0.054 0.022 0.068 0.134 0.112 0.156

1.023 0.203 1.138 0.550 0.843 0.168 1.001 0.467 0.075 0.014 0.082 0.042 0.140 0.244 0.245 0.253

1.800 0.450 2.360 1.100 0.916 0.168 1.058 0.492 0.104 0.018 0.109 0.062 0.489 0.480 0.723 0.460

0.280 0.078 0.333 0.167 0.113 0.087 0.165 0.102

27 39 29 30 81 36 67 40

0.984 0.208 1.110 0.502 0.864 0.184 1.020 0.432 0.120 0.024 0.090 0.070

0.964 0.186 1.112 0.526 0.110 0.216 0.192 0.210

0.123 0.021 0.087 0.047 0.033 0.044 0.040 0.050

13 11 8 9 30 20 21 24

F3
Round Robin XIX Laboratory Results

All Lab Report Page 3 / 4

Symbol

na 

nd 

<x Value less than x

italics Value calculated from reported results

n 

Min

Mean Average over all non-NIST reported values.

Max

SD

CV

Median 

eSD 

eCV 

Table Legend

Interpretation

Not available (not reported by participant)

Not detected (not reported or reported as '0', 'not determined', etc.)

Number of non-NIST laboratories reporting quantitative results

Minimum non-NIST reported value.

Maximum non-NIST reported value.

Standard deviation over all non-NIST values.

Coefficient of Variation (% relative standard deviation): 100*SD/Mean

Median over all non-NIST reported values

Robust estimate of SD based on the adjusted median absolute difference from the median (MADe)

Robust estimate of CV, 100*eSD/Median

F4
Round Robin XIX Laboratory Results

All Lab Report Page 4 / 4

Lab TR aT bC Label Definition

FSV-BA 3±2 -2±3 0±6 Lab Participant code

FSV-BD -1±2 -1±2 TR Total Retinol

FSV-BE -1±3 -2±4 aT a-Tocopherol

FSV-BH -5±3 0±3 -4±6 bC Total b-Carotene

FSV-BI -4±2 0±1 -11±5 % Bias (Mean ± SD) of individual serum biases

FSV-BJ -3±3 4±2 4±6

FSV-BK -4±4 0±2 Mean Average of (xi

-Mediani)/Mediani

FSV-BL -10±3 20±1 SD Standard deviation of (xi

-Mediani)/Mediani

FSV-BM -3±7 6±4 xi Result for analyte in serumi

FSV-BY -13±9 -2±1 1±3 Mediani Median of non-NIST results in serumi

FSV-BZ 21±30

FSV-CA -5±10 7±4

FSV-CH 7±9 22±7 75±49

FSV-CJ 7±6 9±1 -3±3

FSV-CM 4±11

FSV-CN -3±10 -1±4 1±6

FSV-CO -2±3 -1±2 3±5

FSV-CQ 3±10 0±5 -13±35

FSV-CS 2±2 -25±2

FSV-CV 1±2 2±14 8±10

FSV-CY 0±3 1±1 -3±9

FSV-DC -6±4 2±4

FSV-DE 0±1

FSV-DG 7±3 1±5 10±3

FSV-DH 11±7 -3±10 -2±6

FSV-DL 1±7 1±9

FSV-DN 84±6 -59±2 107±15

FSV-DO -26±7 69±124 23±11

FSV-DY 9±49 -69±3

FSV-DZ 10±17 -15±15

FSV-EB 2±2 -5±3 -5±7

FSV-ED -1±3 1±2 -7±7

FSV-EF 10±3 -8±6

FSV-EJ -27±20 -67±12 19±33

FSV-EO -21±2 3±6

FSV-EV 20±12 6±5

FSV-EY 2±8 0±6

FSV-FA -3±10 -32±16 6±10

FSV-FQ 1±10 -12±9

FSV-FV 13±5

NISTa 2±8 -4±6 2±7

%Bias Summary

The original analysis listed % Bias for each result for 

each serum calculated relative to the "Trimmed Core 

Lab Average" of that analyte in the serum. The 

summary values reported here are the (arithmetic mean 

± standard deviation) of each laboratory's reported 

results for the analyte estimated relative to each serum's 

median value.

F5
Appendix G. Shipping Package Inserts for RR20 

Two items were included in each package shipped to an RR20 participant:

• Cover letter. The original letter has been lost. It likely would have described the five 

sample materials (liquid frozen sera 138 and 139; lyophilized sera 140, 141, and 142), 

given guidance on reconstituting the lyophilized samples, stated that results were required

by October 22, 1990, to whom they should be sent, and who to contact with technical 

questions. It is likely that this letter also provided details on the 1990 QA Workshop, 

held at NIST on November 15, 1990. 

• Datasheet. The following two pages reproduce the form.

The cover letter and datasheets were attached to the shipping box. 

G1 
REPORT ON NIST/NCI SAMPLES FROM LABORATORY # _________ 

RR XX DATE OF ANALYSIS _____________ 

RESULTS IN μg/mL

SAMPLE # ANALYTE

SERUM 138

RETINOL

VIAL # ___

B-CAROTENE

Trans Total

A-TOCOPHEROL

SERUM 139

RETINOL

VIAL # ___

B-CAROTENE

Trans Total

A-TOCOPHEROL

SERUM 140

RETINOL

VIAL # ___

B-CAROTENE

Trans Total

A-TOCOPHEROL

SERUM 141

RETINOL

VIAL # ___

B-CAROTENE

Trans Total

A-TOCOPHEROL

SERUM 142

RETINOL

VIAL # ___

B-CAROTENE

Trans Total

A-TOCOPHEROL

 Add 1.0 mL of Distilled water to samples 140, 141, and 142.

G2 
REPORT ON NIST/NCI SAMPLES FROM LABORATORY # _________

OPTIONAL ANALYTES

DATE OF ANALYSIS _____________ 

RESULTS IN μg/mL

SAMPLE # ANALYTE

SERUM 138

RETINYL PALMITATE

VIAL # ___

LYCOPENE

GAMMA-TOCOPHEROL

SERUM 139

RETINYL PALMITATE

VIAL # ___

LYCOPENE

GAMMA-TOCOPHEROL

SERUM 140

RETINYL PALMITATE

VIAL # ___

LYCOPENE

GAMMA-TOCOPHEROL

SERUM 141

RETINYL PALMITATE

VIAL # ___

LYCOPENE

GAMMA-TOCOPHEROL

SERUM 142

RETINYL PALMITATE

VIAL # ___

LYCOPENE

GAMMA-TOCOPHEROL

G3 
Appendix H. Final Report for RR20 

There is no available record of the complete final report for RR20. The following four 

pages present the results and summary statistics for the samples as interpreted at the time:

• Tables 1 thru 3 list retinol, α-tocopherol, total β-carotene;

• Tables 4 to 7 list trans-β-carotene, retinyl palmitate, lycopene, and γ-tocopherol.

It is likely that most participants reported “total lycopene” (the sum of all isomers.) Since 

resolution of γ-tocopherol and β-tocopherol is challenging, the results reported as 

γ-tocopherol can be confidently assumed to be γ/β-tocopherol. 

Due to the complex formatting used in the tabular listings, the original laboratory codes 

have been deleted without replacement. However, Appendix I provides a complete 

listing of the RR20 results where the original codes have been altered to ensure 

confidentiality. Appendix I also provides more relevant summary statistics.

H1 
H2
H3
H4
H5
Appendix I. Updated “All-Lab Report” for RR20 

The following four pages are an updated version of an “All-Lab” report for RR20. This 

report has three parts: 

• pages 1 and 2 list results for all analytes reported by at least twice, counting both

participants and NIST analysts.

• page 3 lists values for all analytes reported by only once. This page also provides

a legend for pages 1 and 2.

• page 4 summarizes each participants’ performance for total retinol, α-tocopherol,

and total β-carotene. These summaries are compatible with the percent bias

evaluation advice given in the RR20 Report. However, the current bias

summaries are estimated relative to the median of all reported values for each

analyte in each serum rather than to the “Trimmed Core Lab Average” used in the

original and detailed in Appendix J. These original reference values were

estimated from on-time results of the more experienced participants, with

subjective exclusion of results deemed non-representative.

In the original data sheets for RR20, one participant commented that the two “Serum 

141”vials they received yielded quite discordant results. Only the most concordant of 

their two sets of results were included in the original Final Report (see Appendix H). 

When reviewing the data for this report, it was noted that the excluded Serum 141 results 

from this participant as well as those reported by two other participants matched the 

results expected for Serum 121 distributed in RR18; the intended Serum 141 material was 

distributed as Serum 122 in RR18. Thus it is quite plausible that several vials of Serum 

121 were incorrectly relabeled and distributed in RR20. For this reason, the updated AllLab Report lists the three sets of discordant Serum 141 results under the heading “Serum 

141a”. The median values listed for Serum 141a are those for Serum 121 in RR18. 

To ensure confidentiality, the laboratory identifiers used in this “All-Lab Report” have 

been altered from those used in RR20. 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. 

Note: The results designated NISTa and NISTc in this updated All-Lab report are both 

designated “NIST” in the Tables of Appendix H. 

I1 
Round Robin XX Laboratory Results

All Lab Report 

Total Retinol Retinyl Palmitate α-Tocopherol 

Lab 138 139 140 141 141a 142 138 139 140 141 141a 142 138 139 140 141 141a 142 138 139 

FSV-BA 0.562 0.646 0.761 0.86 0.234 10.6 9.67 11.71 9.0 3.95

FSV-BD 0.588 0.550 0.739 0.73 0.232 10.3 8.30 10.90 8.9 3.60

FSV-BE 0.549 0.631 0.671 0.79 0.236 10.0 9.88 11.62 9.9 4.09

FSV-BF 0.619 0.759 0.727 0.77 0.244 9.4 9.50 11.60 9.8 3.78 1.49 2.17 

FSV-BH 0.550 0.651 0.679 0.74 0.204 0.212 0.064 nd nd nd 10.4 9.86 11.53 9.3 3.61 1.33 2.20 

FSV-BI 0.532 0.594 0.714 0.80 0.216 0.259 0.079 nd nd nd 10.0 9.38 11.25 8.9 3.65 1.46 2.25 

FSV-BJ 0.564 0.581 0.680 0.59 0.230 12.0 10.95 12.16 11.4 3.91 1.93 3.17 

FSV-BK 0.560 0.630 0.737 0.91 0.218 9.8 9.14 11.17 9.7 3.68

FSV-BM 0.508 0.589 0.724 0.78 0.225 10.2 9.60 12.10 9.5 3.90

FSV-BY 0.611 0.715 0.738 0.438 0.209 0.214 0.052 nd nd nd 10.5 10.38 11.73 6.24 3.66 1.15 2.01 

FSV-BZ 8.7 8.60 10.00 10.3 5.50

FSV-CA 0.500 0.599 0.700 0.86 0.485 0.231 9.4 9.18 11.48 9.6 6.50 3.60

FSV-CH 0.625 0.659 0.877 0.99 0.269 13.6 11.41 13.09 11.5 5.09

FSV-CJ 0.627 0.740 0.884 0.95 0.257 11.6 10.61 12.57 10.4 4.09

FSV-CM 10.2 9.80 11.90 9.8 4.60

FSV-CO 0.549 0.632 0.760 0.84 0.224 10.4 9.83 11.61 8.8 3.58

FSV-CQ 0.762 0.622 0.760 0.81 0.215 12.0 8.90 11.30 9.1 3.39

FSV-CV 0.510 0.610 0.755 0.86 0.229 10.1 9.83 11.90 11.0 4.20 1.12 1.88 

FSV-CY ns ns 0.780 0.88 0.230 ns ns 11.46 9.1 3.68 ns ns 

FSV-DC

FSV-DE 10.2 9.65 11.39 9.2 3.70 1.27 2.16 

FSV-DG 0.510 0.580 0.750 0.86 0.220 9.7 9.45 11.13 8.9 3.87

FSV-DH 0.552 0.688 0.707 0.77 0.195 0.084 0.081 0.036 0.021 0.011 11.5 11.24 13.27 10.1 3.36 0.98 1.77 

FSV-DL 0.551 0.657 0.655 0.72 0.203

FSV-DN 0.360 0.450 0.570 0.74 0.180 10.3 9.60 11.20 10.4 3.60

FSV-DO 0.350 0.420 0.470 0.550 0.200 6.1 8.76 6.36 5.76 4.89

FSV-DT 0.474 0.570 0.593 0.73 0.202 10.2 9.80 11.33 9.3 3.46

FSV-EB 0.572 0.694 0.738 1.00 0.225 10.9 10.23 10.76 10.1 3.76

FSV-EF 0.490 0.540 0.720 0.83 0.230 9.9 9.30 14.20 12.8 4.70 1.30 1.90 

FSV-EV 0.723 0.827 0.900 1.03 0.272 11.5 10.60 12.60 9.6 3.70

FSV-EY 0.553 0.650 0.825 0.89 0.229 11.6 10.75 13.02 10.3 3.77

FSV-FA 0.384 0.434 0.570 0.61 0.150 9.2 8.49 10.50 8.2 3.52 1.40 2.07 

FSV-FQ 0.493 0.538 0.613 0.76 0.186 0.352 0.109 nd nd nd 11.4 9.79 11.70 8.3 1.94

n 28 28 29 27 3 29 5 5 1 1 0 1 30 30 31 29 3 31 10 10 

Min 0.350 0.420 0.470 0.589 0.438 0.150 0.084 0.052 6.05 8.30 6.36 8.15 5.76 1.94 0.98 1.77 

Mean 0.544 0.616 0.717 0.818 0.491 0.220 0.224 0.077 10.39 9.75 11.57 9.75 6.17 3.87 1.34 2.16 

Max 0.762 0.827 0.900 1.031 0.550 0.272 0.352 0.109 13.57 11.41 14.20 12.80 6.50 5.50 1.93 3.17 

SD 0.090 0.092 0.095 0.106 0.056 0.025 0.097 0.021 1.29 0.78 1.29 1.00 0.38 0.63 0.26 0.39 

CV 17 15 13 13 11 12 43 28 12 8 11 10 6 16 19 18 

NISTa 0.583 0.669 0.827 0.90 0.230 10.6 10.06 11.35 8.9 3.30 1.69 2.60 

NISTc 0.537 0.624 0.746 0.84 0.229 0.220 0.072 0.016 nd nd 10.1 9.45 11.40 8.9 3.45 1.74 2.75 

Median 0.551 0.626 0.727 0.812 0.485 0.225 0.214 0.079 10.27 9.73 11.60 9.60 6.24 3.70 1.31 2.12 

eSD 0.062 0.067 0.050 0.101 0.015 0.067 0.022 0.74 0.69 0.59 0.87 0.27 0.23 0.18 

eCV 11 11 7 12 7 31 28 7 7 5 9 7 17 8 

I2
Round Robin XX Laboratory Results

All Lab Report 

Lab

FSV-BA

FSV-BD

FSV-BE

FSV-BF

FSV-BH

FSV-BI

FSV-BJ

FSV-BK

FSV-BM

FSV-BY

FSV-BZ

FSV-CA

FSV-CH

FSV-CJ

FSV-CM

FSV-CO

FSV-CQ

FSV-CV

FSV-CY

FSV-DC

FSV-DE

FSV-DG

FSV-DH

FSV-DL

FSV-DN

FSV-DO

FSV-DT

FSV-EB

FSV-EF

FSV-EV

FSV-EY

FSV-FA

FSV-FQ

n

Min

Mean

Max

SD

CV

NISTa

NISTc

Median

eSD

eCV

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

138 139 140 141 141a 142 138 139 140 141 141a 142 138 139 140 141 141a 142 138 13

1.74 0.46 0.472 1.58 0.86 1.660 0.420 0.429 1.460 0.793 0.080 0.043 0.043 0.120 0.068

1.67 0.50 0.490 2.28 0.92 0.44 0

1.68 0.46 0.505 2.12 0.94 1.610 0.437 0.480 1.987 0.878 0.071 0.026 0.025 0.131 0.060 0.37 0

1.50 0.42 0.482 1.53 0.89 0.25 0

2.10 0.55 0.599 2.39 1.09 1.21 1

1.90 0.51 0.525 1.14 0.93 0.48 0

1.38 0.44 0.434 1.67 0.75

1.92 0.48 0.579 2.53 1.08

1.70 0.47 0.564 2.16 0.91

3.54 0.37 0.648 3.53 1.55

1.46 0.49 0.625 2.14 1.12 0.56 0

ns ns 0.510 2.37 0.89 ns n

1.77 0.45 0.503 2.25 0.88 0.27 0

1.42 0.38 0.530 1.75 0.91

1.25 0.37 0.489 1.95 0.78 1.200 0.345 0.448 1.822 0.722 0.054 0.026 0.041 0.128 0.059 0.37 0

1.13 0.39 0.503 1.73 0.84

1.49 0.41 0.490 1.40 0.86

2.32 0.43 0.720 1.17 0.88

1.59 0.45 0.477 1.90 0.82

1.61 0.40 0.508 1.70 0.93

0.83 0.35 0.390 0.94 0.60 0.27 0

1.67 0.39 0.402 1.65 0.68

21 21 22 20 2 22 3 3 3 3 0 3 3 3 3 3 0 3 9 

0.829 0.350 0.390 0.935 1.136 0.595 1.200 0.345 0.429 1.460 0.722 0.054 0.026 0.025 0.120 0.059 0.251 0.2

1.699 0.437 0.520 1.978 1.153 0.914 1.490 0.401 0.452 1.756 0.798 0.068 0.032 0.036 0.126 0.062 0.468 0.4

3.540 0.551 0.720 3.530 1.170 1.550 1.660 0.437 0.480 1.987 0.878 0.080 0.043 0.043 0.131 0.068 1.209 1.0

0.532 0.053 0.078 0.536 0.187 0.252 0.049 0.026 0.270 0.078 0.013 0.010 0.010 0.006 0.005 0.297 0.2

31 12 15 27 20 17 12 6 15 10 19 31 27 5 8 63 

1.97 0.70 0.514 1.58 0.95 1.840 0.533 0.444 1.350 0.845 0.130 0.171 0.070 0.230 0.107

1.85 0.53 0.587 1.90 0.93 1.690 0.441 0.466 1.930 0.817 0.160 0.087 0.121 nd 0.115 0.38 0

1.670 0.443 0.504 1.924 1.153 0.888 0.371 0.4

0.311 0.062 0.039 0.443 0.067 0.153 0.1

19 14 8 23 8 41 

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Round Robin XX Laboratory Results

All Lab Report Page 3 / 4

Analytes Reported By One Laboratory

Values in μg/mL

Analyte Code 138 139 140 141 141a 142

Total α-Carotene FSV-BJ 0.083 0.041 0.032 0.043 0.036

Symbol

na 

nd 

ns 

italics Value calculated from reported results

n 

Min

Mean Average over all non-NIST reported values.

Max

SD

CV

Median 

eSD 

eCV Robust estimate of CV, 100*eSD/Median

Minimum non-NIST reported value.

Maximum non-NIST reported value.

Standard deviation over all non-NIST values.

Coefficient of Variation (% relative standard deviation): 100*SD/Mean

Median over all non-NIST reported values

Robust estimate of SD based on the adjusted median absolute 

difference from the median (MADe)

Table Legend

Interpretation

Not available (not reported by participant)

Not detected (not reported or reported as '0', 'not determined', etc.)

No sample (sample either damaged or not sent)

Number of non-NIST laboratories reporting quantitative results

I4
Round Robin XX Laboratory Results

All Lab Report Page 4 / 4

Lab TR aT bC Label Definition

FSV-BA 4±1 1±5 -4±9 Lab Participant code

FSV-BD -2±8 -6±6 TR Total Retinol

FSV-BE -1±5 3±5 aT a-Tocopherol

FSV-BF 7±11 -1±4 6±9 bC Total b-Carotene

FSV-BH -4±6 -1±2 4±4 % Bias (Mean ± SD) of individual serum biases

FSV-BI -3±1 -4±2 -8±8

FSV-BJ -7±12 12±6 23±3 Mean Average of (xi

-Mediani)/Mediani

FSV-BK 2±6 -3±3 SD Standard deviation of (xi

-Mediani)/Mediani

FSV-BM -4±3 1±3 xi Result for analyte in serumi

FSV-BY 2±11 1±5 9±5 Mediani Median of non-NIST results in serumi

FSV-BZ 3±27

FSV-CA -2±5 -3±3

FSV-CH 16±7 24±10 -12±7

FSV-CJ 17±3 10±2 19±9

FSV-CM 6±10

FSV-CO 2±2 -2±4 7±5

FSV-CQ 8±18 -2±11 57±50

FSV-CV 0±5 6±7 12±16

FSV-CY 6±3 -2±3 8±13

FSV-DC 4±7

FSV-DE -1±2

FSV-DG -2±6 -3±5 -6±9

FSV-DH -2±8 7±10 -11±10

FSV-DL -5±7 -12±12

FSV-DN -23±10 0±5 -10±10

FSV-DO -21±21 -15±31 18±22

FSV-DT -12±4 -2±3 -4±4

FSV-EB 8±9 2±6 -4±7

FSV-EF -4±8 15±18

FSV-EV 27±5 6±6

FSV-EY 6±6 9±4

FSV-FA -28±5 -11±4 -36±15

FSV-FQ -13±4 -10±23 -14±9

NISTa 8±4 -3±7 14±28

NISTc 1±2 -4±3 10±8

%Bias Summary

The original analysis listed % Bias for each result for 

each serum calculated relative to the trimmed "Avg" of 

that analyte in the serum. The summary values 

reported here are the (arithmetic mean ± standard 

deviation) of each laboratory's reported results for the 

analyte estimated relative to each serum's medianbased reference value. 

For all sera except 141a, the reference value is the 

median of results in this study. For serum 141a, the 

reference value is the median of of results for serum 

121 in Round Robin XVIII.

I5