Skip to main content

Reference materials to evaluate measurement systems for the nutrient composition of foods: results from USDA’s National Food and Nutrient Analysis Program (NFNAP)

Abstract

Over a 6.5-year period a total of 2554 values were reported by nine laboratories for 259 certified or reference nutrient concentrations in 26 certified reference materials (CRM) submitted to contract laboratories, blinded, as part of the qualifying process for analytical contracts and in the routine sample stream as part of the National Food and Nutrient Analysis Program. Each value was converted to a Z′-score, reflecting the difference from the assigned value related to the combined expected analytical uncertainty plus the uncertainty in the CRM value. Z′-scores >|3.0| were considered unacceptable. For some nutrients (Na, folate, dietary fiber, pantothenic acid, thiamin, tocopherols, carotenoids, monounsaturated, and polyunsaturated fatty acids), >20% of Z′-scores were >|3.0|. For total fat, vitamin C, and niacin >25% of Z′-scores were >|2.0|. Components for which CRM data were best (more than 90% of Z′-scores <|2.0|) were Mg, P, Mn, Se, and vitamin B12. In some cases deviations from assigned values were not uniform across laboratories and materials. For Na almost all high Z′-scores were for low-Na matrices, suggesting analytical problems related to concentration.

Z′-scores for vitamins in certified reference materials

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2

References

  1. 1.

    Phillips KM, Wolf WR, Patterson KY, Sharpless, KE, Amanna KR, Holden JM (2007) Accred Qual Assur, in press, DOI 10.1007/s00769-007-0257-6

  2. 2.

    US Department of Agriculture, Agricultural Research Service. USDA National Nutrient Database for Standard Reference., US Nutrient Data Laboratory, Beltsville MD. http://www.ars.usda.gov/Services/docs.htm?docid=8964

  3. 3.

    Pehrsson PR, Haytowitz DB, Holden JM (2003) J Food Comp Anal 16:331–341

    Article  Google Scholar 

  4. 4.

    Phillips KM, Patterson KY, Rasor AS, Exler J, Haytowitz DB, Holden JM, Pehrsson PR (2006) Anal Bioanal Chem 384:1341–1355

    Article  CAS  Google Scholar 

  5. 5.

    Ollilainen V, Finglas PM, van den Berg H, de Froidmont-Görtz I (2001) J Agric Food Chem 49:315–321

    Article  CAS  Google Scholar 

  6. 6.

    Sharpless KE, Schiller SB, Margolis SA, Thomas JB, Iyengar V, Colbert JC, Gills TE, Wise SA, Tanner JT, Wolf WR (1997) J Assoc Off Anal Chem Int 80:611–621

    CAS  Google Scholar 

  7. 7.

    Sharpless KE, Gill LM, Margolis SA, Wise SA, Elkins E (1999) J Assoc Off Anal Chem Int 82:276–287

    CAS  Google Scholar 

  8. 8.

    Sharpless KE, Thomas JB, Nelson BC, Phinney CS, Sieber JR, Wood LJ, Yen JH, Howell DW (2002) J Agric Food Chem 50:7069–7075

    Article  CAS  Google Scholar 

  9. 9.

    Sharpless KE, Phinney CS, Wood LJ, Yen JH, Howell DW (2003) J Agric Food Chem 51:6745–6751

    Article  CAS  Google Scholar 

  10. 10.

    Welch MJ, Colbert JC, Gill LM, Phinney CS, Sharpless KE, Sniegoski LT, Wood LJ (2001) Fresenius J Anal Chem 370:42–47

    Article  CAS  Google Scholar 

  11. 11.

    Finglas PM, Wigertz K, Vahteristo L, Southon S (1999) Food Chem 64:245–255

    Article  CAS  Google Scholar 

  12. 12.

    European Committee for Standardization TC275, http://www.cenorm.be/CENORM/BusinessDomains/TechnicalCommitteesWorkshops/CENTechnicalCommittees/Standards.asp?param=6256&title=CEN%2FTC+275

  13. 13.

    Pennington JAT (2000) J Food Comp Anal 13:539–544

    Article  CAS  Google Scholar 

  14. 14.

    Association of Official Analytical Chemists (1990) Official methods of analysis of the Association of Official Analytical Chemists, method 934.01, 15th edn. Association of Official Analytical Chemists, Washington DC

    Google Scholar 

  15. 15.

    Sheppard AJ (1992) Lipid manual: methodology suitable for fatty acid-cholesterol analysis. William C. Brown Publishers, Dubuque IA

    Google Scholar 

  16. 16.

    Association of Official Analytical Chemists (1995) Official methods of analysis of the association of official analytical chemists, methods 991.43 and 985.29, 16th edn. Association of Official Analytical Chemists, Washington DC

    Google Scholar 

  17. 17.

    Jorhem L (2004) Accred Qual Assur 9:305–310

    Article  CAS  Google Scholar 

  18. 18.

    McClure FD, Lee J-K (2003) Computation of HORRAT values. J AOAC Int 86:1056–1058

    CAS  Google Scholar 

  19. 19.

    Thompson M, Lowthian PJ (1997) J AOAC Int 80:676–679

    CAS  Google Scholar 

  20. 20.

    IUPAC (1993) The international harmonized protocol for the proficiency testing of (chemical) analytical laboratories. Pure Appl Chem 65:2123–2144

    Google Scholar 

  21. 21.

    Jorhem L, Engman J, Schröder T (2001) Fresenius J Anal Chem 370:178–182

    Article  CAS  Google Scholar 

  22. 22.

    Linsinger TPJ, Josephs RD (2006) Trends Anal Chem 25:1125–1130

    Article  CAS  Google Scholar 

  23. 23.

    Koontz JL, Phillips KM, Wunderlich KM, Exler J, Holden JM, Gebhardt SE, Haytowitz DB (2005) J AOAC Int 88:805–815

    CAS  Google Scholar 

  24. 24.

    Oliver J, Palou A (2000) J Chromatogr A 881:543–555

    Article  CAS  Google Scholar 

  25. 25.

    Kimura M, Rodriguez-Amaya DB (1999) Arch Latinoam Nutr 49:58S–66S

    CAS  Google Scholar 

  26. 26.

    Devries JW (1993) Water soluble vitamins, chap 9. In: Sullivan DM, Carpenter DE (eds) Methods of analysis for nutrition labeling. AOAC International, Gaithersburg, MD

    Google Scholar 

  27. 27.

    Moser U, Bendich A (1991) Vitamin C. In: Machlin LJ (ed) Handbook of vitamins. Marcel Dekker, New York, pp 214–232

    Google Scholar 

  28. 28.

    Montano A, Casado FJ, Rejano L, Sanchez AH, de Castro A (2006) J Agric Food Chem 54:2206–2210

    Article  CAS  Google Scholar 

  29. 29.

    Johnston CS, Bowling DL (2002) J Am Diet Assoc 102:525–529

    Article  Google Scholar 

  30. 30.

    Konings EJM (2006) J AOAC Int 89:1–5

    Google Scholar 

  31. 31.

    Joint Committee for Traceability in Laboratory Medicine, http://www.bipm.org/utils/en/xls/jctlm_listI.xls

  32. 32.

    Ellerbe P, Meiselman S, Sniegoski LT, Welch MJ, White VE (1989) Anal Chem 61:1718–1723

    Article  CAS  Google Scholar 

Download references

Acknowledgments

The statistics advice and assistance on statistics by David Duewer, of the NIST in developing Eq. 1 for Z′-scores used in this study is acknowledged. This study was conducted as part of specific cooperative agreement #Y1-HV-8116-11 between the United States Department of Agriculture (USDA) Nutrient Data Laboratory and Virginia Polytechnic Institute and State University, with support from the National Heart, Lung, and Blood Institute, National Cancer Institute, the National Institute for Dental and Craniofacial Research, the Office of Dietary Supplements, and numerous other Offices and Institutes through the interagency agreement #Y1-HV-8116 between the National Institutes of Health and the USDA.

Author information

Affiliations

Authors

Corresponding author

Correspondence to Katherine M. Phillips.

Additional information

Disclaimer: Certain commercial equipment, instruments, or materials are identified in this paper in order to specify the experimental procedure adequately. Such identification is not intended to imply recommendation or endorsement by the National Institute of Standards and Technology, or the United States Department of Agriculture, nor is it intended to imply that the materials or equipment identified are necessarily the best available for the purpose.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Phillips, K.M., Wolf, W.R., Patterson, K.Y. et al. Reference materials to evaluate measurement systems for the nutrient composition of foods: results from USDA’s National Food and Nutrient Analysis Program (NFNAP). Anal Bioanal Chem 389, 219–229 (2007). https://doi.org/10.1007/s00216-007-1366-0

Download citation

Keywords

  • Reference materials
  • Uncertainty
  • Accuracy
  • Food composition data