Assessment of detection methods in trace analysis by means of a statistically based in-house validation concept

Abstract

A matrix-considering in-house validation concept for analytical methods is presented which takes into account the uncertainty due to matrix- and time-induced deviations. It is based on a variance component model for univariate quantitative measurement data that can be adapted to both screening and confirmation methods and to both zero-tolerance and threshold decisions. The model allows the calculation of critical concentrations for given α-errors and the calculation of the corresponding power function to evaluate the performance of an analytical method. The model is applied to a real-life validation experiment.

References

1. Codex Alimentarius, Volume Three, Residues of Veterinary Drugs in Foods, Codex Alimentarius Commission, Rome, 2nd edn., 1996.
2. Analytical Chemistry Laboratory, Guidebook—Residue Chemistry, USDA Food Safety and Inspection Service, Washington, DC, 1991.
3. EEC Directive 93/256, Off. J. Eur. Commun., 1993, No. L 118/64.
4. EEC Directive 85/591, Off. J. Eur. Commun., 1985, No. L 372/50.
5. Accreditation for Chemical Laboratories: Guidance on the Interpretation of the EN 45000 Series of Standards and ISO/IEC Guide 25, EURACHEM Secretariat, Teddington, 1993.
6. Food and Drug Administration, Guideline for Industry, Text on Validation of Analytical Procedures, 60 FR 11260, Center for Drug Evaluation and Research, Rockville, MD, 1995.
7. Food and Drug Administration, Draft Guideline on the Validation of Analytical Procedures: Methodology; Availability; Notice, 61 FR 9315, Center for Drug Evaluation and Research, Rockville, MD, 1996.
8. IUPAC, ISO and AOAC, J. Assoc. Off. Anal. Chem., 1989, 72, 694.
9. Capability of Detection—Part 1: Terms and Definitions, ISO/DIS 11843-1, International Standards Organization, Geneva, 1995.
10. Deutsches Institut für Normung, DIN 32645, Chemical Analysis; Decision Limit, Detection Limit and Determination Limit; Estimation in Case of Repeatability, Terms, Methods, Evaluation, Beuth Verlag, Berlin, 1994.
11. Deutsches Institut für Normung, DIN 55350, Teil 34, Concepts in the Field of Quality and Statistics; Limit of Detection, Limit of Determination and Capability of a Method for Determination, Beuth Verlag, Berlin, 1991.
12. IUPAC, Pure Appl. Chem., 1990, 62(1), 149.
13. Guidelines for Collaborative Studies, J. Assoc. Off. Anal. Chem., 1989, 72(4), 694.
14. Accuracy (Trueness and Precision) of Measurement Methods and Results; General Principles and Definitions, ISO 5725-1, International Standards Organization, Geneva, 1994.
15. Bundesgesundheitsamt, Planning and Statistical Evaluation of Ring Tests, Collection of official methods under Article 35 of the German Federal Foods Act, Beuth Verlag, Berlin, 1983.
16. G. T. Wernimont, in Use of Statistics to Develop and Evaluate Analytical Methods, ed. Spendley, W., Association of Official Analytical Chemists, Arlington, VA, 4th edn., 1993.
17. R. W. Stephany, in Residues of Veterinary Drugs in Food: Proceedings of the EuroResidue Conference in Noordwijkerhout, The Netherlands, May 21–23, 1990, ed. Haagsma, A., Ruiter, A., and Czedik-Eysenberg, P. B., University of Utrecht, Utrecht, 1990, pp. 76–85.
18. Quantifying Uncertainty in Analytical Measurement, EURACHEM Secretariat, Teddington, 1995.
19. Analytical Methods Committee, Analyst, 1995, 120, 2303.
20. R. Zimmermann and J. von Lengerken, Arch. Anim. Nutr., 1987, 37, 723.