AN INNOVATIVE STRATEGY BASED ON UNCERTAINTY PROFILE FOR THE VALIDATION OF MICROBIOLOGICAL METHODS FOR COUNTING ENTEROBACTERIACEAE IN FOODS Original Article

Objective: A new and powerful statistical approach known as the uncertainty profile concept has been suggested for both testing the validity and making easy and straightforward interpretation of results obtained during the validation of an analytical method. The main goal of this paper is to confirm the applicability of this new strategy for the validation of a commercial kit, microbiological method, for the enumeration of the Enterobacteriaceae in foods and the estimate of the measurement uncertainty by using the newly provided formula and without referring to any additional experiments. Methods: An innovative formula to assess the uncertainty by using validation data and without recourse to other additional experiments was proposed. The uncertainty was evaluated through the two-sided β-content, γ-confidence tolerance interval, which is computed with three manners: the Mee’s approach, the Generalized Pivotal Confidence, and the Modified Large Simple procedure Results: After the use of the three chemometric method of calculation of tolerance intervals, the obtained results with uncertainty profile show without doubt that the enumeration method is valid over the range of target values given that the upper and the lower 66.7 %-content, 90 %confidence tolerance limits have fallen within the two acceptance limits of±0.25 Log unit. If the β is stretched to 80 %-content, 90 %-confidence, the three computed tolerance intervals lead to different decisions. Conclusion: we have demonstrated the ability of the uncertainty profile to be used for testing the validity of enumeration method which represents the first application of an uncertainty profile to food microbiological methods, and provides good estimations of the uncertainty measurements for each concentration level.

[1]  Rob G. Visser,et al.  Measurement uncertainty: practical problems encountered by accredited testing laboratories , 2004 .

[2]  R. G. Visser.  Measurement uncertainty: Opinions of the Government, the Accreditation Council and the Candidate accredited laboratory , 2002 .

[3]  T. Saffaj,et al.  Response to comments on "Uncertainty profiles for the validation of analytical methods". , 2012, Talanta.

[4]  Robert W. Mee.  β-Expectation and β-Content Tolerance Limits for Balanced One-Way ANOVA Random Model , 1984 .

[5]  P. Hubert,et al.  Improvement of the decision efficiency of the accuracy profile by means of a desirability function for analytical methods validation. Application to a diacetyl-monoxime colorimetric assay used for the determination of urea in transdermal iontophoretic extracts. , 2007, Analytica chimica acta.

[6]  M. Angeles Herrador,et al.  Practical digest for evaluating the uncertainty of analytical assays from validation data according to the LGC/VAM protocol. , 2005, Talanta.

[7]  T. Saffaj,et al.  Remarks on "Reply to the responses to the comments on "uncertainty profiles for the validation of analytical methods" by Saffaj and Ihssane". , 2013, Talanta.

[8]  M Laurentie,et al.  Harmonization of strategies for the validation of quantitative analytical procedures. A SFSTP proposal--part III. , 2007, Journal of pharmaceutical and biomedical analysis.

[9]  Guide to the use of repeatability , reproducibility and trueness estimates in measurement uncertainty estimation , 2002 .

[10]  Tsai-Yu Lin,et al.  One- and Two-Sided Tolerance Intervals for General Balanced Mixed Models and Unbalanced One-Way Random Models , 2005, Technometrics.

[11]  S. Ellison,et al.  Quantifying uncertainty in analytical measurement , 2000 .

[12]  T. Saffaj,et al.  Comments on "innovative method for carbon dioxide determination in human postmortem cardiac gas samples using headspace-gas chromatography-mass spectrometry and stable labeled isotope as internal standard" by Varlet et al. , 2014, Analytica chimica acta.

[13]  Vicki J. Barwick,et al.  VAM Project 3 . 2 . 1 Development and Harmonisation of Measurement Uncertainty Principles Part ( d ) : Protocol for uncertainty evaluation from validation data , 2000 .

[14]  M Laurentie,et al.  Harmonization of strategies for the validation of quantitative analytical procedures. A SFSTP proposal--part II. , 2004, Journal of pharmaceutical and biomedical analysis.

[15]  Appendix D : Guidelines for Collaborative Study Procedures To Validate Characteristics of a Method of Analysis { , 2001 .

[16]  A. G. González,et al.  Accuracy profiles from uncertainty measurements. , 2006, Talanta.

[17]  E. Iso,et al.  Measurement Uncertainty and Probability: Guide to the Expression of Uncertainty in Measurement , 1995 .

[18]  J. Smeyers-Verbeke,et al.  Measurement uncertainty from validation and duplicate analysis results in HPLC analysis of multivitamin preparations and nutrients with different galenic forms. , 2003, Journal of pharmaceutical and biomedical analysis.

[19]  Achour Sanae,et al.  A STATISTICAL APPROACH BASED ON THE TOTAL ERROR CONCEPT FOR VALIDATION THE BIOANALYTICAL METHOD: APPLICATION TO THE SPECTROPHOTOMETRIC DETERMINATION OF TRACES AMOUNT OF ACETAMINOPHEN IN HUMAN PLASMA , 2014 .

[20]  A. Gustavo González,et al.  A practical guide to analytical method validation, including measurement uncertainty and accuracy profiles , 2007 .

[21]  Philippe Hubert,et al.  New advances in method validation and measurement uncertainty aimed at improving the quality of chemical data , 2004, Analytical and bioanalytical chemistry.

[22]  Jean-Francois David,et al.  Validation of an alternative method for counting Enterobacteriaceae in foods based on accuracy profile. , 2009, Journal of AOAC International.

[23]  T. Saffaj,et al.  Uncertainty profiles for the validation of analytical methods. , 2011, Talanta.

[24]  H Bouchafra,et al.  An overall uncertainty approach for the validation of analytical separation methods. , 2013, The Analyst.

[25]  Chen-Tuo Liao,et al.  A TOLERANCE INTERVAL FOR THE NORMAL DISTRIBUTION WITH SEVERAL VARIANCE COMPONENTS , 2004 .

[26]  Max Feinberg,et al.  Validation of analytical methods based on accuracy profiles. , 2007, Journal of chromatography. A.

[27]  F. Broto,et al.  Estimation of the uncertainty associated with the results based on the validation of chromatographic analysis procedures: application to the determination of chlorides by high performance liquid chromatography and of fatty acids by high resolution gas chromatography. , 2012, Journal of chromatography. A.

[28]  R Albert,et al.  The concept of uncertainty as applied to chemical measurements. , 1997, The Analyst.

[29]  David Hoffman,et al.  TWO-SIDED TOLERANCE INTERVALS FOR BALANCED AND UNBALANCED RANDOM EFFECTS MODELS , 2005, Journal of biopharmaceutical statistics.

[30]  C. Ubide,et al.  Uncertainty due to the quantification step in analytical methods. , 2007, Talanta.

[31]  Anwar Hadi,et al.  Sistem Manajemen Mutu Laboratorium - Sesuai ISO/IEC 17025: 2000 General Requirements for the Competence of Testing and Calibration Laboratories , 2000 .

[32]  H. J. van de Wiel,et al.  Inter-laboratory, time, and fitness-for-purpose aspects of effective validation , 1999 .

[33]  S. Grabherr,et al.  Innovative method for carbon dioxide determination in human postmortem cardiac gas samples using headspace-gas chromatography-mass spectrometry and stable labeled isotope as internal standard. , 2013, Analytica chimica acta.

[34]  D. Massart,et al.  Interlaboratory study of a liquid chromatography method for erythromycin: determination of uncertainty. , 2003, Journal of chromatography. A.

[35]  Johanna Smeyers-Verbeke,et al.  Comparison of different approaches to estimate the uncertainty of a liquid chromatographic assay , 2003 .

[36]  S. Rudaz,et al.  LC method for the determination of R-timolol in S-timolol maleate: Validation of its ability to quantify and uncertainty assessment. , 2006, Talanta.