2014 ERP New Member Book

G UIDELINES FOR S TANDARD M ETHOD P ERFORMANCE R EQUIREMENTS

AOACO FFICIAL M ETHODS OF A NALYSIS (2012)

Appendix F, p. 8

Table A3. Recommendations for evaluation Bias (if a referencematerial is available)

Aminimum of five replicate analyses of aCertifiedReferenceMaterial. a

Environmental interference

Analyze test portions containing a specified concentration of one environmental materials panel member. Materialsmay bepooled. Consult withAOAC statistician. Analyze one test portion containing a specified concentration of one exclusivity panel member. More replicates can be used. Consult withAOAC statistician. Analyze one test portion containing a specified concentration of one inclusivity panel member. More replicates can be used. Consult withAOAC statistician. (blank). Measure blank sampleswith analyte at theestimated LOQ. Calculate themean average and standarddeviation of the results. Guidance b : ForML≥ 100 ppm (0.1mg/kg): LOD=ML  1/5. ForML< 100 ppm (0.1mg/kg): LOD=ML  2/5. Use ISO 21748: Guidance for the use of repeatability, reproducibility, and trueness estimates in measurement uncertainty estimation to analyze data collected for bias, repeatability, and intermediate precision to estimatemeasurement uncertainty . Prepare and homogenize three unknown samples at different concentrations to represent the full, claimed range of themethod.Analyze each unknown sample by the candidatemethod seven times, beginning each analysis fromweighing out the test portion through to final result withno additional replication (unless stated to do so in themethod).All of the analyses for one unknown sample should be performedwithinas short a period of time as is allowed by the method. The second and third unknownsmay be analyzed in another short time period. Repeat for each claimedmatrix. Determine the desiredPOD at a critical concentration. Consult withTableA7 to determine the number of test portions required to demonstrate the desiredPOD. Consult Probability of Identification (POI): AStatistical Model for theValidation of Qualitative Botanical IdentificationMethods c . Determined from spiked blanks or sampleswith at least seven independent analyses per concentration level at aminimum of three concentration levels covering the analytical range. Independent means at least at different times. If no confirmed (natural) blank is available, the average inherent (naturally containing) level of the analyte should be determined on at least seven independent replicates. Marginal % recovery = (C f –C u )  100/C A Total % recovery = 100(C f )/(C u +C A ) whereC f = concentration of fortified samples, C u = concentration of unfortified samples, andC A = concentration of analyte added to the test sample. d Usually total recovery is usedunless the nativeanalyte is present in amounts greater than about 10% of theamount added, inwhich case use themethod of addition. e Estimate the LOQ= average (blank) +10  s 0 Usedata from collaborative study.

Exclusivity/cross-reactivity

Inclusivity/selectivity

Limit of quantitation (LOQ)

Measurement uncertainty

POD(0)

POD (c) Repeatability

Probability of detection (POD)

Probability of identification (POI)

Recovery

Reproducibility (collaborativeor interlaboratory study) Quantitativemethods: Recruit 10–12 collaborators; must have eight valid data sets; two blind duplicate replicates at five concentrations for each analyte/matrix combination to each collaborator. Qualitativemethods: Recruit 12–15 collaborators; must have 10 valid data sets; six replicates at five concentrations for each analyte/matrix combination to each collaborator. a Guidance for Industry for Bioanalytical MethodValidation (May 2001) U.S. Department of HealthandHumanServices, U.S. Food andDrugAdministration, Center for DrugEvaluation andResearch (CDER), Center for VeterinaryMedicine (CVM). b CodexAlimentariusCodexProcedureManual. c LaBudde, R.A., &Harnly, J.M. (2012) J. AOAC Int . 95 , 273–285. d Guidelines for CollaborativeStudyProcedures toValidateCharacteristics of aMethodof Analysis (2012) Official Methods of Analysis , 19thEd., AppendixD, AOAC INTERNATIONAL, Gaithersburg, MD. e AOACGuidelines for Single-LaboratoryValidation of Chemical Methods for DietarySupplements andBotanicals (2012) Official Methods of Analysis , 19thEd., AppendixK ,AOAC INTERNATIONAL, Gaithersburg, MD.

©2012AOAC INTERNATIONAL