©2012AOAC INTERNATIONAL
G
UIDELINES
FOR
S
TANDARD
M
ETHOD
P
ERFORMANCE
R
EQUIREMENTS
AOACO
FFICIAL
M
ETHODS
OF
A
NALYSIS
(2012)
Appendix F, p. 2
policy. SMPRworkinggroups are expected to apply their expertise
in the development of SMPRs.
TableA1:PerformanceRequirements
.Providesrecommended
performance parameters to be included into an SMPR. Table A1
is organized by five method classifications: (
1
) main component
quantitative methods; (
2
) trace or contaminant quantitative
methods; (
3
) main component qualitative methods; (
4
) trace or
contaminant quantitativemethods; and (
5
) identificationmethods.
The table is designed to accommodate both microbiological and
chemical methods. Alternate microbiological/chemical terms are
provided for equivalent concepts.
Table A2: Recommended Definitions
. Provides definitions
for standard terms in the SMPR Guidelines. AOAC relies on
The International Vocabulary of Metrology Basic and General
Concepts and Associated Terms
(VIM) and the International
Organization for Standadization (ISO) for definition of terms not
included inTableA2.
TableA3:Recommendations forEvaluation
.Providesgeneral
guidance for evaluation of performance parameters.More detailed
evaluation guidance can be found in
Appendix D, Guidelines for
Collaborative Study Procedures to Validate Characteristics of
a Method of Analysis
(2);
Appendix I, Guidelines for Validation
of Biological Threat Agent Methods and/or Procedures
(3);
Appendix K, AOAC Guidelines for Single-Laboratory Validation
of ChemicalMethods forDietary Supplements andBotanicals
(4);
Codex Alimentarius Codex Procedure Manual (5); and ISO
Standard 5725-1-1994 (6).
TableA4: Expected Precision (Repeatability) as a Function
of Analyte Concentration
. The precision of a method is the
closeness of agreement between independent test results obtained
under stipulated conditions. Precision is usually expressed in terms
of imprecision and computed as a relative standard deviation
(RSD) of the test results. The imprecision of a method increases
as the concentration of the analyte decreases. This table provides
target RSDs for a range of analyte concentrations.
Table A5: Expected Recovery as a Function of Analyte
Concentration
. Recovery is defined as the ratio of the observed
mean test result to the truevalue.The rangeof the acceptablemean
recovery expands as the concentration of the analyte decreases.
This table provides target mean recovery ranges for analyte
concentrations from 1 ppb to 100%.
Table A6: Predicted Relative Standard Deviation of
Reproducibility (PRSD
R
)
. This table provides the calculated
PRSD
R
using theHorwitz formula:
PRSD
R
= 2C
–0.15
whereC is expressed as amass fraction.
Table A7: POD and Number of Test Portions
. This table
provides the calculated probability of detection (POD) for given
sample sizes and events (detections).Amethod developer can use
this table to determine the number of analyses required to obtain a
specificPOD.
Informative annexes
.—The SMPR Guidelines contain
informative annexes on the topics of classificationofmethods, POD
model,HorRat values, referencematerials, andmethodaccuracyand
review.Aswith the informative tables, these annexes are intended to
provideguidance and information to theworkinggroups.
Initiationof anSMPR
See
Figure 1 for a schematic flowchart diagram of the SMPR
development process.
Figure 1. Schematicflowchart diagramof theSMPRdevelopment process.
