AOAC CASP Meeting Book

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4.2.4 Study Design 592 593 The study design for validation of qualitative methods in the independent study follows the 594 Method Developer Validation Study design. Contamination levels, number of test portions, 595 test portion size, source of contamination, preparation of samples, confirmation of test 596 portions, and data analysis and reporting are found in Section 4.1.3. If composite test 597 portions or pooling was validated in the Method Developer Validation Study, include it also in 598 the Independent Validation Study. 4.3.1 Scope 603 604 The Collaborative Study (CS) report is a formal submission requirement for OMA methods only. 605 The purpose of the Collaborative Study is to estimate the reproducibility and determine the 606 performance of the candidate method among collaborators. 609 610 At least 12 collaborators per matrix should be included due to potential failure to follow 611 protocol. A minimum of 10 valid laboratory data sets per matrix are required. 614 615 The reference method used in the Collaborative Study must be the same as that used in the 616 Method Developer Study or SLV (PCS). The reference method should be carried out by the 617 organizing laboratory and collaborators. 620 621 At least one matrix from those studied in the PTM or PCS shall be chosen by the appropriate 622 volunteer expert(s) in consultation with the Study Director for collaborative study. For 623 methods with more than one sample preparation/enrichment, one matrix per procedure may 624 be required in the collaborative study. The determination if the procedures differ 625 significantly to warrant expanding the collaborative study is made by the appropriate method 626 volunteer expert(s) in consultation with the Study Director. The Statistical Advisor and 627 reviewers can be consulted during this determination. Examples of what constitutes a 628 different sample preparation procedure would include different test portion size, different 629 enrichment media or conditions, different dilution volume and different homogenization 630 equipment. The AOAC appropriate method volunteer, Statistical Advisor and collaborative 631 study protocol reviewers shall make the final selection of the matrix(es) with consideration of 632 the PTM or PCS data and the relative importance of the matrices to food safety. The data 633 607 608 4.3.2 Number of Laboratories 612 613 4.3.3 Reference Method 618 619 4.3.4 Matrix Selection 599 600 601 602 4.3 Collaborative Study (CS)