AOAC Performance Tested Method

AOAC Official Methods AOAC Performance-Tested Methods AOAC Peer-Verified Methods... 

There are several types of validation for analytical methods. AOAC is the leading organization that conducts methods validation under its auspices. AOAC conducts the following types of method validation performance tested method (PTM), peer verified method (PVM), and official methods of analysis (OMA). 

AO AC RI Performance Tested Method approval of three peanut ELISAs AOAC Research Institute... 

In 1993, two external interlaboratory studies were conducted using commercially available peanutkits. In North America, three kits (BIOKITS, Ridascreen, and Veratox) were evaluated in three laboratories and the data submitted to the AOAC Research Institute (RI), and Performance Tested Method stams was awarded to all three kits by May of that year (Park et al, 2005). In Europe, Poms et al. (2005) evaluated the performance of five test kits (BIOKITS, ELISA Systems, Prolisa, Ridascreen, and Veratox) to detect and quantify peanut residues in biscuit and dark chocolate at four concentrations (0, 2, 5, and 10 mg peanut/kg) using 31 laboratories in 14 countries. 

AOAC Research Institute Performance Tested Methods Program Policies and Procedures, AOAC Research Institute, Gaithersburg, MD, 2009 (available at http //www. 

As microwave sample preparation has evolved, standard microwave procedures have been developed and approved by numerous standard methods organisations (ASTM, AOAC International, EPA, etc.), see ref. [64]. Examples are standard test methods for carbon black/ash content (ASTM Method D 1506-97), lead analysis in direct paint samples (ASTM Method E 1645-94), etc. Table 8.15 shows some microwave ashing references (detection weight). A French AFNOR method utilises the atmospheric pressure single-mode microwave method as an alternative sample preparation procedure for Kjeldahl nitrogen determination [84], The performance of a microwave-assisted decomposition for rapid determination of glass fibre content in plastics for QC has been described [85]. 

Foster and Gonzales [10] reported a collaborative study by 11 laboratories of Soxtec and Soxhlet methods for the determination of total fat in meat and meat products. Each lab analyzed six samples canned ham, ground beef, frankfurters, fresh pork sausage, hard salami, and beef patties with added soy. In general, results for the Soxtec system showed improved performance. The method was first adopted by AOAC International for the extraction of fat from meat. Membrado et al. [11] tested Soxtec against Soxhlet extraction for the extraction of coal and coal-derived products. Optimization of Soxtec operating conditions reduced the total extraction time to 10% of what was needed by Soxhlet extraction. The recovery and precision by the two methods were comparable. 

The AOAC Performance-Testing Program is designed essentially for test kits, to provide third-party verification of performance claims for commercial, proprietary test kit analytical methods. Operation of this program is under the AOAC Research Institute, a subsidiary of AOAC INTERNATIONAL. 

In order to estimate these indicators, it is necessary to use various analytical methods, generally approved by USEPA or standardized by others national or international organizations such as APHA (American Public Health Association) ASTM, AOAC-Intemational or ISO. In addition to reference methods, alternative procedures or new methods can be tested and approved, according to EPA guidelines or APHA, ASTM, AOAC-intemational, and ISO protocols (AOAC, 1999 APHA, 1998 ASTM, 1999 ISO, 2001). In order to approve and validate new test procedures, confirm laboratory performance and update approved methods (Table 1.2.4) USEPA publishes both approved test methods and procedures and those that have not been promulgated. 

The AOAC PVM program is intended to provide a class of tested methods that have not been the subject of a full collaborative study. Through a less intensive process, the program provides a rapid enuy point for method,s that arc recognized by the AOAC at a level of validation for methods not otherwise evaluated. The distinguishing aspect of an AOAC PVM is that its performance has been checked in at least one other independent laboratory. It is expected that eventually most PVMs will undergo full interlaboratory collaborative studies and obtain OMA status. 

Standard analytical procedures were used to evaluate the composition of ingredients. Of the proximate analyses, nitrogen, lipids, and crude fiber were measured by American Oil Chemists Society (AOCS) methods (12) and moisture and ash by Association of Official Analytical Chemists (AOAC) methods (13). Amino acid analyses were performed by gas-liquid chromatography (14) except for tryptophan, which was analyzed colormetrically Tl5). In addition to these assays, certain tests of ingredient safety or spoilage were also performed, which space does not permit to be reported in this paper, to assure that ingredients met accepted standards for food safety (16). 

By using the combination of specific method accreditation and generic accreditation it will be possible for laboratories to be accredited for all the analyses of which they are capable and competent to undertake. Method performance validation data demonstrating that the method was fit-for-purpose shall be demonstrated before the test result is released and method performance shall be monitored by on-going quality-control techniques where applicable. It will be necessary for laboratories to be able to demonstrate quality-control procedures to ensure compliance with the EN 45001 Standard,3 an example of which would be compliance with the ISO/AOAC/IUPAC Guidelines on Internal Quality Control in Analytical Chemistry Laboratories.12... 

The ideal validated method would be the one that has progressed fully through a collaborative study in accordance with international protocols for the design, conduct, and interpretation of method performance studies. A typical study of a determinative method conducted in accordance with the internationally harmonized International Organization for Standardization (ISO)/International Union for Pure and Applied Chemistry (IUPAC)/AOAC International (AOAC) protocol would require a minimum of up to five test materials including blind replicates or split-level samples to assess within-laboratory repeatability parameters, and eight participating laboratories (15). Included with the intended use should be recommended performance criteria for accuracy, precision and recovery. 

A considerable number of immunoassay kits for several mycotoxins are now being marketed under various trade names and while most of these kits give satisfactory results when compared with other accepted methods their evaluation can be a source of controversy. Consequently, AOAC Intervention in the USA has established a new Research Institute to test the performance of such proprietary test kit methods (Smith et al., 1994) (Table 11.5). 

For most regulatory applications, the method chosen will have been subjected to preliminary method development studies and a collaborative study, both carried out according to standard protocols. This process, and subsequent acceptance, forms the validation of the method. For example, the AOAC/IUPAC protocol [5, 6] provides guidelines for both method development and collaborative study. Typically, method development forms an iterative process of performance evaluation and refinement, using increasingly powerful tests as development progresses, and culminating in collaborative study. On the basis of the results of these studies,... 

Quality measurements have several elements. Quality assurance plans and quality control procedures are an essential beginning. In addition, it is necessary to have qualified scientists whose training needs to be documented and updated on a continuous basis. Quality measurements also require proper use of reference materials where available, and laboratories must repeatedly test their ability to perform through taking part in proficiency testing schemes. The provision of another essential element in quality measurements, namely validated methods, is the primary contribution from the work of AOAC. 

The purposes of this book are to present the principles of operation of the most commonly used chemical separations, to describe the apparatus that is used, and to provide an experiment to illustrate the techniques required to perform each separation correctly. The samples used are commercial products and naturally occurring materials. The methods are, for the most part, official methods from the Association of Official Analytical Chemists, International (AOAC, Inti.) the United States Pharmacopeia (USP) the American Society for Testing and Materials (ASTM) and from university and industrial laboratories. 

Interlaboratory - collaborative testing with foodstuffs (Ihnat, 1979) plant materials (Honvitz, 1980) and human body fluids (Kumpulainen and Koivistoinen, 1981 Ihnat et al., 1986a, 1986b N ve et al.. 1992) has demonstrated excellent performance leading to its acceptance e.g. by the AOAC as an official method for the determination of selenium in foods and plants. The organic matrix of the sample is destroyed by an acid mixture such as nitric/perchloric or nitric/perchlorio/sulphuric, the analyte complexed with 2,3-diaminonaphthalene (DAN) and quantitated by molecular fluorescence. 

The mouse bioassay (MBA) was developed 70 years ago by Sommer and Meyer as part of their pioneering work that related the dinoflagellate Alexandrium catenella (Gonyaulax) as a causative agent of PSP (see Wekell et al ). At the time, the identity of the paralyzing toxic compounds was not known and the MBA remained for several years as a field test to help health officials manage toxic outbreaks in Alaska and British Columbia.Only after a purified saxitoxin dihydrochloride was made available in 1950 was it possible to calibrate the assay, and the AOAC accepted the new version of the MBA as an official method. Reasons for the sustained application of the MBA lie in its simplicity of application, relatively low cost, and availability of test protocols to calibrate mice strains to compare operator performance and to perform repeatability and reproducibility studies (National Shellfish Sanitation Program, USA ). 

Koll K, Reich E, Blatter A, and Veit M (2003) Validation of standardized high-performance thin-layer chromatographic methods for quahty control and stahihty testing of herhals. Journal of AOAC International 86(5) 909-915. 

In the food industry, microbial tests are performed to screen the product for dangerous pathogens as well as to guarantee that the total microbial concentration is below the allowed threshold values. The sampling inspection can be conducted at the site and if the results are suspicious, therefore further analysis of contaminated sample can be done in the laboratory using expensive techniques [47]. The impedance method was approved by the Association of Ofiicial Analytical Chemists International (AOAC) as a first action method for screening Salmonella in food samples [48]. 

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