Association of Official Analytical Chemists

These data are adapted from Steiner, E. H. Planning and Analysis of Results of Collaborative Tests published in Statistical Manual of the Association of Official Analytical Chemists, Association of Official Analytical Chemists Washington, DC, 1975. 

Official Methods of Analysis, 11th ed.. Association of Official Analytic Chemists, Washington, DC, 1970, p. 475. 

The design of a collaborative test must provide the additional information needed to separate the effect of random error from that due to systematic errors introduced by the analysts. One simple approach, which is accepted by the Association of Official Analytical Chemists, is to have each analyst analyze two samples, X and Y, that are similar in both matrix and concentration of analyte. The results obtained by each analyst are plotted as a single point on a two-sample chart, using the result for one sample as the x-coordinate and the value for the other sample as the -coordinate. ... 

Agency. A second example of an external method of quality assessment is the voluntary participation of the laboratory in a collaborative test (Chapter 14) sponsored by a professional organization such as the Association of Official Analytical Chemists. Finally, individuals contracting with a laboratory can perform their own external quality assessment by submitting blind duplicate samples and blind standard samples to the laboratory for analysis. If the results for the quality assessment samples are unacceptable, then there is good reason to consider the results suspect for other samples provided by the laboratory. 

Association of Official Analytical Chemists American Oil Chemists Society... 

In the United States the analytical methods approved by most states are ones developed under the auspices of the Association of Official Analytical Chemists (AOAC) (3). Penalties for analytical deviation from guaranteed analyses vary, even from state to state within the United States (4). The legally accepted analytical procedures, in general, detect the solubiUty of nitrogen and potassium in water and the solubiUty of phosphoms in a specified citrate solution. Some very slowly soluble nutrient sources, particularly of nitrogen, are included in some specialty fertilizers such as turf fertilizers. The slow solubihty extends the period of effectiveness and reduces leaching losses. In these cases, the proportion and nature of the specialty source must be detailed on the labeling. 

Initially, there was some ovedap on proposed analytical methods to accomplish a particular analysis. The Association of Official Analytical Chemists (AOAC) methods and Bacteriological Analytical Manual (BAM) methods in some cases dupHcated ASTA methods, but the procedures differed. Most spice companies, particulady those who are members of ASTA, use ASTA recommended methods. In an attempt to ensure that equivalent specifications are reported, the Technical Group of ASTA develops specifications and in some cases recommends that a BAM or AO AC method be used. 

K. Helrich, ed.. Official Methods oJA.naljsis, Vol. 2,15th ed.. Association of Official Analytical Chemists, Arlington, Va., pp. 910—928. 

Test Methods. In addition to that provided by proper sampling and rephcation of analysis, a test method also has a significant impact on the accuracy and precision of the results. Preferred methods are those which are accepted in the chemical industry such as those from the American Society of Testing Materials (ASTM), Association of Official Analytical Chemists (AO AC), or from compendia such as the United States Pharmacopoeia (USP) or the Pood Chemical Codex (FCC) (36). The use of such methods eliminates the need for method vahdation. 

For most assays, the incorporated pantothenic acid has to be Hberated en2ymatically. Usually, a combination of pantotheinase and alkaline phosphatase is used to hberate the bound pantothenic acid. The official method for pantothenic acid of the Association of Official Analytical Chemists (AOAC) is the microbiological assay that uses U. Plantarium (A.TCC 8014) as the test organism (71). Samples are extracted at 121°C at pH 5.6—5.7, proteins are precipitated at pH 4.5, and the resulting clear extracts are adjusted to pH 6.8 prior to assay. This procedure is only suitable to determine calcium pantothenate or other free forms of pantothenic acid. 

The United States Pharmacopeia XXIII (USP XXIII-NF XVHI), The United States Pharmacopeia Convention, Inc., Rockville, Md., 1995, p. 1631. Pood and Nutrition Board, National Research Council, Food Chemicals Codex, 3rd ed.. National Academy Press, Washiagton, D.C., 1981, p. 330. K. Helrich, ed.. Official Methods of Analysis of the Association of Off dal Analytical Chemists, 15th ed.. Association of Official Analytical Chemists, Inc., Arlington, Va., 1990, pp. 1070—1079. 

Grams per 100 Hters at 100° proof (50%). Determinations were made according to the official methods of analysis of the Association of Official Analytical Chemists, 15th ed., 1990. 

Robert Koch, in Germany in 1881, did scientific laboratory tests on 70 different chemicals, at different concentrations and in different solvents, to assess thek abiUty to kill spores of anthrax bacteria (7). Refinement of the testing methods were made in 1897, 1903, and 1908 (8). They continued to be improved, standardized, and pubUshed under the auspices of organizations like the Association of Official Analytical Chemists (AOAC) (now called AO AC International). 

The purpose of this chapter is to describe the analytical methods that are available for detecting, measuring, and/or monitoring methyl parathion, its metabolites, and other biomarkers of exposure and effect to methyl parathion. The intent is not to provide an exhaustive list of analytical methods. Rather, the intention is to identify well-established methods that are used as the standard methods of analysis. Many of the analytical methods used for environmental samples are the methods approved by federal agencies and organizations such as EPA and the National Institute for Occupational Safety and Health (NIOSH). Other methods presented in this chapter are those that are approved by groups such as the Association of Official Analytical Chemists (AOAC) and the American Public Health Association (APHA). Additionally, analytical methods are included that modify previously used methods to obtain lower detection limits and/or to improve accuracy and precision. 

Analysis of methyl parathion in sediments, soils, foods, and plant and animal tissues poses problems with extraction from the sample matrix, cleanup of samples, and selective detection. Sediments and soils have been analyzed primarily by GC/ECD or GC/FPD. Food, plant, and animal tissues have been analyzed primarily by GC/thermionic detector or GC/FPD, the recommended methods of the Association of Official Analytical Chemists (AOAC). Various extraction and cleanup methods (AOAC 1984 Belisle and Swineford 1988 Capriel et al. 1986 Kadoum 1968) and separation and detection techniques (Alak and Vo-Dinh 1987 Betowski and Jones 1988 Clark et al. 1985 Gillespie and Walters 1986 Koen and Huber 1970 Stan 1989 Stan and Mrowetz 1983 Udaya and Nanda 1981) have been used in an attempt to simplify sample preparation and improve sensitivity, reliability, and selectivity. A detection limit in the low-ppb range and recoveries of 100% were achieved in soil and plant and animal tissue by Kadoum (1968). GC/ECD analysis following extraction, cleanup, and partitioning with a hexane-acetonitrile system was used. 

AOAC. 1984. Organophosphoms pesticide residues sweep codistillation method Final action. AOAC Official methods of analysis. 10th ed. Washington, DC Association of Official Analytical Chemists. 

Other methods presented in this chapter are those that are approved by groups such as the Association of Official Analytical Chemists (AOAC) and the American Public Health Association (APHA). Additionally, analytical methods are included that modify previously used methods to obtain lower detection limits and/or to improve accuracy and precision. 

Horwitz, W. Official Methods of Analysis of the Association of Official Analytical Chemists, 12th Edition AO AC Washington, D. C, 1975, pp 319-321. 

Beer Samples. The beer samples were examined as part of the American Society of Brewing Chemists (ASBC) and Association of Official Analytical Chemists (AOAC) collaborative studies of NDMA in beer. Duplicate samples were analyzed by the column extraction procedure and the ASBC distillation procedure (35). The AOAC procedure (36) was similar, except that a larger sample (50 vs. 25 g) was examined and sulfamic acid was added to minimize artifactual formation of nitrosamines. Both methods utilize N-nitrosodipropylamine (NDPA) as an internal standard. 

AOAC, The Association of Official Analytical Chemists International, describes methods for analyzing a wide range of materials. These methods are often adopted by other organizations and government regulatory agencies as standards. 

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