Reference materials for agricultural and food analysis: preparation and physical characterization of a bovine muscle powder candidate reference material

The most cost-effective way of monitoring and maintaining reliability of an analytical procedure is by the incorporation of appropriate, compositionally-similar reference materials into the scheme of analysis. Agricultural and food commodities represent an extremely wide range of composition in respect of both the sought-for analyte and the remainder of the supporting material (matrix) which are not reflected in currently-available biological reference materials (BRM's). In an attempt to fill some of these gaps in the world repertoire of reference materials, cooperative work is underway to prepare and characterize a number of materials for data quality control for inorganic constituents. The first two products of this venture, maize stalk and maize kernel reference materials 8412 and 8413, respectively, with recommended concentrations for eleven elements are available from USNBS. A third product, a powdered bovine muscle candidate re1509ference material has been prepared in quantity. Meat from beef cattle (Bos Taurus) comprising muscles commonly-denoted round steak was trimmed, ground, freeze-dried, gamma-ray sterilized, ball milled, sieved, blended and packaged. The final product was a finely powdered, visually uniform material consisting of muscle fibers with over 70 per cent of the particles with radius of an equivalent sphere in the range 10-40 mum (median 25 mum). Efforts are underway to develop a number of other BRM's representative of the large number of important food classes. Cooperative work with expert analytical laboratories is anticipated to lead to characterization of the Bowine Muscle candidate reference material and the other materials in respect of concentration of a large number of nutritionally, toxicologically and environmentally-important major, minor and trace chemical elements as well as proximate constituents such as protein, fibre, fat and