A method for determination of inorganic dust content of grain in the presence of grain dust

Abstract

Summary. A method was developed for the determination of insecticidal ‘inert dusts’, particularly the diatomaceous earth product Dryacide, on grain. The method was also evaluated for another physical insecticide, magnesite, and 2 standard clays, bentonite and kaolin. The method consists of isolation of dusts (both inert dust and grain dust) from grain, followed by density centrifugation and ashing of the bottom pellet. The ash content of the bottom pellet is linearly related to the percentage inorganic dust in grain dust (w/w). The method can serve 2 functions. First, it can quantify total inorganic ash. Second, it can quantify the total amount of a specific inorganic additive, for example, Dryacide, thus enabling studies on the fate of inorganic additives during grain processing.