Abstract
Several cereal products were exposed to gaseous hydrogen phosphide in sealed glass flasks under different conditions of exposure period, temperature, concentration of fumigant and particle size of the cereal product. The amount of hydrogen phosphide adsorbed to these samples were measured colorimetrically.The concentration of hydrogen phosphide adsorbed to the surface of seeds of millet, wheat, azuki bean and soy bean was 27 ng/cm2, while that on hulled rice was 17 ng/cm2 following a 6 day exposure at an air concentration of 0.37% and temperature of 25°C.With a rise in temperature or increase in the concentration of fumigant, the amount of hydrogen phosphide adsorbed to samples showed an increase.A reduction in particle size favored the adsorption. Furthermore, it was demonstrated that the adsorption of hydrogen phosphide to cereal seeds is mainly dependent on the surface area.
