The Analytical Method of the Residual Blasticidin-S in Unpolished Rice-grains

For the purpose to determine the residual amount of blasticidin-S (Bla-S) in an unpolished rice cropped from rice plant which was treated with Bla-S, the extract of the unhulled rice powder from water was treated with strong acid cation-exchange resin. The eluate was evaporated to a small volume and assayed by using Cladosporium fulvum as a test organism. From the results by this method the analytical flow-sheet shown in this report was presented. The recovery of Bla-S by this procedure showed about 60%. In the case that the sample dose not show any inhibitory diameter by the biological assay, the residual amount of Bla-S in the sample seems to be estimated below 0.05 ppm.