QUANTITATIVE ESTIMATION OF FUNGICIDE BENOMYL USING A BIOAUTOGRAPH TECHNIQUE

When the fungicide benomyl [methyl 1-(butylcarbamoyl)-2-benzimidazolecarbamate] was dissolved in water or chloroform, two fungitoxic chemicals were detected. One was the original benomyl and the other, a breakdown product (methyl 2-benzimidazolecarbamate). The breakdown product was relatively stable in aqueous solution and within plants, but the benomyl disappeared within a week. Fungitoxic chemicals were determined both quantitatively and qualitatively using a bioautograph technique in which a thin-layer plate was sprayed with a mixture ofagar and Penicillium spores; the diameter of the zone of inhibited growth above the fungitoxic spot was related to the amount of fungitoxic chemical in the spot. © 1969, American Chemical Society. All rights reserved.