Carbofuran residues in organic soils in southwestern Ontario, 1977

Abstract

Organic soils from 22 farms with a history of carbofuran use for soil insect control were sampled in November, 1977. Analysis for carbofuran was by electron capture gas chromatography of the heptafluorobutyric derivative. Nineteen of the 22 soils contained detectable (sensitivity 0.02 ppm) carbofuran residues. However only 8 of the soils contained >0.5 ppm total carbofuran. The highest total carbofuran residue was 1.5 ppm, of which 0.31 ppm was 3‐ketocarbofuran. In other soil samples 3‐ketocarbofuran comprised 7–50% of the total carbofuran residue. No 3‐hydroxy‐carbofuran was detected. The order of persistence of granular application of 3 insecticides as seed‐furrow treatments was ethion>fonofos>carbofuran.