Residual piperonyl butoxide in agricultural products.

The residual levels of piperolyn butoxide (PB) in agricultural products were investigated for 531 samples of 10 species. For the determination of PB a high speed liquid chromatograph equipped with a fluorometric detector was used. The detection limit of PB was 0.1 ppm. PB was detected from 3 barleys and 3 wheats harvested in U.S.A. ans Australia. It was not detected from the others. The residual range was from 0.2 to 1.4 ppm.