Abstract
A simple, rapid and inexpensive sample preparation method using extraction by shaking and sulfuric acid treatment was developed for determining eight organochlorine pesticides in kampo products by gas chromatography/mass spectrometry with negative chemical ionization. The recoveries were between 71% and 117%, and most relative standard deviations were less than 10%. The proposed method was applied to twenty-three samples of kampo formulae, and no samples were contaminated by eight organochlorine pesticides over the quantification limit.