Principle: Ground cereal grain is extracted with acetone/methanol (1:1). Water is added beforehand in an amount that takes full account of the natural water content of the sample, so that during extraction the acetone : water ratio remains constant at 2:1. The extract is saturated with 3% sodium chloride solution and diluted with dichloromethane, resulting in separation of excess water. The evaporation residue of the organic phase is cleaned up by gel permeation chromatography on Bio Beads S-X3 (polystyrene gel) using a mixture of cyclohexane and ethyl acetate as eluant. The residue-containing fraction is concentrated and analysed directly by gas chromatography using a phosphorus selective detector for organophosphorus and electron-capture detector for organohalogen pesticides. For the analysis of synthetic pyrethroids by electron capture detection, a supplemental clean-up on silica or alumina (neutral) sep-pak is always necessary.