Determination of organophosphorus insecticides in edible oils and fats by splitless injection of the oil into a gas chromatograph (injector-internal headspace analysis).

Abstract

Direct injection of oil or fat into a moderately heated injector enables performance of a kind of headspace technique in the injector: oil or fat is diluted 1:1 with acetone and injected into a vaporizing chamber at 200 degrees C. Components, for example organophosphorus insecticides, evaporate from the oil film on the insert wall and are transferred into the column in the splitless mode; the oil slowly flows along the wall to the bottom of the insert and is retained there in a kind of a bag. Using a flame photometric detector, detection limits are below 10 micrograms/kg.