Zum chemischen und photochemischen Abbau der Cyclodien-Insektizide Aldrin, Dieldrin, Endosulfan und weiterer Hexachlorbicyclo-[2.2.1]-hepten-Derivate / The Chemical and Photochemical Degradation of the Cyclodien-Insecticides Aldrin, Dieldrin, Endosulfan and other Hexachloronorbornene Derivatives

Abstract

The conversion of the hexachloronorbornene-moiety of persistent cyclodiene pesticides has been studied by hydrolysis- and photolysis (UV) reactions. The chemical changes have been monitored by means of a microtitration method for chloride ions and electron capture gas chromatography. The 2,3-disubstituted hexachloronorborn-5-enes give a comparably easy loss of 1 mole chloride ions per mole compound if one of the substituents is a hydroxymethylene group, whereas with two carboxylic acid groups in the 2,3-position — that is chlorendic acid — or a further cycle or bicycle — that is endosulfanether or dieldrin — the compounds proved to be very stable. The alkaline stability of aldrin and dieldrin corresponds to their persistence in the ecosystem.