Counter-current extraction of dioxins from cod liver oil by supercritical carbon dioxide

Abstract

Dioxins and dibenzofurans are chlorinated toxic compounds. They are formed in many different processes involving chlorine. They are found everywhere in nature. As they are nonpolar they accumulate in fat containing environments and are, for example, found in breast milk, fatty fish, and cod liver oil. For those cases where it is possible to get rid of the dioxins, it is important to try this. Counter-current extraction of dioxins from cod liver oil has been studied using supercritical carbon dioxide. The results show that 80% of the dioxins can be extracted together with the 17% of the oil. The best conditions so far, in a 1 m/14-mm i.d. column filled with glass rings, are 150 bar and 40 °C and an oil-to-carbon dioxide ratio of 1:100.