THERMAL-BEHAVIOR OF ORGANOCHLORINE PESTICIDES IN THE PRESENCE OF ALKALINE SUBSTANCES

Selected organochlorine pesticides, namely lindane, PCNB, p,p'-DDT and p,p'-methoxychlor, and some related compounds (p,p'-DDE and p,p'-DMDE) were heated in the presence of powdered KOH, Na2CO3, CaO and CaCO3 in order to check whether degradation of the compounds is feasible in moderate conditions and temperatures. Thermal analyses, as well as investigations concerning the search for the reaction products revealed that processes occurring at atmospheric pressure are either simple volatilization of organic molecules, observed upon heating of mixtures containing lindane, PCNB, p,p'-DDE and p,p'-DMDE, or volatilization accompanied with decomposition towards HCl and p,p'-DDE and p,p'-DMDE, noted when heating mixtures of p,p'-DDT and p,p'-methoxychlor with alkaline substances, respectively. Complementary theoretical calculations enabled insight into the mechanism of HCl elimination from p,p'-DDT and p,p'-methoxychlor.