A study of the transfer processes of phthalate esters to the marine environment

Abstract

In recent years, environmental scientists have been concerned with the release of phthalate plasticizers into the environment (1). To determine their distribution, rates of input and accumulation, and to identify their major transfer processes in the marine environment, analytical methods for the determination of phthalate esters (PAEs) in the open-ocean samples had to be developed. The chlorinated hydrocarbons, such as DDT and the polychlorinated biphenyls (PCBs) which are present in almost all marine biota samples (2-5), interfere with the electron-capture detector-gas chromatographic (ECD-GC) analysis of the phthalates. Thus, a separation of these classes of compounds is required prior to GC analysis; this separation was achieved with column chromatography on deactivated (3% water) Florisil. The very low levels of phthalates anticipated in these samples required the reduction of background contamination to levels much lower than had previously been reported. With careful decontamination of all reagents and equipment and precautions to avoid recontamination during the procedure, background levels as low as 25 ng of dibutyl phthalate (DBP) , 50 ng of di-2-ethylhexyl phthalate (DEHP), 5 ng of PCBs and 0.5 ng DDT were attained. A method was also developed for the chemical derivatization of the phthalates through the formation of N-2-chloroethvl phthalimide for the confirmation by ECD-GC.