Analysis of Styrene Oligomer Contaminants Generated from Marine Debris Polystyrene on the Coast of Okinawa

Abstract

Marine debris plastics (50000 to 150000 tons) have washed up every year to Japan. Seventy percent of this stranded debris is polystyrene (PS). Drift and stranded PS is presumed to generate styrene oligomer (SO) in the marine environment. In this study, field work was carried out to clarify the pollution of the coastal area by such chemicals as SO derived from PS. Therefore, sea water and sand were collected at the investigation sites, while visual observations were made in Okinawa island and Yaeyama islands (Iriomoteshima Island and Ishigakishima Island). These are representative islands to which many drift plastics arising from Asian countries are washed up. From a SIM-GC/MS analysis of picked-up sea water and sand, SO (styrene monomer phenylethylene, SM ; styrene dimer, 2,4-diphenyl-1-butene, SD ; styrene trimer, 2,4,6-triphenyl-1-hexene, ST) were detected at every sampling site. Among SO, ST was found to be contained most abundantly in the sea sand ; 4400 ng/g of ST was detected as the maximum level. The SO composition determined by an analysis of sea sand and water tended to be almost similar to the SO composition of the purified PS thermal decomposition of the markets PS. © 2012, The Japan Society for Analytical Chemistry. All rights reserved.