Determination Method of Styrene Dimers and Trimers in Instant Noodles Contained in Polystyrene Cups

Abstract

A determination method was developed for styrene dimers and trimers in instant noodles contained in polystyrene cups. Soup and drained water were extracted by shaking with n-hexane, and the noodles were extracted by sonicating with n-hexane. Samples containing both noodles and soup were extracted by a combination of both methods. The extracts were cleaned by partition with acetonitrile and then eluted through a Florisil column. The styrene dimers and trimers were determined by GC-FID using 1, 3-diphenylpropane and benzyl n-butyl phthalate as standards. The recoveries of two dimers and four trimers from spiked samples ranged from 77.5% to 111.7%. The quantitation limits were 5ppb in the samples. The migration test was carried out using eight instant noodle samples and the migration levels of the styrene trimers in the noodles were ND-62ppb, while styrene dimers were not detected.