Determination of adipic acid esters potentially migrated from plastic films for foods-wrapping by gas chromatography/gas chromatograph combined with mass spectrometry.

Bis(2-ethylhexyl)adipate (DEHA) has been found to reduce the binding of tritiated 17β-estradiol to its receptor by screening an inhibitory effect on that to the rainbow-trout estrogen receptor (Jobling et al. 1995). Adipic acid esters (AAEs) are utilizable to a plasticized polyvinyl chloride and are also migratory from plastics. We studied the identification of AAEs potentially migrated from plastic films for food wrapping, and estimated their migration. Approximately fifty pieces of used wrapping films for foods were collected for about one month. DEHA was not found in those samples but di-n-hexyl, -n-heptyl, di-n-octyladipate, -n-nonyl and -n-decyladipates were identified by gas-liquid chromatography and mass spectrometry. Additionally, an unidentified adipate (AAEX) was found in 12 films. Approximately fourteen mg of total amounts of AAEs was migrated into n-heptane solvent from one side of the surface of 9 cm × 9 cm films, equivalent to ca. 0.2 g. The daily intake of AAE from food-wrapping film was estimated as 0.04 mg kg-1 day-1. A portion of thirteen percent of the film weight was migratory to natural and human environments. Approximately one tenth of a million tons of the films is annualy produced by factories in Japan. Further studies on endocrine disruption by plastic materials in our daily lives will be needed.