Oleamide, a bioactive compound, unwittingly introduced into the human body through some plastic food/beverages and medicine containers

Abstract

The purpose of the study was to investigate the migration of oleamide, a polymer lubricant, and a bioactive compound, from various plastic, marketed containers for food/beverages and medicines into polymer contact liquid. Methanol, food/medicine simulants or real samples were used to extract polymer leachables and extractables. Migrated oleamide into polymer contact liquids was determined by ultra-high performance liquid chromatography coupled to mass spectrometry (UHPLC-MS). The concentration of oleamide in the extracts of medicinal and insulin syringes was 7351 ng mL-1 and 21,984 ng mL-1, respectively. The leachates of intravenous (i.v.) infusion bottle, medicinal and insulin syringes contained 17 ng mL-1, 12 ng mL-1 and 152 ng mL-1, respectively. Oleamide in the extracts of dummies ranged from 30 to 39 ng mL-1, while in the leachates of baby bottles, from 12 to 23 ng mL-1. Leachates of soft drink bottles contained from 6 to 15 ng mL-1 oleamide, milk bottles from 3 to 9 ng mL-1, liquid yogurt bottles 17 ng mL-1 and water bottles from 11 to 18 ng mL-1. Bottled real matrices of oil and milk contained oleamide in the range from 217 to 293 ng mL-1. Moreover, the source of migrated oleamide (e.g., containers, caps, other parts) was identified. Oleamide is listed in the current EU regulations without a specific migration limit. Accordingly, these values are considered of no concern, unless future toxicological studies prove the opposite.