Investigation of DEHA plasticizer migration from PET into lemon juice model system by optimized liquid- liquid microextraction technique

Polyethylene terphthalate (PET) is one of the plastics that are widely used for packaging of foods, especially, beverages and edible oils. In this study, the migration of di (2- ethylhexyl) adipate (DEHA), which is convenient plasticizer in PET, from PET bottles into the lemon juice stimulant was investigated. According to EC directives, specific migration limit (SML) for DEHA is 18 µg/L. In present work, air associate liquid-liquid micro-extraction (AALLM) was offered as extraction method to the DEHA and the effect of some important parameters such as type of extraction solvent, extraction solvent volume, salt amount was optimized. According to EC regulations, 3% acetic acid (w/v) was chosen as simulant. The samples were stored at 5, 25, and 40°C for three months and analyzed at 10,30,60,90 by gas chromatography. The diffusion coefficients of DEHA from PET bottle were calculated by using Fick’s second law. The migration of DEHA was increased with increasing of storage temperature and storage time. After 90 days, level of migrated DEHA were below and above of SML in 25˚C and 40˚C, respectively. The diffusion coefficients (D) determined for DEHA were 0.109, 0.12, and 0.092 ×10-9 cm2/s at 5, 25, and 40˚C, respectively. Storage of lemon juice packaged in PET bottle can potentially cause risk by DEHA migration in warm climate. However, it seems there are not high risks in moderate climate and the storage of it in refrigerator can reduce risks of DEHA migration into lemon juice.