Migration of di-(2-ethylhexyl)adipate and acetyltributyl citrate plasticizers from food-grade PVC film into isooctane: Effect of gamma radiation

The effect of gamma radiation on the migration of both di-(2-ethylhexyl)adipate (DEHA) and acetyltributyl citrate (ATBC) plasticizers from PVC film into the food simulant isooctane was studied as a function of time (0–48 h) at 20 °C. Food-grade PVC cling-film used contained 5.3% (w/w) DEHA, 3.0% (w/w) ATBC and polyadipate polymeric plasticizer. Irradiation of the films was carried out at doses of 5, 10 and 25 kGy using a [60Co] gamma-radiation source. Determination of both plasticizers was performed using a direct gas chromatographic method. No radiation-induced transformation of the two plasticizers was observed after absorbed doses of 5–25 kGy. DEHA migrated rapidly into isooctane in contrast with ATBC. ATBC migrating amounts at equilibrium were approximately three times lower than the corresponding amounts of DEHA. Irradiation at doses 10 and 25 kGy had a small but statistically significant (P < 0.05) effect on the migration of both DEHA and ATBC into isooctane. Migration amount increased with increasing irradiation dose and contact time. The irradiation-induced increase of ATBC migration was significantly higher than the corresponding increase of DEHA migration. Results are discussed in relation to EU proposed upper limit for DEHA specific migration (18 mg/L). Diffusion coefficients for both plasticizers calculated, showed differences between irradiated and control samples.