Effect of graphene on the migration of two ultraviolet absorbents from graphene-LDPE composite films into a fatty food simulant

The effect of graphene on the migration of ultraviolet absorbents from graphene-low density polyethylene (LDPE) composite films into fatty food simulant was studied. First, a gas chromatography mass spectrometry (GC-MS) method was developed to detect the total content of the two ultraviolet absorbents 2-hydroxy-4-n-octyloxybenzophenone (UV-531) and 2-(2′-hydroxy-5′-methylphenyl) (UV-P) in graphene-LDPE composite films. Toluene soluble extraction was selected to process the samples with different additives for its better extract effect. The standard curves were linear in the range of 0.01-1 μg/mL and had a good linear relationship (R > 0.99). The recoveries were 82.0%-99.3% with RSD 3.7%-10.0%. The limits of detection of UV-531, UV-P were 0.3 ng/mL and 0.5 ng/mL, respectively. The migration test reveals that the two ultraviolet absorbers had no interaction with each other on their migration into isooctane, but graphene hindered the migration of the two ultraviolet absorbers. The reason might be that the incorporated graphene reduce the number and/or the size of free volume within the polymer by occupying some of the free volume, which may affect the diffusion of the two ultraviolet absorbers; in addition, they are absorbed by the nearby graphene within the polymer.