A screening strategy for vinyl acetate materials for solid-phase microextraction based on dynamic vapor sorption

In solid-phase microextraction (SPME) research, selecting a coating adsorbent with good compatibility for target molecules can be difficult, and there is no specific migration testing method for vinyl acetate monomer, which is commonly used in the production of food contact materials (FCMs). First, 13 metal-organic frameworks (MOFs) with different structural characteristics and surface chemical environments were prepared and divided into three groups (good, medium, and poor) based on the dynamic vapor sorption (DVS) method. The distinction of superiority and inferiority determined by the DVS method was completely consistent with that determined by the extraction effect of the SPME probe, and the data from the two variables exhibited a statistically significant positive correlation. Then, the electrostatic potential (ESP) distribution on the typical material surface and target molecule and the charge density difference (CDD) of their interaction during adsorption were obtained using a computational simulation method. The results showed that ZIF-68 and ZIF-70 had the highest adsorption energy, which was consistent with the adsorption performance. Finally, ZIF-68 was selected as the optimal adsorption material, and the extraction conditions were optimized. The optimized method was successfully applied to test the specific migration amounts of several ethylene vinyl acetate (EVA) copolymer materials.