Comparison of traditional and fullerene-based adsorbents for extraction of 1,4-dioxane and 2-methyl-1,3-dioxolane from milk

Using density functional methods, the results of the analysis of traditional adsorbents and adsorbents based on nanosized particles capable of trapping 1,4-dioxane and 2-methyl-1,3-dioxolane molecules in milk are presented. We considered the following interacting compounds: 1,4-dioxane - primary amine, 1,4-dioxane - secondary amine, 1,4-dioxane - fullerene C-20, 1,4-dioxane-a fragment of the structure of activated carbon, 2-methyl-1,3-dioxolane - primary amine, 2-methyl-1,3-dioxolane-secondary amine, 2-methyl-1,3-dioxolane - fullerene C-20, 2-methyl-1,3-dioxolane - a fragment of the structure of activated carbon. We determined the optimal configurations of the corresponding interacting structures, estimated their binding energies and chemical potentials. The highest binding energy was obtained for 1,4-dioxane adsorbed on C-20 fullerene. At the same time, the energy gaps between the occupied HOMO and unoccupied LUMO molecular states were calculated, which makes it possible to characterize the reactivity and stability of molecules. Compounds of 1,4-dioxane and 2-methyl-1,3-dioxolane with amines have rather large gaps HOMO-LUMO. Using the concept of the electronic localization function, we found that a covalent bond is formed between 1,4-dioxane and C-20 fullerene with a sufficiently high degree of electron localization in the bond region. In other cases, the value of the localization function indicates the absence of a chemical bond between the compounds. The proposed study gives recommendations on the adsorption of 1,4-dioxane and 2-methyl-1,3-dioxolane for further solid-phase microextraction, which will allow them to be found in milk by gas chromatography using a flame ionization detector.