Core-shell molecularly imprinted polymers for the monitoring of dimethyl phthalate in the children's toys.

Plastic materials contain many additives, among which plasticizers from the group of phthalates are added during the production of everyday products, including children's toys. Even if the European Union and many other regions, for example Canada and the United States, have established restrictions on phthalate esters in children's toys or food contact materials and electronic and electrical products, there is still a danger that products imported from regions where there are no such restrictions can contain these dangerous compounds belonging to the group of endocrine disruptors. The additives introduced into plastics are not chemically bound to the polymer chain, so they can easily migrate to the external environment. This paper presents the process of synthesis of the core-shell type of molecularly imprinted polymers (MIPs) toward dimethyl phthalate (DMP). The most suitable polymerization mixture, which was selected to obtain the MIP layer, was prepared from the 4:6 wt ratio of methyl methacrylate and ethylene glycol dimethacrylate in the n-octane environment and with the addition of 5 wt% of the template. This material was characterized with the highest value of DMP removal, the maximum sorption capacity of this thin layer of MIP was about 3.0 mg/L. Additionally, DMP was about 3 times and about 5 times more efficient sorbed by core-shell MIP, than diethyl phthalate (DEP) and dibutyl phthalate (DBP), respectively. The best sorbed core-shell molecularly imprinted polymer was used as a column filler for solid phase extraction and was used to identify the phthalates present from rubber duck extraction solutions, showing the presence of this compound in the analyzed samples. The method developed in this work has a low limit of detection (LOD) and a low limit of quantification (LOQ) and a wide linear range, allowing DMP to be determined at both at trace levels (0.151 mg/L) and at higher concentrations.