DETERMINATION OF POTASSIUM SORBATE AND SODIUM BENZOATE IN NON-ALCOHOLIC DRINKS WITH PIEZOSENSORS BASED ON MOLECULAR-IMPRINTED POLYMERS

Abstract

Preservatives such as potassium sorbate and sodium benzoate are commonly used in the food industry. It is necessary to control the content of preservatives in food products, because exceeding the permissible limit of the concentration can affect human health. To determine the contents of potassium sorbate and sodium benzoate in non-alcoholic drinks, a piezoelectric sensor based on molecularly imprinted polymers (MIPs) was used. Molecularly imprinted polymers were synthesized by copolymer of dianhydride 1,2,4,5-benzenetetracarboxylic acid with 4,4'-diaminodiphenyl oxide in N,N-dimethylformamide in the presence of a template by the non-covalent imprinting method. To assess the selectivity and ability to recognize target molecules, the values of the imprinting factor and the selectivity coefficient of the sensors were calculated. Based on the data obtained, it was found that molecularly imprinted polymers with imprints of potassium sorbate and sodium benzoate had better selectivity and ability to recognize target potassium sorbate and sodium benzoate molecules than polymers without imprints. In this study, the ranges of determined concentrations (5-500 mg/l) and detection limits of potassium sorbate (1.6 mg/l) and sodium benzoate (2 mg/l) were experimentally established. The results of the determination of potassium sorbate and sodium benzoate in non-alcoholic drinks by piezosensors were compared with the spectrophotometric method. It had been established that the difference in the determination results did not exceed 10%. Thus, the possibility of using piezosensor based on molecularly imprinted polymers with imprints of potassium sorbate and sodium benzoate for their determination in non-alcoholic drinks has been established.