Development of a Kinetic Microplate Immunoenzyme Determination of Dibutyl Phthalate

Phthalic acid esters are integral components of modern plastic products and packaging materials, which causes significant contamination of food products and the environment, leading to the need for simple productive monitoring methods. This article presents a rapid enzyme-linked immunosorbent assay (ELISA) for the determination of dibutyl phthalate (DBP) in fruit juices, based on the competitive interaction between free and bound antigen for the binding sites of specific antibodies. The analytical characteristics of the method were studied in various kinetic regimes of the competition stage. Optimal conditions have been established to provide the minimum detection limit and high measurement accuracy. The duration of the competitive stage of ELISA was chosen as 30 min; the range of determined concentrations of DBP was from 0.37 to 68.34 ng/mL with a detection limit of 0.08 ng/mL. The efficiency of the proposed ELISA for testing fruit juices was shown for the chosen DBP extraction mode.