Copolymers of N-vinylcaprolactam with 1-vinyl- and 1-methacryloyl-3,5-dimethylpyrazole as sorbents of essential α-amino acids in liquid- and solid-phase extraction

Radical copolymerization of N-vinylcaprolactam with 1-vinyl- and 1-methacryloyl-3,5-dimethylpyrazole was performed with the aim of development of effective extraction systems based on nontoxic copolymers for the recovery of essential amino acids histidine, threonine, and tryptophan from aqueous media. Water-soluble and water-insoluble products were obtained. As follows from the copolymerization data, N-vinylcaprolactam exhibits relatively high activity, and the copolymerization constants r1 and r2 for both pairs of comonomers are lower than unity. The influence of the composition and structure of copolymers on the quantitative characteristics (degree of recovery R and distribution coefficient D) of liquid- and solid-phase extraction was studied. The probable mechanism of the interaction of the polymers with α-amino acids was considered. The synthesized copolymers show high performance in recovery of α-amino acids from aqueous media.