Polímero de impressão molecular sintetizado por microondas para extração em fase sólida e pré-concentração de sertralina em amostras ambientais

Abstract

This paper has two main lines of work: the synthesis of molecularly imprinted polymers (MIP) assisted by microwave energy and the use of this material in solid-phase extraction (SPE) for environmental analysis and remediation for sertraline. Eight polymers were synthesized using the precipitation method. Microwave-assisted MIP occurred at different parameters of power, heating ramp and amount of solvent employed. After the synthesis, the materials were subjected to analysis its structures (FTIR), thermal stability (TG and STA), surface area, pore size (BET) and average particle size (SEM). It was confirmed the incorporation of EGDMA (crosslinker) and methacrylic acid (monomer) in the polymer structure by the Fourier-transform infrared spectroscopy (FTIR). The polymers were used in adsorption and desorption studies for sertraline, and the average removal rate was: 95%, 61%, 93% and 98%, for MIPs I, II, III e IV, respectively. To measure the polymers selectivity the respective drugs were used: 17α ethinyl estradiol, diclofenac sodium and sertraline. The studies confirmed the existence of selective sites in the MIP structure. The selected best material was MIP III, its selection was made based on their results in adsorption studies, and mainly because of its higher value of IF (imprinted factor). The MIP III capacity of preconcentration up to 200 times a solution with 5 μg. L-1 sertraline was confirmed by studies performed in ultrapure water. The environmental samples used was obtained by four different sources: sewage, treated sewage, mineral water source and ultrapure water. The environmental sample tests were carried out for all the MIPs synthetized, and the adsorption efficiency for the polymers was similar to the test performed with ultra-pure water. The possibility of reuse/regeneration of the MIPs were confirmed in at least one adsorption cycle.