Desenvolvimento de uma metodologia analítica utilizando nanopartículas magnéticas funcionalizadas no preparo de amostra para determinação de hormônios em águas

Abstract

Estrogens estriol (E3), 17 -estradiol (E2), 17 -ethinylestradiol (EE2) and estrone (E1) are emerging contaminants belonging to the endocrine interfering class. The main ways of introducing these compounds into water bodies is through the discharge of sewage. Studies indicate that continuous exposure to these contaminants can cause feminization of fish, anomalies in the reproductive system of some animals species, incidence of some types of cancer in humans, decrease in sperm in men, among other effects. Therefore, it is necessary to develop methods to identify and quantify the presence of these substances in surface waters. In this work, an analytical methodology was validated to determine the four estrogens, using high performance liquid chromatography (HPLC) coupled to the diode array (DAD). The validation of the method was selective, with a linear range from 10 to 1000 g L􀀀1 and r = 0.99 for all hormones, intraday repeatability and intermediate precision showed CV < 4, 43 %. In the stage of sample preparation, the magnetic solid phase extraction technique (MSPE) was used. For this purpose, nine magnetic nanoparticles were synthesized and tested through the development of design experiments to optimize the extraction conditions, the best results were obtained using 10 mg of the nanoparticle 50TEOS:1C16 initially dispersed in 1 mL of methanol that remain in contact with the working solution for 10 minutes under magnetic stirring. For elution, 1,8mL of a mixture of water:methanol 25:75 % v v􀀀1 stayed in contact with the nanoparticles for 10 minutes.