Navegando por Palavras-chave "17α-ethinylestradiol"

Agora exibindo 1 - 1 de 1
  • Nenhuma Miniatura disponível
    Item
    Somente Metadadados
    Estudo da degradação eletroquímica dos estrogênios 17α-etinilestradiol e 17β-estradiol utilizando os eletrodos de diamante dopado com boro
    (Universidade Federal de São Paulo (UNIFESP), 2020-04-03) Fernandes Filho, Calixto [UNIFESP]; Oliveira, Lucia Codognoto de [UNIFESP]; Universidade Federal de São Paulo
    In this work, the electrochemical behavior of estrogenic hormones 17α-ethinylestradiol (EE2) and 17β-estradiol (E2) on the boron doped diamond electrode (BDD) was studied. A methodology was developed for the electroanalytical determination of these hormones in natural waters and removal via destructive oxidation to controlled potentials, using the BDD electrode. After parameter optimization, analytical curves were built in BR pH 8.0 buffer in the concentration range of 9.90x10-6 to 9.09x10-5 mol L-1 , with LOD and LOQ of 0.68 and 1.48 being obtained μmol L-1 for E2 and 0.92 and 1.33 and μmol L-1 for EE2, respectively. The developed method was evaluated in the determination of E2 in natural waters, collected in the Billings dam, in the region of Diadema - SP and LOD and LOQ of 2.65 and 4.05 µmol L-1 were obtained, values within the expected for this one sample type. The electrochemical oxidation of 17α-ethinylestradiol and 17β-estradiol was carried out using exhaustive electrolysis. The monitoring of electrolysis and the possible products formed were performed by square wave voltammetry, ultraviolet-visible spectrometry (UV-vis), High Efficiency Liquid Chromatography (HPLC) coupled with fluorescence detector and analysis of total organic carbon (TOC). The parameters that involved exhaustive electrolysis were optimized through a 2k3 factorial design, which indicated the potential of +2.0 V and pH 9.0 as the best conditions for its exhaustive electrolysis. A decrease in signs for 17α-ethinylestradiol was observed in about 90%; and close to 70% for 17β-estradiol, during a period of 4 hours of electrolysis. For the Billings water sample, the decrease in EE2 concentration was monitored by HPLC-FL, in the retention time in 4.8 minutes, starting from 3.45 µmol L-1 up to the limit of 0.5 µmol L-1 in 240 minutes, generating 85.5% of EE2 degradation. In addition, E2 formation was observed with a retention time of 6.0 minutes.