Anti-Estriol-6 polyclonal antibody

Photodegradation of pollutants is classically explained by reaction with reactive oxygen species. However Mn(III) may also remove pollutants, but direct evidence is actually lacking. Here we investigated the role of soluble Mn(III) on phototransformation of four typical estrogens, namely estrone (E1), 17 beta-estradiol (E2), estriol (E3), and 17 alpha-ethynylestradiol (EE2), in the presence of Mn(II) and humic acid. Conversion rates of 602%, 89.0%, 87.6%, and 80.2% were achieved for E1, E2, E3, and EE2, respectively, after 72 h visible light irradiation. A detailed quenching experiments revealed that soluble Mn(III), and not reactive oxygen species, was the oxidant responsible for estrogen removal. The determination of Mn(III) concentration provided direct proof of the role of Mn(III)-based oxidizers in the conversion of estrogens. Soluble Mn(III) can form complexes with humic acid, and about 6.51 mu M of Mn(III)-humic acid was formed from 20 mu M of Mn(II) in the presence of 5 mg/L of humic acid. Furthermore, product identification and theoretical computation demonstrated that estrogens are mainly converted into oligomers (dimers, trimers, tetramers, etc.) via a single-electron process. According to these results, the oxidation of Mn(II) to Mn(III) is initiated by superoxide ion (O-2(center dot-)) generated from dissolved oxygen in the presence of humic acid under visible light irradiation. The formed soluble Mn(III) strips the estrogens of a single electron to generate phenoxyl radicals, which undergo oligomerization, while leads to regeneration of Mn(II). Hence, the photochemical Mn(II)-Mn(III) redox cycling may significantly influence the fate and transformation of estrogens in waters. (C) 2018 Elsevier Ltd. All rights reserved.

This paper describes the development of a new method in which histamine-functionalized magnetic nanoparticles (HIS-MNP) are used as the extraction phase associated with thin-film microextraction and a 96-well plate system. This approach was applied to the determination of estrone, estriol, 17-beta-estradiol, 17 alpha-ethynylestradiol, 4-octylphenol and 4-nonylphenol in aqueous samples by HPLC-FLD. Extraction and liquid desorption steps were optimized employing multivariate and univariate procedures. The optimum extraction conditions were 50 min of extraction time, no salt addition and sample pH 5. Liquid desorption was carried out for 30 min with 300 mu L of acetonitrile:methanol (50:50 v/v). The quantification limits varied between 0.5 and 20 mu g L-1. The method showed recovery values between 82 and 120%, and relative standard deviations varied from 0.1 to 13.6%. (C) 2019 Elsevier B.V. All rights reserved.