Characterization of the interactions between endocrine disruptors and aquatic humic substances from tropical rivers

Abstract

Interações entre substâncias húmicas aquáticas (SHA), de rios tropicais, e dois interferentes endócrinos (IE) foram estudados utilizando sistema de ultrafiltração em fluxo tangencial equipado com membrana de celulose de 1 kDa com a finalidade de separar os IE livres da fração ligada as SHA. A quantificação de 17a-etinilestradiol e bisfenol A foi realizada utilizando cromatógrafo a gás acoplado a espectrômetro de massas (GC-MS). O tempo de equilíbrio entre as SHA e IE foi de aproximadamente 30 min, e as capacidades complexantes do 17a-etinilestradiol e bisfenol A foram em torno de 18,53 e 2,07 mg g -1 de carbono orgânico total (COT), respectivamente. A maior interação das SHA ocorreu para 17a-etinilestradiol, em relação ao bisfenol A, devido a presença de hidrogênio na estrutura do 17a-etinilestradiol, que podem interagir com os grupos oxigenados presentes nas SHA. Os resultados indicam que as SHA podem influenciar fortemente no transporte e reatividade dos interferentes endócrinos presentes em sistemas aquáticos.Interactions between two endocrine disruptors (ED) and aquatic humic substances (AHS) from tropical rivers were studied using an ultrafiltration system equipped with a 1 kDa cut-off cellulose membrane to separate free ED from the fraction bound in the AHS. Quantification of 17a-ethynylestradiol and bisphenol A was performed using gas chromatography-mass spectrometry (GC-MS). The times required for establishment of equilibrium between the AHS and the ED were ca. 30 min, and complexation capacities for 17a-ethynylestradiol and bisphenol A were 18.53 and 2.07 mg g -1 TOC, respectively. The greater interaction of AHS with 17a-ethynylestradiol, compared to bisphenol A, was due to the presence of hydrogen in the structure of 17a-ethynylestradiol, which could interact with ionized oxygenated groups of the AHS. The results indicate that AHS can strongly influence the transport and reactivity of endocrine disruptors in aquatic systems.Keywords: water, pollution, endocrine disruptors, aquatic humic substances, complexation capacity IntroductionPopulation increase, the development of new products, and intensified use of terrestrial and aquatic resources in industry and agriculture have resulted in the introduction into the environment of new compounds that may cause toxicity in humans and animals. Endocrine disruptors (ED) are often found in surface waters and effluents, where they can pose health risks even at low concentrations. In 1996, the European Commission defined this class of compounds as "exogenous substances that cause adverse health effects in the intact organism, or in its descendents, resulting in alterations of endocrine functions". 1,2 ED can block cellular receptor sites or increase the production and/or secretion of hormones, hence interfering in the reproductive systems of living organisms. 3-5 Many Characterization of the Interactions between Endocrine Disruptors and Aquatic Humic Substances J. Braz. Chem. Soc. 1104 compounds are suspected of interfering with the endocrine system, 6 inclu...

Interaction of arsenic species with tropical river aquatic humic substances enriched with aluminum and iron

“…The total organic carbon contents of the AHS solutions (Table 2) also showed similarity, with a slightly higher value for AHS-S. The results obtained in this work were similar to those reported previously for rivers rich in humic materials (Botero et al 2011).…”

“…The presence of these groups makes HS attractive for environmental remediation, because it is by means of these groups that the HS can bind to organic and inorganic pollutants, decreasing the toxicity and availability of these substances in the environment (Batista et al 2009;Botero et al 2011;Gungor and Bekbolet 2010;Ruiz et al 2013;Zhou et al 2005).…”

Remediation efficiency of three treatments on water polluted with endocrine disruptors: Assessment by means of in vitro techniques

“…Aquatic humic substances (AHS) constitute the most important class of complexation agents present in the natural aquatic environment and they play a key role in the transport and behavior of EDCs (Sun et al, 2007). In a study conducted by Botero et al (2011), it was observed that the availability of endocrine disruptors can be directly influenced by the presence of humic substances in aquatic systems. Therefore, studies about the interaction between AHS and endocrine disruptors are vital for a better understanding of the transport and availability of EDCs in the environment.…”

Determination of polychlorinated biphenyls in seawater using headspace solid-phase microextraction coupled with gas chromatography-mass spectrometry with the aid of experimental design

“…[1][2][3][4] However, concentration levels of PCBs in contaminated environment are typically low in complex matrices. 5,6 Proper sampling and enrichment methods have to be employed to recover sufficient targeted compounds from suspended particulate matter or water phase. 7 This has promoted rapid developments in sample preparation and chromatographic techniques in the analysis of PCBs.…”

“…11,12 Thus, a relatively simple, rapid, cost-effective, and virtually solvent-free sample preparation method, SPME, has been greatly developed and applied to the determination of PCBs in different matrices, e.g., soil, sediments, water, urine and milk. [13][14][15][16][17][18] As for water samples, humic substances are major components of dissolved organic matter (DOM) 5,19 and aquatic humic substances have been excellently characterized. 20 Humic acids significantly reduce the retention of PCBs and might cause insufficient recoveries attained.…”