Carla Patrícia Silva

Processes for the elimination of estrogenic steroid hormones from water: A review

Natural estrogens such as estrone (E1), 17β-estradiol (E2), estriol (E3), and the synthetic one, 17α-ethinylestradiol (EE2), are excreted by humans and animals and enter into environment through discharge of domestic sewage effluents and disposal of animal waste. The occurrence of these substances in aquatic ecosystems may affect the endocrine system of humans and wildlife so it has emerged as a major concern for water quality. Extensive research has being carried out during the last decades on the efficiency of the degradation and/or removal of these hormones in sewage treatment plants (STPs). Conventional and advanced treatments have been investigated by different authors for the elimination of estrogens from water. This paper aims to review the different processes and treatments that have been applied for the elimination of E1, E2, E3 and EE2 from water. With this purpose, physical, biological and advanced oxidation processes (AOP) have been addressed.

Application of dispersive liquid-liquid microextraction for estrogens' quantification by enzyme-linked immunosorbent assay.

Estrogens, such as 17β-estradiol (E2) and 17α-ethinylestradiol (EE2), are the major responsible for endocrine-disrupting effects observed in aquatic environments due to their high estrogenic potency, even at concentrations ranging from pgL(-1) to ng L(-1). Thus, it is essential to develop analytical methodologies suitable for monitoring their presence in water samples. Dispersive liquid-liquid microextraction (DLLME) was used as a pre-concentration step prior to the quantification of E2 and EE2 by enzyme-linked immunosorbent assay (ELISA). First, an evaluation of the effect of DDLME on the E2 and EE2 ELISA calibration curves was performed. Since the extraction procedure itself had an influence on the ELISA optical density (OD), it became necessary to subject, not only the samples, but also all the standards to the DLLME process. Working ranges were determined, being between 1.2 and 8000 ng L(-1), for E2, and between 0.22 and 1500 ng L(-1), for EE2. The influence of organic matter, both in the extraction and quantification, was evaluated and it was observed that its presence in the solution did not affect considerably the calibration curve. Recovery rates were also determined, ranging from 77% to 106% for ultrapure water and from 104% to 115% for waste water samples, the most complex ones in what concerns matrix effects. Results obtained when applying the proposed method to real water samples can be considered quite satisfying. Moreover, the obtained working ranges encompass values generally reported in literature, confirming the practical use of the method for environmental samples.

Evaluation of the anthropogenic input of caffeine in surface waters of the north and center of Portugal by ELISA.

This study comprises the development of an enzyme-linked immunosorbent assay (ELISA) for the quantification of caffeine in complex aqueous matrices without any sample clean-up procedure. Salinity and dissolved organic matter were selected as potential interfering agents. The addition of a sample buffer containing bovine serum albumin (BSA) prior to the sample was found to decrease the influence of those interfering agents. The working range of the developed method was 0.1-100 μg L(-1). Quantification of caffeine was possible in 43 out of 51 real aqueous samples, at values between <LOD and 15 μg L(-1). Results correlate well with those obtained by LC-MS/MS. To the best of our knowledge this is the first study dealing with the quantification of caffeine in Portugals surface waters.

Photosensitized Degradation of 17β-estradiol and 17α-ethinylestradiol: Role of Humic Substances Fractions.

Photodegradation of 17α-ethinylestradiol (EE2) and 17β-estradiol (E2) was investigated under simulated solar radiation. Photodegradation kinetics in the absence and presence of humic substances (HSs) fractions (humic acids [HAs], fulvic acids [FAs], and XAD-4), were compared. Although all three fractions were responsible for a noticeable increase on photodegradation rates, the effects were greater for FA and XAD-4. Half-life time decreased from 46 and 94 h (direct photodegradation) for EE2 and E2, respectively, to 6.4, 2.1, and 2.7 h (for EE2) and 5.7, 2.9, and 3.1 h (for E2) in the presence of HAs, FAs, and XAD-4, respectively. The XAD-4 fraction results were similar to those of FAs, which is considered the most photochemically active fraction of HSs. Studies were also conducted in organic matter-rich environmental water matrices. After 5 h, photodegradation ranged from 44 to 94% for EE2 and from 27 to 95% for E2, compared with 16% for EE2 and 6% for E2 in ultrapure water. The maximum photodegradation was obtained in an estuarine water sample, known to be rich in FAs and XAD-4 fractions and poor in HAs, showing that not only is the presence of organic matter an important factor for the photodegradation increase, as also the type of organic matter is determinant.

Development of an ELISA procedure to study sorption of atrazine onto a sewage sludge-amended luvisol soil

Pesticides may contaminate ground and surface waters and one of the major factors governing this property is soil sorption. Sorption can be assessed by batch equilibrium technique which produces lots of extracts with high dissolved organic carbon concentration in which the pesticide concentration has to be determined. We developed an ELISA procedure to analyse atrazine based on polyclonal antibodies (C193) for which tracer structure and dilutions of immunochemical reagents were adapted to fit the purpose. After a 1000-fold dilution (or after an SPE clean-up procedure) extracts of a sewage-sludge amended luvisol (used as an example application of the methodology developed) could be reliably analysed. The Freundlich model is able to describe adsorption for this system (r(2)=0.977) delivering a distribution coefficient K(F) of 1.6±0.2 (mg kg(-1)) (mg L(-1))(-N) and an isotherm nonlinearity factor N of 0.70±0.09.

Effect of natural aquatic humic substances on the photodegradation of estrone.

Photodegradation of estrone (E1) was investigated under simulated solar radiation in absence and presence of the different fractions of humic substances (HS), namely humic acids (HA), fulvic acids (FA) and XAD-4 fraction. The pseudo-first order photodegradation rate constants increased from 0.1137 h(-1), in ultrapure (MQ) water, to 0.1774, 0.1943 and 0.3109 h(-1), in presence of HA, FA and XAD-4, respectively. Half-life time decreased from 6.10 h in MQ water to 3.91, 3.57 and 2.23 h in presence of HA, FA and XAD-4, respectively. These results evidence the relevant photosensitizing effect of XAD-4 fraction of HS on the degradation of E1, which, to the best of our knowledge have never been studied. Photodegradation studies were also conducted in organic matter-rich environmental aquatic matrices, namely fresh, estuarine and waste water. After 2 h, photodegradation achieved values ranged between 35.6 and 57.1% in natural water samples, compared with 26.4% in ultrapure water. The higher photodegradation occurred in an estuarine water sample, known to be rich in XAD-4 fraction and poor in HA, indicating that not only the presence of organic matter, but also its type, are determinant in the E1 photodegradation rate. Finally, the use of sodium azide as singlet oxygen ((1)O2) scavenger during the phototransformation of E1 in ultrapure and in two wastewater samples allowed to conclude that (1)O2 has an important role in the E1 photodegradation.

Adaptation and validation of WHODAS 2.0 in patients with musculoskeletal pain

OBJETIVO Validar la version en portugues del World Health Organisation Disability Assessment Schedule (WHODAS 2.0). METODOS La version original con 36 items del WHODAS 2.0, administrada por entrevista, fue traducida al portugues de acuerdo con orientaciones internacionales, y evaluada en nueve participantes de la poblacion en general. La version en portugues fue aplicada en 204 pacientes con patologia musculoesqueletica. Se colectaron los datos sociodemograficos y de salud de los pacientes, asi como el numero de lugares donde presentaban dolor y su intensidad. El WHODAS 2.0 fue nuevamente aplicado por un segundo entrevistador, uno a tres dias posteriores a la primera entrevista para evaluar la confiabilidad inter-evaluadores. La validez del constructo fue evaluado con relacion a: capacidad del WHODAS 2.0 para diferenciar participantes con diferentes lugares con dolor y asociacion entre el WHODAS 2.0 y la intensidad del dolor. La consistencia interna tambien fue evaluada. RESULTADOS La version en portugues del WHODAS 2.0 fue de facil comprension, presento buena consistencia interna (α= 0,84) y confiabilidad inter evaluadores (CCI=0,95). Mostro ser capaz de detectar diferencias estadisticamente significativas entre individuos con diferente numero de lugares con dolor (p˂0,01) e indicar que mayor incapacidad esta asociada con la mayor intensidad del dolor (r=0,44, p˂0,01), indicando validez del constructo. CONCLUSIONES la version en portugues del WHODAS 2.0 se mostro confiable y valida al ser utilizada en pacientes con dolor asociado a la patologia musculo esqueletica.

Comparison between MEKC and UV spectral deconvolution to follow sorption experiment in soil.

In this study a simple and rapid procedure for monitoring sorption of atrazine onto soil samples was developed. This method is based on a multiwavelength UV spectral deconvolution (UVSD) where the UV spectrum of a sample is considered as a linear combination of absorption spectra, named reference spectra. The combination of the reference spectra allows the restitution of the shape of the UV spectrum of any unknown sample. In order to evaluate the accuracy of this method, a sorption study of atrazine to three different soil samples was monitored using both UVSD and micellar electrokinetic chromatography (MEKC) methods. The Freundlich parameters (K(F) and N) obtained for all soil samples tested were similar for both methods and UVSD has proven to be an accurate methodology, since the results did not present statistical significant differences at 95% confidence level. Moreover, the LOD obtained using UVSD presented lower values (0.066-0.12mgL(-1)) than the one obtained using MEKC (0.26mgL(-1)). The proposed UVSD method has been proven useful as a valid alternative, to the more common procedures to follow sorption experiment in soil matrix samples with no need of sample pre-treatment or column conditioning. This method is much faster and requires less sample manipulation than traditional analytical separation methods. Moreover, most modern spreadsheet-applications, such as Excel, now include statistical packages that allow performing multi-linear regression, which make this approach particularly inexpensive since the only requirement is a UV spectrometer. The regression output was made using the Microsoft Excel, a very easy and fast program, allowing anyone, with less knowledge about complex statistical programs, to perform the UV spectral.

Structural considerations on the selectivity of an immunoassay for sulfamethoxazole.

Sulfamethoxazole (SMX), a sulfonamide, is a widely used bacteriostatic antibiotic and therefore a promising marker for the entry of anthropogenic pollution in the environment. SMX is frequently found in wastewater and surface water. This study presents the production of high affinity and selective polyclonal antibodies for SMX and the development and evaluation of a direct competitive enzyme-linked immunosorbent assay (ELISA) for the quantification of SMX in environmental water samples. The crystal structures of the cross-reacting compounds sulfamethizole, N(4)-acetyl-SMX and succinimidyl-SMX were determined by x-ray diffraction aiming to explain their high cross-reactivity. These crystal structures are described for the first time. The quantification range of the ELISA is 0.82-63µg/L. To verify our results, the SMX concentration in 20 environmental samples, including wastewater and surface water, was determined by ELISA and tandem mass spectrometry (MS/MS). A good agreement of the measured SMX concentrations was found with average recoveries of 97-113% for the results of ELISA compared to LC-MS/MS.

Adaptacao e validacao do WHODAS 2.0 em utentes com dor musculoesqueletica

OBJETIVO Validar la version en portugues del World Health Organisation Disability Assessment Schedule (WHODAS 2.0). METODOS La version original con 36 items del WHODAS 2.0, administrada por entrevista, fue traducida al portugues de acuerdo con orientaciones internacionales, y evaluada en nueve participantes de la poblacion en general. La version en portugues fue aplicada en 204 pacientes con patologia musculoesqueletica. Se colectaron los datos sociodemograficos y de salud de los pacientes, asi como el numero de lugares donde presentaban dolor y su intensidad. El WHODAS 2.0 fue nuevamente aplicado por un segundo entrevistador, uno a tres dias posteriores a la primera entrevista para evaluar la confiabilidad inter-evaluadores. La validez del constructo fue evaluado con relacion a: capacidad del WHODAS 2.0 para diferenciar participantes con diferentes lugares con dolor y asociacion entre el WHODAS 2.0 y la intensidad del dolor. La consistencia interna tambien fue evaluada. RESULTADOS La version en portugues del WHODAS 2.0 fue de facil comprension, presento buena consistencia interna (α= 0,84) y confiabilidad inter evaluadores (CCI=0,95). Mostro ser capaz de detectar diferencias estadisticamente significativas entre individuos con diferente numero de lugares con dolor (p˂0,01) e indicar que mayor incapacidad esta asociada con la mayor intensidad del dolor (r=0,44, p˂0,01), indicando validez del constructo. CONCLUSIONES la version en portugues del WHODAS 2.0 se mostro confiable y valida al ser utilizada en pacientes con dolor asociado a la patologia musculo esqueletica.