A New Strategy for the Analysis of Steroid Hormones in Industrial Wastewaters by Paper Spray Ionization Mass Spectrometry.

A new approach using paper spray ionization mass spectrometry (PSI-MS) for the analysis of steroid hormones in wastewater samples has been demonstrated. Triangular papers containing paraffin barriers as microfluidic channels were used to direct the sample solution to the paper tip, preventing the sample from spreading over the corners of the paper. The method was used to analyze the hormones levonorgestrel and algestone acetophenide in industrial wastewaters. Analytical curves presented a correlation coefficient (R2) above 0.99. Limits of quantification were below 2.3 ppm and limits of detection below 0.7 ppm. Values of precision (coefficient of variation) and accuracy (relative error) were less than 15% for all analyses. Recovery results ranged from 82% to 102%. Levonorgestrel was also analyzed by high-performance liquid chromatography coupled to mass spectrometry in order to compare the analytical performance with PSI-MS. No statistically significant differences were found between both methods. This study demonstrates the usefulness of PSI-MS for rapid analysis of hormones in industrial wastewater samples and also indicates its potential to be employed as a simple and reliable analytical method in environmental sciences.

Ecotoxicological assessment and electrochemical remediation of doxorubicin.

Doxorubicin (DOX) is an anthracycline widely used in treatments of several cancers, so it has found in hospital effluents with a significant concentration (above 1 µg L-1). Electrochemical remediation is an alternative to promote its degradation. The aim of this work was to evaluate the ability of nanostructured graphite electrodes with metallic oxides to degrade DOX by electro-oxidation (EO). Graphite, TiO2@graphite and AuO-TiO2@graphite electrodes were used in medium with tap water or 10 mmol L-1 NaCl. DOX treatments at concentrations of 1.25-5 mg L-1 were carried out in a voltage source with 1.5-5 V. The cathode used was the platinum electrode. The treatment of DOX 1.25 mg L-1 with 10 mmol L-1 NaCl electrolyte using the AuO-TiO2@graphite electrode at 5 V and 1 mA was the best methodology to promote its degradation. Also, the modified electrode was efficient to DOX degradation after 17 cycles of reuse. An energy expenditure of 1.11 and 0.2 kWh m-3 were obtained for 3 and 50 mL of treatment, respectively. Fish embryo acute toxicity test with zebrafish (Danio rerio) were performed before and after treatment by EO using NaCl. This treatment caused no effect on embryo-larval development, however it induced significant damage in the DNA of the zebrafish larvae after 96 h of exposure, which emphasizes the importance of a depth ecotoxicological evaluation during the development of EO methodologies.

External control of fluoridation in public water supply systems in the state of Goiás, Brazil. / Heterocontrole da fluoretação da água de abastecimento público em cidades do estado de Goiás, Brasil.

The addition of fluoride to the public water supply is a method used for reducing tooth decay. In this sense, the control of fluoridation is important for maintaining its efficiency and, at the same time, for avoiding the risk of fluorosis as a result of the consumption of water with excess of fluoride. The objective of this study was to evaluate the adequacy of fluoride levels in the water distributed to populations of the state of Goiás, Brazil. Towards this aim, 5,039 water samples collected between 2011 and 2013 in 225 municipalities of the state of Goiás were analyzed for fluoride level. The results were assessed with regard to season, type of water source and geographic location. Fluoride levels were found to vary between complete absence and 2.5 mg F/L, with 28.2% of the samples being between 0.6 and 0.8 mg F/L, and 39.1% between 0.55 and 0.84 mg F/L. The rainy season produced a greater number of atypical results and higher values than the dry period. The systems supplied by groundwater sources were shown to have a limited control of fluoride concentration compared to systems supplied by surface water sources. Lower concentrations of fluoride were found in samples collected in the North and East Mesoregions of Goiás, with less than 7.5% being between 0.6 and 0.8 mg F/L, which systems are mainly supplied by groundwater sources with fluoride addition .

A adição do flúor na água é um método empregado na redução de cárie dentária. O controle da fluoretação é importante para manter a sua eficiência e, ao mesmo tempo, evitar o risco de ocorrência de fluorose, fruto do consumo de água com flúor em excesso. O objetivo deste trabalho foi avaliar a adequação dos níveis do fluoreto na água distribuída à população do estado de Goiás, Brasil. Foram analisadas 5.039 amostras de água coletadas em 225 municípios de Goiás, entre 2011 e 2013. Os resultados foram analisados por sazonalidade, tipo de manancial e localização geográfica. Ocorreu uma variação entre ausência e 2,5 mg F/L, com 28,2% das amostras entre 0,6 e 0,8 mg F/L e 39,1% entre 0,55 e 0,84 mg F/L. No período de chuva ocorreu um maior número de resultados atípicos e maiores valores quando comparados ao período da seca. Verificou-se que os sistemas abastecidos por água proveniente de mananciais subterrâneos possuem um menor controle de fluoreto quando comparados a sistemas provenientes de mananciais superficiais. Observou-se menores concentrações nas amostras coletadas no Norte e Leste goianos, com menos de 7,5% entre 0,6 e 0,8 mg F/L, para aquelas coletadas de sistemas de abastecimento que utilizam água de manancial subterrâneo com adição de fluoreto, existindo dificuldades na manutenção dos seus teores.

Nanostructured TiO2 Carbon Paste Based Sensor for Determination of Methyldopa.

Methyldopa is a catecholamine widely used in the treatment of mild to moderate hypertension whose determination in pharmaceutical formulae is of upmost importance for dose precision. Henceforth, a low-cost carbon paste electrode (CPE) consisting of graphite powder obtained from a crushed pencil stick was herein modified with nanostructured TiO2 (TiO2@CPE) aiming for the detection of methyldopa in pharmaceutical samples. The TiO2-modified graphite powder was characterized by scanning electron microscopy and X-ray diffraction, which demonstrated the oxide nanostructured morphology. Results evidenced that sensitivity was nonetheless increased due to electro-catalytic effects promoted by metal modification, and linear response obtained by differential pulse voltammetry for the determination of methyldopa (pH = 5.0) was between 10⁻180 µmol/L (Limit of Detection = 1 µmol/L) with the TiO2@CPE sensor. Furthermore, the constructed sensor was successfully applied in the detection of methyldopa in pharmaceutical formulations and excipients promoted no interference, that indicates that the sensor herein developed is a cheap, reliable, and useful strategy to detect methyldopa in pharmaceutical samples, and may also be applicable in determinations of similar compounds.

Risco de contaminação pela presença de disposição final de resíduos sólidos em bacias de captação superficial de água / Contamination risk due to the presence of an urban solid waste disposal site within the surface water catchment basins

RESUMO Modelos de vulnerabilidade são importantes ferramentas no estudo da contaminação da qualidade das águas. Esta pesquisa avaliou o risco de contaminação pela presença de disposição final de resíduos sólidos urbanos (DRS) em bacias de captação superficial de água (BCSs) no Estado de Goiás, Brasil. Foi realizada a identificação e caracterização das BCSs e das DRSs em um sistema de informações geográficas utilizando o software QGis 2.12.0 Lyon. A sobreposição das informações permitiu a identificação das BCSs com DRSs em suas delimitações, aplicando a elas o índice de susceptibilidade (IS), composto por características intrínsecas e extrínsecas das BCSs. Pelo cálculo da vulnerabilidade média foram selecionadas as BCSs com maior risco de contaminação, bem como as DRSs presentes, as quais foram analisadas por seis parâmetros técnicos. Dessa forma, foram identificadas 204 BCSs e 228 DRSs, sendo 93% classificadas como lixões. O IS foi calculado para as 43 BCSs com presença de 69 DRSs em suas áreas, selecionando as nove mais vulneráveis com a existência de 18 DRSs. A interdependência dos parâmetros avaliados possibilitou o cálculo do risco nessas DRSs. Conclui-se que a avaliação da vulnerabilidade se mostrou eficaz e de grande relevância para a identificação das BCSs mais susceptíveis à contaminação de suas águas, podendo ser aplicada a outras áreas de estudo. Em Goiás, a análise permitiu o cálculo do risco existente em 18 DRSs, sendo 4 delas classificadas como de risco alto, devendo ser consideradas prioritárias para adequação ou remediação de suas áreas.

ABSTRACT Vulnerability models are important in the study of water contamination by different soil usage activities. This research's goal is to evaluate the contamination risk by the presence of an urban solid waste disposal site (UWDS) within the surface water catchment basins (SWCB) used in the public water supply of Goiás, Brazil. Identification and characterization of SWCBs and UWDSs have been done in a geographical identification system using the QGis2.12.0 Lyon software. The information overlapping allowed the identification of SWCBs that had an UWDS within its limits, applying to them the Susceptibility Index (SI), composed by intrinsic and extrinsic SWCB characteristics. Calculating the average vulnerability, SWCBs, which presented the highest risk of water contamination, were selected and had their UWDSs analyzed by six technical parameters. This way, 204 SWCBs and 228 UWDSs were identified, out of which 93% were classified as irregular dumping sites. The SI was calculated for each SWCB that had the presence of UWDSs within their areas (43 SWCBs with 69 UWDSs), pointing the 9 most vulnerable ones, which had 18 UWDSs within its limits. The interdependence of the evaluated parameters allowed to calculate the risk in these UWDSs. In conclusion, the vulnerability evaluation has been proven effective and of great relevance in the identification of the SWCBs most susceptible to water contamination, and it can be applied to other studies. In Goiás, the analysis allowed the existing risk calculation for each of the 18 UWDSs, out of which 4 were found high-risk being in need of priority adequation and remediation.

Electrochemical remediation of amoxicillin: detoxification and reduction of antimicrobial activity.

Amoxicillin (AMX) is one of the most commonly prescribed antibiotics around the world to treat and prevent several diseases in both human and veterinary medicine. Incomplete removal of AMX during wastewater treatment contributes to its presence in water bodies and drinking water. AMX is an emerging contaminant since its impact on the environment and human health remains uncertain. This contribution was aimed to evaluate the electrochemical oxidation (EO) of AMX using different anodes in tap water, NaCl or Na2SO4 solutions and to evaluate the potential toxicity of remaining AMX and its by-products on zebrafish early-life stages. Chemical intermediates generated after EO were determined by mass spectrometry and their resulting antimicrobial activity was evaluated. AMX did not induce significant mortality in zebrafish during extended exposure but affected zebrafish development (increased body length) from 6.25 mg/L to 25 mg/L and inhibited enzymatic biomarkers. Carbon modified with titanium oxide (TiO2@C) anode achieved complete AMX removal in just a few minutes and efficiency of the supported electrolytes occurred in the following order: 0.1 M NaCl > 0.1 M Na2SO4 > 0.01 M NaCl > tap water. The order of potential toxicity to zebrafish early life-stages related to lethal and sublethal effects was as follows: 0.1 M Na2SO4 > 0.1 M NaCl >0.01 M NaCl = tap water. Additionally, the EO of AMX using TiO2@C electrode with 0.01 M NaCl was able to inhibit the antimicrobial activity of AMX, reducing the possibility of developing bacterial resistance.

Antioxidant activity evaluation of dried herbal extracts: an electroanalytical approach

ABSTRACT The prevention of chronic and degenerative diseases, is a health concern deeply associated with oxidative stress. Such progressive phenomena can be avoided through exogenous antioxidant intake, which set up a reductant cascade, mopping up damaging free radicals. Medicinal herbs are commonly associated with high antioxidant potential, and hence their health benefits. The commerce of dried herbal extracts movements a big portion of developing countries economy. The determination of medicinal herbs the antioxidant activity capacity is of utmost importance. The assessment of antioxidant activity in phytotherapics is mostly achieved by spectrophotometric assays, however colored substances can produce interferences that do not occur in electroanalytical methods. Therefore, the aim of this paper is to compare spectrophotometric and voltammetric techniques to evaluate antioxidant activity in herbal drugs such as: Ginkgo biloba L., Camellia sinensis (L.) Kuntze, Theaceae; Hypericum perforatum L., Hypericaceae; Aesculus hippocastanum L., Sapindaceae; Rosmarinus officinalis L., Lamiaceae; Morinda citrifolia L., Rubiaceae; Centella asiatica (L.) Urb., Apiaceae; Trifolium pratense L., Fabaceae; Crataegus oxyacantha L., Rosaceae; and Vaccinium macrocarpon Aiton, Ericaceae. The spectrophotometric methods employed were DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) and the Folin-Ciocalteu assays. The electroanalytical method used was voltammetry and it was developed a phenoloxidase based biosensor. The redox behavior observed for each herbal sample resulted in distinguishable voltammetric profiles. The highest electrochemical indexes were found to G. biloba and H. perforatum, corroborating to traditional spectrophotometric methods. Thus, the electroanalysis of herbal drugs, may be a promising tool for antioxidant potential assessment.

Development of a Polyphenol Oxidase Biosensor from Jenipapo Fruit Extract (Genipa americana L.) and Determination of Phenolic Compounds in Textile Industrial Effluents.

In this work, an innovative polyphenol oxidase biosensor was developed from Jenipapo (Genipa americana L.) fruit and used to assess phenolic compounds in industrial effluent samples obtained from a textile industry located in Jaraguá-GO, Brasil. The biosensor was prepared and optimized according to: the proportion of crude vegetal extract, pH and overall voltammetric parameters for differential pulse voltammetry. The calibration curve presented a linear interval from 10 to 310 µM (r² = 0.9982) and a limit of detection of 7 µM. Biosensor stability was evaluated throughout 15 days, and it exhibited 88.22% of the initial response. The amount of catechol standard recovered post analysis varied between 87.50% and 96.00%. Moreover, the biosensor was able to detect phenolic compounds in a real sample, and the results were in accordance with standard spectrophotometric assays. Therefore, the innovatively-designed biosensor hereby proposed is a promising tool for phenolic compound detection and quantification when environmental contaminants are concerned.

Heterocontrole da fluoretação da água de abastecimento público em cidades do estado de Goiás, Brasil / External control of fluoridation in public water supply systems in the state of Goiás, Brazil

Resumo A adição do flúor na água é um método empregado na redução de cárie dentária. O controle da fluoretação é importante para manter a sua eficiência e, ao mesmo tempo, evitar o risco de ocorrência de fluorose, fruto do consumo de água com flúor em excesso. O objetivo deste trabalho foi avaliar a adequação dos níveis do fluoreto na água distribuída à população do estado de Goiás, Brasil. Foram analisadas 5.039 amostras de água coletadas em 225 municípios de Goiás, entre 2011 e 2013. Os resultados foram analisados por sazonalidade, tipo de manancial e localização geográfica. Ocorreu uma variação entre ausência e 2,5 mg F/L, com 28,2% das amostras entre 0,6 e 0,8 mg F/L e 39,1% entre 0,55 e 0,84 mg F/L. No período de chuva ocorreu um maior número de resultados atípicos e maiores valores quando comparados ao período da seca. Verificou-se que os sistemas abastecidos por água proveniente de mananciais subterrâneos possuem um menor controle de fluoreto quando comparados a sistemas provenientes de mananciais superficiais. Observou-se menores concentrações nas amostras coletadas no Norte e Leste goianos, com menos de 7,5% entre 0,6 e 0,8 mg F/L, para aquelas coletadas de sistemas de abastecimento que utilizam água de manancial subterrâneo com adição de fluoreto, existindo dificuldades na manutenção dos seus teores.

Abstract The addition of fluoride to the public water supply is a method used for reducing tooth decay. In this sense, the control of fluoridation is important for maintaining its efficiency and, at the same time, for avoiding the risk of fluorosis as a result of the consumption of water with excess of fluoride. The objective of this study was to evaluate the adequacy of fluoride levels in the water distributed to populations of the state of Goiás, Brazil. Towards this aim, 5,039 water samples collected between 2011 and 2013 in 225 municipalities of the state of Goiás were analyzed for fluoride level. The results were assessed with regard to season, type of water source and geographic location. Fluoride levels were found to vary between complete absence and 2.5 mg F/L, with 28.2% of the samples being between 0.6 and 0.8 mg F/L, and 39.1% between 0.55 and 0.84 mg F/L. The rainy season produced a greater number of atypical results and higher values than the dry period. The systems supplied by groundwater sources were shown to have a limited control of fluoride concentration compared to systems supplied by surface water sources. Lower concentrations of fluoride were found in samples collected in the North and East Mesoregions of Goiás, with less than 7.5% being between 0.6 and 0.8 mg F/L, which systems are mainly supplied by groundwater sources with fluoride addition .

Bio-electro oxidation of indigo carmine by using microporous activated carbon fiber felt as anode and bioreactor support.

The bioremediation and electro-oxidation (EO) processes are included among the most promising cleaning and decontamination mechanisms of water. The efficiency of bioremediation is dictated by the biological actuator for a specific substrate, its suitable immobilization and all involved biochemical concepts. The EO performance is defined by the anode efficiency to perform the complete mineralization of target compounds and is highlighted by the low or null use of reagent. Recently, the combination of both technologies has been proposed. Thus, the development of high efficient, low cost and eco-friendly anodes for sustainable EO, as well as, supporting devices for immobilization of biological systems applied in bioremediation is an open field of research. Therefore, the aim of this work was to promote the bio-electrochemical remediation of indigo carmine dye (widely common in textile industry), using new anode based on a microporous activated carbon fiber felt (ACFF) and ACFF with immobilized Laccase (Lcc) from Pycnoporus sanguineus. The results were discolorations of 62.7% with ACFF anode and 83.60% with ACFF-MANAE-Lcc anode, both for 60 min in tap water. This remediation rates show that this new anode has low cost and efficiency in the degradation of indigo dye and can be applied for other organic pollutant.

Electroanalysis and laccase-based biosensor on the determination of phenolic content and antioxidant power of honey samples.

Honey is a functional food widely consumed. Thus, the evaluation of honey samples to determine its phenolic content and antioxidant capacity (AOC) is relevant to determine its quality. Usually AOC is performed by spectrophotometric methods, which lacks reproducibility and practicality. In this context, the electroanalytical methods offer higher simplicity and accuracy. Hence, the aim of this work was to use of electroanalytical tools and laccase based biosensor on the evaluation of AOC and total phenol content (TPC) of honey samples from different countries. The antioxidant power established by electrochemical index presented good correlation with the spectrophotometric FRAP (Ferric Reducing Ability of Plasma) and DPPH (2,2-Diphenyl-1-Picrylhydrazyl) radical scavenging assays. Also, TPC results obtained by the biosensor agreed with the Folin-Ciocalteu (FC) assay. In addition to the semi quantitative results, the electroanalysis offered qualitative parameters, which were useful to indicate the nature of major phenolic compounds.