Avaliação dos níveis de cromo total em águas para consumo humano / Evaluation of total chromium levels in drinking water

Níveis elevados de cromo associados às águas naturais não são comuns, mas concentrações elevadas desse elemento, de ocorrência natural, têm sido relatadas nas águas subterrâneas de vários sistemas aquíferos, incluindo o Aquífero Bauru, SP, Brasil. Este fato está associado à ocorrência de rochas máficas/ultramáficas e às condições alcalinas e oxidantes. Neste estudo foi desenvolvido e aplicado um método para monitorar a concentração de cromo total em amostras de água da cidade de São José do Rio Preto. Esta cidade está localizada no estado de São Paulo, na região onde concentrações superiores ao limite estabelecido pela legislação brasileira (0,05 mg/L) foram detectadas em águas subterrâneas de poços de abastecimento. O cromo total foi determinado usando-se Espectrometria de Massas com Plasma Indutivamente Acoplado (ICPMS) em 104 amostras de água coletadas, entre 2013 e 2017, em diferentes pontos de distribuição (zona rural, residencial, distrito industrial, comercial, reservatório de distribuição e estação de tratamento de água), considerando-se 52 locais. Em 99 % das amostras as concentrações de Cr estavam acima do limite de quantificação calculado para o método (0,001 mg/L). E 15% apresentaram concentrações acima do limite de regulação na água potável (Portaria 2914/2011), sendo, portanto, consideradas impróprias para o consumo humano. (AU)

Elevated chromium levels in the natural waters are not common, but the high concentrations of naturally occurring Cr have been reported in the groundwater of several aquifer systems.This finding is linked with the occurrence of mafic/ultramafic rocks and associated with the alkaline and oxidizing conditions. This study aimed at monitoring the total chromium concentration in drinking water samples from São José do Rio Preto city. Cr concentrations higher than the limit established by the Brazilian Legislation (0.05 mg/L) were detected in the groundwater from the deep supply wells. Total chromium was determined by using an Inductively Coupled Mass Spectrometer (ICP-MS) in 104 samples collected from the public drinking water distribution networks in 52 sites, from 2013 to 2017. Cr concentrations above the method limit of quantification (0.001 mg/L) were found in 99% of the analyzed samples. Approximately 15% of the collected samples presented Cr in concentrations above the established legislation limit for drinking water (Ordinance 2914/2011), that should be considered as improper for consumption.

Avaliação dos níveis de cromo total em águas para consumo humano / Evaluation of total chromium levels in drinking water

Níveis elevados de cromo associados às águas naturais não são comuns, mas concentrações elevadas desse elemento, de ocorrência natural, têm sido relatadas nas águas subterrâneas de vários sistemas aquíferos, incluindo o Aquífero Bauru, SP, Brasil. Este fato está associado à ocorrência de rochas máficas/ultramáficas e às condições alcalinas e oxidantes. Neste estudo foi desenvolvido e aplicado um método para monitorar a concentração de cromo total em amostras de água da cidade de São José do Rio Preto. Esta cidade está localizada no estado de São Paulo, na região onde concentrações superiores ao limite estabelecido pela legislação brasileira (0,05 mg/L) foram detectadas em águas subterrâneas de poços de abastecimento. O cromo total foi determinado usando-se Espectrometria de Massas com Plasma Indutivamente Acoplado (ICPMS) em 104 amostras de água coletadas, entre 2013 e 2017, em diferentes pontos de distribuição (zona rural, residencial, distrito industrial, comercial, reservatório de distribuição e estação de tratamento de água), considerando-se 52 locais. Em 99 % das amostras as concentrações de Cr estavam acima do limite de quantificação calculado para o método (0,001 mg/L). E 15% apresentaram concentrações acima do limite de regulação na água potável (Portaria 2914/2011), sendo, portanto, consideradas impróprias para o consumo humano.

Elevated chromium levels in the natural waters are not common, but the high concentrations of naturally occurring Cr have been reported in the groundwater of several aquifer systems. This finding is linked with the occurrence of mafic/ultramafic rocks and associated with the alkaline and oxidizing conditions. This study aimed at monitoring the total chromium concentration in drinking water samples from São José do Rio Preto city. Cr concentrations higher than the limit established by the Brazilian Legislation (0.05 mg/L) were detected in the groundwater from the deep supply wells. Total chromium was determined by using an Inductively Coupled Mass Spectrometer (ICP-MS) in 104 samples collected from the public drinking water distribution networks in 52 sites, from 2013 to 2017. Cr concentrations above the method limit of quantification (0.001 mg/L) were found in 99% of the analyzed samples. Approximately 15% of the collected samples presented Cr in concentrations above the established legislation limit for drinking water (Ordinance 2914/2011), that should be considered as improper for consumption.

Total Arsenic, Cadmium, and Lead Determination in Brazilian Rice Samples Using ICP-MS.

This study is aimed at investigating a suitable method for rice sample preparation as well as validating and applying the method for monitoring the concentration of total arsenic, cadmium, and lead in rice by using Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Various rice sample preparation procedures were evaluated. The analytical method was validated by measuring several parameters including limit of detection (LOD), limit of quantification (LOQ), linearity, relative bias, and repeatability. Regarding the sample preparation, recoveries of spiked samples were within the acceptable range from 89.3 to 98.2% for muffle furnace, 94.2 to 103.3% for heating block, 81.0 to 115.0% for hot plate, and 92.8 to 108.2% for microwave. Validation parameters showed that the method fits for its purpose, being the total arsenic, cadmium, and lead within the Brazilian Legislation limits. The method was applied for analyzing 37 rice samples (including polished, brown, and parboiled), consumed by the Brazilian population. The total arsenic, cadmium, and lead contents were lower than the established legislative values, except for total arsenic in one brown rice sample. This study indicated the need to establish monitoring programs for emphasizing the study on this type of cereal, aiming at promoting the Public Health.

Expanding resolution of metalloprotein separations from soybean seeds using 2D-HPLC-ICP-MS and SDS-PAGE as a third dimension.

This work reports on the use of a three dimensional separation system to enhance metalloprotein information when considering soybean seeds. Separations using size exclusion chromatography (SEC) allowed identification of three metal fractions. Following an anion exchange (AEX) chromatographic separation in the second dimension, the resultant sub-fractions were lyophilized and subjected to a third dimension of separation using a polyacrylamide gel electrophoresis (SDS-PAGE). After the separation, the bands were digested, and, in addition to others, the following proteins, previously associated with metals, were identified: 3-lipoxygenase A chain (soybean) complex with 13(S)-hydroperoxy-9(Z),11(E)-octadecadienoic acid, beta-amylase [Glycine max], seed lipoxygenase-1, lipoxygenase [G. max], seed lipoxygenase-2 (Pisum sativum) and beta-conglycinin. BIOLOGICAL SIGNIFICANCE: Techniques presenting high resolution are desired due to their capability in resolving great amount of signals (responses) generated from hundreds of proteins generally found in different samples. To the best of our knowledge, this is the first time that bidimensional chromatographic system which allied to another separation dimension is applied for improving protein identification, so that higher number and different proteins were found when comparing 2D dimension with 3D dimension. In fact, this strategy is welcoming in proteomics studies, in order to improve the comprehension of those systems that present large number of proteins. This article is part of a Special Issue entitled: Environmental and structural proteomics.

Speciation analysis of selenium in plankton, Brazil nut and human urine samples by HPLC-ICP-MS.

The HPLC (anion exchange)-ICP-MS technique was used for the identification (based on retention time of standards) and determination of four selenium species (selenite, selenate, selenomethionine and selenocystine) in plankton (BCR-414), Brazil nuts and urine samples. A recovery of 91% was attained for certified reference materials (BCR-414). Se(IV) was the predominant species in plankton, with the highest selenium concentration in the extract. The Brazil nuts showed only the organic species selenomethionine and selenocystine after water extraction, but after simulated gastrointestinal digestion, only selenomethionine was found as bioaccessible, corresponding to 74% of the total selenium (54.8±4.6 µg g(-1)). Analyses of the urine samples suggested the presence of selenocystine, and significant differences were observed between samples from men and women in terms of the concentration of this species after consumption of Brazil nuts (1 nut per day during 15 days).

Validation of methodology for determining As, Pb and Cd in fish byusing ICP-MS: Preliminary studies / Validação de método para análise de As, Pb e Cd em peixe por meio de ICP-MS: Estudos preliminares

The progress of industry has led to the increased emission of pollutants into ecosystems, and fish consumption has been a remarkable source of human exposure to toxic metals. Arsenic, cadmium andlead constitute a potentially significant threat to human health because they are associated with severaladverse health effects. Therefore, fish biomonitoring has been a crucial tool for assessing the environmental exposure to contaminants. This study aimed at determining arsenic, cadmium and lead contents in fishsamples from a Proficiency Testing for Metals conducted by the Nuclear and Energy Research Institute(IPEN), in order to develop a routine analytical methodology using ICP-MS. The methodology was evaluated by using the certified reference oyster tissue material, which indicated good agreement between the certified and the determined concentrations for As, Cd and Pb. The report on the Proficiency Testperformance evaluation, based on the z-score index, evidenced satisfactory results in both samples of theanalyzed elements.

O progresso das indústrias tem causado aumento da emissão de poluentes em ecossistemas, e o consumode peixe tem sido importante fonte de exposição dos homens aos metais tóxicos. Arsênio, cádmio echumbo constituem uma potencial ameaça para a saúde humana, pois estão associados a efeitos adversosà saúde. Portanto, o biomonitoramento em peixe é fundamental ferramenta para realizar a avaliação daexposição aos contaminantes ambientais. O objetivo deste estudo foi de determinar a ocorrência de arsênio,cádmio, e chumbo em amostras de peixe, a fim de iniciar o desenvolvimento de um método analítico derotina por meio de ICP-MS. Para conduzir este estudo, foram utilizadas as amostras provenientes doTeste de Proficiência em Metais organizado pelo Instituto de Pesquisas Energéticas e Nucleares (IPEN). Ametodologia foi avaliada de acordo com os valores obtidos em material de referência certificado de tecidode ostra, que indicaram boa concordância entre as concentrações certificadas e aquelas determinadas paraAs, Cd e Pb. O relatório de avaliação de desempenho para o Teste de Proficiência, com base no índicez-score, mostrou resultados satisfatórios para as duas amostras dos elementos analisados.

Improving metallomics information related to transgenic and non-transgenic soybean seeds using 2D-HPLC-ICP-MS and ESI-MS/MS.

This work reports the use of 2D-HPLC-ICP-MS to enlarge metallomics information when considering soybean seeds. Separations using size exclusion chromatography (SEC) allowed the identification of three metal fractions: the first corresponding to molecular weights from 38.1 to 181.1 kDa, the second from 8.2 to 17.2 kDa and the third from 0.4 to 3.8 kDa. In a second dimension, using anion exchange chromatography (AEX), three sub-fractions containing Fe, Mg and Mn, one containing Cu, and three containing Co, Cu, Mg, Mn and Zn were obtained. After these separations, 33 proteins were identified using the ESI-MS/MS technique, and divided into four functional categories: plant growth/cell division, protein destination and storage, metabolism and unclassified proteins. Among the identified proteins, proteins previously related to metals were found.

Evaluation of a simple and low cost potentiometric biosensor for pharmaceutical and in vivo adrenaline determination.

In this work the polyphenol oxidase (PPO) was the main component of a biosensor for adrenaline determination. The activity of this enzyme was measured in several vegetables. Banana (Musa sp.) extracts presented better results with 974 UA (units of activity). The biosensor was constructed with a polyethylene tube (0.8 mm i.d.) filled with: carbon paste containing 50 UA of the PPO in phosphate buffer (pH=7.00) solution and vaseline as agglutinant. When the biosensor was applied in medicine samples it provided a linear range from 8.00×10(-9) to 8.00×10(-4) mol L(-1); the results obtained with the proposed method and the Brazilian Pharmacopoeia method were in agreement (t-test). When it was applied in blood samples, the matrix-matching calibration was used, and the linear range was from 8.00×10(-7) to 8.00×10(-3) mol L(-1). In vivo studies were also done. The obtained results for those electrodes, which were inserted in the jugular vein of Wistar rats, were very promising.

A comparative study of element concentrations and binding in transgenic and non-transgenic soybean seeds.

Transgenic and non-transgenic soybean seeds were compared in terms of total element concentrations, behavior of elements during sequential extraction fractionation and element bioaccessibility using an in vitro simulated gastrointestinal digestion. The analysis were carried out by ICP-sector field-MS or size-exclusion ICP-MS (25 elements in concentrations varying from ng g⁻¹ to the % level). It seems that transgenic and non-transgenic soybean seeds exhibit statistically significant differences in concentrations of Cu, Fe and Sr, which are also reflected by element contents in water extracts and residues. Additionally, contributions of bioaccessible fractions of Cu, Fe and other elements (Mn, S, Zn) for transgenic soybean seeds appear to be larger than those found in non-transgenic soybean seeds.