Caracterização de contaminantes presentes em sistemas de tratamento de esgotos, por cromatografia líquida acoplada à espectrometria de massas tandem em alta resolução

This work shows results on the characterization, by liquid chromatography coupled to high resolution tandem mass spectrometry (LC-IT-TOF-MS) with electrospray ionization, of organic compounds present in raw and treated effluents from a combined sewage treatment systems (upflow anaerobic sludge blanket-trickling filter). The sewage samples were prepared by C18 solid phase extraction and the spectra obtained from the various extracts were submitted to principal component analysis to evaluate their pattern and identify the major deprotonated species. Some target compounds were submitted to semiquantitative analysis, using phenolphtalein as internal standard. The results showed the anaerobic step had little impact on the removal of anionic surfactants (LAS), fatty acids, and some contaminantes such as bisphenol A and bezafibrate, whereas the aerobic post-treatment was very efficient in removing these organics

Remoção de Carbendazim em águas de abastecimento por clarificação acoplada à adsorção em escala de bancada

O objetivo deste artigo é avaliar a remoção do fungicida Carbendazim da água durante a clarificação acoplada ou não à adsorção em carvão ativado em pó (CAP) em escala de bancada. Para a clarificação, utilizaram-se os coagulantes sulfato de alumínio, o cloreto de polialumínio e o cloreto férrico em dose e pH otimizados previamente para remoção de sólidos em suspensão de águas de baixa (20 NTU) ou alta (200 NTU) turbidez. A adsorção com CAP (2,5; 5 e 10 mg L-1) foi testada adicionando-o com o coagulante ou após a clarificação. A etapa de clarificação resultou em remoções variadas do agrotóxico, sendo o cloreto férrico mais eficiente para águas de alta turbidez (67%) e o cloreto de polialumínio para água de baixa turbidez (86%). A adição de CAP com o coagulante resultou em uma melhoria na eficiência de remoção apenas na dose mais elevada do adsorvente, chegando a 87% de eficiência para a dose de 10 mg L-1 de CAP em águas de baixa turbidez

Determinação de carbamato de etila em aguardentes de cana por CG-EM

A simple, specific and sensitive GC-MS procedure with ion m/z 62 was validated for the determination of ethyl carbamate (EC) in spirits. It exhibited linearity over the concentration of 30 to 600 μg/L with 30 μg/L limit of quantification. EC was detected in 70 of the 71 samples analyzed with levels from 33 to 2609 μg/L (mean level = 893 μg/L). 35% of the samples contained 500 to 1000 μg/L and 23% contained 150 to 500 and 1000 to 1500 μg/L. No significant correlation was found between EC and the levels of copper, pH and alcohol content of the samples

Evaluation of removal of pharmaceuticals and endocrine disrupters in drinking water by clarification at bench scale.

In this work, the efficiency of clarification treatment (coagulation, flocculation and sedimentation) with polyaluminum chloride (PAC) and aluminum sulfate (SA) as coagulants was evaluated in the removal of 7 microcontaminants (diclofenac - DCF, sulfamethoxazole - SMX, ethinylestradiol - EE2, bisphenol-A - BPA, estradiol - E2, estrone - E1 and estriol - E3) in water of low and high turbidity. The clarification treatment led to poor removal rates (40% at most) for all microcontaminants except SMX which exhibited intermediate removal efficiency (67 to 70%). Overall, PAC application yielded better performance compared to SA

AVALIAÇÃO DA PRESENÇA DE PESTICIDAS N-METILCARBAMATOS E SEUS PRODUTOS DE DEGRADAÇÃO NAS ÁGUAS DA REGIÃO DE PARÁ DE MINAS (MG) BRASIL

Os pesticidas N-metilcarbamatos e alguns de seus metabólitos são altamente tóxicos para o homem e o meio ambiente. Por esta razão desenvolveu-se método analítico utilizando extração em fase sólida e cromatografia líquida de alta eficiência com detector de ultravioleta (CLAE/UV) para análise destes compostos em amostras de água. O método apresentou índice de recuperação para 10 compostos de 57 a 99%, com desvio padrão relativo (CV) de 5,67 a 7,67% para n=6. A repetitividade do método forneceu CV entre 5,94 a 8,46% para n=6. O limite de detecção do método (MDL) situou-se na faixa de 0,07 a 0,38 µg/L para 10 compostos. Este método foi aplicado na análise de amostras de águas coletadas na cidade de Pará de Minas-MG, Brasil, e também em alguns pontos selecionados nas bacias dos Rios Paciência e Bom Sucesso, situadas no município de Pará de Minas. Os resultados das análises em amostras de água mostraram-se abaixo dos limites estabelecidos pela legislação brasileira. EVALUATION OF THE PRESENCE OF N-METHYLCARBAMATE PESTICIDES AND DEGRADATION PRODUCTS IN WATERS OF PARÁ DE MINAS (MG) REGION IN BRAZIL Abstract The N-methylcarbamate pesticides and some of the their metabolites are highly toxic for men and environment. Then, an analytical method utilizing solid phase extraction and high performance liquid chromatography with ultraviolet detector (SPE/CLAE/UV) to analyze these compounds in water was developed. The accuracy of the method for 10 compounds varied from 57 to 99%, presenting relative standard deviation (RSD) from 5,67 to 7,67% for n=6. The repeatability supplied RSD among 5,94 to 8,46% for n=6. The method detection limit (MDL) is in the ranging of 0,07 to 0,38 µg/L for 10 compounds. This method was utilized in water samples collected in the city of Pará de Minas (MG) and in several points of the rivers Paciência e Bom Sucesso, situated in Pará de Minas (MG), Brazil. The results of the analysis of water samples are bellow of the limits permitted by Brazilian legislation

Removal of pharmaceuticals and endocrine disruptor compounds from natural waters by clarification associated with powdered activated carbono.

This work has evaluated the efficiency of two coagulants, aluminum sulfate (AS) and polyaluminum chloride (PACl), combined with the adsorption process using powdered activated carbon (PAC) on the removal of diclofenac (DCF), sulfamethoxazole (SMX), ethinylestradiol (EE2), estradiol (E2), estrone (E1), estriol (E3), and bisphenol-A (BPA) from low- and highturbidity waters. The results have shown that the concomitant application of PAC and either coagulant has worsened the removal efficiency for all pharmaceuticals and endocrine disruptors tested, which might have occurred due to the covering of adsorption sites by aluminum hydroxide particles. In this configuration (coagulation in the presence of PAC, 10 mg L−1), the best removal efficiency (∼40 %) was obtained for E1 and EE2 when AS was used as coagulant in contact times that varied from 13.5 to 23.5 min. When the coagulant was the PACl, contact times were lower (8.5 to 13.5 min) and the highest removal efficiency was observed for EE2 (∼52 %).When PAC was added as a pretreatment (before addition of coagulant), the removal e f f i c i e n cy was gr e a t l y i n c r eased f o r al l microcontaminants and the application of 2.5 mg L−1 of PAC with 120 min of contact led to removal efficiencies varying from 30 to 99.9 %