A hybrid molecular imprinted polymer (HMIP) obtained by the organic monomer 4-vinylpyridine (4-VP) and the inorganic precursor tetraethyl orthosilicate (TEOS) was synthesized for the selective extraction of urinary S-phenylmercapturic acid (u-SPMA), a biomarker of benzene exposure. The chemical and structural characterization of the synthetic adsorbent was performed by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), and textural analysis employing N2 adsorption-desorption isotherms. Selective and adsorptive performance of the imprinted polymers were evaluated by kinetic, isothermal, thermodynamic, and selectivity studies. The kinetic data were well adjusted to pseudo-second order and intraparticle diffusion models, leading to selectivity coefficient (K) value of 0.03 g mg-1 min-1 for HMIP. In addition, the adsorption isotherms were better described by the Sip model achieving a maximum adsorption capacity of 284.81 μg g-1 (at 288.15 K).

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.

Foi desenvolvido e validado um método para determinação de três perturbadores endócrinos (estradiol, etinilestradiol e bisfenol A) e cinco produtos farmacêuticos (sulfametoxazol, trimetoprima, diclofenaco, bezafibrato e miconazol) em amostras de esgoto bruto, utilizando extração em fase sólida (SPE) e cromatografia líquida à espectrometria de massas em alta resolução (HPLC-HRMS) com ionização por eletrospray, nos modos positivo e negativo. Foi utilizado na extração em fase sólida um cartucho de troca iônica forte (Strata SAX) e um cartucho contendo divinilbenzeno-pirrolidona, para reduzir os níveis dos alquilbenzeno-sulfonados de cadeia linear (LAS) e para concentrar os analitos de interesse das amostras de esgoto. A influência do efeito matriz na eficiência da ionização, a recuperação da EFS e a sensibilidade do método foi identificada e quantificada. O método foi aplicado com sucesso na determinação dos analitos em amostras de esgoto coletadas na entrada da estação de tratamento de efluentes (ETE) do Arrudas em Belo Horizonte, MG, Brasil.

A new method for the determination of three endocrine disrupters (estradiol, ethinyl estradiol, and bisphenol A) and five pharmaceuticals (sulfamethoxazole, trimethoprim, diclofenac, bezafibrate and miconazole) in raw sewage samples using tandem solid phase extraction (SPE) sorbents and high-performance liquid chromatography-negative and positive electrospray high-resolution mass spectrometry (HPLC-HRMS) was developed and validated. The SPE procedure used both a strong ion exchange sorbent (SAX) and a modified divinylbenzene-pyrrolidone SPE sorbent to reduce the levels of linear alkylbenzene sulfonate (LAS) and to concentrate the analytes of interest from the sewage samples. The influence of matrix composition on the ionisation efficiency, the SPE recoveries, and the sensitivity of the method was identified and quantified. The method was successfully applied to the determination of analytes in raw sewage samples collected from the entrance of the Arrudas Sewage Treatment Plant, Belo Horizonte, Brazil.

Extraction/concentration is a crucial step for the analysis of organic compounds at trace level concentrations and dispersed in complex matrices. Solid-phase extraction (SPE) is one of the techniques used for this purpose. In this work, a low cost apparatus for SPE was developed that uses nitrogen under positive pressure and ensures the maintenance of the sample flow, while also allows the simultaneous extraction of different samples without cross-contamination and sample contact with plastic materials. For the system set up, easily accessible materials were used such as hypodermic needles, stainless steel tubes, rubber stoppers, and 3-way valves from serum delivery apparatus.

Three analytical methods for the determination of BTEX in water were optimized and validated. With the best method the analytes were extracted of 10 mL of sample with 2.50 g of NaCl in headspace vial of 20 mL by HS and SPME to 40 ºC for 30 min for adsorption and to 250 ºC for 4 min for desorption and were analyzed by GC-MS. The recovery was between 97.9% and 104.3%, and the limit of detection was 2.4 ng L-1 for o-xylene. This method was using to analyze BTEX in water supply and surface water in Ouro Preto city. No sample had concentrations of BTEX above the legislation.

Compostos voláteis da cúrcuma (Curcuma longa L.) cultivada no Brasil foram isolados por microextração por fase sólida. Os rizomas foram cozidos em solução de bicarbonato de sódio 0,1%, fatiados, secos e triturados. Visando estabelecer o sistema ideal para a microextração, fibras de polidimetilsiloxano de 100µm de espessura foram expostas ao headspace de frascos de 10mL. Estudou-se a influência das seguintes variáveis sobre o rendimento dos compostos voláteis obtidos: amostras em pó (0,1 a 1,0g) e em solução (40mg/L), diferentes temperaturas (40 a 70ºC) e tempos (2 a 20min) de partição. O efeito da temperatura (210 a 240ºC) e do tempo (3 e 5min) de dessorção também foi avaliado. As melhores condições para a partição dos compostos voláteis foram 0,1g do pó, 70ºC e 5min. A temperatura de 220ºC e o tempo de 5 minutos foram os de maior eficiência para a dessorção. A cromatografia gasosa foi conduzida em coluna capilar, detecção por ionização de chama e identificação por espectrometria de massas. A análise dos espectros de massas obtidos para os nove compostos voláteis predominantes indicou a presença de ar-curcúmeno, ar-turmerona, zingibereno, beta-sesquifelandreno, sabineno, 1,8-cineol e 1,4-terpineol.

Volatile compounds from turmeric (Curcuma longa L.) cultived in Brazil were isolated by solid phase microextraction. The rhizomes were cooked in 0.1% sodium bicarbonate solution, sliced, dried and ground. Polydimethyldiloxanes fibers (100 mm diameter) were exposed to the headspace of 10 mL flasks with the aim of establishing an ideal microextraction system. The influence of the following parameters on the volatile substances obtained was studied: powder samples (0.1 to 1.0 g) and dissolved samples (40 mg/L), different temperatures (40 to 70ºC) and partition periods (2 to 20 min). The effect of temperature (210 to 240ºC) and time (3 to 5 min) on desorption efficiency was also evaluated. Optimum conditions for the partition of the volatiles were 0.1 g of powder sample, 70ºC and 5 min. A temperature of 220ºC and a 5 min period were of better efficiency for desorption. Gas chromatography was performed using capillary column and flame ionization detector. The eluates were identified by mass spectrometry. The mass spectra obtained for the predominant volatile compounds indicated the presence of ar-curcumene, ar-tumerone, zingeberene, beta-sesquiphellandrene, sabinene, 1,8-cineol and 1,4-terpineol.