ABSTRACT The phenolic content of the medicinal species Connarus perrottetti var. angustifolius Radlk., Connaraceae, Cecropia obtuse Trécul, Cecropia palmata Willd., Urticaceae; and Mansoa alliacea (Lam.) A.H.Gentry, Bignoniaceae, collected in three different years was evaluated. Plant infusions and hydroalcoholic, butanol and ethyl acetate extracts were analyzed by high-performance liquid chromatography with diode array detection. In order to endorse these results, analysis by electrospray mass spectrometry was also performed. Were identified: gallic acid, catechin, caffeic acid, ferulic acid, rutin, quercitrin and resveratrol. C. perrottetti showed greater diversity of polyphenols. M. alliacea had the higher concentration of caffeic acid even though it was found in all species. Catechin was the major antioxidant, but was not detected in M. alliacea. However, we discuss the popular use of these species, as well as their phenolic constitution and the interannual distribution of phenolic compounds.

The sequential voltammetric determination of chromium, thallium, cadmium, lead, copper and antimony in dialysate concentrates (DCs), is presented herein. Chromium was quantified by adsorptive cathodic stripping voltammetry and thallium, cadmium, lead, copper and antimony were assayed by anodic stripping voltammetry. The novel method developed to test these samples exploits the effect of electrolyte pH gradient on voltammetric response. The limits of detection (LOD) ranged from 0.03 µg L-1 for cadmium to 0.27 µg L-1 for copper. Recoveries from spiked samples were 92.0-117.5%. This method was applied to the analysis of commercial DCs, where the investigated metals were found in some samples at concentrations between 0.16 µg L-1 for antimony and 140.00 µg L-1 for copper. Interferences and the reference method are discussed

A contaminação de pacientes com insuficiência renal por espécies metálicas pode estar associada a presença destes na medicação empregada durante o tratamento. Dentre os possíveis contaminantes estão metais nefrotóxicos tais como alumínio, cromo e níquel. No presente trabalho, a presença de Al, Cr e Ni como contaminantes em formulações de eritropoetina (EPO) foi investigada através da otimização de métodos analíticos empregando a voltamétria adsortiva de redissolucao catódica (AdCSV) associada a foto-decomposição de amostras com radiação UV. A irradiação UV de amostras acidificadas de EPO pelo período de 2 a 3 horas na presença de H2O2 possibilitou a decomposição eficiente da amostra e a determinação dos contaminantes por AdCSV sem a interferência da matriz. O método otimizado foi aplicado na determinação dos metais em formulações comerciais de EPO utilizadas rotineiramente no tratamento da anemia em pacientes com insuficiência renal crônica. Os níveis de contaminação encontrados nas amostras estudadas variaram de 420,2 a 840,5 ng mL-1 (RSD 2-5%) para o Al, de 12,0 a 40,0 ng mL-1 (RSD 2-6%) para o Cr e de 4,1 a 8,2 ng mL-1 (RSD 3-8%) para o Ni. Os resultados obtidos por AdCSV foram comparáveis aos obtidos por espectrometria de absorção atômica com atomização em forno de grafite (GFAAS). A contaminação de formulações EPO com Al, Cr e Ni mostrou ser uma fonte de contaminação importante para pacientes anêmicos com insuficiencia renal crônica.

The contamination of renal failure patients by metals can be associated to the presence of toxic metals in the medication, since they can be absorbed by the organism. Among the possible contaminants, there are nephrotoxic metals such as aluminum, chromium and nickel. In the present work, the presence of Al, Cr and Ni as contaminants in erythropoietin formulations (EPO) was investigated by optimizing the adsorptive cathodic stripping voltammetric (AdCSV) method and the photo-decomposition of samples by UV irradiation. The UV irradiation of acidified EPO samples from 2 to 3 h in the presence of H2O2 allowed the efficient sample decomposition and the determination of the contaminants by AdCSV without matrix interferences. The method was applied for the determination of the metals in commercial EPO formulations used routinely in the treatment of anemia in patients undergoing chronic renal failure. The contamination levels determined in the samples ranged from 420.2 to 840.5 ng mL-1 (RSD 2-5%) for Al, 12.0 to 40.0 ng mL-1 (RSD 2-6%) for Cr and 4.1 to 8.2 ng mL-1 (RSD 3-8%). The results obtained by AdCSV were in good agreement with those obtained by the comparative GFAAS measurements. The contamination of EPO formulations with Al, Cr and Ni was shown to be a serious contamination source for anemic patients undergoing chronic renal failure.

The theoretical aspects of Voltammetry of Immobilized Microparticles (VIM) were discussed. The immobilization of microparticles on electrode surface, the electrode cleaning processes and the electrode materials were analyzed. The three-phase electrode model and the possible reactions between the immobilized particle and the electrolytic solution were discussed. In addition, this work discusses some selected applications of VIM published in the last years.

This work describes the development of a home-made capillary electrophoresis (CE) system based on the capacitively coupled contactless conductivity detection (C4D) for the separation of the metallic species Zn2+, Cr3+, Pb2+, Cd2+, Co2+, Cu2+, Ni2+ e Tl+. A background electrolyte composed of MES/Histidine 0,02 mol L-1 (pH 5.0) was optimized for the separation of the metallic species by using organic solvents and complexing agents as additives. The system allowed the determination of the metallic species using MES/Histidine 0,02 mol L-1 and methanol 5% (pH 5.0) as a background electrolyte, 15 kV separation voltage and hydrodynamic injection by gravity.

This work describes the optimization of pretreatment steps for the destruction of organic matter in samples of waters and biological fluids, by using an UV irradiation system with a high power UV radiation source (400 W). The efficiency of the system constructed for the photo-decomposition of samples of model waters, natural waters and biological fluids was investigated by performing recovery experiments of the metallic species Zn(II), Cd(II), Pb(II), Cu(II), Al(III) and Fe(III). The use of UV irradiation allowed the liberation of metals bound to the organic matrix and the determination of the total content of elements in the samples.

INTRODUÇÃO: O cobre é um nutriente essencial para os humanos, e a manutenção dos seus níveis é importante, uma vez que seu metabolismo está envolvido com estresse oxidativo e patologias, como a Doença de Wilson. Neste trabalho, um método de espectrofotometria visível (espectrofotometria Vis) foi validado, aplicado em indivíduos jovens e comparado com espectrometria de absorção atômica com chama (EAA-chama). MÉTODOS: Concentrações séricas de cobre foram medidas por EAA-chama e por espectrofotometria Vis, através da reação de cobre com batocuproína, l = 484 nm. Curvas analíticas em solução aquosa e com adição de padrão foram efetuadas para verificar linearidade, recuperação e precisão do método espectrofotométrico. Amostras de sangue de 12 indivíduos (média de idade 22 anos) foram analisadas por ambos os métodos e comparadas entre si. Os resultados foram expressos em média ± desvio-padrão. RESULTADOS: As curvas com adição de padrão e aquosa (n = 5) apresentaram coeficientes de regressão superiores a 0,99 e de variação inter e intradia inferiores a 15%. Os valores de cobre sérico encontrados para o método espectrofotométrico foram 1,17 ± 0,39 e 0,73 ± 0,14 mg/l para mulheres e homens, respectivamente. Para EAA-chama foram encontrados 1,13 ± 0,43 e 0,59 ± 0,13 mg/l para mulheres e homens, respectivamente. Os resultados mostraram correlação de Pearson significativa (r = 0,946; p < 0,05). Os níveis séricos de cobre foram significativamente maiores em mulheres do que em homens (p < 0,05). CONCLUSÃO: O método espectrofotométrico visível demonstrou ser linear, reprodutível e aplicável, oferecendo uma alternativa confiável à quantificação de cobre por EAA-chama. Além disso, é uma técnica simples, rápida e barata, que pode ser utilizada na rotina laboratorial clínica.

BACKGROUND: Copper is an essential nutrient for humans and maintenance of its adequate levels is important, since its metabolism is involved with oxidative stress and patolologies, such as Wilson's disease. In this work, a visible spectrophotometric method was validated, applied in young subjects and compared to flame atomic absorption spectrometry (FAAS) in serum copper levels determination. METHODS: Serum copper concentrations were measured by FAAS and by spectrophotometry, through copper reaction with bathocuproine, l = 484 nm. Aqueous curves and spiked serum curves were realized to verify linearity, recovery and precision of the visible spectrophotometric method. Blood samples from 12 subjects (mean 22 years) were analyzed in both methodologies and compared to each other. The results were expressed by mean ± standard deviation. RESULTS: Spiked serum and aqueous curves (n = 5) showed coefficient of regression superior to 0.99 and inter and intra-day coefficient of variation lower than 15%. The serum copper values found to Vis spectrophotometric method were 1.17 ± 0.39 and 0.73 ± 0.14 mg/l to women and men, respectively. To FAAS 1.13 ± 0.43 and 0.59 ± 0.13 mg/l were found to women and men, respectively. Both results showed a significant Pearson correlation (r = 0.946; p < 0.05). Besides, serum copper levels were significantly higher in women than in men (p < 0.05). CONCLUSION: The Vis spectrophotometric method demonstrated to be linear, reproducible and applied, offering a reliable alternative to FAAS copper quantification. Moreover, Vis spectrophotometry is a simple, quickly and not expensive technique, and it could be widely used as routine in clinical laboratory.

Este trabalho descreve um estudo sistemático do comportamento voltamétrico da anfepramona no eletrodo de mercúrio de gota pendente (HMDE) por voltametria cíclica (CV) e voltametria de corrente alternada (AC). Os estudos mostraram o comportamento adsortivo da anfepramona no HMDE e foram realizados em soluções de H2SO4 0,1 mol L-1 (pH 1.0) e tampão de Ringer (pH 11,0) como eletrólito suporte. A faixa linear para a determinação de anfepramona por voltametria de pulso diferencial de varredura linear (DPV) foi de 0,05 a 2,0 mg L-1 (r = 0,998) em meio ácido e de 0,25 a 4,0 mg L-1 (r = 0,994) em meio alcalino. Os desvios padrão relativos calculados para 5 medidas de anfepramona 0,5 mg L-1 em meio ácido e meio alcalino foram de 2,5 e 4,0%, respectivamente. Os limites de detecção calculados para a determinação de enfepramona em meio ácido e meio alcalino foram de 0,035 e 0,18 mg L-1, respectivamente. As metodologias foram aplicadas para a determinação de anfepramona por DPV em cápsulas e comprimidos de formulações farmacêuticas usadas no tratamento da obesidade. Os valores de recuperação entre 90,0 e 101,0% para anfepramona adicionada a misturas sintéticas contendo femproporex, mazindol, sibutramina, fluoxetina, cafeína, diazepan e metformina provam a aplicabilidade do método para a sua determinação na presença de outras drogas normalmente adicionadas de forma ilegal a formulações farmacêuticas comercializadas como medicamentos naturais.

This paper describes a systematic study of the voltammetric behavior of amfepramone at the hanging mercury drop electrode (HMDE) by cyclic (CV) and alternating current (AC) voltammetric methods. The studies showed the adsorptive behavior of amfepramone at the HMDE and were performed in H2SO4 0.1 mol L-1 (pH 1.0) and Ringer buffer (pH 11.0) as supporting electrolytes. The linear range for the amfepramone determination by differential pulse voltammetry (DPV) was 0.05 to 2.0 mg L-1 (r = 0.998) in acidic medium and 0.25 to 4.0 mg L-1 (r = 0.994) in alkaline medium. The relative standard deviation calculated was 2.5% and 4.0 % for five measurements of 0.5 mg L-1 amfepramone in acidic and alkaline medium, respectively. The detection limits calculated for the amfepramone determination in acidic and alkaline medium were 0.035 e 0.18 mg L-1, respectively.The methods were applied for the determination of amfepramone by DPV in tablets and capsules of pharmaceutical formulations used in the treatment of obesity. Recoveries values ranging from 90.0 to 101.0% for amfepramone added to synthetic mixtures containing fenproporex, mazindol, sibutramine, fluoxetine, caffeine, diazepam, and metformin as interferents prove the applicability of the method for its determination in the presence of other drugs normally added illegally to pharmaceutical formulations commercialized as natural medicaments.

A determinação de herbicidas 2-metiltio-4,6-dialquilamino-1,3,5-triazina (triazinas) em soluções salinas utilizadas em hemodiálise foi investigada por voltametria. Os herbicidas foram detectados com grande sensibilidade nas soluções salinas, após extração em fase de acetonitrila (ACN), utilizando o eletrodo de mercúrio de gota pendente. O efeito de salting out originado pelo meio salino existente nas soluções viabilizou as extrações. A relação de volumes entre as fases salina e de ACN foi investigada para alcançar a melhor sensibilidade na detecção das triazinas. A especiação entre as triazinas investigadas (ametrina, desmetrina, prometrina e terbutrina) não foi possível e recuperações entre 88 e 107% foram calculadas em amostras fortificadas com os analitos. Utilizando esta metodologia, limites de detecção de 0,03 mimol L-1 foram calculados para as triazinas nas amostras salinas.

A method for the voltammetric determination of 2-methylthio-4,6-dialkylamino-1,3,5-triazine (triazines) herbicides in hemodialysis (HD) saline solutions was developed. The herbicides were detected in the saline solutions at the hanging mercury drop electrode (HMDE) with high sensitivities only after extraction of the analytes in acetonitrile (ACN). The salting out effect originated by the saline environment existing in the solutions enabled the extractions. The volume ratio between the saline and ACN phases was investigated in order to find the best sensitivity to detect the triazines. The speciation amongst them (ametryn, desmetryn, prometryn and terbutryn) was not possible. Recoveries between 88 and 107% were calculated in spiked samples, and detection limits of 0.03 mumol L-1 were calculated for the triazines in the saline samples using this methodology.