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INTRODUCTION: The usual quality control for Uncaria tomentosa (Willd. ex Schult.) DC. barks requires highly specific analytical standards and methods based on high-performance liquid chromatography (HPLC), which impacts the costs of the analytical process and the final products. OBJECTIVE: To obtain an analytical reference standard of mitraphylline by isolation from U. tomentosa barks and develop a spectrophotometric method for determination of total alkaloids in samples of U. tomentosa. METHODOLOGY: An alkaloid-enriched extract was obtained by acid-base partition and mitraphylline was selectively precipitated using an 80:20 v/v toluene/hexane solution. The compound was characterised by HPLC-UV/DAD (diode-array detector), mass spectrometry, UV-visible, infrared (IR) and 1 H- and 13 C-nuclear magnetic resonance (NMR) spectroscopy. Sample preparation for the spectrophotometric method consisted of an extraction with boiling methanol (3 × 10 mL, 15 min), followed by a strong cation exchange solid phase extraction (SCX-SPE) clean-up. RESULTS: Mitraphylline with a purity of 98% was isolated in 0.05% m/m yield. All characterisation results were in agreement with previous published data. The spectrophotometric method showed linear range between 0.40 and 20 µg/mL; limits of detection and quantification of 0.15 and 0.49 µg/mg, respectively; dispersion of results lower than 5% for repeatability and intermediate precision; statistically proven accuracy by comparison with reference values obtained by Soxhlet and an HPLC-UV/DAD method; and robustness in relation to sample mass extracted and extraction time. CONCLUSION: The methods developed to obtain mitraphylline analytical standard from U. tomentosa barks and to determine total alkaloids by spectrophotometry provided a cheaper and faster quality control alternative for U. tomentosa samples.
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Alcaloides , Uña de Gato , Oxindoles , Extractos VegetalesRESUMEN
A highly sensitive analytical method was developed and validated, following international guidelines, for the determination of the residues of five macrocyclic lactones (MLs) (abamectin, doramectin, eprinomectin, ivermectin and moxidectin) in cheese. The extracts were concentrated by rotary-evaporation and derivatized; no clean-up was necessary. Despite matrix complexity, no significant matrix-effect was verified, and standards were prepared in solvents. Linear working ranges varied from 0.25 to 5.0⯵gâ¯L-1. Excellent limits of quantification (0.58-0.87⯵gâ¯kg-1), mean recoveries (91-103%), and repeatability and intermediate precision (<5.8%) were obtained. Twenty-two samples of bovine and non-bovine cheeses were analyzed. Twenty-one samples showed residues of at least one ML (between 0.59 and 15.3⯵gâ¯kg-1), but moxidectin was never detected; a sample of mozzarella was free of MLs. To the best of our knowledge, this is the first method describing the simultaneous evaluation of these MLs in cheese using HPLC and fluorescence detection.
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Queso/análisis , Análisis de los Alimentos/métodos , Lactonas/análisis , Lactonas/aislamiento & purificación , Límite de Detección , Compuestos Macrocíclicos/química , Espectrometría de Fluorescencia , Animales , Antibacterianos/análisis , Antibacterianos/química , Antibacterianos/aislamiento & purificación , Bovinos , Cromatografía Líquida de Alta Presión , Frío , Contaminación de Alimentos/análisis , Lactonas/química , Extracción en Fase Sólida , Factores de TiempoRESUMEN
The interest in charcoal for agricultural use (biochar) has sharply increased in recent years. However, biochar can contain groups of compounds such as polycyclic aromatic hydrocarbons (PAHs) that are considered persistent pollutants, and are formed concomitantly with biochar during its production by pyrolysis. Soil samples were collected in three experimental areas at different intervals (1, 3, 5 or 6 years) after the application of 16â¯Mgâ¯ha-1 of biochar. The total concentrations of PAHs; benzo[a]pyrene; and the estimated total cancer risk in biochar treated plots were larger than found in the control ones, but they decreased over time, equaling the control values after three years in the high C content soil (11.2â¯gâ¯C kg-1 soil), or after six years in the low C content soil (6.8â¯gâ¯C kg-1 soil). Nevertheless, the sum of PAH concentrations found in the biochar amended plots, in the range of 15.80-39.40â¯ngâ¯g-1, were around two orders of magnitude below the limits of prevention established by Brazilian legislation (8100â¯ngâ¯g-1) and some European regulations for soils (3000â¯ngâ¯g-1) and also lower than the observed in previous studies about biochar amended soils. Our results indicate that, under the conditions evaluated, the application of biochar to soil in the studied proportion (16â¯Mgâ¯ha-1, every six years) is safe concerning soil contamination by PAHs.
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Carbón Orgánico/química , Hidrocarburos Policíclicos Aromáticos/química , Contaminantes del Suelo/química , Agricultura , Brasil , Contaminación Ambiental , Suelo/química , Factores de TiempoRESUMEN
The present work reports the variation of 31 carbonyl compounds (CC) in an apartment located at Niterói City, Rio de Janeiro State, Brazil. Eight sampling campaigns were conducted through a 1-year period, and three areas (living room, kitchen, and bedroom) were evaluated before, during, and after the renovation activities and reoccupation of the apartment. Samples were collected using SEP-PAK cartridges impregnated with 2,4-dinitrophenylhydrazine, and the hydrazones were analyzed using rapid resolution liquid chromatography with UV detection. The lowest total concentration of CC (19.0 ± 1.5 µg m(-3)) was found before the renovation when the apartment was empty, but door varnishing resulted in highest contamination of the apartment (1386 ± 384 µg m(-3)); however, an important dispersion of CC was observed in the subsequent sampling (148 ± 1.8 µg m(-3)). After apartment reoccupation, the indoor contamination seemed to depend on the routine activities taken there, such as household product use and cooking activities, but apparently, local temperature increase favored the vaporization of the volatile CC from the building materials in the apartment. As far as we are concerned, this is the first study comparing the concentrations of 31 CC in residential areas before, during, and after renovation activities taken in Brazil.
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Contaminación del Aire Interior/análisis , Compuestos Orgánicos/análisis , Brasil , Materiales de Construcción/análisis , Culinaria , Vivienda , HumanosRESUMEN
Diabetic retinopathy (DR), the main cause of blindness among diabetic patients, affects both neuronal and vascular cells of the retina. Studies show that neuronal cell death begins after 4 weeks of diabetes and could be related with an increase in oxidative stress. System [Formula: see text] is a glutamate/cystine exchanger, formed by a catalytic subunit called xCT and a regulatory subunit 4F2hc, whose activity is crucial to the synthesis of glutathione, which is a key antioxidant molecule for cells. Although some studies have shown that glutamate transport mediated by excitatory amino acid transporters (EAATs) in diabetic rats is downregulated, there are no studies investigating system [Formula: see text] in this context. To evaluate whether system [Formula: see text] is modified by early onset of diabetes, primary retinal cell culture exposed to high glucose and retinas of rats 3 weeks after streptozotocin injection were used. We observed that xCT subunit protein expression both in cultures and in vivo were diminished. Furthermore, system [Formula: see text] activity and GSH levels were also decreased whereas oxidative stress was increased in retinas of diabetic animals. Therefore, this study raises the possibility that alterations in system [Formula: see text] expression and activity could occur during early onset of diabetes. In that way, system [Formula: see text] modifications could be related to increased ROS in diabetic retinopathy.
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Diabetes Mellitus Experimental/metabolismo , Retinopatía Diabética/metabolismo , Glutatión/metabolismo , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo , Retina/metabolismo , Animales , Animales Recién Nacidos , Western Blotting , Muerte Celular , Células Cultivadas , Diabetes Mellitus Experimental/patología , Retinopatía Diabética/patología , Ácido Glutámico/metabolismo , Inmunohistoquímica , Masculino , Ratas , Retina/patología , Factores de TiempoRESUMEN
Macrocyclic lactones (ML) are commonly used in drug formulations for the treatment of parasites in cattle. In Brazil, except for drugs (or formulations) with long-term (half-life) effects, ML are registered for use in bovines. Indiscriminate use of ML may result in the presence of residues in milk and dairy products due to their lipophilic properties and thermal stability. This study applied a method of liquid chromatography with fluorimetric detection, recently developed and validated for the determination of residues of abamectin, doramectin, ivermectin, and moxidectin in butter. The method was applied to 38 samples of commercial butter purchased in the metropolitan area of Rio de Janeiro, Brazil, between June and September 2013, analyzed in triplicate. Ivermectin was detected in 89.5% of the samples, with concentrations between 0.3 and 119.4 µg/kg; 76.3% of the samples contained doramectin (0.6 to 64.7 µg/kg) and 55.2% contained abamectin (0.7 to 4.5 µg/kg). Most butter samples (76.3%) contained residues of more than 1 ML; however, no residues of moxidectin were detected. The results showed a high incidence of the presence of avermectins in butter samples. Butter is not included in the Brazilian National Plan for Control of Residues and Contaminants in Animal Products. As ML residues concentrate in lipophilic compounds, butter and other fatty dairy products should be screened for the presence of ML residues.
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Antiparasitarios/química , Mantequilla/análisis , Residuos de Medicamentos/análisis , Análisis de los Alimentos , Lactonas/química , Animales , Brasil , Bovinos , Cromatografía Liquida/métodos , Leche/químicaRESUMEN
A method based on CZE for the determination of glutamic acid, glycine, and alanine in a biopharmaceutical formulation containing recombinant human erythropoietin was developed. The separation was achieved within less than 5 min, using a fused-silica capillary column (55 cm × 50 µm id) and 30 mmol/L phosphate buffer at pH 11.5, containing 0.6 mmol/L CTAB and 10% v/v methanol, as BGE solution. Applied potential of -25 kV, temperature of 15°C and hydrodynamic injection time of 15 s, at 50 mbar, were employed. The detection of the analytes was carried out without any derivatization reaction, at 220 nm using an UV-DAD detector. Linear ranges from 50 to 2500 mg/L and quantification limits of 40, 39, and 37 mg/L were obtained for glutamic acid, glycine, and alanine, respectively. Sample preparation required only a dilution step. Considering peak area and migration time values, the method presented good repeatability (RSD <1.7%; n = 9) and intermediate precision (RSD <1.0%; n = 6). Recovery evaluation using a commercial sample led to values between 97.5 ± 5.2% and 101.5 ± 4.6%, demonstrating the feasibility of the method, which was successfully applied in the quantification of the amino acids of interest in biopharmaceutical samples.
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Aminoácidos/análisis , Eritropoyetina/química , Proteínas Recombinantes/química , Anemia/tratamiento farmacológico , Electroforesis Capilar/métodos , Eritropoyetina/análisis , Eritropoyetina/uso terapéutico , Humanos , Concentración de Iones de Hidrógeno , Límite de Detección , Modelos Lineales , Proteínas Recombinantes/análisis , Proteínas Recombinantes/uso terapéutico , Reproducibilidad de los ResultadosRESUMEN
This study describes the determination of 30 carbonyl compounds (CCs) in three areas (bus boarding platform, passenger circulation area, and a pastry shop) of the Presidente João Goulart Bus Terminal, located at Niterói City, RJ, Brazil, and in an open area 700 m distant from the terminal. Samples were collected using SEP-PAK cartridges impregnated with 2,4-dinitrophenylhydrazine, during May to July 2012. The hydrazones formed were analyzed using rapid resolution liquid chromatography with UV detection. The studied locations showed distinct profiles of distribution of CC. The circulation area, which is influenced by different pollution sources, presented an intermediate profile between that of the pastry shop and boarding platform. Formaldehyde and acetaldehyde were the most abundant CC, but acetaldehyde predominated in the pastry shop once it is a by-product of baking yeast fermentation. Samples taken in the pastry shop and circulation area showed significant concentrations of hexanaldehyde and nonanaldehyde emitted during cooking. The pastry shop showed the largest level of total CC among the studied areas followed by the circulation area, the boarding platform, and the open area.
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Monitoreo del Ambiente/métodos , Contaminantes Ambientales/química , Vehículos a Motor , Transportes , Brasil , Compuestos Orgánicos , Emisiones de Vehículos/análisisRESUMEN
PAHs and BTEX were studied in groundwater from monitoring wells of gasoline stations of Rio de Janeiro City, Brazil during 2003 and 2004. Total PAH concentration ranged from 0.05 to 84.9 microg/L. Total BTEX concentration varied between not-detected to 3.6 x 10(3) microg/L. Some samples exceeded the maximum concentration limit of Brazilian regulations for benzene in fresh or drinking water. Carcinogenic PAHs were found in few samples but only one sample in each year exceeded the regulated concentrations for benzo[a]pyrene. The concentrations of PAHs and BTEX indicate that some places may be contaminated by gasoline leakage.