21 research outputs found

    Determination of copper and alcohol contents in sugar cane spirits produced in the state of Minas Gerais, Brazil.

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    The objective of this work was to investigate if producers of sugar cane spirits in Minas Gerais, Brazil, have improved the copper content of their products and also if they have adjusted to the new standards of identity for ?cacha?a? and ?aguardente?. Seventy-one samples, obtained from May 2003 until March 2004, were analyzed. Mean copper content was 2.30 mg/L, which indicates a significant reduction in levels. The mean alcohol content was 45.6 % v/v. All of the ?aguardente? but only 79% of the ?cacha?a? attended to the standard of identity for alcohol content for these products

    High resolution mass spectrometry elucidation of captopril?s ozonation and chlorination by-products.

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    The article evaluated the degradation of the captopril in aqueous solution after ozonation and chlorination. The process was continuously monitored focusing on the identification, mass spectrometry and elucidation of its by-products by applying direct infusion and high performance liquid chromatography, electrospray ionization high resolution mass spectrometry, in the negative ion mode. The cytotoxicity of its by-products solutions were evaluated with 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. It was observed through that after 30 min of ozonation and chlorination, there was complete oxidation of captopril, i .e ., 100% removal efficiency. At these conditions, the rate of mineralization, by total organic carbon, was only 7.63% for ozonation and 6.40% for chlorination, evidencing the formation of degradation by-products. Ten captopril by-products were identified and their respective chemical structures elucidations are proposed. The treated samples and their by-products were nontoxic to HepG2 cells by MTT assay

    Nutrition status and quantification of blood minerals by TXRF spectroscopy in vegetarian and non-vegetarian university students.

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    This study investigated whether university students following a vegetarian diet differed from non-vegetarian students in nutrient intake, biochemical, hematological and blood mineral profile of nutritionally relevant elements. In total, 107 students from a university, following either a non-vegetarian or a vegetarian diet for at least 1 year prior to the study, were recruited in two stages, setting up two experiments. Nutrient intake (experiment 1, n = 58), and biochemical and hematological parameters (experiment 2, n = 49) were evaluated. TXRF spectroscopy was used for determination of trace elements in whole blood. Vegetarians showed differences in nutrient intake, mainly higher consumption of unsaturated fatty acids and fiber. No significant differences in the biochemical and hematological parameters were found. The prevalence of abnormal parameters in a considerable number of vegetarians and non-vegetarians were found, mainly regarding high density lipoprotein (HDL-c) and total cholesterol (TC). TXRF spectroscopy proved to be a simple tool for determining nutrition-relevant elements (K, Fe, Cu and Zn) in blood samples. The high incidence of abnormal parameters, regardless of the dietary pattern, raises concern about the high prevalence of bad eating habits among young university students. Particularly for the vegetarian students, these results may partly counteract the beneficial lifestyle of a vegetarian diet evidenced by previous studies. It is important for students to be aware of its potential nutritional limitations. In this context, food and nutrition education programs in the academic context could contribute to set up autonomous and healthy subjects, regardless of the diet chosen

    Effect of cooking method on the formation of 7-ketocholesterol in Atlantic hake (Merluccius hubbsi) and smooth weakfish (Cynoscion leiarchus) fillets.

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    The levels of cholesterol and 7-ketocholesterol were measured in raw Atlantic hake (Merluccius hubbsi) and smooth weakfish (Cynoscion leiarchus) fillets and in fillets subjected to the following cooking methods: baking in an electric or microwave oven; baking, grilling or stewing in a steam-convection oven; simmering on a stove; electric grilling; and deep frying. The raw samples from both fishes exhibited significantly (p < 0.05) higher cholesterol levels (62.71 ? 6.06 mg/100 ge74.16 ? 3.96 mg/ 100 g) than the processed fillets. In all of the samples, 7-ketocholesterol was detected at significantly (p < 0.05) different levels depending on the cooking method and the type of fish. Steam cooking keeping the surface of the product moist produced small decrease in the cholesterol content (26.65%e29.96%) and a low level of 7-ketocholesterol in the samples (6.90 ? 0.21 mg/ge6.47 ? 0.28 mg/g). Baking in electric or steam-convection ovens at high temperatures and long times greatly reduced the cholesterol content (52.77%e65.08%), which was associated with a large increase in 7-ketocholesterol levels (11.54 ? 0.45 mg/ge13.94 ? 1.17 mg/g). These results indicate the necessity of revising the baking procedures for fish to increase the healthiness of food

    Influence of harvest season and maturation of different sugarcane (Saccharum spp.) cultivars on the chemical composition of alembic Brazilian sugarcane spirit.

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    Contrary to the ethanol industrial production, the quality and composition of sugar cane as raw material for the production of alembic cacha?a have until now not been completely addressed. This work evaluated the influence of five different sugarcane cultivars and degree of maturation over the physicochemical composition of cacha?a produced under strict controlled conditions. Three harvest seasons were used in order to obtain different stages of maturation. The sugarcane quality was assessed by the juice brix, sugarcane POL, reducing sugars, and purity. The cultivars quality did not differ within each harvest stage. However, significant quality differences were observed among sugarcane harvested in June and the other harvest months, particularly on reducing sugar content. This indicates different stages of sugarcane maturation. The 45 samples of cacha?a produced from those sugarcanes were submitted to physicochemical and gas chromatography/mass spectrometry (GC/MS) qualitative analysis. The GC/MS composition pattern showed that the type of cultivar did not alter the composition of the cacha?a at the same harvest stage. Otherwise, the production of acetic acid, ethyl lactate and nbutyl alcohol was higher in the first harvest (June) when compared to the others. The results from sugar cane quality and GC/MS when submitted to principal component analysis (PCA) showed consistently the separation between the groups of cacha?a produced in the three seasons, indicating the influence of sugarcane ripening over the cacha?a composition

    Determination of nine pharmaceutical active compounds in surface waters from Paraopeba River Basin in Brazil by LTPE-HPLC-ESI-MS/MS.

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    A simple, inexpensive, versatile, and environment-friendly extraction method, using low-temperature partitioning extraction (LTPE), was validated to quantify pharmaceutical-active compounds (PhACs) in surface water samples by high-performance liquid chromatography coupled to electrospray ionization tandem mass spectrometry (HPLC-ESI-MS/MS). The PhACs analyzed were acetaminophen, bezafibrate, diclofenac, diltiazem, fluconazole, linezolid, miconazole, ondansetron hydrochloride, and trimethoprim. The detection and quantification limits ranged from 0.15 to 12.30 ng L?1 and 0.43 to 40.60 ng L?1, respectively. Recovery rates ranged from 46 to 135%, and relative standard deviation (RSD%) varied between 0.49 and 6.13%. This method was applied to monitor water contamination by PhACs in the Paraopeba River Basin (PRB), Minas Gerais state, Brazil. All PhACs, except linezolid which was not detected, were found in PRB water samples in concentrations that ranged from 2.6 ng L?1 to 2.62 ?g L?1

    Validation of a liquid chromatography methodology for the analysis of seven volatile fatty acids intermediates of anaerobic digestion.

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    ?cidos graxos vol?teis (AGV) s?o importantes compostos intermedi?rios indicadores da digest?o anaer?bia. Este artigo apresenta dados de valida??o de uma metodologia para an?lise de uma mistura de sete AGV (C1 a C5) em amostras ambientais por cromatografia l?quida de alta efici?ncia (CLAE). Foi utilizada uma coluna de exclus?o i?nica a 55?C, volume de inje??o de 10 ?L e fase m?vel (0,01 mol.L-1 H2SO4) a 0,6 mL.min-1. Os crit?rios de valida??o foram: limites de detec??o e de quantifica??o, que ficaram na faixa de 5,0 a 10 mg.L-1 e 15 a 30 mg.L-1, respectivamente; linearidade (comprovada para todos os ?cidos); repetitividade e sensibilidade (muito boa para a maioria dos ?cidos); efeito de matriz (efeito de supress?o observado para o ?cido isobut?rico) e exatid?o (85 a 104%). Sendo assim, as condi??es operacionais adotadas se mostraram v?lidas para a quantifica??o de AGV em efluentes de reatores anaer?bios.Volatile fatty acids (VFA) are important intermediate compounds that somehow indicate the efficiency of anaerobic systems. This paper presents results of method validation for seven VFA (C1 to C5) analysis in environmental samples by high performance liquid chromatography (HPLC). It was used an ion exclusion column kept at 55?C; injection volume of 10 ?L and mobile phase (0.01 mol.L-1 H2SO4) at 0.6 mL.min-1. The validation criteria adopted were: limits of detection and quantification, that fell in the ranges of 5.0 ?10 mg.L-1 and 15?30 mg.L-1, respectively; linearity (verified for all acids); repeatability and sensibility (very good for most acids); matrix effect (suppression effect observed for isobutyric acid) and accuracy (from 85 to 104%). Therefore, the operational conditions adopted seemed to be adequate and valid to measure VFA in samples from anaerobic reactors

    Validation of a new high-throughput method to determine urinary S-phenylmercapturic acid using low-temperature partitioning extraction and ultra high performance liquid chromatography?mass spectrometry.

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    A new highly sensitive and environmentally friendly analytical method, using low-temperature partition extraction and ultra-high-performance liquid chromatography with tandem mass spectrometry, without the use of a labeled analyte, was developed and validated to determine and quantify urinary Sphenylmercapturic acid in urine samples. TheWorld Health Organization, in its guidelines for air quality in Europe, recognizes that benzene is carcinogenic to humans and there is no safe level of exposure. Urinary S-phenylmercapturic acid is a sensitive and specific biological marker of exposure to benzene. The new analytical method, extraction, and analysis, were linear in the working range between 0.1 and 200.0 ?g/L, precise (relative standard deviation lower than 6.0%), accurate (97.0?105.0%), and sensitive. The method?s limits of detection and quantification were 0.02 and 0.084 ?g/L, respectively. The recovery with the lowtemperature partition extraction was 96.1%, with relative standard deviation less than 3.8%. The method is simple, accurate, and reproducible, and has been successfully applied in the evaluation of nonoccupational exposure to benzene, by urinary S-phenylmercapturic acid in urine samples

    Method for the determination of benzene metabolite t,t-Muconic acid in urine by HPLC-UV with an Ion exclusion column.

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    The benzene metabolite trans,trans-muconic acid (tt-MA) is widely used as a biological indicator of exposure to this xenobiotic. An analytical method was developed and validated for the determination of urinary tt-MA using solid phase extraction onto a Strata SAX cartridge. The analysis was performed by HPLC with an Aminex HPX-87H ion exclusion column and a UV diode array detector. The sample preparation conditions were optimized using a 24 1 factorial design. Comparison of the slopes of standard analytical curves prepared in aqueous solution and urine showed that the biological matrix suppressed the tt-MA signal by around 50%, so the analytical curves were prepared with tt-MA standard at low concentrations in pooled urine. The analytical curves in the range of 5?500 g L 1 showed determination coefficients values (R2) > 0.99 for tt-MA standard in water and R2 > 0.98 for tt-MA standards in pooled urine. The coefficients of variation obtained using seven replicates were lower than 3.6%, and recoveries of tt-MA from solutions containing 5, 25, 50 and 100 g L 1 of the analyte were in the range 85%?90%, demonstrating the satisfactory precision and accuracy of the method. The limits of detection and quantification were 0.11 and 0.36 g L 1, respectively. The benefits of this new method developed is the possibility of complete chromatographic peak separation for the determination of tt-MA at baseline, without matrix components? interference as normally found in the C18 column. This is the first time that this chromatographic column has been used for the analysis of tt-MA in urine

    Behaviour of pharmaceuticals and endocrine disrupting chemicals in simplified sewage treatment systems.

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    This work assessed the behaviour of nine pharmaceuticals and/or endocrine disrupting chemicals (EDCs) in demo-scale upflow anaerobic sludge blanket reactors (UASB reactors) coupled to distinct simplified post-treatment units (submerged bed, polishing ponds, and trickling filters) fed on raw sewage taken from a municipality in Brazil. The dissolved concentration of the studied micropollutants in the raw and treated sewage was obtained using solid phase extraction (SPE) followed by analysis in a liquid chromatography system coupled to a hybrid high resolution mass spectrometer consisting of an ion-trap and time of flight (LC-MS-IT-TOF). The UASB reactors demonstrated that they were not appropriate for efficiently removing the assessed compounds from the sewage. Furthermore, this study demonstrated that the hydraulic retention time (HRT) was an important parameter for the removal of the hydrophilic and less biodegradable compounds, such as trimethoprim and sulfamethoxazole. The post-treatment units substantially increased the removal of most target micropollutants present in the anaerobic effluents, with a greater removal of micropollutants in simplified systems that require a large construction area, such as the submerged bed and polishing ponds, probably because of the higher HRT employed. Alternatively, compact post-treatment systems, such as trickling filters, tended to be less effective at removing most of the micropollutants studied, and the type of packing proved to be crucial for determining the fate of such compounds using trickling filters
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