Análise de sedimento de fundo: uma amostragem representativa do estuário Potengi/RN

The aim of this study is to quantify the presence of major and minor elements in the sediments of estuary Potengi. Four georeferenced sampling points were used in the study, at which sediment samples were collected in the channel of the river and on the right and left banks. In addition, dissolved oxygen, salinity and water conductivity were taken in situ at the time of sample collection. The percentage of organic matter, determined by gravimetry, and granulometric analysis of the sediment samples were conducted in the laboratory. To quantify the major and minor elements a prior test to open the sample was conducted with standard NIST 1646ª estuarine sediment to choose the best methodology to be adopted. The sediment samples were dissolved in microwaves with nitric acid and chloridric acid, according to methodology proposed by US EPA 3051ª. Quantitative analyses of the elements Al, Fe, Cd, Cr, Cu, Mn, Ni, Pb and Zn were conducted by inductively coupled plasma optical emission spectrometry (ICPOES). The results showed that the partial concentrations of the elements analyzed are below average worldwide shale levels, the standard described by Turekian and Wedepohl (1961)

efeito da aplicação de uma solução salina no crescimento e na composição química da atriplex nummularia

This study aimed to analyze the effect of a saline solution on growth and chemical composition of Atriplex nummularia, shrubby plant, absorbing salts used in the diet of animals and the management of water and saline soils. These plant seedlings were planted and grown in a reserved area at the Federal University of Rio Grande do Norte. The plantation was divided into two blocks, in which one of them was irrigated with saline solution with a concentration of 2840 mgL-1 of NaCl and the second group was irrigated with drinking water. After six months, the plants were collected, harvested and divided into three parts: leaf, thin and thick stem. Monthly, dimension measurements were carried out for cataloging the growth of Atriplex. Ion Chromatography (IC) and Optical Emission Spectroscopy Inductively Coupled Plasma (ICP-OES) were used to analyze the chemical composition of the partition plant parts. The results of these analyses revealed that an absorption process of anions and cations by Atriplex nummularia plant during its growth was achieved, in particular by a higher concentration of sodium and chloride ions. Scanning electron microscopy images showed and confirmed the presence of small crystals on the leaf surface. Electrical conductivity and pH measurements of the aerial parts of the plant were carried out and these results showed that the leaf is the plant part where there is a largest concentration of ions. In addition, measurements of specific surface were obtained from irrigated plants with saline solution, achieving higher surface area, in all cases. Plant dimensions obtained monthly showed that the plants irrigated with water grew 5% more than those plants irrigated with saline solution. Based on results obtained, Atriplex plant showed a higher potential to survive and adapt to environments (aquatic or geological) with high levels of salinity and this property can be used as a tool for removing salts/metals from industrial contaminated soils and effluents.

Determinação da composição química do molusco anadara notabilis encontrado em Galinhos no Rio Grande do Norte

Tendo em vista a grande biodiversidade existente no litoral brasileiro, onde muitas espécies ainda são pouco conhecidas, inclusive sob o aspecto nutricional, e considerando que os moluscos bivalves se constituem em um recurso natural de boa aceitação pela população mundial, escolheu-se o molusco bivalve Anadara notabilis, por não ter sido encontrado na literatura nenhuma informação nutricional ou toxicológica sobre ele e devido seu tamanho ser bem maior que outras espécies de moluscos mais popularmente encontrados nessa região. Foram determinados neste trabalho teores de umidade, cinzas, proteínas, macro e microminerais, além de íons metálicos de importância toxicológica. Todas as determinações seguiram as Normas Analíticas do Instituto Adolfo Lutz. A determinação de proteína foi realizada pelo método de Kjeldahl. Todos os íons metálicos foram determinados por espectroscopia de emissão ótica com plasma indutivamente acoplado (ICP-OES) descrito pela metodologia USEPA 6010C. Os resultados mostraram que a Anadara notabilis pode ser introduzida na alimentação dos seres humanos, tendo em vista sua riqueza mineral. Merecem destaque entre os macronutrientes o magnésio e o fósforo que apresentaram os respectivos valores em mg/kg 918,7 e 586,7. Com relação aos micronutrientes destacam-se o ferro presente com 586,7 mg/kg e o Zinco com 12,31 mg/kg. Não foi encontrado índice elevado de metais contaminantes para este molusco, o que impediria seu consumo, apenas o cromo esta 0,7 mg/kg acima do valor estabelecido pela legislação brasileira. Os resultados obtidos certamente serão muito úteis em futuras pesquisas nutricionais e para construção de uma tabela brasileira de composição química de alimentos

Determinação da composição química do molusco Anadara notabilis encontrado em Galinhos no Rio Grande do Norte

Given the large existing biodiversity in the Brazilian coast, where many species are still little known, even under the nutritional aspect, and considering that bivalve molluscs are constituted by a natural resource of well accepted by the population, chose the bivalve Anadara notabilis, it was not found in the literature any nutritional or toxicological information about it and because its size is much larger than other species of mollusks commonly found in this region. Were studied moisture, ash, protein, macro and micro minerals, and metal ions of toxicological significance. All analytical determinations followed the standards of the Institute Adolfo Lutz. The protein determination was performed by the Kjeldahl method. All metal ions were determined by optical emission spectroscopy with inductively coupled plasma (ICP-OES) method described by USEPA 6010C. The results showed that Anadara notabilis can be introduced into food for human beings, in view of its mineral wealth. Noteworthy among the macronutrients phosphorus and magnesium showed that their values in mg / kg 918.7 and 586.7. With regard to micronutrients stand out with this iron 586.7 mg / kg and zinc with 12.31 mg / kg. Was not found high content of metal contaminants to this mollusc, which would prevent their use, only this chromium 0.7 mg / kg above the value established by Brazilian legislation. The results will certainly be very useful in future studies of nutrition and to build a table of chemical composition of Brazilian foods

Monitoramento das águas da bacia hidrográfica pirangi pela determinação dos índices de qualidade da água-iqa e índice de toxidez-it

The problems of water supply in Northeast Brazil are severe and require more focused studies. This work was intended to assess water quality in the watershed Pirangi, located in the Northeastern state of the newborn using the Water Quality Index, AQI associated with the Index of Toxicity-IT. The data presented in this study were collected in November 2008, June 2009 and March 2010 at eight sampling stations distributed throughout the basin. The study covered nine parameters, based on guidelines established by CETESB, and seven members of Metal Toxicity index-IT. These waters are framed in the classification between GOOD and BAD showing AQI 41.34 minimum and a maximum of 76.23. Virtually all seven metals analyzed were below the detection limits of ICP-OES giving IT a water equal to one when they are absent and 0 when there are levels of trace metals

Avaliação da influência da matéria orgânica, na determinação quantitativa de metais em amostras de sedimento, por espectrometria de absorção atômica e análise de metais traços por fluorescência de raios-X

The proposal of this work is to evaluate the influence of the organic matter on the results of the analyses of the metals (Zn, Pb, Al, Cu, Cr, Fe, Cd e Ni) for Atomic Absorption Spectrometry (AAS), so much in the extraction stage as in the reading using for that the chemometrics. They were used for this study sample of bottom sediment collected in river Jundiaí in the vicinity of the city of Macaíba-RN, commercial humus and water of the station of treatment of sewer of UFRN. Through the analyses accomplished by EAA it was verified that the interference of the organic matter happens in the extraction stage and not in the reading. With relationship to the technique of X Ray Fluorescence Spectrometry (XRFS), the present work has as intended to evaluate the viability of this technique for quantitative analysis of trace metals (Cr, Ni, Cu, Zn, Rb, Sr and Pb) in having leached obtained starting from the extraction with acqua regia for an aqueous solution. The used samples constitute the fine fraction (<0.063 mm) of sediments of swamp of the river Jundiaí. The preparation of tablets pressed starting from the dry residue of those leached it allowed your analysis in the solid form. This preliminary study shows that, in the case of the digestion chemistry partially of the fine fractions of bottom sediments used for environmental studies, the technique of applied EFRX to the analysis of dry residues starting from having leached with acqua regia, compared her it analyzes of the leached with ICP-OES, it presents relative mistakes for Cu, Pb, Sr and Zn below 10%

Determinação do teor de cálcio através da termogravimetria, em medicamentos utilizados no tratamento da osteoporose: um estudo comparativo

The present study utilized the thermogravimetry (TG) and optical emission spectroscopy with inductively coupled plasma - ICP / OES to determine the calcium content in tablets of carbonate, citrate and calcium lactate used in the treatment of osteoporosis. The samples were characterized by IR, SEM, TG / DTG, DTA, DSC and XRD. The thermal analysis evaluated the thermal stability and physical-chemical events and showed that the excipients influence the decomposition of active ingredients. The results of thermogravimetry indicated that the decomposition temperature of the active CaCO3 (T = 630.2 °C) is lower compared to that obtained in samples of the tablets (633.4 to 655.2 °C) except for sample AM 2 (Ti = 613.8 oC). In 500.0 °C in the samples of citrate and calcium lactate, as well as their respective active principles had already been formed calcium carbonate. The use of N2 atmosphere resulted in shifting the initial and final temperature related to the decomposition of CaCO3. In the DTA and DSC curves were observed endo and exothermic events for the samples of tablets and active ingredients studied. The infrared spectra identified the main functional groups in all samples of active ingredients, excipients and tablets studied, such as symmetric and asymmetric stretches of the groups OH, CH, C = O. Analysis by X-ray diffraction showed that all samples are crystalline and that the final residue showed peaks indicative of the presence of calcium hydroxide by the reaction of calcium oxide with moisture of the air. Although the samples AM 1, AM 2, AM 3 and AM 6 in their formulations have TiO2 and SiO2 peaks were not observed in X-ray diffractograms of these compounds. The results obtained by TGA to determine the calcium content of the drugs studied were satisfactory when compared with those obtained by ICP-OES. In the AM 1 tablet was obtained the content of 35.37% and 32.62% for TG by ICP-OES, at 6 AM a percentage of 17.77% and 16.82% and for AM 7 results obtained were 8.93% for both techniques, showing that the thermogravimetry can be used to determine the percentage of calcium in tablets. The technique offers speed, economy in the use of samples and procedures eliminating the use of acid reagents in the process of the sample and efficiency results.

Análises bromatológicas e fitoquímicas de frutos de Licania tomentosa (Benth) FRITSCH

This study conducted chemical analyzes of the fruits of Licania tomentosa Benth belonging to the Chrysobalanaceae family, order and superorder Rosiflorae Rosales. Samples were collected in February 2011 in the city of Natal - RN. The fruits were separated into peel, pulp and seed, and the samples were analyzed on moisture and ash by thermogravimetric methods, reducing and total sugars, lipids by Soxhlet extraction, minerals by ICP / OES and other analyzes by physical measurements of the fruit. The fruits for the analysis of determination of flavonoids and phenolic compounds were dried at 40 ° C and ground. For the analyzes to determine the content of phenolics and flavonols was used spectroscopy in the visible region, and also performed the characterization of ethanol extracts by high performance liquid chromatography and test for antioxidant activity hydroethanolic extracts. The results obtained are about 83.9% of the fruits have a length between 4.0 to 6.0 cm with respect to the diameter of the fruit about 97.4% of the fruits have a diameter between 2.0 - 4, 0 cm, mean weight of 36.14 g (7.86), the bark showed 60.5 (1.5)% relative humidity, the flesh 72.3 (0.9) and 44.4 seeds (0.4 )%, the bark showed 0.22 (0.00)% ash, the pulp 1.41 (0.01)% and the seed 1.18 (0.01)%, the bark showed 3.73 (0, 09) mg lipids / 100 g sample of the pulp 0.40 (0.04) and the seed 0.05 (0.00). With respect to reducing sugars and total gave the results, 16.23 (0.23) g/100g and 20.70 (0.24) g/100g. The fruit is presented with a good source of nutrients especially carbohydrates and lipids. The analysis for determining the antioxidant activity tests were performed reducing power and antioxidant capacity, the antioxidant capacity of hydroethanolic extracts of peel and pulp showed similar results, with higher concentrations however hydroethanolic bark extract. Regarding the content of phenolics and flavonoids hidroetanílico bark extract showed higher concentration values. The characterization of the extracts by high performance liquid chromatography identified the following compounds by retention time indicated by the race of the standards: galic acid, kaempferol and kaempferol derivatives. Considering the results of the fruit Licania tomentosa Benth may be an alternative food by analysis of their nutritional content and has substances with antioxidant action

Assinaturas antropogênicas de elementos maiores e traços em poeira urbana na cidade do Natal-RN

Although there are many studies on urban dust contamination by heavy metals in developed countries, little attention has been paid to this type of study in developing countries, including Brazil. Therefore, a series of investigations were performed to provide signatures of heavy metals in urban dust and assess the potential sources in the city of Natal - RN-Brazil. The fraction of these sediments was studied to pass through a sieve of 63 micrometers. For the study analyzed two groups of samples, one collected in September 2009 at the end of the rainy season (9 samples) and one collected in January 2010 in the dry season (21 samples). So in all, thirty sediment samples were collected from the street. Then, in Fluorescence Spectrometry X-rays were determined major elements SiO2, Na2O, K2O, Al2O3, MgO, P2O5, Fe2O3, MnO, TiO2 and CaO, and trace Rb, Cr, Ni, Cu, Zn, Sr and Pb by an ICPOES was determined Zn, V, Na, K, Ni, Mn, Mg, P, Fe, Cr, Cu, Pb, Ba, Ca and Al from leaching HCl 0.5 mol L-1 . The results of the concentrations of elements show that the greater presence of these occurs in the dry season, except for Si which is higher in the rainy season. Analyses by geoaccumulation Index (IGEO) Enrichment Factor (EF), Contamination Factor (CF), analysis correlation and Hierarchical Cluster, confirm that Zn, Cu and Pb is anthropogenic character. Zinc may be derived from various sources related to motor vehicles or the road signs and street grids. The elements Na, K, Mg and Ca may be related to droplets suspended in air containing cations and anions present in seawater (salty), common in Christmas throughout the year, brought by winds SE-NW. The elements Na, Mg, Ca and K are the most abundant in seawater and were analyzed in this study. This indicates that the source of these additional elements detected by analyzing the contamination factor may be the very sea. Moreover, Ni, Fe, Cr and Ba can be either as a source of anthropogenic geogênica. The source of Ca is different, because it comes in lime and paint (painting guides of buildings and streets) in construction materials, but may also be present in sediments in the fragments of shells or carbonate bioclasts common in the coastal area

Evaluation of Lines of Phosphorus and Potassium by High-Resolution Continuum Source Flame Atomic Absorption Spectrometry for Liquid Fertilizer Analysis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Characterization of humic-rich hydrocolloids and their metal species by means of competing ligand and metal exchange - an on-site approach

An improved on-site characterization of humic-rich hydrocolloids and their metal species in aquatic environments was the goal of the present approach. Both ligand exchange with extreme chelators ( diethylenetetraaminepentaacetic acid ( DTPA), ethylendiaminetetraacetic acid ( EDTA)) and metal exchange with strongly competitive cations (Cu(II)) were used on-site to characterize the conditional stability and availability of colloidal metal species in a humic-rich German bogwater lake ( Venner Moor, Munsterland). A mobile time-controlled tangential-flow ultrafiltration technique (cut-off: 1 kDa) was applied to differentiate operationally between colloidal metal species and free metal ions, respectively. DOC ( dissolved organic carbon) and metal determinations were carried out off-site using a home-built carbon analyzer and conventional ICP-OES ( inductively-coupled plasma-optical emission spectrometry), respectively. From the metal exchange equilibria obtained on-site the kinetic and thermodynamic stability of the original metal species ( Fe, Mn, Zn) could be characterized. Conditional exchange constants K ex obtained from aquatic metal species and competitive Cu(II) ions follow the order Mn > Zn >> Fe. Obviously, Mn and Zn bound to humic-rich hydrocolloids are very strongly competed by Cu( II) ions, in contrast to Fe which is scarcely exchangeable. The exchange of aquatic metal species (e.g. Fe) by DTPA/EDTA exhibited relatively slow kinetics but rather high metal availabilities, in contrast to their Cu(II) exchange.

Extraction and exchange behavior of metal species in therapeutically applied peat

The binding and availability of metals (Al, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Ni, Pb, Zn) in therapeutically applied peat (GroBes Gifhorner Moor, Sassenburg/North Germany) was characterized by means of a versatile extraction approach. Aqueous extracts of peat were obtained by a standardized batch equilibrium procedure using high-purity water (pH 4.5 and 5.0), 0.01 mol l(-1) calcium chloride solution, 0.0 1 mol l(-1) ethylenediaminetetraacetic acid (EDTA) and 0.01 mol l(-1) diethylenetriarnine pentaacetic acid (DTPA) solution as metal extractants. In addition, the availability of peat-bound metal species was kinetically studied by collecting aliquots of extracts after different periods of extraction time (5, 10, 15, 30, 60 and 120 min). Metal determinations were performed by atomic spectrometry methods (AAS, ICP-OES) and dissolved organic matter (DOM) was characterized by UV/Vis measurements at 254 and 436 nm, respectively. of the extractants studied Ca, Mg and Mn were the most available metals, in contrast to peat-bound Fe and Al. The relative standard deviation s(r) of the developed extraction procedures was mostly in the range of 4 to 20%, depending on the metal and its concentration in peat. A pH increase favored the extraction of metals and DOM from peat revealing complex extraction kinetics. Moreover, a competitive exchange between peat-bound metal species and added Cu(II) ions showed that > 100 mg of Cu(II) per 50 g wet peat was necessary to exchange the maximum of bound metals (e.g. 21.8% of Al, 3.9% of Fe, 79.0% of Mn, 81.9% of Sr, related to their total content). (C) 2002 Elsevier B.V. B.V. All rights reserved.

Speciation analysis of Sn(II) and Sn(IV) using baker's yeast and inductively coupled plasma optical emission spectrometry

The use of Saccharomyces cerevisiae as a substrate to selectively retain Sn(II) and Sn(IV) has been investigated. Several factors affecting the retention of the analytes by yeast, such as pH, amount of biomass, temperature and time of contact were evaluated. Based on this study, a method for determination of Sn(II) and Sn(IV) combining inductively coupled plasma optical emission spectrometry (ICP OES) and solid phase extraction using Saccharomyces cerevisiae is proposed. The procedure consists of the selective retention of Sn(IV) by yeast at pH = 2.0 while Sn(II) remains in solution. Determination of tin in the solid phase was easily carried out by submitting a slurry of the yeast (0.5 g/40 mL) directly to ICP OES. The precision of the extraction procedure was characterized by an RSD lower than 4%. The detection limits of tin (3 sigma) in the solid phase and the liquid phase were 1.1 and 0.7 mu g L-1, respectively. The proposed approach was evaluated for determination of Sn(II) and Sn(IV) in spiked river water and real samples of industrial waste water (untreated and treated). For all samples, recoveries of spiked Sn(II) and Sn(IV) were between 85 and 112%.

The use of silica-immobilized brown alga (Pilayella littoralis) for metal preconcentration and determination by inductively coupled plasma optical emission spectrometry

The brown alga Pilayella littoralis was used as a new biosorbent in an on-line metal preconcentration procedure in a flow-injection system. Al, Co, Cu and Fe were determined in lake water samples by inductively coupled plasma optical emission spectrometry (ICP-OES) after preconcentration in a silica-immobilized alga column. Like other algae, P. littoralis exhibited strong affinity for these metals proving to be an effective accumulation medium. Metals were bound at pH 5.5 and were displaced at pH < 2 with diluted HCl. The enrichment factors for Cu-II, Fe-III, Al-III and Co-II were 13, 7, 16 and 11, respectively. Metal sorption efficiency ranged from 86 to 90%. The method accuracy was assessed by using drinking water certified reference material and graphite furnace atomic absorption spectrometry (GFAAS) as a comparison technique. The column procedure allowed a less time consuming, easy regeneration of the biomaterial and rigidity of the alga provided by its immobilization on silica gel. (C) 2003 Elsevier B.V. All rights reserved.

On-line preconcentration and speciation analysis of Cr(III) and Cr(VI) using baker's yeast cells immobilised on controlled pore glass

A study was undertaken to evaluate Saccharonzyces cerevisiae as a substrate for the biosorption of Cr(III) and Cr(VI) aiming to the selective determination of these species in aqueous solutions. The yeast cells were covalently immobilised on controlled pore glass (CPG), packed in a minicolumn and incorporated in an on-line flow injection system. The effect of chemical and physical variables affecting the biosorption process was tested in order to select the optimal analytical conditions for the Cr retention by S. cerevisiae. Cr(III) was retained by the immobilised cells and Cr(VI) were retained by CPG. The speciation was possible by selective and sequential elution of Cr(III) with 0.05 mol L-1 HCl and 2.0 mol L-1 HNO3 for Cr(VI). The influence of some concomitant ions up to 20 mg L-1 was also tested. Quantitative determinations of Cr were carried out by means of inductively coupled plasma optical emission spectrometry (ICP OES). Preconcentration factors of 12 were achieved for Cr(III) and 5 for Cr(VI) when 1.7 mL of sample were processed reaching detection limits of 0.45 for Cr(III) and 1.5 mu g L-1 for Cr(VI). The speciation of inorganic Cr in different kinds of natural waters was performed following the proposed method. Spiked water samples were also analysed and the recoveries were in all cases between 81 and 103%. (c) 2005 Elsevier B.V. All rights reserved.