Exploring potentialities of the HR-CS FAAS technique in the determination of Ni and Pb in mineral waters

National Health Surveillance Agency (ANVISA) established in the decree number 54 maximum allowed levels for Ni and Pb in mineral and natural waters at 20 µg L-1 and 10 µg L-1, respectively. For screening analysis purposes, the high-resolution continuum source flame atomic absorption spectrometry technique (HR-CS FAAS) was evaluated for the fast-sequential determination of nickel and lead in mineral waters.Two atomic lines for Ni (232.003 nm - main and 341.477 nm - secondary) and Pb (217.0005 nm - main and 283.306 nm - secondary) at different wavelength integrated absorbance (number of pixels) were evaluated. Sensitivity enhanced with the increase of the number of pixels and with the summation of the atomic lines absorbances. The main figures of merit associated to the HR-CS FAAS technique were compared with that obtained by line-source flame atomic absorption spectrometry (LS FAAS). Water samples were pre-concentrated about 5-fold by evaporation before analysis. Recoveries of Pb significantly varied with increased wavelength integrated absorbance. Better recoveries (92-93%) were observed for higher number of pixels at the main line or summating the atomic lines (90-92%). This influence was irrelevant for Ni, and recoveries in the 92-104% range were obtained in all situations.

Flow-batch analyser for preparation of calibration standard mixtures in simultaneous multicomponent spectrometric analysis

The application of multivariate calibration techniques to multicomponent analysis by UV-VIS molecular absorption spectrometry is a powerful tool for simultaneous determination of several chemical species. However, when this methodology is accomplished manually, it is slow and laborious, consumes high amounts of reagents and samples, is susceptible to contaminations and presents a high operational cost. To overcome these drawbacks, a flow-batch analyser is proposed in this work. This analyser was developed for automatic preparation of standard calibration and test (or validation) mixtures. It was applied to the simultaneous determination of Cu2+, Mn2+ and Zn2+ in polyvitaminic and polymineral pharmaceutical formulations, using 4-(2-piridilazo) resorcinol as reagent and a UV-VIS spectrophotometer with a photodiode array detector. The results obtained with the proposed system are in good agreement with those obtained by flame atomic absorption spectrometry, which was employed as reference method. With the proposed analyser, the preparation of calibration and test mixtures can be accomplished about four hours, while the manual procedure requires at least two days. Moreover, it consumes smaller amounts of reagents and samples than the manual procedure. After the preparation of calibration and test mixtures, 60 samples h-1 can be carried out with the proposed flow-batch analyser.

Effects of aluminum sulfate on delta-aminolevulinate dehydratase from kidney, brain, and liver of adult mice

The purpose of the present study was to investigate the in vitro and in vivo effects of aluminum sulfate on delta-aminolevulinic acid dehydratase (ALA-D) activity from the brain, liver and kidney of adult mice (Swiss albine). In vitro experiments showed that the aluminum sulfate concentration needed to inhibit the enzyme activity was 1.0-5.0 mM (N = 3) in brain, 4.0-5.0 mM (N = 3) in liver and 0.0-5.0 mM (N = 3) in kidney. The in vivo experiments were performed on three groups for one month: 1) control animals (N = 8); 2) animals treated with 1 g% (34 mM) sodium citrate (N = 8) and 3) animals treated with 1 g% (34 mM) sodium citrate plus 3.3 g% (49.5 mM) aluminum sulfate (N = 8). Exposure to aluminum sulfate in drinking water inhibited ALA-D activity in kidney (23.3 ± 3.7%, mean ± SEM, P<0.05 compared to control), but enhanced it in liver (31.2 ± 15.0%, mean ± SEM, P<0.05). The concentrations of aluminum in the brain, liver and kidney of adult mice were determined by graphite furnace atomic absorption spectrometry. The aluminum concentrations increased significantly in the liver (527 ± 3.9%, mean ± SEM, P<0.05) and kidney (283 ± 1.7%, mean ± SEM, P<0.05) but did not change in the brain of aluminum-exposed mice. One of the most important and striking observations was the increase in hepatic aluminum concentration in the mice treated only with 1 g% sodium citrate (34 mM) (217 ± 1.5%, mean ± SEM, P<0.05 compared to control). These results show that aluminum interferes with delta-aminolevulinate dehydratase activity in vitro and in vivo. The accumulation of this element was in the order: liver > kidney > brain. Furthermore, aluminum had only inhibitory properties in vitro, while in vivo it inhibited or stimulated the enzyme depending on the organ studied.

Pharmacokinetic and parasitological evaluation of the bone marrow of dogs with visceral leishmaniasis submitted to multiple dose treatment with liposome-encapsulated meglumine antimoniate

The aim of the present study was to evaluate the impact of a multiple dose regimen of a liposomal formulation of meglumine antimoniate (LMA) on the pharmacokinetics of antimony in the bone marrow of dogs with visceral leishmaniasis and on the ability of LMA to eliminate parasites from this tissue. Dogs naturally infected with Leishmania chagasi received 4 intravenous doses of either LMA (6.5 mg antimony/kg body weight, N = 9), or empty liposomes (at the same lipid dose as LMA, N = 9) at 4-day intervals. A third group of animals was untreated (N = 8). Before each administration and at different times after treatment, bone marrow was obtained and analyzed for antimony level (LMA group) by electrothermal atomic absorption spectrometry, and for the presence of Leishmania parasites (all groups). There was a significant increase of antimony concentration from 0.76 µg/kg wet organ (4 days after the first dose) to 2.07 µg/kg (4 days after the fourth dose) and a half-life of 4 days for antimony elimination from the bone marrow. Treatment with LMA significantly reduced the number of dogs positive for parasites (with at least one amastigote per 1000 host cells) compared to controls (positive dogs 30 days after treatment: 0 of 9 in the LMA group, 3 of 9 in the group treated with empty liposomes and 3 of 8 in the untreated group). However, complete elimination of parasites was not achieved. In conclusion, the present study showed that multiple dose treatment with LMA was effective in improving antimony levels in the bone marrow of dogs with visceral leishmaniasis and in reducing the number of positive animals, even though it was not sufficient to achieve complete elimination of parasites.

Lead and cadmium content of Brazilian beers

The elements called heavy metals when ingested are not completely eliminated from animal bodies and are responsible for chronic and acute intoxications. Sixty-three samples of beer, produced in the states of São Paulo, Paraná, Rio de Janeiro, Rio Grande do Sul, Minas Gerais, and Pará, were analysed for lead and cadmium content by atomic absorption spectrometry with graphite furnace atomization and Zeeman correction. The concentrations of Pb and Cd of dark differed significantly from light beers, being higher in the former. No significant difference was found between the beers produced in predominantly rural areas and the ones produced in industrialized areas. The concentrations of lead and cadmium in all samples were bellow the maximum accepted by present Brazilian regulations and ranged from not detected to 290mugPb/L and from not detected to 14.3mugCd/L. The average concentrations were 37mugPb/L and 1.6mugCd/L.

Development of gluten-free cookie from medicinal plants (Guaraná - Paullinea cupana and Catuaba - Anemopaegma mirandum) aiming at copper, iron, and zinc supplementation

Two flavors of cookies were developed (savory and peppery) containing a mixture of plants such as "guaraná" (Paullinia cupana) and "catuaba" (Anemopaegma mirandum). A test of acceptance and buying intention was applied to 48 consumers through a structured hedonic scale of 9 points. Afterwards, the centesimal compositions of these cookies were obtained as well as their total contents of copper, iron, and zinc through the method of atomic absorption spectrometry with flame. Sensorial tests indicated that the cookies presented good acceptance with potential to sensorial growth. The amount of fibers in the samples, 3 g/100 g, surpassed expectations since the product was not invented with the intention of being a source of this nutrient. The total amount of copper (0.41 mg.100 g-1), iron (4.50 mg.100 g-1), and zinc (1.32 mg.100 g-1) was considered good. The cookies produced can be considered good sources of fibers, copper, iron, and zinc. Furthermore, they are beneficial to people affected by celiac disease because they lack gluten. They also present functional properties. In addition, the medicinal plants used are considered energetic.

Sugar fractionation and pectin content during the ripening of guava cv. Pedro Sato

Guava is one of the most complete and balanced fruits in in terms of s nutritional value. Highly perishable, due to its intense metabolism during ripening, its shelf life can reach 3 to 5 days under room temperature. The firmness of the green and mature fruits is due mainly to the pectin polymers. The loss of firmness during the guava ripening is due to hydrolytic enzyme activity, which promotes intense solubilization of the cell wall pectins. Given the above, with the purpose of trying to explain the rapid firmness decrease, the centesimal composition and sugar fraction of the guava fruit were determined during ripening at room temperature. The guavas were picked at the half-mature stage and stored for 8 days at 22 ± 1 ºC and 78 ± 1% relative humidity. The analyses conducted were: centesimal composition, sugar fractionation, and infrared absorption spectrometry. The results showed that the guava sugars did not vary during ripening. The estimated pectin levels (5.7%) were higher than those mentioned in the literature (2.4%), which can better explain the role of the pectin in the fruit firmness.

Cadmium determination in Lentinus edodes mushroom species

Many studies have drawn attention to the occurrence and concentration of toxic elements found in the fruiting body of mushrooms. Some edible mushroom species are known to accumulate high levels of inorganic contaminants, mainly cadmium, mercury, and lead. There are about 2,000 known edible mushroom species, but only 25 of them are cultivated and used as food. In Brazil, the most marketed and consumed mushroom species are Agaricus bisporus, known as Paris champignon, Lentinus edodes, or Shitake and Pleurotus sp, also called Shimeji or Hiratake. In this study, the concentration of cadmium was determined in Lentinus edodes mushrooms from different cities in São Paulo state and some samples imported from Japan and China. The analyses were performed by graphite furnace atomic absorption spectrometry after HNO3-H2O2 digestion. The results showed a lower concentration of Cd in the mushrooms cultivated in São Paulo (0.0079 to 0.023 mg.kg-1 in natura) than that of the mushrooms cultivated abroad (0.125 to 0.212 mg.kg-1 in natura). Although there is no tolerance limit for Cd in mushrooms in Brazil, the results show that Lentinus edodes mushrooms can be safely consumed.

Physicochemical properties and mineral and protein content of honey samples from Ceará state, Northeastern Brazil

This study evaluated the physicochemical properties and protein and mineral content of honey samples from Ceará State, Northeastern Brazil, one of the major honey exporters in the country. Nutritional importance of the minerals detected was also analyzed. Physicochemical properties were examined according to the AOAC and CAC official methods; the protein content was determined using the Bradford method, and the minerals were analyzed by atomic absorption spectrometry. All analyses were performed in triplicate. The levels of macrominerals sodium (Na), potassium (K), calcium (Ca), and magnesium (Mg) varied from 1.80-47.20, 21.30-1513.30, 14.58-304.82, and 2.48-28.33 mg/kg, respectively, and the trace elements iron (Fe), copper (Cu), manganese (Mn), zinc (Zn), selenium (Se), and chromium (Cr) varied from 0.12-8.76, 0.07-1.29, 0.06-1.96, 0.07-1.85 mg/kg, 0.36 × 10-3-62.00 × 10-3 and 22.50 × 10-3-170.33 × 10-3 µg/kg, respectively. Myracrodruon urundeuva honey sample had high contents of macrominerals (Na, K, Ca, and Mg). Protein content of the Anacardium occidentale honey sample was the highest (1121.00 µg/g) among the samples analyzed. Among the minerals detected in the honey samples, K showed the highest concentration, followed by Ca, Na, and Mg. The presence of trace elements can show environmental contamination. The honey samples studied were free of trace elements contamination, except for Mn; the Piptadenia moniliformis was the only honey sample that was in compliance with the law requirements. The variations of the chemical constituents in the honey samples are probably related to differences in the floral origin and mineral and protein contents and confirm the nutritional importance of Ceará State honey.

Heavy metals investigation in bovine tissues in Brazil

The aim of this study was to investigate the presence of arsenic, lead, and cadmium residues in samples of liver, kidney, and muscle of cattle during the years of 2002 to 2008. A total of 1017 samples from 20 Brazilian States were used. The samples were analyzed at the National Agricultural Laboratory using the atomic absorption spectrometry technique. Arsenic residues were detected in 15.7% of liver samples and 28.7% of kidney samples although no results have exceeded the MRL. With regard to lead, 16 samples of liver and 74 samples of kidney were contaminated (5.2 and 10.9%, respectively). Among these samples, only one liver and two of kidney samples had lead levels above the MRL. Cadmium was found with levels below the MRL in 12.5% of the liver samples, and only 3 samples (1%) were quantified above the MRL. Among the kidney samples, 420 (60.8% of the total tested) had cadmium residues, and five of them exceeded the limits established by legislation. It is concluded that the Brazilian meat meets the legislation requirements without putting consumer's healthy at risk since as it satisfies the national and international food-safety conditions.

Screening of iron-enriched fungus from natural environment and evaluation of organically bound iron bioavailability in rats

Iron is an essential element for nearly all living organisms, and its deficiency is the most common form of malnutrition in the world. The organic forms of trace elements are considered more bioavailable than the inorganic forms. Although Saccharomyces cerevisiae can enrich metal elements and convert inorganic iron to organic species, its tolerability and transforming capacity are limited. The aim of this study was to screen higher biomass and other iron-enriched fungi strains besides Saccharomyces cerevisiae from the natural environment. A PDA medium containing 800 μg/mL iron was used for initial screening. Fifty strains that tolerated high iron concentration were isolated from the natural environment, and only one strain, No.BY1109, grew well at Fe (II) concentration of 10,000μg/ml. According to morphological characterization, 18S rDNA sequence analysis, and biophysical and biochemical characterization, the strain No.BY1109 was identified as Rhodotorula. The iron content of No.BY1109 (10 mg Fe/g dry cell) was determined using atomic absorption spectrometry. The results of distribution of iron in the cells showed that iron ion was mainly chelated in the cell walls and vacuoles. The bioavailability in rats confirmed that strain No.BY1109 had higher absorption efficiency than that of ferrous sulfate after single dose oral administration. The present study introduces new iron supplements, and it is a basis for finding new iron supplements from natural environment.

Effet du calcium, plomb et cuivre sur la bioaccumulation du cadmium et la production des phytochélatines par Chlamydomonas reinhardtii

Dans les milieux contaminés par les métaux, les organismes vivants sont exposés à plusieurs d’entre eux en même temps. Les modèles courants de prédiction des effets biologiques des métaux sur les organismes (p. ex., modèle du ligand biotique, BLM ; modèle de l’ion libre, FIAM), sont des modèles d’équilibre chimique qui prévoient, en présence d'un deuxième métal, une diminution de la bioaccumulation du métal d’intérêt et par la suite une atténuation de ses effets. Les biomarqueurs de toxicité, tels que les phytochélatines (PCs), ont été utilisés comme étant un moyen alternatif pour l’évaluation des effets biologiques. Les phytochélatines sont des polypeptides riches en cystéine dont la structure générale est (γ-glu-cys)n-Gly où n varie de 2 à 11. Leur synthèse semble dépendante de la concentration des ions métalliques ainsi que de la durée de l’ exposition de l’organisme, aux métaux. L'objectif de cette étude était donc de déterminer, dans les mélanges binaires de métaux, la possibilité de prédiction de la synthèse des phytochélatines par les modèles d’équilibres chimiques, tel que le BLM. Pour cela, la quantité de phytochélatines produites en réponse d’une exposition aux mélanges binaires : Cd-Ca, Cd-Cu et Cd-Pb a été mesurée tout en surveillant l’effet direct de la compétition par le biais des concentrations de métaux internalisés. En effet, après six heures d’exposition, la bioaccumulation de Cd diminue en présence du Ca et de très fortes concentrations de Pb et de Cu (de l’ordre de 5×10-6 M). Par contre, avec des concentrations modérées de ces deux métaux, le Cd augmente en présence de Cu et ne semble pas affecté par la présence de Pb. Dans le cas de la compétition Cd-Cu, une bonne corrélation a été observée entre la production de PC2, PC3 et PC4 et la quantité des métaux bioaccumulés. Pour la synthèse des phytochélatines et la bioaccumulation, les effets étaient considérés comme synergiques. Dans le cas du Cd-Ca, les quantités de PC3 et PC4 ont diminué avec le métal internalisé (effet antagoniste), mais ce qui était remarquable était la grande quantité de cystéine (GSH) et PC2 qui ont été produites à de fortes concentrations du Ca. Le Pb seul n’a pas induit les PCs. Par conséquent, il n’y avait pas de variation de la quantité de PCs avec la concentration de Pb à laquelle les algues ont été exposées. La détection et la quantification des PCs ont été faites par chromatographie à haute performance couplée d’un détecteur de fluorescence (HPLC-FL). Tandis que les concentrations métalliques intracellulaires ont été analysées par spectroscopie d’absorption atomique (AAS) ou par spectrométrie de masse à source plasma à couplage inductif (ICP-MS).

Untersuchungen zur Eliminierung und Resorption von Zink aus Säugerspermatozoen während der Nebenhodenpassage

Während der Spermatogenese wird das Element Zink an die Sulfhydrylreste der Cysteine in den Mantelfaserproteinen der Spermienflagellen gebunden. So kann in den noch unreifen Mantelfasern die ungerichtete Ausbildung von Disulfidbrücken verhindert werden. Im Zuge der Spermatozoenreifung während der Nebenhodenpassage wird dieses Zink androgenabhängig zu einem hohen Prozentsatz wieder eliminiert. Die nun gerichtete Ausbildung von Disulfidbrücken ermöglicht die Versteifung der Mantelfasern. Diese Rigidität stellt die Voraussetzung zur progressiven Motilität dar, ohne die eine Fertilisierung der Eizelle im weiblichen Genitaltrakt nicht möglich ist. Da eine negative Korrelation zwischen dem Zinkgehalt von Flagellen und ihrer Motilität besteht (Henkel et al., 1999), hat die Zinkeliminierung während der Nebenhodenpassage eine entscheidende Bedeutung in der Entwicklung der Spermatozoen. Die vorliegende Arbeit untersucht die Mechanismen der epididymalen Zinkeliminierung sowie die an diesem Prozess beteiligten Komponenten und den Verbleib des eliminierten Zinks am System des Bullen, der Ratte und des Menschen. Mittels proteinchemischer Verfahren kann im bovinen System ein zinkbindendes 60 kDa-Protein als Albumin identifiziert werden. Ein 80 kDa-Protein mit zinkbindenden Eigenschaften bleibt unidentifiziert. Die Zinkbindungskapazität der fraktionierten Proteine ist dabei im Caput epididymidis am stärksten ausgeprägt. Atomabsorptionsspektralphotometrische Untersuchungen zeigen die höchsten flagellären Zinkwerte in den Spermien des Rete testis und eine Abnahme des Zinkgehalts zwischen Nebenhodenkopf und -körper. Durch Autometallographie kann eine epitheliale Zinkresorption im Nebenhodenschwanz nachgewiesen werden. Dort erfolgt auch die basale Anreicherung des Zinks. Am Zinkstoffwechsel scheint auch der Macrophage Migration Inhibitory Factor (MIF) beteiligt zu sein. Dieser ist ein Zytokin mit Oxidoreduktasecharakter und kommt unter anderem im Nebenhodenepithel sowie in den Vesikeln des Nebenhoden-Fluids der Ratte vor. MIF zeigt in den hier durchgeführten Untersuchungen sowohl in systemhomologer, als auch in rekombinanter Form in vitro eine Zink-eliminierende Wirkung auf Rattenspermatozoen des Caputs und der Cauda epididymidis und hat somit möglicherweise Einfluss auf den Reifungsprozess der Spermien im Nebenhoden. Lit.: Henkel R, Bittner J, Weber R, Hüther F, Miska W (1999). Relevance of zinc in human sperm flagella and its relation to motility. Fertil Steril 71: 1138-1143

Aluminium in human breast tissue

Aluminium is omnipresent in everyday life and increased exposure is resulting in a burgeoning body burden of this non-essential metal. Personal care products are potential contributors to the body burden of aluminium and recent evidence has linked breast cancer with aluminium-based antiperspirants. We have used graphite furnace atomic absorption spectrometry (GFAAS) to measure the aluminium content in breast biopsies obtained following mastectomies. The aluminium content of breast tissue and breast tissue fat were in the range 4-437 nmol/g dry wt. and 3-192 nmol/g oil, respectively. The aluminium content of breast tissue in the outer regions (axilla and lateral) was significantly higher (P = 0.033) than the inner regions (middle and medial) of the breast. Whether differences in the regional distribution of aluminium in the breast are related to the known higher incidence of tumours in the outer upper quadrant of the breast remains to be ascertained. (c) 2007 Elsevier Inc. All rights reserved.

The aluminium content of breast tissue taken from women with breast cancer

The aetiology of breast cancer is multifactorial. While there are known genetic predispositions to the disease it is probable that environmental factors are also involved. Recent research has demonstrated a regionally specific distribution of aluminium in breast tissue mastectomies while other work has suggested mechanisms whereby breast tissue aluminium might contribute towards the aetiology of breast cancer. We have looked to develop microwave digestion combined with a new form of graphite furnace atomic absorption spectrometry as a precise, accurate and reproducible method for the measurement of aluminium in breast tissue biopsies. We have used this method to test the thesis that there is a regional distribution of aluminium across the breast in women with breast cancer. Microwave digestion of whole breast tissue samples resulted in clear homogenous digests perfectly suitable for the determination of aluminium by graphite furnace atomic absorption spectrometry. The instrument detection limit for the method was 0.48 μg/L. Method blanks were used to estimate background levels of contamination of 14.80 μg/L. The mean concentration of aluminium across all tissues was 0.39 μg Al/g tissue dry wt. There were no statistically significant regionally specific differences in the content of aluminium. We have developed a robust method for the precise and accurate measurement of aluminium in human breast tissue. There are very few such data currently available in the scientific literature and they will add substantially to our understanding of any putative role of aluminium in breast cancer. While we did not observe any statistically significant differences in aluminium content across the breast it has to be emphasised that herein we measured whole breast tissue and not defatted tissue where such a distribution was previously noted. We are very confident that the method developed herein could now be used to provide accurate and reproducible data on the aluminium content in defatted tissue and oil from such tissues and thereby contribute towards our knowledge on aluminium and any role in breast cancer.