Metal levels and foraminifera occurrence in sediment cores from Guanabara Bay,Rio de Janeiro,Brazil

Summary Guanabara Bay, located at Rio de Janeiro, is an example of an impacted coastal environment due to the high influx of industrial and domestic effluents. Four sediment cores were sampled in areas with different levels of pollution and were analyzed for trace elements and foraminifera for abundance. Instrumental neutron activation analysis (INAA) was used to determine As, Ba, Co, Cr, Fe, Sb, Sc, and Zn. The effects of metal concentrations in the benthic foraminifera were studied. The low concentrations of the benthic foraminifera and the dominance of opportunistic species in coastal regions such as Ammonia may be correlated to natural stress or anthropogenic impact.     

Thermal analysis as a tool in the study of GMM in Angra Dos Reis region,Rio de Janeiro,Brazil

Angra dos Reis/Itaguai region of the state of Rio de Janeiro, Brazil, is a very problematic area due to the instability of slope and landslides, due to geological and geomorphological conditions and to the significant and continuous human occupation over favorable areas is prone to the triggering of landslides. The samples were analyzed by thermogravimetry (TG), derivative thermogravimetry (DTG) and differential thermal analysis (DTA). This paper analyzes and characterizes the clay minerals and presence of water, gravitational mass movements’ sites and compares it with sites where gravitational mass movements do not occur. Indeed, this analysis also attempts to verify the presence of minerals.     

Study of the chemical composition of particulate matter from the Rio de Janeiro metropolitan region,Brazil, by inductively coupled plasma-mass spectrometry and optical emission spectrometry

Air quality in the metropolitan region of Rio de Janeiro was evaluated by analysis of particulate matter (PM) in industrial (Santa Cruz) and rural (Seropédica) areas. Total suspended particles (TSP) and fine particulate matter (PM_2.5) collected in filters over 24 h were quantified and their chemical composition determined. TSP exceeded Brazilian guidelines (80 μg m^− 3) in Santa Cruz, while PM_2.5 levels exceeded the World Health Organization guidelines (10 μg m^− 3) in both locations. Filters were extracted with water and/or HNO₃, and the concentrations of 20 elements, mostly metals, were determined by inductively coupled plasma mass spectrometry (ICP-MS) and optical emission spectrometry (ICP OES). Water soluble inorganic anions were determined by ion chromatography (IC). To estimate the proportion of these elements extracted, a certified reference material (NIST SRM 1648a, Urban Dust) was subjected to the same extraction process. Concordant results were obtained by ICP-MS and ICP OES for most elements. Some elements could not be quantified by both techniques; the most appropriate technique was chosen in each case. The urban dust was also analyzed by the United States Environmental Protection Agency (US EPA) method, which employs a combination of hydrochloric and nitric acids for the extraction, but higher extraction efficiency was obtained when only nitric acid was employed. The US EPA method gave better results only for Sb. In the PM samples, the elements found in the highest average concentrations by ICP were Zn and Al (3–6 μg m^− 3). The anions found in the highest average concentrations were SO₄^2 − in PM_2.5 (2–4 μg m^− 3) and Cl⁻ in TSP (2–6 μg m^− 3). Principal component analysis (PCA) in combination with enrichment factors (EF) indicated industrial sources in PM_2.5. Analysis of TSP suggested both anthropogenic and natural sources. In conclusion, this work contributes data on air quality, as well as a method for the analysis of PM samples by ICP-MS.     

Trace and major elements in rock samples from Itingussú River Basin, Coroa-Grande, Rio de Janeiro

Summary The goal of the present work was to determine the concentration of 23 elements by instrumental neutron activation analysis in rock samples from the vicinity of Itingussú River, in order to investigate the contribution of trace and major elements from the local lithology to the river basin. The Itingussú River Basin ends in a mangrove area not yet largely impacted by antropogenic activities. So far, there are no data for the concentration of trace elements in that region, even though these data are important to the understanding of the influence of the rocks on the composition of the mangrove sediments. The results showed some enrichment of Th and some light rare earths, probably because of the presence of the mineral allanite and other accessory minerals, as identified by petrographic analysis.     

Trace and major elements in geological samples from Itingusssú River Basin, Sepetiba Bay––Rio de Janeiro

The Itingussú drainage basin is situated at 22°44′–22°55′ SL and 44°53′–43°55′ WL, in Coroa-Grande district, Sepetiba Bay, southwest of Rio de Janeiro, Brazil. Its total area is less than 10 km² and includes a waterfall with three drop offs. The study area is located in a granitic pre-Cambrian embasement, discharging in a mangrove forest fringe. This work attempts to investigate the influence of lithology types in the elemental composition of soil of region and sediments of related mangrove. Instrumental neutron activation analysis and subsequent gamma-ray spectrometry were used. This technique enabled the measurement of at least twenty-one chemical elements. The more representative soil samples were enriched with U and Th. Multivariate Statistical Analysis showed that the soil and sediments formed in this area have been influenced by the leucocratic rocks, enriched with LREE and Th. The factorial analysis enables the identification of five factors of influence in the ordination of elements: presence of iron minerals (biotite); presence of allanite; marine influence in the sediment; differentiated kinetic of transport and diagenesis.     

Secretory cavities and volatiles of Myrrhinium atropurpureum Schott var. atropurpureum (Myrtaceae): an endemic species collected in the restingas of Rio de Janeiro, Brazil

In this study, we investigated the leaf anatomy and the composition of volatiles in Myrrhinium atropurpureum var. atropurpureum endemic to Rio de Janeiro restingas. Particularly, leaf secretory structures were described using light microscopy, and histochemical tests were performed from fresh leaves to localize the secondary metabolites. To observe secretory cavities, fixed leaf samples were free-hand sectioned. To evaluate lipophilic compounds and terpenoids the following reagents were employed: Sudans III and IV, Red oil O and Nile blue. Leaf volatiles were characterized by gas chromatography after hydrodistillation (HD) or simultaneous distillation-extraction (SDE). Leaf analysis showed several cavities in mesophyll that are the main sites of lipophilic and terpenoid production. Monoterpenes, which represented more than 80% of the major volatiles, were characterized mainly by alpha- and beta-pinene and 1,8-cineole. In order to provide tools for M. atropurpureum identification, the following distinguishing characteristics were revealed by the following data: 1) adaxial face clear and densely punctuated by the presence of round or ellipsoidal secretory cavities randomly distributed in the mesophyll; 2) the presence of cells overlying the upper neck cells of secretory cavities; 3) the presence of numerous paracytic stomata distributed on the abaxial leaf surface, but absent in vein regions and leaf margin; and 4) non-glandular trichomes on both leaf surfaces. Our study of the compounds produced by the secretory cavities of M. atropurpureum led us to conclude that volatile terpenoid class are the main secretory compounds and that they consist of a high concentration of monoterpenes, which may indicate the phytotherapeutic importance of this plant.     

Chemical characterization and recent sedimentation rates in sediment cores from Rio Grande reservoir,SP, Brazil

The Rio Grande reservoir lies southeast of the Metropolitan Area of São Paulo. In order to evaluate if the sediments contain a historical registration of anthropogenic activity, four sediment cores were sampled from the reservoir. In these cores the Hg concentration was determined by the CV AAS technique, major and trace elements by instrumental neutron activation analysis and the sedimentation rates by the ²¹⁰Pb method. The results obtained for Hg are much higher than expected, showing an anthropogenic contribution. As a general trend, the elemental concentration decreases with depth, indicating recent contamination.     

Assessment of metals and trace elements in sediments from Rio Grande Reservoir,Brazil, by neutron activation analysis

The Rio Grande Reservoir, Southeast of the São Paulo Metropolitan Area, supplies water for four counties (about 1.6 million people). It has been seriously affected by urban expansion due to chaotic urban occupation and improper use of the surrounding areas. In this study bottom sediment samples were collected during the dry season and rainy season. Four sampling points were defined and located at the mouth of the Rio Grande and Ribeirão Pires Rivers (points 1 and 2), in the middle of the reservoir (point 3) and near the catchment point of the water supply (point 4). Samples were submitted to instrumental neutron activation analysis and some metals, trace and rare earth elements were determined. The methodology validation according to precision and accuracy was carried out by reference material analyses. The results obtained were compared to earth crust values and also with results already published in the literature. The enrichment factor in relation to earth crust values using Sc as reference element was calculated and a strong enrichment was found for the elements As, Br, Sb, Th, U and Zn. A strong anthropogenic influence was observed for some elements, mainly in the points located in the entrance of the reservoir that receives domestic and industrial effluents from the rivers that reach the reservoir.     

Isomerizing olefin metathesis as a strategy to access defined distributions of unsaturated compounds from Fatty acids

The dimeric palladium(I) complex [Pd(μ-Br)(t)Bu(3)P](2) was found to possess unique activity for the catalytic double-bond migration within unsaturated compounds. This isomerization catalyst is fully compatible with state-of-the-art olefin metathesis catalysts. In the presence of bifunctional catalyst systems consisting of [Pd(μ-Br)(t)Bu(3)P](2) and NHC-indylidene ruthenium complexes, unsaturated compounds are continuously converted into equilibrium mixtures of double-bond isomers, which concurrently undergo catalytic olefin metathesis. Using such highly active catalyst systems, the isomerizing olefin metathesis becomes an efficient way to access defined distributions of unsaturated compounds from olefinic substrates. Computational models were designed to predict the outcome of such reactions. The synthetic utility of isomerizing metatheses is demonstrated by various new applications. Thus, the isomerizing self-metathesis of oleic and other fatty acids and esters provides olefins along with unsaturated mono- and dicarboxylates in distributions with adjustable widths. The cross-metathesis of two olefins with different chain lengths leads to regular distributions with a mean chain length that depends on the chain length of both starting materials and their ratio. The cross-metathesis of oleic acid with ethylene serves to access olefin blends with mean chain lengths below 18 carbons, while its analogous reaction with hex-3-enedioic acid gives unsaturated dicarboxylic acids with adjustable mean chain lengths as major products. Overall, the concept of isomerizing metatheses promises to open up new synthetic opportunities for the incorporation of oleochemicals as renewable feedstocks into the chemical value chain.     

Retention behavior of silica-bonded and novel polymeric reversed-phase sorbents in studies on flavones as chemotaxonomic markers of Scutellaria L. genus

In this study, the effectiveness of both classical and novel polymeric sorbents used in solid-phase extraction (SPE) for isolation of pharmacologically active flavones (baicalin, luteolin, apigenin, wogonin and chrysin) from aerial parts of 13 species of Scutellaria L. (Skullcap) genus was assessed. The highest recoveries of hydrophilic (baicalin, luteolin) flavones for Oasis HLB were obtained, whereas for medium hydrophobic (apigenin) and hydrophobic (wogonin, chrysin) flavones better quantitative results for BakerBond phenyl cartridges were stated. Eluates were analysed using reversed-phase high-performance liquid chromatography with diode array detection (RP-HPLC-DAD). For the five target compounds the determined concentrations ranged from approximately 4 to approximately 15,500 microg/g dry wt. Very good linearities (r(2)>0.9995) of calibration curves were achieved for each flavone. The accuracy was below 5% for most compounds examined. This is the first method reported that enabled simultaneous qualification and quantitation of five flavones (being chemotaxonomic markers) in 13 species of Scutellaria L. genus.     

Mass spectrometric analysis for carboxylic acids as viable markers of petroleum hydrocarbon biodegradation

The characterization of metabolites, which are considered markers of bacterial degradation of hydrocarbons, is gaining in importance. Over the years, carboxylic acids have served as useful indicators of aerobic and anaerobic hydrocarbon biodegradation. This interest has been accompanied by the extensive and robust development of analytical methods for monitoring, untargeted identification, and specific and sensitive determination of carboxylic acids in complex matrices. This review discusses critically the state-of-the-art of mass spectrometry as a reliable analytical technique to identify and quantify carboxylic acid metabolites. Attention is paid to sample pre-treatment, selective group pre-concentration, and gas and liquid chromatography preceding mass spectrometry to alleviate matrix effects and ionization discrimination. Recent specific applications of mass spectrometry in monitoring carboxylic acids for assessing hydrocarbon biodegradation are reviewed. Presently, no single technique is sufficient for holistic profiling of carboxylic acids. The direct characterization of carboxylic acids by mass spectrometry is the ultimate goal but despite recent significant developments, challenges persist.     

Formation of dihydroxy acids from Z-monounsaturated alkenoic acids and their use as biomarkers for the processing of marine commodities in archaeological pottery vessels

Distributions of erythro and threo dihydroxy acids, extracted from ‘bound’ forms of organic residues preserved in archaeological pottery cooking vessels are shown to be the direct products from Z-monounsaturated alkenoic acids present in the original commodities, and are useful biomarkers for detecting marine animal product processing/consumption by ancient people.     

Volatile constituents of two species of Protium from the Atlantic rainforest in the state of Pernambuco, Brazil

The chemical composition of the essential oils from Protium giganteum and P. aracouchine was determined, for the first time, using GC-MS analysis. From the oil of P. giganteum, 32 components were identified, representing 93.9% of the oil, and from P. aracouchine, 29 components, representing 97.8% of the oil. Among the compounds identified in the P. giganteum oil, 93.6% were sesquiterpenes, with beta-caryophyllene (26.0 +/- 0.8%), globulol (9.3 +/- 0.2%), alpha-cadinol (7.0 +/- 0.5%), alpha-humulene (6.4 +/- 0.1%) and germacrene D (6.2 +/- 0.3%) as the major components. Among the 29 compounds identified in the P. aracouchine oil, 95.9% were sesquiterpenes as well, with spathulenol (31.8 +/- 1.6%), alpha-cis-bergamotene (8.8 +/- 0.2%) and viridiflorol (9.7 +/- 0.7%) as the major components.     

Spiculoic acids A and B, new polyketides isolated from the Caribbean marine sponge Plakortis angulospiculatus

[structure: see text] Two novel polyketides, spiculoic acids A (1) and B (2), have been isolated from extracts of the Caribbean marine sponge Plakortisangulospiculatus. The structures of 1 and 2 were elucidated by detailed analysis of spectroscopic data. Spiculoic acid A (1) showed in vitro cytotoxicity against human breast cancer MCF-7 cells. It has a putative polyketide biogenetic origin that involves incorporation of four butyrate units and a Diels Alderase catalyzed intramolecular [4 + 2] cycloaddition reaction.     

Moringa oleifera leaves from Brazil: Influence of seasonality,regrowth age and,region in biochemical markers and antioxidant potential

Moringa oleifera leaves are cultivated in warm regions of Brazil for commercial ends due to their nutritional and biological properties. This study evaluated, by chemometric tools, the influence of seasonality (winter, spring, autumn, and summer), growing area in Brazil (South, Southeast, and Northeast), and regrowth age (40 and 80 days) in antioxidant potential, and biochemical markers determined by HPLC-DAD. The results obtained in the present study showed that all the parameters evaluated were affected by seasonality, regrowth age, and growing region. The content of phenolic compounds and antioxidant activity using the ABTS method was higher in samples cultivated in the southeast (59.4 mg GAE g^?1 and 346 µmol TEAC g^?1, respectively). The highest antioxidant activities evaluated by DPPH and FRAP methods were obtained from leaves of the southeast and northeast. In addition, young leaves presented higher antioxidant potential and total phenolic content. The cultivation region significantly influenced the content of chlorogenic acid, isoquercitrin, and astragalin, which ranged from 4.2 to 7.2 mg g^?1, 8.0 to 10.7 mg g^?1, and 2.2 to 3.8 mg g^?1, respectively. In addition, a positive correlation between solar radiation and temperature with caffeic acid, rutin, phenolic compounds, and antioxidant assay from the DPPH method was observed. Additionally, the RGB pattern of the images of these leaves was correlated with the levels of compounds with antioxidant activity. Models generated through machine learning showed good performances, and ABTS and rutin analyses developed the best models with a coefficient of determination above 75 %. Thus, color patterns can be used to measure the antioxidant activity by the ABTS method and to determine the rutin concentration in M. oleifera leaves.     

Calorimetric analysis of three hydroxy acids as markers for quality and safety in food

A new analytical methodology to quantify three hydroxy acids (orotic, ascorbic, L-malic acids), by isothermal solution microcalorimetry, was outlined and applied to different foods. Three specific enzymatic reactions were used to ensure the correctness of the results. The considered acids can be considered as markers in food quality for their biochemical peculiarities. The enzymatic microcalorimetric method is very reliable and linearity is satisfied in the concentration ranges useful for food analyses. The analytical results of the underlined method are very accurate, precise, sensitive and in good agreement with the values obtained with other common methods.     

Ratios between content of fatty acids as markers for mixture of cow and goat milk

The fat of mixture of goat and cow milk, extracted by di-ethylic ether, was gas chromatographically analysed in order to propose an analytical procedure suitable to reveal small additions of cow milk to goat milk. The obtained results show evident differences in the percentages of some fatty acids. An attempt to apply the peak area ratios, corresponding to the methyl esters of fatty acids, suggested by the literature for cow milk did not yield good results. Other ratios suitable to reveal even the presence of low percentages (up to 5 %) of cow milk in goat milk were found and proposed in this paper. Such ratios are sensitive and can be defined markers towards cow or goat milk and also towards extraneous fat like lard or colza seeds oil.