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Journal of Radioanalytical and Nuclear Chemistry
Authors: Felipe Fonseca, Elisabete De Nadai Fernandes, Vanessa Rodrigues, Isabel de Oliveira Cavalca, Leandro Camilli, Claudiney Bardini, and Elvis De França

Abstract  

The quality of environmental studies depends on the utilization of adequate sampling protocol and analytical method for obtaining reliable results and minimizing analytical uncertainties. In order to demonstrate the applicability of INAA for determining chemical element composition of invertebrates, this work evaluated sample representativeness in terms of subsampling and sample size. Br, Co, Fe, K, Na, Sc and Zn could be determined in very small samples despite increasing of analytical uncertainties. Special attention should be directed to invertebrate species with small structures because of the high chemical variation observed among different sample sizes tested.

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Abstract  

Homogeneity study is one of the steps in reference material, RM, characterization. Due to its inherent characteristics, Instrumental Neutron Activation Analysis, INAA, is an analytical technique of choice for homogeneity testing. An interesting possibility is the use of complementary gamma ray photopeaks to confirm INAA homogeneity test results. In this study, the use of the complementary gamma ray photopeaks of 110mAg, 82Br, 60Co, 134Cs, 152Eu, 59Fe, 140La, 233Pa (for Th determination), 46Sc and 75Se radionuclides was investigated in the between bottle homogeneity study of a mussel candidate RM under preparation at IPEN–CNEN/SP. Although some photopeaks led to biased element content results, the use of complementary gamma ray photopeaks proved to be helpful in supporting homogeneity study conclusions for the new RM under characterization.

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Abstract  

In this work, 50 ceramic fragments from the Lago Grande and 30 from the Osvaldo archaeological site were compared to assess elemental similarities. The aim is to perform a preliminary comparison between the sites, which are located in the central Amazon, Brazil. The analytical technique employed to obtain the ceramics elemental composition was instrumental neutron activation analysis (INAA). The data set obtained was explored by the multivariate statistical techniques of cluster, principal component and discriminant analysis. The analyzed elements were: Na, Lu, U, Yb, La, Th, Cr, Cs, Sc, Fe, Eu, Ce and Hf. The results showed the existence of at least two compositional groups for Lago Grande and Osvaldo. Each compositional group of Osvaldo archaeological site matches with one group of Lago Grande. Correlated with the archaeological background, the results suggest commercial or cultural exchange in the region, which is an indicative of socio-cultural interactions between those sites.

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Abstract  

In this study, instrumental neutron activation analysis (INAA) and inductively coupled plasma-mass spectrometry (ICP-MS) were used to compare results obtained by both techniques for sediment samples collected from the Patras Harbour, Western Greece. The accuracy of the methods was tested using reference materials. In total seven elements were measured by both techniques (Zn, Ni, Cr, Ba, As, U, Co). Results obtained by ICP-MS were compared with those obtained by INAA by applying paired t-test. Insignificant differences in mean concentration values were found for Zn, Ni, Cr and Ba, whereas the differences for As, Co and U were significant. Correlations between element concentrations measured by both techniques are also discussed.

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Abstract  

Instrumental neutron activation analysis (INAA) was used in the homogeneity study of a Perna perna (Linnaeus 1758) mussel reference material. Simultaneous determination of 15 elements in six bottles of the material, from a total of 171, was performed. The bottles were considered homogeneous for the analyzed elements, at the 95% confidence level, according to the analysis of variance test performed. Elements were also determined in one bottle with five different sample masses for minimum sample intake estimation. Results varied from 50 to 350 mg, depending on the element.

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Abstract  

Soil as an impurity in sugarcane is a serious problem for the ethanol industry, increasing production and maintenance costs and reducing the productivity. Fe, Hf, Sc and Th determined by INAA were used as tracers to assess the amount of soil in sugarcane from truckloads as well as in the juice extraction process. Quality control tools were applied to results identifying the need for stratification according to soil type and moisture. Soil levels of truckloads had high variability indicating potential for improving cut and loading operations. Samples from the juice extraction process allowed tracking the soil in the mill tandem.

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Abstract  

The phyto-accumulation efficacy of selenium (Se) from soil by chickpea plant is reported. Chickpea plants were grown in soil having different concentrations (1–4 mg kg−1) of Se. Samples of soil and different parts of chickpea plants in Se rich soil were analyzed for determination of Se concentrations by instrumental neutron activation analysis (INAA). Samples were irradiated in self-serve facility of CIRUS reactor, BARC, Mumbai at a neutron flux of the order of 1013 cm−2 s−1. The gamma activity at 264.7 keV of 75Se (119.8 d) was measured using a 45% relative efficiency HPGe detector coupled to MCA. Dependence of Se distribution in soil and plants on its spiking concentration was evaluated in this work. The Se concentrations determined in plant parts grown in control soil and in soil spiked with Se (4 mg kg−1) are in the range of 0.6–0.8 and 65–68 mg kg−1 respectively.

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Abstract  

Phosphorus is an essential element for plants and animals, playing a fundamental role in the production of biochemical energy. Despite its relevance, phosphorus is not commonly determined by instrumental neutron activation analysis (INAA), because 32P does not emit gamma-rays in its decay. There are alternative methods for the determination of phosphorus by INAA, such as the use of beta counting or the measurement of bremsstrahlung originated from the high energy beta particle from 32P. Here the determination of phosphorus in plant materials by measuring the bremsstrahlung production was further investigated, to optimize an analytical protocol for minimizing interferences and overcoming the poor specificity. Eight certified reference materials of plant matrices with phosphorus ranging between 171 and 5,180 mg kg−1 were irradiated at a thermal neutron flux of 9.5 × 1012 cm−2 s−1 and measured with a HPGe detector at decay times varying from 7 to 60 days. Phosphorus solutions added to a certified reference material at three levels were used for calibration. Counts accumulated in the baseline at four different regions of the gamma-ray spectra were tested for the determination of phosphorus, with better results for the 100 keV region. The Compton scattering contribution in the selected range was discounted using an experimental peak-to-Compton factor and the net areas of all peaks in the spectra with energies higher than 218 keV, i.e. Compton edge above 100 keV. Amongst the interferences investigated, the production of 32P from sulfur, and the contribution of Compton scattering should be considered for producing good results.

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Abstract  

The growing concern about air quality in harbours is a result of the high impact of the operations on human health and environment. Harbour activities such loading, unloading and transport of dusty materials are important emission sources of Atmospheric particulate matter (APM). The assessment of these fugitive emissions is a difficult task because they depend on the materials, the type of operation and the meteorological scenarios. The main objectives of this work were (1) to evaluate if the techniques k0-based Instrumental neutron activation analysis (k0-INAA) and Particle induced X-ray emission (PIXE) are suitable techniques to assess fugitive emissions in harbours and (2) to estimate the impact of harbour activities on APM levels and composition. Several experimental campaigns were carried out in a Portuguese harbour, during unloading operations of fertilizer and phosphorite provided from Syria and Morocco. PM2.5 and PM2.5–10 were collected, in polycarbonate filters, by Gent samplers. The techniques k0-INAA and PIXE were applied as sensitive analytical tools to perform a complete chemical characterization of the collected samples. Results showed that manipulation of these materials during harbour operations resulted in high emissions of particles, principally from the coarse fraction. These emissions were very affected by the granulometry and nature of the handled materials. Fertilizer emissions were characterized by high concentration of Ca, P, K, Cr, Br and Zn, whereas phosphorite handling contributed principally for the increase of Ca, P and Cr levels.

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Journal of Radioanalytical and Nuclear Chemistry
Authors: S. Almeida, C. Ramos, A. Marques, A. Silva, M. Freitas, M. Farinha, M. Reis, and A. Marques

Abstract  

The objective of this paper was to assess the air pollution and the main sources of Air Particulate Matter in the Setúbal urban/industrial area, Portugal. PM2.5 and PM2.5–10 were sampled in Nuclepore filters and lichens transplants were exposed during 9 months. The levels of elements in these two matrixes were measured by INAA and PIXE. A large data base was created and source apportionment was performed by using Principal Component Analysis. The results showed that the main sources of fine particles were anthropogenic and were related with traffic and local industry. There was an important contribution of natural sources, mainly for the coarse fraction, associated with the sea and the soil. Lichens characterization and mapping showed that different site-specific characteristics controlled the spatial distribution of different elements. This study showed that biomonitoring is an effective complementary method to traditional sampling systems.

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