Characterization and phytoremediation of abandoned contaminated mining area in Portugal by INAA

This study aims to find out a vascular plant species that accumulate relatively high concentrations of arsenic (As) for its use as phytoremediator at abandoned and contaminated mining areas, such as São Domingos mines (Portugal). The assessment of As contamination levels in soils and plants of other similar sites in the north of the country (Castromil and Poço de Freitas) was also conducted; and the sample analyses were made by instrumental neutron activation analysis. Agrostis genera have shown higher As transfer coefficients than other studied plant species and, in particular, Agrostis curtisii has shown a reasonable ability to accumulate high concentration of this toxic element.     

Contents of heavy metals in lotus seed from REEs mining area

At rare earth mining area, the pollution of heavy metals has been paid little attention. In lotus seeds and soil samples sampled from a typical rare earth elements mining area were detected the contents of eight kinds of heavy metals (Cr, Mn, Cu, Zn, As, Cd, Hg and Pb) to investigate the pollution from rare earth elements mining by ICP-MS (Inductively Coupled Plasma Mass Spectrometry). The results showed that the contents of the heavy metals Cr, Mn, Cu, Zn, As, Cd, Hg and Pb in lotus seeds were 0.25, 86.94, 8.32, 19.76, 0.13, 0.08, 0.01, and 0.20 μg/g in lotus seeds, respectively, and corresponding contents in soil were 27.68, 168.71, 20.23, 47.16, 1.83, 0.13, 0.04, and 23.15 μg/g. These data showed that the contents of heavy metals in lotus seeds from REEs mining area are no higher than reference area and meet national food safety standards of China.     

Redistribution of uranium and thorium by soil/plant interaction in a recultivated mining area

During the recultivation of the uranium mining area of K?vágósz?l?s (Hungary), the tailings were covered with clay and loess soil layers having a thickness of 30 cm and 100 cm, respectively. In the loess covering layer, acacia (Robinia pseudoacacia), poplars (Populus × albus, Populus × canescens), oak (Quercus pubescens), silver tree (Eleagnus angustifolia) were planted between 1996 and 2004. In order to establish the extent of the uranium and thorium transport from the sludge to the leaves by uptake and translocation processes through roots with a length higher than 1.3 m results in a remarkable redistribution of these pollutants, a gray poplar tree, growing spontaneously in the last uncovered tailing, being selected as reference tree. The U and Th concentrations in the leaves of the above-mentioned trees, in the covering layers as well as in the original sludge were determined by inductively coupled plasma sector field mass spectrometry (ICP-SF-MS). Generally, the Th concentration of the soils was about 4 times higher than that of uranium, while uranium concentration was about 10-130 times higher than that of thorium in the leaf samples and its concentration ranged from 28 to 1045 ng g^− 1, the last value belonging to the poplar tree growing on the last uncovered tailing. In order to assume the mobility and bioavailability of uranium if the dry leaves fall down, the uranium species in the leaves of the poplar tree growing in the uncovered reservoir were determined applying ultrasound-assisted extraction with distilled water and ammonium acetate as well as high performance liquid chromatographic (HPLC)-ICP-SF-MS technique. About 20% of total uranium could be extracted in form of uranyl cations and a presumably negatively charged uranium compound. Estimations revealed that the annual increment of U in the soil surface layer due to the dead fallen leaves in case of the investigated gray poplar (Populus × canescens) is about 1.2%.     

Application of INAA for phyto-accumulation study of selenium by chickpea plant

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.     

Arsenic bioaccumulation and species in marine polychaeta

Published whole tissue arsenic concentrations in polychaete species tissues range from 1.5–2739 µg arsenic/g dry mass. Higher mean total arsenic concentrations are found in deposit‐feeding polychaetes relative to non‐deposit‐feeding polychaete species collected from the same locations. However, mean arsenic concentrations at some of the locations are skewed by the high arsenic concentrations of Tharyx marioni. There appears to be no direct correlation between sediment arsenic concentrations and polychaete arsenic concentrations. Arsenic bioaccumulation by polychaetes appears to be more controlled by the physiology of the polychaetes rather than exposure to arsenic via ingested material or the prevailing physiochemical conditions. Arsenic concentrations in polychaete tissues can vary greatly. Most polychaete species contain the majority of their arsenic as arsenobetaine (57–98%), with trace concentrations of inorganic arsenic (<1%) and other simple methylated species (<7.5%). However, this is not always the case, with unusually high proportions of arsenite (57%), arsenate (23%) and dimethylarsinic acid (83–87%) in some polychaete species. Arsenobetaine is probably accumulated by polychaetes via organic food sources within the sediment. The presence of relatively high proportions of phosphate arsenoriboside (up to 12%) in some opportunistic omnivorous Nereididae polychaete species may be due to ingestion of macroalgae, benthic diatoms and/or phytoplankton. Consideration of the ecology of individual polychaete species in terms of their habitat type, food preferences, physiology and exposure to arsenic species is needed for the assessment of arsenic uptake pathways and bioaccumulation of arsenic. Future research should collect a range of polychaete species from a wide variety of uncontaminated marine habitats to determine the influence of these ecological factors on total arsenic concentrations and species proportions. Copyright © 2005 John Wiley & Sons, Ltd.     

Multielement determination in Tillandsia by INAA

Instrumental neutron activation analysis was employed to measure 43 elements, including some macroconstituents, in the leaves of some species of the epiphytic genusTillandsia (Bromeliaceae). The results, confirming the oligotrophyc nature of the genus, are briefly discussed with regard to a possible role as multielemental environmental monitors.     

Analysis of bioaccessible concentration of trace elements in plant based edible materials by INAA and ICPMS methods

The total metal concentration and bioaccessible concentration of Cr, Mn, Fe, Cu, Zn, Se in Momordica charantia, Asparagus racemosus, Terminalia arjuna and Syzyzium cumini were measured by instrumental neutron activation analysis and by inductively coupled plasma mass spectrometry analysis (ICP-MS). The bioaccessible concentrations were determined in the gastrointestinal digest obtained after treating dried powdered samples sequentially in gastric and intestinal fluid of porcine origin at physiological conditions. The bioaccessible concentration of Fe was in the range of 58–67 mg kg^?1, Mn was 10.2–14.6 mg kg^?1, Cu was 3.7–4.8 mg kg^?1 and Zn was 10.6–18.4 mg kg^?1, were within the safety limits set for vegetable food stuff set by Joint FAO/WHO. The bioaccessibility of Zn, an essential element, was high (40–50 %) in M. charantia and in S. cumini. In addition, the total metal contents and bioaccessible concentration of Ni, Se, Cd and Pb in these samples were measured by ICP-MS. The total Cd content in S. cumini (2.6 ± 0.2 mg kg^?1) and its bioaccessible concentration (0.6 mg kg^?1) were strikingly high as compared to the other samples. Though total Hg contents were determined by ICP-MS, but their bioaccessible concentrations were below the detection limit (0.036 mg kg^?1).     

Determination of phosphorus in polymers by INAA

An INAA technique employing beta spectrometry was developed for the determination of phosphorus in polymers. The (n,γ) reaction on phosphorus produces³²P, half-life 14.3 days, a pure beta emitter with end-point energy 1.71 MeV. Polymer samples in the form of powders, films and pellets are irradiated and then counted with a plastic scintillator. The beta spectrum is corrected for interferences (especially Sb, Zn and Br which are quantified by gamma spectrometry) and for energy loss in the thick sample. Samples must also be analyzed for S and Cl which cause nuclear interferences. With an irradiation time of 4 hours at a neutron flux of 5·10¹¹ n·cm^{−2 s −1}, decay time 10 days and counting time 10 minutes, the sensitivity is 520 counts/μg phosphorus and the detection limit is typically 2μg/g.     

Contamination of crop vegetation with trace elements from a fertilizer plant: An INAA study

Instrumental neutron activation analysis (INAA) was used to determine various trace elements in crop vegetation (potato, carrot and maize) grown around a phosphate fertilizer plant in Romania. INAA using long-lived radionuclides was applied at NIPNE in Bucharest, and based on short-lived radionuclides at JINR in Dubna. The results for Na, Mg, Cl, K, Ca, Mn, Fe, Zn, As, and Hg were compared with Romanian norms for the alimentary products, as well as with literature data. Concentration ratios to control samples for both soil and crop as well as concentration factors of crop to host soil were assessed. This revised version was published online in July 2006 with corrections to the Cover Date.     

Estimation of thorium intake due to consumption of vegetables by inhabitants of high background radiation area by INAA

A study was conducted to estimate the thorium concentration in locally grown vegetables in high background radiation area (HBRA) of southern coastal regions of India. Locally grown vegetables were collected from HBRA of southern coastal regions of India. Thorium concentration was quantified using instrumental neutron activation analysis. The samples were irradiated at CIRUS reactor and counted using a 40% relative efficiency HPGe detector coupled to MCA. The annual intake of thorium was evaluated using the consumption data provided by National Nutrition Monitoring Board. The daily intake of ²³²Th from the four food categories (green leafy vegetables, others vegetables, roots and tubers, and fruits) ranged between 0.27 and 5.352?mBq?d^?1. The annual internal dose due to ingestion of thorium from these food categories was 46.8?×?10^?8 for female and 58.6?×?10^?8?Sv?y^?1 for male.     

Analysis of Mexican cigarettes by INAA

Due to large consumption of tobacco in Mexico and in order to complement previous work performed by total reflection X-ray fluorescence, the present study has determined 15 elements by INAA in 9 cigarettes brands being marketed in Mexico. As a part of a Quality Control Program, NIST standard reference materials (SRM) and an IAEA reference material were analyzed to confirm the accuracy and reproducibility. Average of As and Cd were 0.56 and 1.15 μg·g⁻¹, respectively, in the range of those of foreign brands.     

Heavy metal in sediments and bioaccumulation in the bivalve Corbula gibba in a drilling discharge area

The longterm bioavailability of heavy metals in sediments of a Northern Adriatic Sea shelf area affected by drilling mud and cutting discharges was discussed. Levels of Mn, Cu, Cr, Zn and Pb in different geochemical phases of the sediment and in soft tissues of the bivalve Corbula gibba were recorded and the relationships between biological and geochemical metal investigated. Total metal content, acetic acid extractable-, exchangeable-, carbonate-, easily reducible-, moderately reducible-, oxidable- and residual-fractions were determined on sediment samples. Corbula gibba was collected from wet sediments at the same times and sites, and the soft-tissue metal contents were determined. Correlations show that the fractions with greatest bioavailability are the exchangeable and carbonate for Cr and the exchangeable, carbonate, easily and moderately reducible fractions for Zn. Data also show a possible bioavailability of Pb only from the residual fraction, consisting of very resistant matter of more recent anthropogenic origin. Near the platform, total Mn content in sediments and in C. gibba tissues show a strong correlation suggesting that this organism is sensitive to variations of the Mn-oxi-hydroxides superficial film. No relationships were found between biological and sediment-bound Cu, however the discharged muds did not cause Cu enrichment. The metal fraction determined by weak acetic acid extraction at no point seems related to metal levels in Corbula gibba.     

Determination of selenium species in plant leaves by HPLC-UV-HG-AFS

The purpose of this work was the development of a method for the determination of Se compounds in leaves of plants. Water-soluble Se compounds were extracted from samples by water. Enzymatic hydrolysis with the non-specific enzyme protease XIV was used for the release of Se compounds bound to proteins. Separation of Se species was made by ion exchange chromatography, using an anion exchange column for Se^IV, Se^VI and selenomethionine (SeMet), and a cation exchange column for selenomethylselenocysteine (SeMeSeCys) and selenocystine (SeCys₂). Columns were connected “on line” to a hydride generation atomic fluorescence spectrometer (HG-AFS) using a UV lamp between the separation and detection system. The repeatability of the results obtained by the developed method was under 15% (R.S.D.) for all Se species; the detection limit was 2-10 ng Se/g of supernatant. The accuracy was checked by comparison with some literature data for reference materials since there were no suitable certified reference materials available. The method was used for the determination of Se compounds in chicory (Cichorium intybus L.) leaves from plants which were cultivated aeroponically with elevated concentrations of Na₂SeO₄ for different periods. Se accumulated efficiently in chicory leaves; up to 480 μg/g after 41 days of exposure, mostly (64%) as Se^VI, i.e. in the form of Se added. Beside inorganic Se, in the extracts from enzyme hydrolysis we also found SeMet (4.2-8.4%) and SeMeSeCys (<DL−0.7%). Some unidentified peaks were also observed in the chromatograms of plant extracts.     

Assessment of 210Po deposition in moss species and soil around coal-fired power plant

In the present study, the depositions of ²¹⁰Po were assessed in the surface soil and some mosses species found in the area around coal fired power plant using radiochemical deposition and alpha spectrometry counting system. The purposes of the study were to determine activity concentrations of ²¹⁰Po in mosses and surface soil collected around coal-fired power plant in relation to trace the potential source of ²¹⁰Po and to identify most suitable moss species as a bio-indicator for ²¹⁰Po deposition. In this study, different species of mosses, Orthodontium imfractum, Campylopus serratus and Leucobryum aduncum were collected in May 2011 at the area around 15 km radius from Tanjung Bin coal-fired power plant located in Pontian, Johor. The ²¹⁰Po activity concentrations in mosses and soil varied in the range 102 ± 4 to 174 ± 8 Bq/kg dry wt. and 37 ± 2 to 184 ± 8 Bq/kg dry wt., respectively. Corresponding highest activity concentration of ²¹⁰Po observed in L. aduncum, therefore, this finding can be concluded this species was the most suitable as a bio-indicator for ²¹⁰Po deposition. On the other hand, it is clear the accumulation of ²¹⁰Po in mosses might be supplied from various sources of atmospheric deposition such as coal-fired power plant operation, industrial, plantation, agriculture and fertilizer activities, burned fuel fossil and forest; and other potential sources. Meanwhile, the main source of ²¹⁰Po in surface soil is supplied from the in situ deposition of radon decay and its daughters in the soil itself.     

Trace elements in natural drugs determined by INAA

Natural drugs are widely used for diuretic, phlegm elimination and stomach invigoration purposes. Seventy-five of the most common remedies used by Chinese people have been subjected to trace element survey analysis by instrumental neutron activition. Within this large number of different natural products, fourteen trace elements (K, Sc, Cr, Fe, Co, Zn, Br, Rb, Cs, La, Sm, Eu, Au and Th) are commonly detected. Among these elements, Fe had the highes: concentration followed by Zn, and Rb, Sm, Eu and Au were found to have the lowest concentations. Although the three groups of natural drugs exhibit a widely different therapeutic action, the concentration ranges of the fourteen elements were very similar. While this suggests no apparent specific role for the trace elements in the drug function, parallels are drawn between the known drug related functions of Rb, Zn, Br, Fe, Co and K and the levels of elements found in the natural drugs. It is concluded that the various natural drugs also provide human benefits through supplements of essential elements such as Fe, Zn, Cr, Sc, Rb and Co.     

Classification of archaeologically stratified pumice by INAA

In the framework of the research program Synchronization of Civilizations in the Eastern Mediterranean Region in the 2nd Millenium B.C. instrumental neutron activation analysis (INAA) was used to determine 30 elements in pumice from archaeological excavations to reveal their specific volcanic origin. The widespread pumiceous products of several eruptions in the Aegean region were used as abrasive tools and were therefore popular trade objects. A remarkable quantity of pumice and pumiceous tephra (several km³ ) was produced by the Minoan eruption ofThera (Santorini), which is assumed to have happened between 1450 and 1650 B.C. Thus the discovery of the primary fallout of Minoan tephra in archaeologically stratified locations can be used as a relative time mark. Additionally, pumice lumps used as abrasive can serve for dating by first appearance. Essential to an identification of the primary volcanic source is the knowledge that pumices from the Aegean region can easily be distinguished by their trace element distribution patterns, as previous work has shown. The elements Al, Ba, Ca, Ce, Co, Cr, Cs, Dy, Eu, Fe, Hf, K, La, Lu, Mn, Na, Nd, Rb, Sb, Sc, Sm, Ta, Tb, Th, Ti, U, V, Yb, Zn and Zr were determined in 16 samples of pumice lumps from excavations in Tell-el-Dab'a and Tell-el-Herr (Egypt). Two irradiation cycles and five measurement runs were applied. A reliable identification of the samples is achieved by comparing these results to the database compiled in previous studies.     

Sampling study in milk storage tanks by INAA

This study investigated the representativeness of samples for assessing chemical elements in milk bulk tanks. Milk samples were collected from a closed tank in a dairy plant and from an open top tank in a dairy farm. Samples were analyzed for chemical elements by instrumental neutron activation analysis (INAA). For both experiments, Br, Ca, Cs, K, Na, Rb and Zn did not present significant differences between samples thereby indicating the appropriateness of the sampling procedure adopted to evaluate the analytes of interest.     

Determination of trace elements in honey by INAA in Turkey

Instrumental neutron activation analysis was applied to the determination of As, Cr, Sb, K, Br, Zn, Fe, Co in Turkish honey. Irradiation time was 6 h underwater at a thermal flux of 10¹³ n cm^–2 s^–1; cooling times of 100 h and 3–4 weeks and counting times of 5000 s and 80.000 sec were used. The detection limit for As is 0.01 ppm for honey matrix under these conditions. A technique was developed for sealing the quartz tube containing the honey with flame.     

Determination of REEs in seawater by ICP-MS after on-line preconcentration using a syringe-driven chelating column

A syringe-driven chelating column (SDCC) was applied to develop an on-line preconcentration/inductively coupled plasma mass spectrometry (ICP-MS) method for preconcentration and determination of rare earth elements (REEs) in seawater samples. The present on-line preconcentration system consists of only one pump, two valves, an SDCC, an ICP-MS, several connectors, and Teflon tubes. Optimizations of adsorption pH condition, sample loading flow rate, and integration range were carried out to achieve optimum measurement conditions for REEs in seawater sample. Six minutes was enough for a preconcentration and measurement cycle using 10 mL of seawater sample, where the detection limits for different REEs were in the range of 0.005 pg mL⁻¹ to 0.09 pg mL⁻¹. Analytical results of REEs in a seawater certified reference material (CRM), NASS-5, confirmed the usefulness of the present method. Furthermore, concentrations of REEs in Nikkawa Beach coastal seawater were determined and discussed with shale normalized REE distribution pattern.     

True coincidence correction for k0-method in INAA of plant materials with well-type detectors

Summary The k₀-method in INAA has been used at CENA/USP Brazil for analyzing geological and biological materials. With the acquisition of a well-type detector, it was realized that the true-coincidence effects, originally corrected by semi-empirical procedures with the in-house k₀-software (Quantu-INAA), would affect the accuracy of results. Thus, new coincidence correction algorithms were developed, based on a theoretical equation for obtaining the correction factors. Validation of the algorithms was performed by analysis of plant certified reference materials.