Speciation of lead in soils and relation with its concentration in fruits

The lead concentrations of the fruit samples were determined by using slotted tube atom trap (STAT)-enrichment-flame and graphite furnace atomic absorption spectrometry (FAAS and GF-AAS). The soil samples related to these fruits were also analysed for Pb after extraction with various chemical reagents. The relation between the fruit-lead and soil-extractable lead concentrations was examined in order to explain the bioavailability of lead. A linear relation was observed between the hot Na₂EDTA extraction-soluble Pb contents in the soil and the Pb concentrations in the mulberry (R²=0.95), strawberry and apple grown on these soils. Probable chemical forms of lead in soil were evaluated. Acceptable agreement (at least 91%) was achieved between the results of STAT-enrichment-FAAS and GF-AAS.     

Determination of Heavy Metals in Soil Extracts and Plant Tissues at Around of a Zinc Smelter

Abstract

Extractable contents of heavy metals such as Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb and Bi in soil and plant tissue samples (fruit, leaf, twig and root) collected, along a distance of 1100 m to the West, from the surroundings of a metallurgical factory producing mainly zinc, cadmium and lead were determined by flame atomic absorption spectrometry (FAAS). In addition, the determinations of Ca and Mg, macro nutrient elements for plants, were also performed. Three extractant solutions were used for dissolution of soil samples, namely aqua regia (1 HNO₃₊ 3 HCl) for total metal analysis, 1 mol L^?1 ammonium acetate for exchangeable metal contents, and a dilute acid mixture (0.1 M HCl in 0.025 M H₂SO₄) for acid soluble metal contents. A mixture of HNO₃ and HClO₄ was used to analyze the fruit samples. The analyses of the leaf, the twig, and the root tissue samples were made by dry ashing method. The detection limits of the metals were in the range of 0.04 to 0.45 μg/mL for all soil extracts and 0.01 to 1.50 μg/mL for the fruit samples. The recovery values for all the determinations were higher than 95%. The results obtained from the analyses of plant tissue and soil samples were evaluated using linear correlation analysis and concentration factors to identify the effect of the factory near the grape-vine area.     

Geochemistry study of soil affected catastrophically by tsunami disaster triggered by 2004 Indian Ocean earthquake using a fourth harmonics (λ = 266 nm) Nd:YAG laser induced breakdown spectroscopy

In this work, laser induced breakdown spectroscopy (LIBS) analysis of the soil samples collected from Aceh, a place in Indonesia worst affected by 2004 Indian Ocean tsunami, was conducted. In the LIBS experimental system, a high energy pulsed laser beam was focused on the tsunami affected soil samples and the atomic emission lines, originating from the laser induced plasma were recorded using locally developed laser induced breakdown spectrometer. Our results show that the concentrations of many elements especially terrestrial markers, namely titanium, iron, and carbonate marker such as magnesium, are higher in the tsunami-affected samples than that in the unaffected samples collected from the same neighborhood. The quantification of Ti, Fe and Mg were carried out using Ti II 334.94, Fe I 438.35, and Mg I 277.98 nm atomic transition lines respectively by drawing the calibration curve by preparing the samples of known concentrations in unaffected soil matrix. In order to ensure accurate quantification, the local thermal equilibrium of the laser-induced plasma was verified using Mc Writher criterion, for which the plasma temperature was estimated using linearized Boltzmann plot for six iron atomic transition lines and the electron number density in the plasma was estimated using Stark broadened Fe I 540.4 nm atomic lines. The estimated temperature and electron number density of the laser induced plasma are 9642 K and 3.5 × 10¹⁶ cm^?3 respectively. The concentrations of Ti, Fe and Mg in tsunami unaffected soil are 0.09, 3.2 and 0.02 w/w% and in tsunami affected soil are 0.14, 7.9 and 0.048 w/w% respectively. These values are in good agreement with XRF data. The elemental ratios extracted from LIBS signal intensity revealed that LIBS emission intensity ratios of several elements, such as Si/Ti, Al/Ti and Sr/Ba are potential candidates as the distinctive geochemical signature for identification the soil impacted and unimpacted by the 2004 Indian Ocean giant tsunami. The advantage of using LIBS for the elemental analysis is that the sample can be analyzed in its pristine form without any need cumbersome sample preparation method, which has the risk of bringing in external additives through chemicals used for the sample preparation. Other advantages of LIBS technique are that the analysis can be in situ and can be carried out remotely.     

Statistical Evaluation of Bioavailability of Metals to Grapes Growing in Contaminated Vineyard Soils using Single Extractants

This article describes the statistical evaluation of concentrations of Cd, Co, Cr, Cu, Fe, Mn. Ni, Pb. Zn, Ca. and Mg metals determined in twenty-two grape and corresponding soil samples from around a zinc smelter in Kayseri. Turkey. In the analyses of soil samples. three different extraetants. 0.1 M HCl in 0.025 M H₂SO₄, 1 M NH₄OAc, and aqua regia (1HNO₃ + 3HCl), were used to extract and determine the leachable metal contents which are acid soluble, exchangeable, and total. respectively. A mixture of HNO₃ and HCIO₄ was used to dissolve grape samples. The determinations of metals were performed by flame atomic absorption spectrometry (FAAS). The analytical data were evaluated by using principal component analysis (PCA). hierarchial cluster analysis (HCA), correlation analysis (CA), and enrichment factors (EF). The relationship between the grapemetal and soil-extractable-metal concentrations was examined to evaluate the bioavailability of metals in soil to grape samples. As a consequence of statistical evaluations. Cd, Pb, Zn. Mn. and Fe labile levels in soil were related to total grape-metal contents indicating the method’s suitability for bioavailability studies in polluted soil–plant systems.     

Elemental analysis of dust trapped in air conditioner filters for the assessment of Lahore city’s air quality

A study was undertaken to assess the air quality of Lahore by the elemental analysis of air conditioner (AC) filter dust samples collected from 15 different commercial sites. Samples were prepared using the Leeds Public Analyst Method and were analyzed using instrumental neutron activation analysis (INAA) for up to 31 elements. The elements Al, As, Ba, Ce, Co, Cr, Cs, Fe, Hf, K, La, Lu, Mn, Na, Nd, Rb, Sc, Sm, Sn, Ta, Th, Yb and Zn were detected in all 15 samples whereas the remaining elements have been detected in fewer samples; i.e. Mg, Sb and Tb were detected in 14 samples, Br and V in ten samples, U in nine samples and Ca and Ti in eight samples only. Al, Ca, Fe, K, Mg and Na were determined in all samples at percentage levels. The concentrations of most elements were found to lie around the mean values for the 15 samples studied and were not orders of magnitude different. However the concentrations of Ca, Mg, Sn and Zn were found to be more variable and were found to be dependant on activities such as construction, fruit and vegetable handling, tin plating and transport, respectively.     

Accumulation of selected metals in the fruits of medicinal plants grown in urban environment of Islamabad,Pakistan

The present study is based on the measurement of selected metals (Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Pb, Sr and Zn) in the fruits of eight medicinal plants (Carrisa opeca, Phyllanthus emblica, Solanum nigrum, Zizyphus nummularia, Zizyphus mauritiana, Physalis minima, Opuntia dillenii and Phoenix dactylifera) and relevant soil samples by atomic absorption spectrometry. Highest average concentrations of Cu (14.4 mg/kg), Cr (19.0 mg/kg), and Zn (125 mg/kg) were found in the fruits of P. minima, C. opeca and Z. nummularia, respectively, while O. dillenii showed the elevated mean levels of Cd (3.49 mg/kg), Sr (61.4 mg/kg), Mg (0.21%), Ca (6.62%) and Mn (44.6 mg/kg). However, highest average levels of Pb (41.7 mg/kg) and Co (38.4 mg/kg) were found in Z. mauritiana. Overall, most of the fruit samples showed higher contributions of Ca and Mg, followed by Fe, Zn, Co and Pb. In the case of soil samples, highest concentration was observed for Ca, followed by Fe, Mg, Mn and Sr, while lowest concentration was shown by Cd. Bioaccumulation factors exhibited significantly higher accumulation of Co (0.813–1.829) and Pb (0.060–2.350) from the soil to the fruits. Principal component analysis revealed significant anthropogenic contributions of Pb, Fe and Co in the fruit samples. Contamination factors and enrichment factors of Cd and Pb in the soil indicated very high contamination and extreme enrichment of these metals.     

Assessment of natural radioactivity and heavy metals in water and soil around seismically active area

The natural radioactivity concentration and some heavy metals in various water and soil samples collected from seismically active area have been determined. Gross-alpha and beta concentrations of different 33 water samples and some heavy metal (Fe, Pb, Cu, K, Mn, Cr and Zn) concentration in 72 soil samples collected from two major fault systems (North and East Anatolian Active Fault Systems) in Turkey have been studied. This survey regarding gross-alpha and beta radioactivity and some heavy metals concentrations was carried out by means of Krieger method using a gross-alpha and beta-counting system and atomic absorption spectrometry (AAS), respectively. Also, gross annual effective dose from the average gross-alpha activity in waters were calculated.     

Investigation of heavy-metal uptake by vegetables growing in contaminated soils using the modified BCR sequential extraction method

The heavy metal (Cu, Fe, Co, Ni, Cd, Cr, Pb, Zn, and Mn) concentrations in soils and in vegetable samples, i.e. lettuce (Lactuca sativa L.), parsley (Petroselinum crispum), dill (Anethum graveolens), and onion (Allium cepa L.), taken from three urban vegetable gardens in Kayseri, Turkey, were determined by FAAS. The modified three-step sequential extraction procedure proposed by the European Bureau of References (BCR), now the Standards, Measurements and Testing Programme, was used in order to evaluate trace elements mobility in soil samples, and heavy-metal uptake by vegetables. Three operationally defined fractions were isolated using the BCR procedure: acid extractable (i.e. bound to carbonates), reducible (bound to Fe/Mn oxides), and oxidizable (bound to organic matter and sulphides). The vegetable samples were prepared to analysis using the wet-ashing procedure. To estimate the accuracy of the method used in analysis of the vegetable samples, the standard reference material (NIST SRM 1573a, Tomato leaves) was used. The results of recovery for all the elements were relatively satisfactory (87.7–108%). For the soil samples, the recovery values were calculated by proportioning the sum of the steps of the BCR procedure to those of the pseudototal digestion (i.e. aqua regia). In soils, the mobility of heavy metals followed the order Mn>Cd>Cu>Pb>Zn>Cr>Ni>Co>Fe. The relationship between the vegetable–metal and soil–extractable metal concentrations was examined in order to evaluate the bioavailability of metals, and the positive correlation, especially for the first (i.e. water, acid-soluble and exchangeable fraction) and for the third (i.e. oxidizable fraction) extraction steps, was obtained.     

Metals content of soil,leaves and wild fruit from Serbia

The concentrations of Zn, Mn, Fe, Pb, Ni, Cu and Cd in soil, leaves and edible wild fruit (Crataegus laevigata L., Cornus mas L. and Prunus spinosa L.) from southeast Serbia were determined by atomic absorption spectroscopy. Metal translocations from soil to fruit were calculated as well as their oral intake and health risk indices. Positive correlations were found among metal concentrations in soil, leaves and fruit.      

Distribution of trace and minor elements in hungarian spice paprika plants

Detailed investigations were carried out to study the distribution of trace and minor elements in different parts (fruit, seed and rib, peduncle, stem, leaf, root) of ripe Hungarian spice paprika plants. Two varieties of paprika plants were analyzed for their Cl, Co, Fe, K, Mg, Mn, Na, Rb, Sc, V and Zn content by non-destructive neutron activation analysis. The results showed that the iron contents of the samples were much higher than those of the other trace elements. For the trace elements Co, Fe, Mn, Sc, V and Zn a considerable enrichment was observed in the leaf, while the Rb and K, Na, Mg showed accumulation mainly in the peduncle. In the other parts (fruit, seed and rib, stem) of the paprika plants no significant enrichment of trace elements was found. Since some of the elements investigated may have been partially eluted during the cleaning of the roots with distilled water and, on the other hand, if the cleaning was not intensive enough, some soil particles could be retained on the samples, the data obtained for the roots should be considered with precaution.     

模拟酸雨对土壤中铁、锰、锌的浸出特征

酸雨是指pH值小于5·6的大气降水,它不仅危害土壤,还通过土壤间接地危害整个生态系统,因此生态系统酸沉降的承受能力很大程度上取决于土壤对酸雨的敏感性〔1,2〕。我国能源以煤炭为主,大气中硫、氮含量较高,酸雨中SO42:-NO3-的比值范围大致在4:1到15:1之间〔3〕。同时,我国酸雨主要分布在长江以南地区,这正好与酸性土壤分布区相重叠,很大程度上加剧了对土壤的破坏程度。本文用ICP-AES法研究了在模拟酸雨作用下,土壤中生物必要元素Fe、Mn、Zn的释放水平和释放特征。1实验部分1.1仪器及工作条件电感耦合等离子体-原子发射光谱分析仪(IC…     

Trace elements distribution and post-mortem intake in human bones from Middle Age by total reflection X-ray fluorescence

The purpose of the present work is to investigate the suitability of TXRF technique to study the distribution of trace elements along human bones of the 13th century, to conclude about environmental conditions and dietary habits of old populations and to study the uptake of some elements from the surrounding soil.In this work, we used TXRF to quantify and to make profiles of the elements through long bones. Two femur bones, one from a man and another from a woman, buried in the same grave were cross-sectioned in four different points at a distance of 1 cm. Microsamples of each section were taken at a distance of 1 mm from each other.Quantitative analysis was performed for Ca, Mn, Fe, Cu, Zn, Sr, Ba and Pb. Very high concentrations of Mn and Fe were obtained in the whole analysed samples, reaching values higher than 2% in some samples of trabecular tissue, very much alike to the concentrations in the burial soil. A sharp decrease for both elements was observed in cortical tissue. Zn and Sr present steady concentration levels in both kinds of bone tissues. Pb and Cu show very low concentrations in the inner tissue of cortical bone. However, these concentrations increase in the regions in contact to trabecular tissue and external surface in contact with the soil, where high levels of both elements were found. We suggest that contamination from the surrounding soil exists for Mn and Fe in the whole bone tissue. Pb can be both from post-mortem and ante-mortem origin. Inner compact tissue might represent in vivo accumulation and trabecular one corresponds to uptake during burial. The steady levels of Sr and Zn together with soil concentration lower levels for these elements may allow us to conclude that they are originated from in vivo incorporation in the hydroxyapatite bone matrix.     

Size-based speciation of iron in clay mineral particles by gravitational field-flow fractionation with electrothermal atomic absorption spectrometry

Gravitational field-flow fractionation (FFF) coupled to UV and ETAAS detectors has been tested for micron-size particles in the range of 5–20 μm using three Fe-rich clay samples. The iron content estimated after aqua regia extraction was about 20–40 mg kg⁻¹. The ETAAS analysis was performed both off-line from collected fractions and in an online continuous sampling mode using a specially designed flow through vial placed in the autosampler of the ETAAS. Comparison of the direct injection method with total analysis after aqua regia digestion shows that slurry injection of the dilute samples in the gravitational field-flow fractionation (GrFFF) effluent is quite efficient in these samples. In the majority of cases, more than 90% recovery was obtained for the slurry injection method. Fe mass-based particle size distributions and Fe concentration versus particle diameter plots can be generated using certain assumptions. This provides detailed information on size-based speciation of particulate samples. Generally, the Fe concentrations in the particles decreased slightly with an increase in particle size as is often found for soil and sediment samples.     

Effect of nitrate on the determination of iron concentration in phytoplankton culture medium by liquid scintillation counting (LSC) method using 55Fe as radioisotope tracer

Liquid scintillation counting (LSC) method using a radioisotope tracer has several advantages such as simple procedure, high sensitivity and low detection limit, and has been used for the determination Fe concentrations in water samples. Several factors such as nitrate concentration, pH, chelating ligand affect the efficiency of this method in the determination of iron (Fe) in waters. In this study, the effect of nitrate in phytoplankton culture medium on the determination of Fe concentration by LSC method using ⁵⁵Fe radioisotope tracer was evaluated. The measured Fe concentrations in the medium were lower than its added concentration (1.5 μM) when liquid samples contain nitrate. Fe concentrations decreased exponentially as nitrate concentrations increased up to 2.64 mM, reaching a constant value of 1.31 μM Fe at nitrate concentrations higher than 2.64 mM. A correction factor (f = 1.14) was calculated from the decrease rate of Fe concentrations at different nitrate concentrations in the phytoplankton culture medium. This correction factor can be used to correct the measurement values of Fe concentrations in phytoplankton culture medium obtained from LSC method. Our results showed that up to 94 % of the added Fe can be determined by LSC using ⁵⁵Fe radioisotope tracer. The remaining 6 % was probably bound to the walls of the culturing vessel. This method is also applicable for the measurement of Fe size-fractionation in phytoplankton culture medium.     

Relationship between vegetable metal and soil-extractable metal contents by the BCR sequential extraction procedure: chemometrical interpretation of the data

The contents of heavy metals in soil and vegetable samples collected from an urban garden in Kayseri, Turkey, were investigated. Both wet- and dry-ashing methods were used for dissolving vegetable samples. A sequential extraction procedure proposed by the Commission of the European Communities, Community Bureau of Reference (now superseded by the Standards, Measurement and Testing Programme, SM&T) was applied to the soil samples to extract the metals which are present in exchangeable and acid soluble (i.e. bound to carbonates), reducible (bound to Fe/Mn oxides), and oxidisable forms (bound to organic matter and sulphides) in the soil samples. Trace metals in the soil and vegetable samples were determined using flame atomic absorption spectrometry (FAAS). The total metal contents acquired by summing of metal levels in all the sequential extraction steps were compared with pseudo-total metal levels obtained with aqua regia for all the soil samples. The recovery values obtained by proportioning the results obtained by the BCR procedure to those of the pseudo-total digestion were found to be satisfactory. The limits of detection for the elements investigated were in the range of 0.04 to 0.59?µg?mL^?1 for all the extraction stages of the BCR procedure. Similarities among the variables were identified by correlation analysis, principal component analysis and hierarchical cluster analysis. The relationship between the vegetable metal and soil-extractable metal concentrations was examined in order to evaluate the bioavailability of metals.     

Systematic Identification of Analytical Indicators to Measure Soil Load on Plants for Safety Assessment Purposes

Abstract

Contaminants in soil can be transferred to humans and other biota when soil dust on plants is ingested as food. Measuring how much soil is on plants, in the absence of artificial tracers or contaminants, is difficult because of the very small amounts involved and the confounding effect of absorption of elements through roots. However, measurements of soil load are essential for assessment modelling. We compared the ability of several analysis strategies, involving naturally occurring elements, to predict the soil load on plants. Large samples of 12 vegetable and fruit crops were collected, along with corresponding soil samples. An independent measure of soil load on the crop samples was derived from a combination of gravimetric measurements, including loss on washing and the acid-insoluble ash content. The best agreement between the elemental-abundance and the gravimetric methods was for Sr in the plant acid-insoluble ash. Through a systematic process of elimination, we conclude that analyses of the acid-insoluble ash fraction of the plant samples for Al, Ba, Fe, Si, Sr and Ti are most reliable. If analyses are to be restricted to the full plant ash, then the choice of analytes is restricted to Al, Fe, Si and Ti. Soil loads in our study averaged 20 mg soil kg^?1 dry plant for leafy tissues and 2 mg soil kg^?1 for fruits, and washing decreased soil loads about 1.5 fold.     

Neutron activation analysis of snow and ice in Antarctica

In order minimize the possible contamination during storing and pre-treatment of such pure samples as ice and snow collected in Antarctica, trace elements in experimental tools such as bottles, beakers, tubings and filters were determined by neutron activation analysis. By using well certified tools, ice and snow samples from Antarctica and high mountains in China and in Japan were analyzed. Relative concentrations of volatile elements such as Zn, Cd, As, Sb or Ag to Al or Fe which are major components in the earth crust were found to be 10 to 1000 times higher than in the ordinary soil for the samples from Antarctica and Mt. Naimonanyi in China.     

Uptake of cadmium, copper, iron, manganese, and zinc in mushrooms (Boletaceae) from Croatian forest soil.

The concentration of trace elements (Cd, Cu, Fe, Mn, and Zn) was measured in different species of mushrooms (Boletaceae) and correlated with corresponding elements in soil. Five different species of Boletaceae mushrooms and soil samples were collected from forests of Varazdin county in Croatia. Trace elements were analyzed by atomic absorption spectrometry in mushrooms and in EDTA-extracted soil. The results showed that Cd, Cu, and Zn are concentrated in mushroom tissue from soil with transfer factors (mushroom/soil) of 27.0,10.5, and 12.5, respectively. Cadmium incorporated much less in Leccinum (mean 0.73 mg/kg dry weight) than in Boletus, Xerocomus, or Gyroporus (respective means, 6.8, 8.4, and 12.3 mg/kg). Copper and Zn were accumulated in all collected mushrooms (14.7-35.6 and 109-179 mg/kg, respectively) with no difference among species. There was no accumulation of Fe and Mn in mushrooms, but concentrations differed between species, with lowest values in Leccinum. Iron varied from 31 to 878 mg/kg and Mn from 2.9 to 409 mg/kg. Correlations between elements in mushrooms and soil were significant only for Mn. Because no significant correlations for Cd, Cu, Zn, and Fe between mushrooms and soil were found, more studies are needed with only one species of mushrooms collected at locations with different levels of soil contamination. In spite of higher concentrations of Cd in some Boletaceae species, it is assumed that Cd intake through moderate mushroom consumption remains below suggested Provisional Tolerable Weekly Intake (FAO/WHO).     

Transfer factors of 31 elements in several agricultural plants collected from 150 farm fields in Aomori, Japan

Soil-to-plant transfer factors of 31 stable elements were determined by neutron activation analysis. The transfer factor is one of the important parameters used to estimate the internal radiation dose from radionuclides through food ingestion. In the present study, 12 species of agricultural plants such as root crops, fruit vegetables, green vegetables and pasture grasses, and their soils were collected from 150 farm fields in Aomori prefecture, Japan. The elements described are those that could be detected by this method, which include both essential and nonessential elements for plant growth. The concentrations of individual elements in the cultivated soil samples for each plant were similar in values and their standard deviations were within one order of magnitude, because of the relatively narrow geographic sampling area. The elements were classified into two groups, each having different transfer factor characteristics. In the first group of elements there was an inverse correlation between the transfer factors and the concentrations of elements in the soil, especially for Cl, K and Ca. In the second group, especially Sc and Co, however, the transfer factors were independent of the concentrations of elements in the soil.     

Validation of a solid-phase microextraction method for the determination of organophosphorus pesticides in fruits and fruit juice

A method for the determination of organophosphorus pesticides (diazinon, fenitrothion, fenthion, quinalphos, triazophos, phosalon and pyrazophos) in fruit (pears) and fruit juice samples was developed and validated. The samples were diluted with water, extracted by solid-phase microextraction (SPME) and analysed by gas chromatography (GC) using a flame photometric detector in phosphorous mode. Limits of detection of the method for fruit and fruit juice matrices were below 2 micrograms/kg for all pesticides. Relative standard deviations for triplicate analyses of samples fortified at 25 micrograms/kg of each pesticide were not higher than 8.7%. Recovery tests were performed for concentrations between 25 and 250 micrograms/kg. Mean recoveries for each pesticide were all above 75.9% and below 102.6% for juice, and between 70 and 99% for fruit except for pyrazophos in the fruit sample (with mean recovery of 53%). Therefore, the proposed method is applicable in the analysis of pesticides in fruit matrices and the use of the method in routine analysis of pesticide residues is discussed.