Energy Dispersive X-ray Fluorescence Technique Research Articles

Compositional characterization of paint sample by neutron and charge particle activation analysis: validation by energy dispersive X-ray fluorescence spectrometry

The elemental composition of the paint was determined by non-destructive nuclear analytical techniques, namely neutron activation analysis (NAA), charge particle activation analysis (CPAA), and energy dispersive X-ray fluorescence (EDXRF). NAA was chosen as the primary method of analysis as there is no matrix effect, requirement of a small quantity of a sample, detection capability down to ppb level, and self-validation. Ba, Ca, and Cr are detected as the major constituents, whereas Co, Hf, Mn, Y, Sr, Sb, W, Zn and Zr were detected at trace levels in the paint sample by NAA. CPAA was also utilized for the analysis, and elements like Ca, Cr, Fe, Sr, Ti and Zr were detected in the sample. The validation of the analytical results obtained in NAA and CPAA was carried out by the EDXRF technique, in which, including Si, most of the transition and high Z elements like Ca, Cr, Fe, Sr, Zr and Ba were detected. Analysis of variance was carried out to establish the statistical indistinguishability and acceptability of the analytical results obtained by these three methods. This study showcases the capability of NAA and CPAA for routine compositional analysis of paint sample without the requirement of a matrix matched standard.

Determination of Sulphur Dioxide (SO<sub>2</sub>) Air Emission of Refined Petroleum Products by Emission Factor Approach for Air Pollution Control

Air pollution control is a safe method for achieving a sustainable environment and can be accomplished by adequately monitoring pollutants that pose significant environmental risks. The combustion of sulfur-containing petroleum products has been a major concern for several decades. Therefore, this study was aimed at determining sulfur levels in refined petroleum products such as Premium Motor Spirit (PMS), Automotive Gas Oil (AGO), and Dual-Purpose Kerosene (DPK). It also investigated the air quality implications of sulfur levels and estimated the contribution of the refinery’s products to sulfur dioxide air emission. Fuel samples were collected from the Warri Refining and Petrochemical Company (WRPC) in Nigeria and analyzed using Ultraviolet-visible spectrophotometer (UV-Vis) and Energy-Dispersive X-ray Fluorescence (EDXRF). Sulfur levels were determined at 425 nm wavelength, and sulfur dioxide air emission were estimated for seven consecutive years from 2010 to 2016 using the emission factor approach. The densities of PMS, AGO, and DPK were 0.77 kg/l, 0.832 kg/l, and 0.82 kg/l respectively. The levels of sulfur in PMS, AGO, and DPK were 2.007 x 10<sup>-4</sup> %, 6.970 x 10<sup>-5</sup> wt%, and 4.233 x 10<sup>-5</sup> wt% respectively from UV-Vis technique and 0.016, 0.087 and 0.029% respectively for EDXRF technique were found below the sulfur limit of 0.015 %, 0.005 % and 0.015 % for PMS, AGO and DPK respectively specified by Standard Organization of Nigeria (SON) specifications of 0.1, 0.5 and 0.15wt% for PMS, AGO and DPK respectively. The annual sulfur dioxide emissions were obtained for seven consecutive years from 2010 to 2016. The results from UV-VIS were observed to have the highest SO<sub>2</sub> emission of 0.1718 tons for PMS in 2011, 0.2593 tons in 2010 for AGO, and 0.0974 tons for DPK in 2010, while the lowest emission was observed to be 0.029 tons for PMS in 2015, 0.0362 tons in 2015 for AGO and 0.0181 tons for DPK also in 2015. The results from EDXRF technique were observed to have the highest SO<sub>2</sub> emission of 13.6939 tons for PMS in 2012, 323.6881 tons for AGO in 2010, and 66.7147 tons for DPK also in 2010, while the lowest emissions for PMS, AGO and DPK were all observed in 2015 to be 2.3122, 45.1872, and 12.4182 tons respectively. The study concluded that the refinery complied with the set requirements.

Solid phase microextraction of rhodamine B in cosmetic samples using ZnS@GO@WMCNTs Nanocomposite with Spectrophotometric Detection

Rhodamine B dye (RhB) has carcinogenicity, genotoxicity, neurotoxicity and toxicity on living cells and therefore its use is prohibited. but it is still secretly used in cosmetics and foods. For this reason, it is important to develop analytical methods for accurate and sensitive analysis of trace levels of RhB dye in cosmetic and food samples. In this study, a new solid phase microextraction method (SPME) was developed for quick and cheap analysis of RhB in cosmetic samples. A new nanohybrid material including graphene oxide (GO), multi-walled carbon nanotubes (MWCNTs) and zinc sulfide nanopartices (ZnS) was synthesized by hydrothermal synthesis method and the new ZnS@GO@WMCNTs nanohybrid material was used as sorbent in simultaneous separation and preconcentration of RhB from cosmetic products by SPME. ZnS@GO@WMCNTs material was characterized by Raman spectroscopy, scanning electron microscopy (SEM), SEM-Mapping and energy dispersive X-Ray fluorescence (EDX) techniques. The effects of experimental parameters such as amount of sorbent, pH of sample solution, sample volume, effects of matrix, eluent solutions on the recoveries of RhB were investigated. RhB dye adsorbed on ZnS@GO@WMCNTs was eluted with acetic acid–ethanol mixture (2:1) and determined by using UV–Visible spectrophotometer at 550 nm. The fact that RhB adsorbed quantitatively on the adsorbent at all pH values shows that strong Van der Waals interactions between the ZnS@GO@WMCNTs and RhB molecules are effective in adsorption. In optimal experimental conditions, the limit of detection (LOD) and preconcentration factor (PF) of the proposed MSPE-UV/Vis spectroscopy procedure were 4.74 and 44, respectively. The MSPE-UV/Vis procedure was successfully applied to the microextraction and determination of RhB in nail polishs ve lipstick samples with recoveries in the range 95–101 %.

Fabrication and characterization of thin 94Zr target with gold backing for nuclear lifetime measurements using DSAM

For lifetime measurements of excited nuclear states in the sub-picosecond range, a thin target with a thick backing of high-Z material is required. To meet these specifications, a thin isotopic94Zr target of thickness 1.14 ± 0.05 mg/cm2, with backing of 4.7 ± 0.2 mg/cm2 thick Au layer, has been fabricated using the cost-effective cold rolling technique at the target laboratory of Inter-University Accelerator Centre (IUAC), New Delhi. The thickness verification and purity check of the fabricated target have been carried out by non-destructive Energy Dispersive X-ray Fluorescence (EDXRF) and Rutherford Backscattering Spectrometry (RBS) techniques. The results of these measurements are in good agreement with each other. The elemental composition, purity and surface morphology have been explored by Energy Dispersive X-ray Spectrometry (EDS) and Scanning Electron Microscopy (SEM) techniques. The fabricated target has been successfully used with a16O ion beam in a recent γ-ray spectroscopy experiment for lifetime measurements using the Doppler Shift Attenuation Method (DSAM) at IUAC, New Delhi.

Heavy Metal Pollution Assessment in the Agricultural Soils of Bonao, Dominican Republic

Heavy metal content in agricultural soils potentially impacts the food chain and human health. The present study assessed the levels of heavy metals in topsoil samples collected within an agricultural region situated in Bonao, Dominican Republic. The Energy-Dispersive X-ray Fluorescence (EDXRF) technique was utilized to measure the concentrations of iron (Fe), manganese (Mn), chromium (Cr), copper (Cu), nickel (Ni), zinc (Zn), lead (Pb), and arsenic (As) in the samples. The assessment of soil pollution status and potential ecological risk (RI) involved the utilization of various soil pollution indices, such as the single pollution index (PI), integrated pollution index (IPI), and enrichment factor (EF). The average total concentrations of Fe, Mn, Cr, Cu, Ni, Zn, Pb, and As were 103,000, 2000, 347, 36, 92, 32, 9.6, and 4.2 mg·kg−1, respectively. The results showed that the Mn, Ni, Cu, and As levels exceeded the Food and Agriculture Organization (FAO)’s recommended levels for healthy agricultural soils. The distribution pattern of each individual metal was different, indicating they had different sources of origin. The average pollution indices indicated low-to-moderate pollution, and the potential ecological risk obtained was low. This study emphasizes the need for soil management practices to mitigate heavy metal contamination for food safety and environmental health.

Assessment of energy dispersive X-ray fluorescence (ED-XRF) for quantification of iodine in non-lyophilized milk.

Iodine represents a fundamental element for human health, with particular regard to thyroid function. Dietary intake of milk naturally rich in iodine becomes of primary importance in the prevention of syndromes related to iodine deficiency. The concentration of iodine in milk is characterized by wide variability, mainly related to animal feed and level of mineral supplementation. Therefore, there is interest in the development of fast analytical techniques which are able to predict milk iodine concentration. The aim of the present study was to investigate the effectiveness of energy-dispersive X-ray fluorescence (ED-XRF) for the prediction of iodine in cow milk. Results showed moderate accuracy of the ED-XRF technique, with a coefficient of determination in cross validation of 0.60. This study represents a first contribution towards the possibility to discriminate milk with high or low iodine concentration, as an essential preliminary step for the introduction into the market of naturally fortified milk.

Heavy metal contamination of surface soils by anthropogenic activities: concomitant ecological and health risk assessment

ABSTRACT The heavy metals in the soil are a condemnatory environmental threat as they expand their toxic effects on the environment as well as human health. The present study is intended to analyse the concentrations of heavy metals (K, Ca, Mg, Ti, Fe, Co, Cu, As, Zn, Rb, Sr, Zr, Pb, and Th) in soil samples congregating near a urea fertiliser factory utilising Energy Dispersive X-ray Fluorescence (EDXRF) technique and evaluate their distinctiveness, emergence and subjection to human. Mean value of Mg, K, Ca, Ti, Fe, Co, Cu, Zn, As, Rb, Sr, Zr, Pb and Th in the sampling area was found 14712, 11828, 8607, 4378, 47358, 10.93, 17.04, 151.57, 8.65, 191.08, 191.42, 263.64, 88.69 and 17.55 mg kg−1 respectively. Geo-accumulation index (Igeo), enrichment factor (EF) and contamination factor (CF) revealed the sampling sites were practically uncontaminated to moderately contaminated, and minimum to moderately enriched by the elements. Besides, a low level of risk was evaluated from the estimated value of the Ecological risk index (RI). Principal Component Analysis (PCA), Correlation Analysis (CA) and correlation coefficient indicated that the geological and the anthropogenic origins have boosted the elemental concentration in the soil samples. Regardless of age, the Hazard quotient (HQ) and Hazard index (HI) values in all three exposure pathways (HQ/HI < 1) and total lifetime carcinogenic risk (TCR < 1E–06) from the complete exposure path stipulated negligible risk and could cause no obvious health hazards on the surrounding populations. However, children manifested potential receptors of heavy metals compared to adults and were more susceptible to carcinogenic and non-carcinogenic risks.

Analysis of Heavy Metals and Other Elements in Soil Samples for its Physicochemical Parameters Using Energy Dispersive X-Ray Fluorescence (EDXRF) Techniques

The present study was conducted to determine the physicochemical properties and the composition of trace elements of soil samples in agriculture lands. This study has been designed to analyze heavy metal contaminations in 12 soil samples collected at a depth 0-20 cm from the agriculture areas of Munshiganj using Energy Dispersive X-Ray Fluorescence (EDXRF) spectroscopy. This study revealed that the maximum Ca, Ti, Mn, Fe, Cu, Zn, Rb, Sr, and Pb contents in soil samples were 76293, 3911, 534, 44652, 57.50, 532, 101.45, 242.11 and 39.31 mg/ kg respectively. A physicochemical study of soil is based on various parameters like soil PH, electrical conductivity (EC), TDS mg/L, Salinity. The value of soil PH found to be 7.53 to 9.24, conductivity was ranging from 22.4-66.5 μs, Total Dissolved Solid (TDS) was ranging from 13.39-37.70mg/L and salinity was ranging 22.40-66.50 μs. Along with the experimental data, several environmental indices (Contamination factor, geo-accumulation index, enrichment factor, pollution load index, Quantification of Anthropogenic Concentration of Metal (QoC) have been identified for comprehensive assessment of our study site, which suggesting that these heavy metals Ca, Ti, Mn, Fe, Cu, Zn, Rb, Sr, and Pb might come in the samples due to anthropogenic activities.

Environmental analysis of heavy metal pollution in Mtondia dumpsite, Kilifi County, Kenya.

Dumping and open burning of waste with no regard to environmental implications is a common occurrence in Kenya. In several health surveys in communities close to dump sites, a wide range of human health problems, such as respiratory symptoms, allergies, irritation of the skin, and gastrointestinal problems, have been reported. The issue of heavy metal pollution brought about by the dump sites has become of concern in recent studies. Heavy metal contamination occurs when their concentrations exceed the recommended limits in the soil, water, or plant resources and have negative effects on humans or animals. The accumulation of heavy metals in agricultural soils is of great concern due to food safety issues, potential health risks, and detrimental effects on the soil’s ecosystems. The samples were obtained through random sampling and analysed in the laboratory using the Energy Dispersive X-ray Fluorescence (EDXRF) technique. The EDXRF technique software was used to calculate the qualitative and quantitative aspects of the heavy metals. SPSS version 22 was used to calculate Pearson's correlation coefficient. It was observed that the soil and plants sampled from the dumpsite recorded higher levels of heavy metals than the control samples. This showed that the soils at the dumpsite were more polluted with heavy metals as compared to those at the farms. The mean concentrations of the heavy metals in soil during the dry season followed the trend Zn&gt;Mn&gt;Pb&gt;Cu&gt;Ni&gt;Co&gt;Cr&gt;As. In conclusion, it was observed that the resources (soil, plants, water, and fish) were indeed polluted with various heavy metals. However, the levels do not exceed the permissible limits set by the WHO and FAO.

Study of bremsstrahlung radiation coming from a transmission type x-ray generator and its application on EDXRF technique

We have demonstrated the use of the bremsstrahlung radiation from a small, portable, transmission type x-ray generator that can be used in energy dispersive x-ray fluorescence technique as a tool to perform non-destructive elemental analysis of solid samples employed in inter-disciplinary science research. As our knowledge goes, till date, this is the first attempt to generate the bremsstrahlung spectrum theoretically from a portable transmission type x-ray generator and compared it with the actual observation. Theoretically generated bremsstrahlung spectra are also found to be in good agreement with the experimentally observed spectra obtained with various operating anode voltages of the x-ray generator. A computer program has been developed utilizing a few atomic parameters to obtain the elemental concentrations in the sample by a single run using the whole bremsstrahlung. The knowledge of incoming x-ray flux, geometry of experimental arrangements are not required in this technique. To validate the technique, we have taken two samples: an Indian one rupee coin of the year 2000 and a NIST made brass sample, whose compositions are well known. We have used these samples to expose to the bremsstrahlung radiation, produced by the operating anode voltages 20, 25, and 30 KV. The relative concentrations of different elements are determined, which is in good agreement with the earlier results.

Experimental measurements of X-rays emission cross sections induced by photons

Abstract The energy-dispersive X-ray fluorescence (ED-XRF) technique has been used for measurements of K α , K β , and total K X-rays emission cross sections induced by photons, as well as K-shell fluorescence yields for pure elements with 22 ⩽ Z ⩽ 49. These metals have been irradiated at 59.54 KeV excitation energy from an 241Am annular radioactive source. The characteristic K X-rays emitted by the targets have been detected with a Silicon drift detector (SDD); the net areas of the K α and K β spectral peaks have been determined using the fitting process of PYMCA software. The obtained experimental values of the K X-ray fluorescence cross sections and the K-shell fluorescence yields were compared to the theoretical calculated ones and also to the experimental results obtained from a different experimental setup using a point source. The obtained values were between (6.84 ± 0.55 b/at.) and (891.0 ± 67.5 b/at.) for pure metals form Scandium to Indium. Experimental values were in good agreement with theoretical values within limits of uncertainty, as well as with the data reported in the literature. Moreover, the experimental determination of K X-ray fluorescence cross-section of scandium (Sc) at 59.54 KeV has not been preceded as far as we know. The value obtained is (6.84 ± 0.55 b/at). This new result obtained maybe contribute to the enrichment of the available databases.

Fabrication of thin Molybdenum backed target using rolling method

A successful attempt was made to fabricate a thin foil of natural Mo target on a thick Au backing with Indium in between to improve adhesion between the foils. Rolling at elevated temperature was considered to fabricate Mo foil while gold foil was fabricated employing conventional rolling technique. The heating of Mo foil under natural environment lead to the oxidation or carbonization on foil surface which was confirmed through Energy Dispersive X-ray Spectroscopy (EDS) measurements. Indium of thickness ∼86μg/cm2 was evaporated on Mo foil to improve adhesion between Mo and Au foils. The characterization of fabricated thin Mo foil was done using the Energy Dispersive X-ray Spectroscopy (EDS) and the Scanning Electron microscope (SEM) techniques. Thickness measurement of the target (Mo-Au) was done using Energy Dispersive X-ray Fluorescence (EDXRF) technique, in the measurements the thickness of the Mo foil and of gold backing are found out to be 1.3 mg/cm2 and 9 mg/cm2 respectively.

“Trace element composition of fine and coarse particles at a background mountain station in Eastern Mediterranean: Assessment aerosol components and their source regions

Components making up aerosol population at a mountain station (1000 m asl) on the Mediterranean coast of Turkey were investigated. Fine (PM2.5) and coarse (PM2.5–10) particle samples were collected at approximately 8 km outside the Marmaris province, on the Mediterranean coast of Turkey. Fifteen elements were measured using energy dispersive x-ray fluorescence (EDXRF) technique. 84%–88% of crustal elements and 48%–51% of anthropogenic elements, except for S, were associated with coarse particles. EFc – Al diagrams showed that relatively high contribution of coarse particles on concentrations of anthropogenic elements is due to coagulation of fine anthropogenic particles on coarse crustal particles. Cluster analysis resulted in seven trajectory clusters. Two of these clusters have potential to bring dust from Sahara and two had potential to bring particles from local sources at western and central parts of Turkey. Concentrations of crustal elements were higher in summer due to limited resuspension in winter. Concentrations of pollution-derived elements were also high in summer due to more effective wet scavenging during winter season. Positive matrix factorization (PMF) analysis resulted in five factors which were identified as sea salt, crustal, local anthropogenic, oil combustion and regional combustion factors. Source regions affecting these anthropogenic components were supported by distributions of PSCF values. Approximately 75% of PM10 mass is accounted for by secondary inorganic ions, crustal material, and sea salt. Dust transported from North Africa accounted for 55%–76% of concentrations of crustal elements, but only 26% of PM10 mass, due to sea salt and secondary ion contribution to PM10 mass concentrations.

Chamotte Clay: A Natural Adsorbent for Separation and Preconcentration of Aluminium

The adsorption behavior of aluminium ions on chamotte clay has been studied in this study. Chamotte clay has been used for the first time for determination of trace levels of aluminium in aqueous solutions. Quantitative adsorption and recovery of aluminium were both rapid and reached an equilibrium in 30 minutes. Aluminium was detected based on the formation of the highly fluorescent Al(III)-morin complex. Two linear calibration graphs were obtained in the range of 0.5-10 µg L-1 and 10-100 µg L-1 with the detection limits of 0.12 µg L-1 and 1.12 µg L-1, respectively. Chamotte clay was characterized by scanning electron microscope coupled with energy-dispersive X-ray spectroscopy, energy dispersive X-ray fluorescence and X-ray photoelectron spectroscopy techniques. Different isotherm models were evaluated and the results showed that the adsorption study was fitted to Freundlich isotherm and a favorable and multilayer adsorption of aluminium was occurred on the heterogeneous surface of the chamotte clay. Thermodynamic and kinetic parameters of aluminium adsorption were also investigated. Various experimental parameters were optimized and the method has been applied to tap and bottled drinking water samples and quantitative recoveries were obtained. The results demonstrated that the chamotte clay, as a natural clay, was expected to be a promising adsorbent for the determination and preconcentration of the trace levels of analyte in real samples.

Correlation Between Toxic Elements and Pesticide Residues in Medicinal Herbs Available in Pharmaceutical Market.

The use of medicinal plants for self-medication of minor health conditions has become a widespread practice in contemporary society. Few consumes, however, question the contamination of these products with toxic factors resulting from the planet's increasingly polluted environment. This paper presents the levels of five toxic elements (As, Cr, Pb, Cd, and Hg) and nine organochlorine pesticides (hexachlorobenzene (HCB), lindane, heptachor, aldrin, dieldrin, endrin, p,p'DDE, p,p'DDD, and p,p'DDT) in 14 brands of regularly consumed medicinal products in Romania. The toxic elements content was determined using energy-dispersive X-ray fluorescence (EDXRF) technique, and organochlorine pesticide residues (OPCs) were quantified using gas-chromatographic method, equipped with electron capture detector (GC-ECD). The results show that in the case of Cr, Cd, and Hg, the concentrations exceeded the limit values established by World Health Organisation (WHO) for raw herbal material. The higher level of OPCs (such as p,p'DDD, p,p'DDT, aldrin, and dieldrin) was found in the samples of Hypericum perforatum-St. John's wort, Crataegus monogyna-hawthorn, and Epilobium parviflorum-hoary willowherb. The correlations between the content of toxic elements and pesticides were determined by statistical analysis. Hierarchical clustering technique was used to detect natural grouping between the toxic elements and pesticides. For herb samples, four clusters were identified, the strongest correlated cluster consisting of Pb, HCB, Cr, and Hg. A further analysis within this cluster suggested that Cr levels are statistically different from the rest of the elements.

Validation of the analytical method using the energy dispersive X-ray fluorescence technique (EDXRF) for application in pharmaceutical sciences

The determination of impurities in raw materials intended for the production of pharmaceutical products is important to guarantee the quality of the final product, as well as to avoid damage to health. Metallic impurities can exhibit toxic effects even at low concentrations and so permissible levels are defined by the regulatory agencies and pharmacopeias. However, few methods are presented in official compendia in Brazil. In this sense, fast, sensitive, and precise techniques such as the energy dispersive X-ray fluorescence technique (EDXRF) must be evaluated for the analysis of metals in materials for pharmaceutical use. This way, therefore, there is the need to investigate the presence of contaminants and their concentration levels. The major goal of this research work was to validate a method for using the Energy Dispersive X-Ray Fluorescence (EDXRF) technique to identify and quantify the chemical composition of raw materials and pharmaceutical products. The methodology used was based on the selection of a microcrystalline cellulose matrix, which was spiked with two classes of contaminant elements, Class 1 (Cd, Pb, As, Hg) and Class 2A (Co, V, Ni) as defined by ICH guideline Q3D. The qualitative and quantitative analyses were carried out using the EDXRF technique, which proved to be quite effective and met all the validation parameters required in the mandatory official compendia (Resolution of the Collegiate Board (RDC) of Brazilian Health Regulatory Agency (Anvisa) nº 166, July 24, 2017), such as selectivity, linearity, precision, detection limit, quantification limit and robustness. This study showed that EDXRF can be used as a technique for detection and quantification of elemental impurities belonging to Class 1 and Class 2A.

Comparison of concentrations of chemical species and emission sources PM2.5 before pandemic and during pandemic in Krakow, Poland

Observations of air pollution in Krakow have shown that air quality has been improved during the last decade. In the presented study two factors affecting the physicochemical characteristic of PM2.5 fraction at AGH station in Krakow were observed. One is the ban of using solid fuels for heating purposes and the second is COVID-19 pandemic in Krakow. The PM2.5 fraction was collected during the whole year every 3rd day between 2nd March 2020 and 28th February 2021 at AGH station in Krakow. In total 110 PM2.5 fraction samples were collected. The chemical composition was determined for these samples. The elemental analysis was performed by energy dispersive X-ray fluorescence (EDXRF) technique, ions analysis was performed by ion chromatography (IC) and black carbon by optical method. In order to identify the emission sources the positive matrix factorization (PMF) was used. The results of such study were compared to similar analysis performed for PM2.5 for the period from June 2018 to May 2019 at AGH station in Krakow. The PM2.5 concentration dropped by 25% in 2020/2021 in comparison to 2018/2019 at this station. The concentrations of Si, K, Fe, Zn and Pb were lowering by 43–64% in the year 2020/2021 in comparison to 2018/2019. Cu, Mn, Zn and Pb come from mechanical abrasion of brakes and tires while Ti, Fe, Mn and Si are crustal species. They are the indicators of road dust (non-exhaust traffic source). Moreover, the annual average contribution of traffic/industrial/soil/construction work source was reduced in 2020/2021 in comparison to 2018/2019. As well the annual average contribution of fuels combustion was declining by 22% in 2020/2021 in comparison to 2018/2019. This study shows that the ban and lockdown, during COVID-19 pandemic, had significant impact on the characteristic of air pollution in Krakow.

Applications of energy dispersive X-ray fluorescence technique in metallic cultural heritage studies

• Synthesise the physical principles of EDXRF and compare different spectrometers. • Review the applications of EDXRF in the study of metallic heritage pieces. • Discuss about the advantages and limitations of the technique through case studies. Cultural heritage is a legacy that allows the expression of values and characteristics of different civilisations over time. Thus, the study of those artworks and their conservation is of paramount importance. In particular, the preservation and restoration of metallic artefacts is a challenge, as these materials are often subjected to corrosion and degradation, originating complex multilayered structures. Characterising materials that compose metallic artworks, as well as possible corrosion products, is extremely useful to understand the composition and evolution of their surface, guiding conservation and restoration procedures that are adapted for each piece. This characterisation must be selective, that is, allow for differentiating all the compounds present in the piece. Ideally, the characterisation technique used for the analysis should be non-destructive and should not modify aesthetic aspects of the artwork's surface. Portable techniques are also a desirable option, as they allow the characterisation of pieces that cannot be moved to a laboratory or sampled. In this context, X-ray fluorescence spectroscopy is a powerful tool that has been used by researchers and conservators in the characterisation of metallic materials and their corrosion products. In this paper, we review the principles, advantages and limitations of energy dispersive X-ray fluorescence spectroscopy applied to metallic cultural heritage studies.

Elemental and Chemical Phase Analyses of Ras-Family Ayurvedic Medicinal Products.

Fifteen Ayurvedic medicines of Ras-family (herbo-mineral-metallic preparations) from three reputed manufactures were analysed for elemental quantification and their chemical phase identification using the energy-dispersive (ED) and wavelength-dispersive (WD) X-ray fluorescence (XRF) techniques, and powder X-ray diffraction (XRD) technique, respectively. The low-Z elements C, H, N, S and O constituting a major portion of these medicines were also determined by CHNSO analyser and further used as input for XRF analyses. The elements of concern, Hg, Pb and As, are identified in different medicine products with disquiet concentration values (maximum concentration values range ~ 4-10%) and that too with substantial variations in the products from different manufacturers. These elements are identified mainly in the cinnabar (α-HgS)/metacinnabar (β-HgS), litharge (PbO) and alacranite (As4S4) phases in different medicines. Keeping in view the high concentration of chemicals of the Hg, Pb and As elements in the Ras-family medicines, it is vitally required to investigate their bioaccessibility and surmise the associated toxicological aspects. It is suggested that the formation of the bioaccessible toxic chemical forms of the Hg, Pb and As elements be avoided during preparation of the mineral ingredients or these soluble chemical forms be removed at suitable stage of the preparation. In view of large variations observed for the Hg, Pb and As based ingredients in the Ras family Ayurvedic medicine products from different manufacturers, adequate quality control mechanisms and production regulations are recommended.

Assessment of the Enrichment of Heavy Metals in Coal and Its Combustion Residues.

Coal-fired thermal power plants remain one of the main sources of electricity generation in Turkey. Combustion of coal creates coal ash and slag, which are often stored in landfills located near residential and agricultural fields, increasing the potential for high environmental contamination and health risks. This study investigates the content and enrichment factor (EF) of heavy metals in pulverized lignite coal and its combustion residues from the Kangal lignite coal-fired thermal power plant situated in the Central Anatolian Region of Turkey. The concentration of heavy metals (Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Sr, Zr, Cd, Hg, and Pb) in lignite coal, slag, and fly ash samples were analyzed using an energy dispersive X-ray fluorescence technique. The concentration of Fe is highest while Hg concentration is lowest in the samples. The concentrations of heavy metals are higher in slag and fly ash samples than in lignite coal. Average values of EF (related to Earth’s crust average) revealed that extreme enrichment has been shown by arsenic and mercury in lignite coal and fly ash samples while very high enrichment has been shown in slag samples.