Energy Dispersive X-ray Fluorescence Spectrometer Research Articles

Determination of the chemical composition and Raman characterization of barite samples from Denizli and Akdamadeni, Turkey, using Energy Dispersive X-ray fluorescence and Raman microscopy

Accurate analysis of samples is very important for scientists working in many fields. XRF device is used very frequently especially in mine analysis. However, researchers are trying to reach accurate results with many different analysis methods. In addition to the known analysis methods, alternative research methods also guide the studies. In this study, two barite ore samples, collected from two regions of different nature (Denizli and Akdağmadeni) by following specified sampling methods, were analyzed using Confocal Raman Spectroscopy (CRS) and Polarized Energy Dispersive X-Ray Fluorescence (PEDXRF) spectrometer. The first sample was from a metamorphic basement, and the second was from an alkali syenite rock unit. The main objective of this paper is to compare the optical characteristics of these two different barite samples collected from different regions under a polarized microscope, using CRS and PEDXRF. The results of polarized microscopy analysis showed that the barite taken from Denizli is associated with calcite. On the other hand, the barite taken from Akdağmadeni is associated with galena, celestite, and quartz. Two different colors were observed in the barite samples. CRS and PEDXRF results showed that the barites collected from two regions differed in mineral association, chemical composition, and physical properties. The accuracy of the chemical analysis technique was ensured by following USGS standards, GBW 7109, and GBW-7309 Sediment. Barite ores were analyzed using HR-800 (HORIBA-Jobin Yvon) CRS and a polarized microscope (Leica DMLP). Thanks to this study, it has been shown that mineral analyzes can be performed with an accuracy close to XRF with Confocal Raman spectroscopy. Confocal Raman spectroscopy will also guide researchers for mineral analysis.

Particulate Matter (PM2.5) Characterization, Air Quality Level and Origin of Air Masses in an Urban Background in Pretoria.

Several sources have been identified as contributing to the concentration of ambient fine particulate matter, which has been associated to a variety of health issues. The chemical characteristics and sources of trace elements in PM2.5, as well as the air quality index, were investigated in this study. Twenty four-hour fine aerosol particles were collected in an urban area in Pretoria, South Africa, from April 2017 to April 2018. Eighteen trace elements were determined using an XEPOS 5 energy-dispersive X-ray fluorescence (EDXRF) spectrometer, while black and organic carbon were estimated using an optical transmissometer from the samples collected. The HYPLIT model (version 4.9) was used to estimate air mass trajectories. Health risk was calculated by comparing it to the World Health Organization's air quality index (AQI). The overall mean PM2.5 concentration of the collected sample equals 21µg/m3. Majority of PM2.5 exceedances were reported during mid-autumn and winter seasons, as compared to daily WHO guidelines and South African standards. S had the highest concentrations, greater than 1µg/m3. Ni, Se, Br and Sb showed they were extremely enriched, (EF > 10) and suggestive of anthropogenic or non crustal origin The 24-h PM, soot, BC and OC were significantly different by the geographical origin of air masses (p < 0.05). The AQI showed that 70% of the samples showed levels above the AQI range of good and healthy air. The findings include details on the concentration, composition, and potential sources of fine PM2.5, which is essential for policy formulation and mitigation strategies in South Africa's fight against air pollution.

Assessment of Potential Human Health Risks from Exposure to Select Heavy Metals in Road Dust Around Mining Sites in Carrascal, Surigao Del Sur, Philippines

Road dust samples around human settlements nearby mining areas in Carrascal, Surigao del Sur, Philippines were investigated to quantify the levels of chromium (Cr), nickel (Ni), manganese (Mn) and zinc (Zn) and assess the potential health risks from selected heavy metals. Metal concentrations of chromium (Cr), nickel (Ni), manganese (Mn) and zinc (Zn) in road dust were analyzed using Energy Dispersive X-ray Fluorescence (EDXRF) spectrometer. Analytical results showed that the average concentrations of Cr, Ni, Mn, and Zn were very high at 15,668, 14,814, 7,054, and 684 mg/kg, respectively. Measured concentrations exceeded standards stipulated in international regulations and guidelines by several orders of magnitude. Mortality and morbidity cases with causes probably related to dust inhalation (e.g., upper respiratory tract infection and pneumonia) noticeably increased during the peak years of mining operations. Non-carcinogenic health risk assessment revealed that children are more prone to develop non-carcinogenic health effects than adults (HI values >1 for Cr, Ni and Mn for children and only Cr for adults), owing to their smaller body weight and activities exposing them to these metals via the ingestion route. Assessment of carcinogenic risk value or the lifetime probability of an individual to develop cancer due to exposure to Ni revealed that such risk is negligible. This study suggests that mining companies and government units should proactively take measures to reduce dust exposure (e.g., dust inhalation) of mine workers and residents in nearby communities. In developing management measures, children should be provided with attention given their greater risk of developing dust-related illnesses and diseases.

A comparative study of heavy metal exposure risk from the consumption of some common species of cultured and captured fishes of Bangladesh

Food toxicity and health risks due to heavy metals exposure through fish consumption have become a major concern for this present era. Since, both cultured and captured fishes are largely consumed in Bangladesh, a comparison of heavy metals between those fishes are must. Seven sample species were collected from a tributary of the Meghna River at Lakhai Kheyaghat, Habiganj, Bangladesh and fish market of Dhaka, Bangladesh. Energy Dispersive X-Ray Fluorescence (EDXRF) Spectrometer were used to measure the metal concentrations. The sequence of metal concentration in the flesh of fishes was Fe > Zn > Cu > Pb>Hg for both fish categories with mean concentrations (mg kg−1) of 69.8 ± 7.5 > 56.42 ± 8.59 > 19.52 ± 2.63 > 0.44 ± 0.18 > 0.39 ± 0.04 respectively for cultured fishes (n = 21). Statistically, mean Cu, Zn, and Pb concentrations from captured fishes flesh samples were not significantly different from cultured fishes (p > 0.05) when analyzed with non-parametric Kruskal-Wallis test. Pb carcinogenicity from the cultured fishes was measured a value of 2.5E-05 for children exceeding the prescribed limit by 25 times which indicates a substantial risk for lifelong exposure. Summarizing the results, the Toxicity Scores (TS) has shown substantial rate of possibility for study area inhabitants to be exposed to heavy metals through heavy metal contaminated fish consumption, specially cultured fishes.

FUXYA2020: A Low-Cost Homemade Portable EDXRF Spectrometer for Cultural Heritage Applications

The project FUXYA2020 was intended to design and prototype a low-cost basic energy dispersive X-ray fluorescence spectrometer for all those cases where there is not enough financial support to buy a commercial device. Indeed, home-made instruments are ideal when funds are low but constant over the years, as this approach allows the costs to be spread over a longer period of time. The FUXYA2020 was intended mostly for cultural heritage (CH) applications: we optimized the geometry to meet the requirements for both low Z matrix objects, such as glasses and ceramics, and medium-high Z materials, such as metals; besides, we designed a positioning system through Arduino components to obtain good results and repeatability for samples with a complex geometry. The FUXYA2020’s performance was tested both for qualitative and quantitative analyses, the former on pigment layers, and the latter on gold-based certified alloys, exploiting Axil-QXAS software for data elaboration. The classification of ancient ceramics based on multivariate analysis obtained through R environment was also carried out. The qualitative data on pigments have also been compared with the same data obtained by a commercial XRF spectrometer, demonstrating how our very simple and inexpensive prototype can be of great help for a rapid and reliable characterization of cultural heritage materials whenever commercial devices are unaffordable.

ЭЛЕКТРОЛИТИЧЕСКОЕ ПОЛУЧЕНИЕ МАГНИЕВЫХ ПОКРЫТИЙ

Magnesium, its compounds, and alloys arise recently the heightened interest among scientists all over the world. The interest in magnesium research is caused by its combination of many promising properties that find practical application in various sectors of the national economy. On an industrial scale, the bulk of magnesium is produced by the electrolysis from the melt. However, there is a problem with the environmental security of this process. This method is environmentally unfriendly since it is accompanied by the release of hazardous chlorine and organochlorine compounds into the environment. In some cases, the electrodeposition from solutions may serve as an alternative. The task to produce magnesium and magnesium-containing coatings using electrodeposition from solutions was already raised, but it is not yet possible to obtain a stable electrolyte that allows obtaining high-quality coatings. The authors propose an electrolyte in which isopropyl alcohol is used as a solvent. Magnesium-containing coatings were produced by electrodeposition on a conductive base. The authors prepared an electrolyte based on anhydrous magnesium sulfate. To increase the conductivity of the electrolyte, sodium, potassium, and calcium chlorides in different concentrations were added to the solution. The authors carried out the experimental studies of the effect of the electrolyte composition and electrodeposition modes on the morphology and elemental composition of magnesium-containing coatings. Electron microscopic studies and the studies of the elemental composition of samples by the energy-dispersive X-ray fluorescence spectrometer show that the non-stationary (two-step) electrodeposition mode is the optimal one for producing magnesium coatings with a fine crystalline structure, low porosity, and high magnesium content.

Assessment of Potentially Toxic Elements in Egbetua Stream Sediments, South-Western Nigeria

The study area is located in Egbetua area in Akoko Edo Local Government Area of Edo State, southwestern Nigeria. the aim of the study is to assess the concentrations of potentially toxic elements in sediments from the study area. Ten samples collected from various locations in Egbetua stream were subjected to standard geochemical analysis using energy dispersive x-ray fluorescence spectrometer model “Minipal 4”. The average concentrations of six elements are V (26.89 ppm), Cr (32.33 ppm), Co (6.13 ppm), Ni (16.10 ppm), Au (21.13 ppm), and Zr (1,285.20 ppm) and they were compared to those of upper continental crust baseline values. V, Cr, Co, and Ni have extremely low concentrations, while Au and Zr have very high concentrations. Moreover, V, Cr, Co, and Ni have average enrichment ratios of 0.28, 0.35, 0.35 and 0.34, respectively, which are &lt; 1 implying their depletion in relation to their average crustal baseline concentrations. On the other hand, Au and Zr are highly enriched in the study area. Au has average geoaccumulation index (Igeo) values of 4.40 indicative of strongly to extremely polluted, while Cr, Co, Ni and Zr have average Igeo values of 10.95, 6.14, 9.98 and 17.34, respectively, indicative of sediments that are extremely polluted. The potentially toxic elements pose very serious environmental geochemical pollution threat in the study area. It is recommended that urgent action should be taken to mitigate and clean the study area of these potentially toxic elements.

ARCHAEOMETRIC CHARACTERIZATION OF A GROUP OF GOLD JEWELRY FROM THE DIYARBAKIR ARCHAEOLOGICAL MUSEUM

Jewelry is a material relic that people have used for various purposes and assigned various meanings to from the past to the present. Jewelry allows us to identify people's beliefs, cultures, social relationships, and even the technologies they used during the time they were made. With the discovery of mines and the advancement of technology, jewelry made from ready-made materials found in nature in the early periods has been replaced by precious metals, stones, and alternative materials. Gold jewelry and jewelry pieces acquired through purchase and confiscation have been examined at the Diyarbakir Archaeological Museum to observe this change. The artifacts cannot be dated because they have not been discovered through systematic excavations and the context in which they had been discovered is unidentified. Furthermore, because there is no method for archaeometrically dating gold artifacts, national and international jewelry catalogues, articles, and theses written on jewelry have been studied in the dating of jewelry covered by the study. Following these reviews, visual comparisons have been used to determine the possible dates of the jewelry. The chemical composition of the gold jewelry and jewelry pieces has been determined using the Portable Energy Dispersive X-ray Fluorescence spectrometer (P-EDXRF) after visual descriptions of the gold jewelry and jewelry pieces have been made. It has been attempted here to comprehend how the gold ratio in jewelry changes on periodically basis in this study, 17 gold artifacts have been introduced, and the analysis results have been interpreted. When the overall chemical composition of the artifacts has been examined, gold + silver and gold + silver + copper content has been determined as a result of the analysis. The gold content in pre-Roman jewelry has been lower than in Roman jewelry, and the majority of the artifacts have been electrum, according to periodic comparisons of the contents of these alloys. It was acknowledged that in ancient gold production technology that artifacts have been produced by using the element of gold and alloys in which the ratio of gold was reduced together with silver. This tradition is found to be coincided with the artifacts after 2800 BC, when gold production began, and the Lydian Period (7th century BC and later), when the separation of gold and silver has been discovered.

Assessing the Grindability Behaviour of Anka (Zamfara State, Nigeria) Manganese Ore towards Effective Manganese Mineral Liberation

The Bond standard grindability test provides a Work Index that is widely used to estimate the energy required for ore grinding. The research investigates the work index of Anka Manganese ore at Anka deposit in Zamfara state, Nigeria. The reference ore (Quartz) was sourced from the studied ore overburden in the mine. The test ore and the reference ore were characterized using Energy Dispersive X-ray fluorescence spectrometer, X - ray Diffractometer and the Scanning Electron Microscope equipped with Energy Dispersive Spectrum. 500 g each of the manganese ore and quartz were sampled and prepared by crushing and grinding to 100% passing 1200 μm sieve. 100 g of prepared ores were charged into array of sieve arranged in √2 series from 1000 μm to 63 μm. Set of sieves were mounted on the Automated Pascal Denver sieve shaker (16153) and was in operation for 20 minutes. The work index of reference ore was used to calculate the work index of the test ore using Gaudin Schuman expression to obtain a work index of 14.16 Kwh/ton for test ore and it lies within the work index of 10-15.14 Kwh/ton for manganese ore stated in the literature and the energy expended to achieve communition at mineral liberation size was calculated to be 3.3984 Kw/ton.

ONLINE X-RAY FLUORESCENCE SCREENING OF ORE FOR SILVER AT THE MINES OPERATED BY KAZAKHMYS CORPORATION LLC

This paper discusses the process and methodological aspects of X-ray fluorescence online monitoring of ore silver grade at the underground mines and open pits operated by Kazakhmys Corporation LLC. The analysis was complicated by the requirement to: a) ensure reliable silver grade determination of the ore, starting at 1+ ppm; b) sample mine faces in vertical sections to a height of up to 7 m. For geophysical online monitoring of the ore material in the walls of mine workings and in the broken rock mass, a portable energy-dispersive X-ray fluorescence spectrometer RPP-12T (Aspap Geo LLC, Alma-Ata) was developed, assembled, and comprehensively tested. The results of investigations carried out using the RPP-12T spectrometer are discussed. The data collected during the investigations made it possible to implement online ore silver grade monitoring in the underground mines and open pits operated by Kazakhmys Corporation LLC.

Стан мікроелементного забезпечення в пацієнтів iз пароксизмальною вегетативною недостатністю на фоні патології щитоподібної залози

Актуальність. Вивчивши зміни в концентрації мікроелементів в організмі в пацієнтів із пароксизмальною вегетативною недостатністю (ПВН) на фоні патології щитоподібної залози, можна встановити їх взаємозв’язок із змінами у фізичному стані. Матеріали та методи. Було обстежено 44 дитини віком 7–17 років (14,06 ± 0,18) із ПВН. Усім хворим був проведений комплекс клініко-інструментальних досліджень. Склад макро- та мікроелементів у плазмі крові та прикореневій зоні волосся вивчався за допомогою методики виконання вимірювань масової частки хімічних елементів у волоссі та плазмі крові рентгенофлуоресцентним методом із використанням портативного енергодисперсійного рентгенофлуоресцентного спектрометра ElvaX. Відхилення індивідуального мікроелементного профілю дитини також фіксувались. Результати. У 100 % пацієнтів із ПВН установлено йододефіцитний стан за результатами визначення мікроелементів у волоссі, що вказує на необхідність профілактики йододефіциту в таких хворих. Висновки. Установлено кореляційні зв’язки між мікроелементами, що беруть участь у функціонуванні щитоподібної залози, та визначено порушення їх вмісту у волоссі та плазмі крові, що свідчить про значний дисбаланс мікроелементного стану у хворих на ПВН і потребує відповідної корекції.

Correction to: Assessment of the physico-chemical characteristics and elemental properties of water and sediments from Owan river in Edo State, Nigeria

The water quality of Owan river, a very important river in Ovia North-East Local Government Area of Edo State, Nigeria was assessed. American Public Health Association (APHA) standard analytical procedures for water and sediment samples were used. Elemental composition of the sediment samples were determined by Energy Dispersive X-ray Fluorescence Spectrometer (EDXRF). Results obtained were statistically analysed (basic descriptive). In water, concentrations (mg/L) of nitrate—(2.65–21.55), sulphate—(58.6–80.0), calcium —(3.21–8.60), dissolved oxygen (5.5–6.53), total hardness (12.60–42.0), alkalinity (32.0–50.5), Cd (0.01), Cr (0.1–0.15), As (0.01–0.05), and Zn (1.4–2.04), electrical conductivity (32.0–38.0 µS/cm) and pH (6.10–6.85) were within environmental standards. However, Fe and Pb were slightly above the standards. In the sediment samples, Al, Si, Fe, and K are the most abundant elements. The highest values were detected as follows: Al—8.09 (SW7), Si—25.08 (SW5), Fe—16.72 (SW6), and K—2.1 (SW7). Urgent checks and monitoring by relevant agencies, government representatives, public health practitioners, and community leaders are required.

Quantitative analysis of trace elements of silver disturbed by pulse pile up based on energy dispersive X-ray fluorescence (EDXRF) technique

The detection of trace elements of silver in refined copper based on the portable energy dispersive X-ray fluorescence spectrometer was disturbed severely by pulse pile-up, so quantitative analysis had a high method detection limit and low accuracy. A new approach was provided to reduce the appearance of the pulse pile-up and lower the detection limit. A robust quantitative model was established. The coefficient of determination R2 of the model was lifted to 0.9927 from 0.9338; the detection limit was reduced to 0.0034 wt%. This model can be used in the metallurgical industry, power plants, and the study of micro-structure enhancement mechanisms.

Influence of Filler Composition on the Refractive Index of Four Different Enamel Shades of Composite Resins

The purpose of this study was to measure the refractive index of four commercially available enamel resin composites, using optical coherence tomography (OCT) and their relationship with the atomic composition of the composite resin fillers utilizing an energy-dispersive X-ray fluorescence spectrometer (EDX). Four different enamel composites, namely Enamel HRi color UE3, Enamel HFO color GE3, Vit-l-escence color Pearl Frost, and Amelogen Plus color Enamel White were tested. For each composite, disks with different thicknesses were fabricated and then light-cured according to the manufacturer's instructions. The disks were then stored in deionized water under 36.5 °C for at least 7 days. Each of the samples from the four different groups was measured in five distinctive points to analyze the optical and physical length using optical coherence tomography (OCT). Elemental analysis of all four different enamel shades of the composite was done using an EDX. The filler contents showed interesting differences in elemental composition and concentration; however, Si seemed to be a common filler component. The HRi composite presented a distinctive composition compared to other materials and was the only composite that showed a smaller percentage of SiO2, and also was the only composite that contained compounds, such as P2O5, ZnO, CaO, La2O3, and V2O5. The optical coherence tomography analysis showed the refractive index values of all tested enamel composites. Among the four different enamel composite resins tested, the enamel HRi composite demonstrated the most ideal refractive index to mimic natural enamel. The enamel HRi composite demonstrated a distinctive filler composition and this could be the main reason behind its higher refractive index. Nonetheless, it remains unclear how much of an impact this feature has in the final esthetic outcome of anterior composite restorations, where many other optical phenomena are also important. The clinical success of any esthetic restorative procedure depends on diagnosing the proper treatment plan and also on executing this treatment with the right materials. On direct esthetic restorations, knowing the optical properties of such materials is fundamental, as they should be able to replicate both natural enamel and dentin. How to cite this article: Beolchi RS, Mehta D, Pelissier B, et al. Influence of Filler Composition on the Refractive Index of Four Different Enamel Shades of Composite Resins. J Contemp Dent Pract 2021;22(5):557-561.

Concentrations, transport characteristics, and health risks of PM2.5-bound trace elements over a national park in central India

Fine particulate matter (PM2.5) mass and its chemical constituents were measured over Van Vihar National Park (VVNP) in Bhopal, central India. Fine PM collected over two years onto Teflon filters using a Mini-Vol® sampler were analyzed for trace elements using an Energy Dispersive X-ray fluorescence (ED-XRF) spectrometer. The temporal behaviour, dry deposition fluxes and transport pathways of elements, in addition to their health risks were examined in this study. S, K, Si, Al, Ca, and Fe accounted for most of the PM2.5-bound trace elements (~88% on average). Pronounced seasonality was observed for major elements (S, K, and Cl) and reconstructed soil (estimated as the sum of oxides of crustal elements, i.e., Si, Al, Ca, Fe, and Ti), with winter and post-monsoon season highs, potentially due to source strengths and favourable metrology during these seasons. The synoptic meteorology during these seasons favoured the fetch of particles from highly polluted regions such as the Indo-Gangetic Plain. The estimated average dry depositional flux of each element in this study was comparable to those measured/estimated for each of these species over other urban areas. The sum of the dry deposition flux for crustal elements (1301.9 ± 880.7 μg m−2 d−1) was in agreement with global dust cycle models. Air-parcel trajectory cluster analysis revealed that S, K, and Cl were influenced by biomass and coal burning in predominantly in central, and northwestern India, while reconstructed soil was influenced by air masses from the Arabian and Thar deserts. Finally, human exposure risk assessment to carcinogens (As, Cr, Cd, Pb and Ni) and non-carcinogens (Cu, Zn, Mn, V, Hg, Se and Al) revealed that no significant risk was posed by these elements. The assessment in this study was a screening for severe adverse effects, rather than a speciated health assessment. Thus, over the study region, monitoring, health risk assessment and mitigation measures, where needed, must be enhanced to ensure that trace elements induced health effects continue to be within safe levels.

Desliming process of kuru columbite (Plateau state) using scrubbing method towards niobium pentoxide recovery

The presence of niobium in nature is associated with pegmatite in the form of columbite which necessitates its recovery process from the crude. Kuru Columbite Ore was sourced from ten different pits properly mixed to obtain homogenization and 20 kg was sampled out using the random sampling method, it was ground using the Denver milling machine and prepared towards characterization followed by desliming process by repeated scrubbing technique. Chemical characterization of the crude sample was carried out using Energy Dispersive X-ray Fluorescence Spectrometer (ED-XRF). Mineralogical analysis was carried out using X-ray Diffractometer (XRD) and Scanning Electron Microscope equipped with Energy Dispersive Spectrometer (SEM-EDS). 100 g of the crude sample using the cone and quartering method was sampled out for the particle size analysis and 1000 g each of sieve fractions –710+500 µm, –500+355 µm, –355+250 µm, –250+180 µm, and –180+125 µm was used for the scrubbing process. ED-XRF analysis revealed that the crude sample contains 11.4% Nb2O5, 39% SiO2, 6.56% Fe2O3, 0.34% TiO2 and other compound in trace forms. Mineralogical analysis of the Kuru columbite revealed the present of niobium oxide, iron tantalum, with other associated minerals. SEM images revealed that the ore contains coarse grains of niobium pentoxide which are disperse within the matrix of the ore, this implies that it requires less energy to liberate niobium pentoxide within the matrix of its ore and are evenly dispersed. The EDS of these microstructures revealed the presence of O, Mg, Al, Si, and Fe. The particle size analysis revealed the liberation size to be -250+180 µm and the chemical analysis of the Kuru Columbite ore of the concentration test using scrubbing process revealed that the economic liberation (-250+180 µm) have the highest assay of 48.6% Nb2O5. Kuru Columbite Ore has successfully being upgraded from 11.4% to 48.6% via repeated scrubbing process.

Identification of heavy metals source within selected active dumpsites in southeastern Nigeria.

Discriminating contaminant sources is crucial for pollution control. The study aimed at identifying the source(s) of heavy metals in active dumpsite soils from selected areas in Southeastern Nigeria using statistical tools. The dumpsites were Enyimba dumpsite Aba (dumpsite-1), Okpuno-Egbu dumpsite Nnewi (dumpsite-2), Rice mill dumpsite Abakaliki (dumpsite-3) and Nekede dumpsite Owerri (dumpsite-4) in Abia, Anambra, Ebonyi and Imo State respectively. After standard sampling, elemental analysis was carried out using an energy dispersive x-ray fluorescence spectrometer; Chromium (Cr), Manganese (Mn), Cobalt (Co), Iron (Fe), Nickel (Ni), Copper (Cu), Zinc (Zn), Arsenic (As), Lead (Pb) and Cadmium (Cd) were quantified and results showed they were present in high concentrations above control and standard values set by the National Environmental Standards and Regulations Enforcement Agency (NESREA) and the Food and Agriculture Organization of the United Nations (FAO) / World Health Organization (WHO). Metals investigated exhibited variable correlations among themselves suggesting potential multi-element contamination, while soil organic matter (OM) and pH displayed both significant positive and negative influence on the metal availability in the studied soils. Test of significance of the observed correlation were positive and significant (r > 0.9 at p < 0.05/0.01) for Cr/Co, Cr/Fe, Mn/Co, Co/Fe, Cu/Zn, Zn/Pb, Cu/As, Cu/Pb, Zn/As, As/Pb in dumpsite-1; in dumpsite-2, only Ni/Cu; in dumpsite-3, Fe/OM and Cd/OM while in dumpsite-4,Co/Fe, Cu/As, Cu/Pb, Zn/Cd, Ni/OM, and As/Pb. Hierarchical cluster analysis (HCA) and Principal component analysis (PCA) extracted two to three components/groups based on square Euclidean distance and eigenvalues > 1, confirming sources to be from organic pigments in plastics, scrap metals and incinerated biodegradable wastes. This study concludes that statistical methods can provide a scientific basis for monitoring heavy metals accumulation in dumpsite soils.

Levels of selected toxic and essential elements in fish and oysters from Western Indian Ocean, Coast of Tanzania

Concentrations of toxic and essential elements in selected finfish and shellfish collected from Dar es Salaam and Tanga, Indian Ocean coast of Tanzania are presented. The elemental concentrations were determined using Energy Dispersive X-ray Fluorescence (EDXRF) spectrometer coupled with X-lab ProTM software. The mean concentrations of metals observed in finfish and shellfish collected from Tanga ranged from 3.40–5.75, 1.8–37.17, 3.5–7.1, 0.6–1.3, 0.53–0.73 and 16.80–96.70 mg kg–1 for As, Cu, Mn, Ni, Pb and Zn, respectively. For Dar es Salaam, the mean concentrations of metals ranged from 3.34–9.46, 2.90–30.53, 3.4–6.9, 0.7–1.0, 0.57–0.80 and 14.2–100.90 mg kg–1 for As, Cu, Mn, Ni, Pb and Zn, respectively. Thumbprint emperor showed the highest levels of Cu and Ni; octopus showed the highest values of As and Pb, while sardines showed the highest level of Mn. Oysters, used as pollution indicators in this study showed the highest elemental concentrations and exceeded their mean levels in finfish from Dar es Salaam by factors of 1.30, 7.15, 6.27, 2.72, 1.29 and 35.57 for As, Cu, Mn, Ni, Pb and Zn, respectively. In samples from Tanga, the metal concentrations in oysters were several times higher (3.76, 17.68, 1.12, 3.89, 1.88 and 66.92 for As, Cu, Mn, Ni, Pb and Zn) than in finfish, respectively. Based on metal concentrations in oysters, it can be concluded that coastal waters are contaminated with heavy metals. However, with an exception of arsenic and copper, the elemental levels in finfish are within the maximum permissible levels recommended by various international standards and guidelines.&#x0D; Keywords: Finfish, toxic elements, essential elements, pollution, EDXRF

ED-XRF analysis of the mediaeval copper-based door in Monte Sant\u2019Angelo (Southern Italy)

This work regards the analysis of a copper-based door (dated 1076 AD) located at the entrance to the sanctuary of Monte Sant’Angelo (Southern Italy) by using a non-destructive technique and in situ chemical analysis. The door does not show serious corrosive phenomena and presents several types of decorative elements such as two inlays (of silver and copper colour) and three engravings (of red, black and green colour). A portable energy dispersive X-ray fluorescence (ED-XRF) spectrometer was used in order to evaluate the chemical composition of the door and of the decorations that adorn the artefact. No sampling or sample preparation was required before the measurements. Preliminary analysis on the materials that make up the door revealed that the panels and the frame of the two sashes are made of the same alloy, while the nails and the handles have a different composition.Graphical abstract

Probabilistic health risk assessment of toxic metals in chickens from the largest production areas of Dhaka, Bangladesh.

Chicken is one of the major protein sources and more affordable for the population of Bangladesh. Its quality monitoring is of high priority for food safety and public health risk assessment. This study determined metals (Fe, Cu, Zn, As, Ni, Cr, Sr, Hg, and Pb) in chickens from different farms of a high production area of Dhaka, Bangladesh, using an energy-dispersive X-ray fluorescence spectrometer to calculate the health risk through chickens consumption. In most cases, the toxic metals (As, Ni, Cr, Hg, and Pb) showed very high concentrations in different parts of chickens, especially livers that contained several times higher concentrations than the maximum allowable concentration (MAC). Analytical results showed some feed and water contain high concentrations of As and Cr that might be bioaccumulated in chicken. The estimated daily intake (EDI) for all metals was below the provisional tolerable daily intake (PTDI) values except As and Fe in few farms. Target hazard quotients (THQs) for most metals were less than 1 but THQs of As and Cr of few farms were higher than 1, indicating that the consumer would possess As- and Cr-based health hazards. Total target hazard quotient (TTHQ) of 42% for composite and 36% for body parts samples were > 1, suggesting potential health risk. The probabilistic risk and individual samples cancer risk (TR) were exceeded the acceptable level (10-4) for As and 75% of composite and 58% of body parts of chicken showed acceptable limit (10-6 to 10-4) for Pb, indicating that the peoples might be exposed to lifetime cancer risk in the long run.