Determination Of Trace Elements Research Articles

Microwave Digestion and ICP-MS Determination of Major and Trace Elements in Waste Sm-Co Magnets

In this article, inductively coupled plasma mass-spectrometry (ICP-MS) and inductively coupled plasma optical-emission spectrometry (ICP-OES) were used for the development of an analytical procedure for analysis of the waste of Sm-Co magnets. Experimental parameters related to microwave digestion processes and acid concentrations were optimized. Microwave digestion was carried out in mixtures of HF, HCl, HNO3 and H2SO4. The complete dissolution of the samples occurred in the system: 10 mL H2O, 2 mL HNO3, 10 mL HCl and 1 mL H2SO4. The dependence of the matrix effect on the ICP-MS analysis of waste Sm-Co magnets was studied and optimal instrumental parameters were investigated (nebulizer gas flow, sampling depth and potential at the extractor lens). The optimal conditions were a nebulizer gas flow of 0.85–0.90 L/min, a sampling depth of 101, potential at the extractor lens of −400 V and a sample flow rate of 50 rpm. A recovery test and inter-method experiments were performed to verify the accuracy of the proposed method.

Determination of trace element and fatty acid levels in tissues of mirror and scaly carp (Cyprinus carpio L., 1758) living in Keban Dam Reservoir (Elazig).

This study investigated the concentrations of some accumulated trace metals (iron, manganese, zinc and copper) and fatty acids in liver and muscle tissues of mirror and scaly carp varieties (Cyprinus carpio L., 1758) living in Keban Dam Reservoir (Elazig), which is the second-largest artificial lake in Turkey that hosts commercially valuable and preferred fish varieties for human consumption. The inductively coupled plasma mass spectrometry (ICP-MS) method was used to analyse the concentrations of trace elements. Fatty acid levels were measured in a gas chromatography mass spectrometry (GC-MS) device, using a flame ionization detector (FID). Considering the two fish varieties and tissues that were studied, the mean metal concentrations (μg g-1 ) were found in the following ranges: Fe 12.32-49.97, Mn 0.12-0.62, Zn 10.45-86.59 and Cu 2.74-11.86. Although the lowest levels were detected in the muscle tissue for all the metals examined, the levels in the liver tissue were significantly higher. According to the results of the analyses on fatty acid concentrations, the mean total saturated fatty acid levels in the muscle tissue of the scaly carp and mirror carp varieties were found to be 31.07 and 31.43 (%), respectively, whereas these values for the liver tissue were consecutively 22.36 and 22.08 (%). Successively, the mean total levels of unsaturated fatty acids were determined as 68.93 and 68.40 (%) in the muscle tissue and 77.64 and 77.92 in the liver tissue. This study, with the finding that the trace (metallic) element accumulation rates were below the upper limits of the tolerable range, and the examined fish varieties were rich in fatty acids, shows that mirror carp and scaly carp living in Keban Dam Reservoir are highly nutritious for human diets.

The Quality of Yıldız River Water and Determining Trace Elements by Liquid-Liquid Micro-Extraction Analytical Method

The present study was carried out between September 2019 and March 2020 in Yıldız River, which is located within the borders of the Yıldızeli district of Sivas province and used for agricultural irrigation purposes, to determine the chemical characteristics of river water and the trace elements. Water’s alkalinity, chemical oxygen demand (COD), chloride (Cl-), calcium (Ca2+), total hardness, total phosphate (PO4-P), dissolved reactive phosphate (SRP), ammonium nitrogen (NH4-N), nitrate-nitrogen (NO3-N), nitrite-nitrogen (NO2-N), soluble reactive silica (SiO2-Si) concentrations, as well as trace elements (ferrous, lead, cadmium). Moreover, during the sampling process, also the water temperature, dissolved oxygen, conductivity, pH, and total dissolved solids measurements were performed. Before using the flame atomic absorption spectrometer (FAAS) in determining the Fe, Pb, and Cd in water samples, a simple, environment-friendly, and new ultrasonic liquid-liquid micro-extraction method was suggested. Several parameters (pH, ionic fluid amount, dispersive solvent volume, and temperature) influencing the performance of micro-extraction were optimized. Under the optimized conditions, the detection thresholds for Fe (II), Pb (II), and Cd (II) were found to be 0.6, 0.15, and 1.5 μg L-1, respectively.

Micro/trace/toxic elements and insecticide residues level in monofloral bee-collected sunflower pollen- health risk assessment

The aim of the current research was to determine the content of (potentially) toxic elements and insecticide residues in monofloral sunflower bee-collected pollen. For micro- and trace elements determination Inductively Coupled Plasma Optical Emission (ICP-OES) analytical method was used while insecticide residue content was monitored by applying Liquid Chromatography-Mass Spectrometry (LC-MS/MS) technique. In total, seventeen micro/trace elements were quantified. None of the twenty four examined insecticides were detected above the limit of detection (LOD) which makes studied sunflower bee-collected pollen eco-friendly both to bees and humans. Based on presence of several toxic as well as potentially toxic elements calculations for estimated weekly intakes (EWI), and oral intakes (OI) were made and used for health risk assessment based on the computation of two different health risk quotients (HQ)- acute (HQA) and long-term (HQL). The obtained results proved that all HQ values for adults were negligible or low except in case of HQL value for arsenic (0.32) which can be characterized as medium. However, in case of children much more precaution is needed due to significant HQL risk for arsenic (1.511). The attained data can help to make additional linkage between bee-collected pollen as food ingredients and potential benefits/risks for human health.

Polycyclic aromatic hydrocarbons and trace elements dietary intake in inhabitants of Athens, Greece, based on a duplicate portion study

Concentration levels of 26 polycyclic aromatic hydrocarbons and 20 trace elements were measured in dietary samples, in order to estimate the dietary intake and the potential exposure risk of the Greek population. Dietary samples were collected with the help of 30 volunteers inhabitants of Athens, Greece, according to the duplicate portion study (DPS) method where the determination of the compounds is conducted in the final consumed meal. DPS was selected as an alternative to a total diet study for its feasibility, low cost and realistic image that it provides. PAHs determination was performed by gas chromatography tandem mass spectrometry (GC-MS/MS) and trace elements determination by inductively coupled plasma mass spectrometry (ICP-MS). The estimated mean daily dietary exposure on 26 PAHs for an adult was estimated at 101.47 ng kg−1 body weight day−1, while moderate to low exposure was related to the type and amount of food consumed. Exposure levels to PAHs do not indicate a possible risk for the health of the study group. For toxic, potentially essential and/or essential trace elements the daily exposure calculated for Greek population was in accordance with the reference values of the health-based guidances and compared to previous diet studies reported for the population of other countries was in general similar to the lower bound exposure.

Toxic and Trace Elements in Seaweeds from a North Atlantic Ocean Region (Tenerife, Canary Islands)

Canary Islands is a North Atlantic Ocean archipelago in the Macaronesian region that stand out for its great algae diversity and its climatic conditions. However, even in this low industrialised area, human activities tend to increase the marine pollution. Asparagopsis spp. and Liagora spp. algae are red algae frequent in the Canary Islands’ coasts. Therefore, they could be used as bio-indicators of marine pollution for trace elements. A total of 30 samples of both algae’s species from Tenerife’s southern coast, specifically in Playa Grande, Porís de Abona, in Arico (Tenerife, Spain) were used to determine trace element content (Mn, B, Ba, Cu, Cd, Co, Fe, Li, Mo, Ni, Pb, Sr, V, Zn, Al, Cr) through inductively coupled plasma atomic emission spectroscopy (ICP—OES). Highest Fe concentrations were found in Liagora spp. concentrations (1190 ± 1545 mg/kg dw) and Al (288 ± 157 mg/kg dw) was more significant in Asparagopsis spp. High concentrations of B were also registered in both species 80.2 ± 34.2 mg/kg dw and 77.9 ± 34.2 mg/kg dw, respectively. The recorded concentrations show a high contamination scenario in the collected area. Porís is known by its marine diversity and by its higher pollution levels, compared with other locations of Tenerife, due to the currents present on the Canary Island and its singular north orientation, actions must be taken to reduce pollution.

Determination of trace elements in placenta by total reflection X-ray fluorescence spectrometry: effects of sampling and sample preparation

Placental elemental composition can serve as an indicator for neonatal health. Medical studies aiming at revealing such cause-and-effect relationships or studies monitoring potential environmental influences consist of large sample series to ensure statistically sufficient data. Several analytical techniques have been used to study trace metals in human placenta. However, most techniques require provision of clear liquid sample solutions and therefore time- and reagent-consuming total digestion of biological tissue is necessary. In total reflection X-ray fluorescence spectrometry (TXRF)—a straightforward multielement analytical technique—in contrast suspensions of minute sample amounts can be analyzed directly. Therefore, herein we report on a valid method to prepare homogenous sample suspensions for sustainable and fast TXRF analysis of large sample series. The optimized method requires only 10 mg of powdered placental tissue and 1 mL nitric acid. Suspensions are readily prepared within 30 min and the found mass fractions of major, minor, and trace elements are in good agreement in comparison to analysis of digests. In addition, possible effects on fixation time and the exact sampling location, i.e., maternal vs. fetal side of the placenta, were studied applying this method. Thereby, significant differences for fetal placenta tissue compared to maternal or intermediate tissue were observed revealing accumulation of trace elements in the fetal side of the placenta. Furthermore, considerable depletion of up to 60% mass fraction with longer fixation duration occurred in particular in fetal placenta tissue. These findings help to understand the large ranges of mass fraction of elements in placenta reported in the literature and at the same time indicate the necessity for more systematic investigation of non-homogenous elements distributed in placenta taking sampling and stabilization methods into account.Graphical

Validation of Trace Element Analysis of Geological Materials by Single-Pulse Laser Ablation-Inductively Coupled Plasma-Mass Spectrometry (LA-ICP-MS)

Laser ablation–inductively coupled plasma – mass spectrometry (LA–ICP–MS) is a powerful tool for determining the elemental and isotopic compositions of various samples. The disadvantage of LA–ICP–MS is that it consumes more sample material than other types of in situ analytical methods. To extend the application of this method to trace element analysis, we conducted single-pulse LA–ICP–MS analysis of the Reference Materials of the National Institute of Standards and Technology (SRM 610, 612, and 614) and the United States Geological Survey (BCR-2G, BHVO-2G, and BIR-1G). The accuracy of the determined concentrations and the precision of the single-pulse LA–ICP–MS analysis were verified by comparison with recommended concentrations for these standards and those obtained by conventional analysis with the same system. Time-resolved profiles of the analyzed elements in the glass samples show that the background-corrected intensity reaches a peak immediately after the start of the laser pulse and then gradually decreases. During each analysis, the isotope ratios are stable until the background-corrected intensity of the elements reaches 5% of the peak values. The relative standard deviation of the single-pulse LA–ICP–MS analyses is significantly higher than for conventional LA–ICP–MS analysis. However, most of the determined concentrations obtained from the reference materials except for NIST SRM614, NIST SRM612, BCR-2G, and BHVO-2G mostly agreed with the recommended values within 20%. In addition, the geochemical features of basaltic reference glasses were accurately reproduced by the single-pulse LA–ICP–MS analyses. In conclusion, the single-pulse LA–ICP–MS method provides usable results for the determination of multiple trace elements in geological materials.

New Method for Detection and Quantitative Determination of Macroelements and Trace Elements in Plant Raw Material by Arc Atomic Emission Spectroscopy with a Multichannel Analyzer

New Method for Detection and Quantitative Determination of Macroelements and Trace Elements in Plant Raw Material by Arc Atomic Emission Spectroscopy with a Multichannel Analyzer

Negative Magnetophoresis Focusing Microchips Online-Coupled with ICP-MS for High-Throughput Single-Cell Analysis.

High-throughput single-cell analysis is critical to elucidate the cell heterogeneity. Recently, droplet microchips using oil/gas phases to generate single-cell encapsulated droplets have been combined with inductively coupled plasma-mass spectrometry (ICP-MS) for determination of trace elements in single cells with a throughput of dozens of cells per min. To improve the sample throughput and avoid the oil phase introduced into ICP-MS, herein, a negative magnetophoresis focusing microchip was established and online-coupled to ICP-MS for single-cell analysis. MCF-7 cells in the paramagnetic salt solution were introduced into the designed focusing microchannel, in which they were focused into a single stream under both the magnetic repulsion force and inertial lift force, and then were introduced into ICP-MS for online single-cell analysis. The important parameters including the chip design, the concentration of the paramagnetic salt solution, flow rate, cell density, and dwell time were optimized. Under the optimal conditions, a high sample throughput of 1390 cells min-1 was obtained. The established online analytical system was applied to study the uptake behaviors of MCF-7 cells for Zn2+ and ZnO nanoparticles (NPs) at a single-cell level. The single-cell analysis results indicate that MCF-7 cells displayed more remarkable heterogeneity when they were treated with ZnO NPs, and the uptake content of ZnO NPs by MCF-7 cells was less than that of Zn2+. Compared with other droplet microdevice-ICP-MS analysis systems, the developed system has the advantages of simple design and fabrication, no organic phase, a high throughput, and a low sample consumption (only 5 μL).

Trace element partitioning during incipient melting of phlogopite-peridotite in the spinel and garnet stability fields

Potassium-rich magmatism represents subordinate magma volumes worldwide but has been observed in many geodynamic settings. Most potassic magmas are thought to derive from very-low degrees of melting of metasomatized mantle lithologies. We performed piston-cylinder experiments to determine trace element partition coefficients between incipient potassic silicate melts and phlogopite ± pargasite peridotite in the spinel (1 GPa) and garnet stability fields (3 GPa). Most of the rare Earth elements (REEs) are compatible in pargasite but incompatible in phlogopite. Although garnet remains the mineral phase most efficiently fractionating heavy from light REEs (DYbgrt/melt/DLagrt/melt > 750), orthopyroxene can also significantly fractionate REEs, e.g., achieving DYbopx/melt/DLaopx/melt > 100 at 3 GPa. Mineral-liquid partition coefficients vary by about one order of magnitude between incipient melts derived from the spinel and garnet stability fields. We thus show that trace element partitioning at the onset of melting is controlled more by pressure (through melt composition) than by the extent of melting. With increasing pressure, Rb and Ba exhibit different behaviors in phlogopite, with DBaphl/melt > DRbphl/meltat 1 GPa and the opposite at 3 GPa. At 1 GPa, a decrease of melt polymerization (lower NBO/T) with increasing melt fraction translates into a significant decrease of most phlogopite partition coefficients. Finally, we show that resolvable inter-element fractionations do occur when phlogopite- (and pargasite)-bearing peridotite are melted, indicating that trace element ratios are not always faithfully representative of that of their sources but bear the imprint of varied P–T conditions of melting and contrasted pre-metasomatic histories. This self-consistent partition coefficient dataset thus gives a new scope to understand the complex petrogenesis of K-rich magmas in orogenic settings.

Evaluation of the Matrix Effect and Selection of Reference Samples for the ICP-MS Trace Elements Determination in Geological Samples

Evaluation of the Matrix Effect and Selection of Reference Samples for the ICP-MS Trace Elements Determination in Geological Samples

Determination of Rare Earths and Other Trace Elements in Ore Samples of Mongolia by WDXRF and INAA

Wavelength dispersive X-ray fluorescence (WDXRF) and Instrumental Neutron Activation Analyses (INAA) were used to determine the REE and other trace elements in rare earth ore samples from province Dornogovi, Lugiin gol. Seven rare-earth elements (REE) namely La, Ce, Sm, Eu, Tb, Dy, and Yb, as well as other trace elements (Zn, As, Rb, Sr, Au, Ba, Br, Ta, Hf, Th and U) have been determined by WDXRF at Central Geological Laboratory of Mongolia, Ulaanbaatar. For comparison, the same elements were determined by INAA using by epithermal neutron activation analyses at the IBR-2 reactor, FLNP JINR, Dubna. It is demonstrated that the WDXRF have satisfactorily agreed with INAA results within the limits of the uncertainty. It is shown that the values of the relative discrepancies between the WDXRF and the INAA results are in the range of 1.5-30.0 %.

Direct non-destructive trace and major elemental analysis in steel samples utilizing micro-focused bremsstrahlung radiation in X-ray fluorescence geometry.

Stainless steel is a very important technological material used in various industries. In this work, a simple non-destructive method is developed for major as well as trace elemental determination in stainless steel samples using micro-X-ray fluorescence (XRF) based technique. The utilization of full bremsstrahlung excitation in combination with micro-focused geometry substantially reduces the detection limit of different elements present in stainless steel. The developed methodology is capable of determining elemental concentrations down to 30-80ppm level in stainless steel matrix without any requirement of cumbersome dissolution or separation procedure. Elements such as Si, P, S and Co were determined simultaneously at trace level using the developed micro-XRF based technique. At the same time this technique is also capable of analyzing elements which are present at percentage levels. Till now there is no such report showing the capability of lab-XRF based non-destructive technique for the analysis of both major as well trace elements down to such low concentration level to the best of our knowledge. Moreover, the methodology involved is very simple and straight forward. The analytical results obtained were very much satisfactory with good accuracy and precision.

Trace elements concentrations in biological samples and their correlation with urinary arsenic metabolites of chronic arsenic exposed people

We collected and analyzed groundwater and other biological samples for the determination of arsenic and other trace elements from an arsenic exposed group and an unexposed group (control group) of people in Bangladesh. The results showed that arsenic in hair, nail, and urine increases with increasing arsenic in drinking water. Along with arsenic in hair and nail samples, I also analyzed Se, Zn, Cu, Hg, Pb, and Sb by ICP-MS after microwave digestion. In both cases (hair and nail), it appears that the mean concentration of Se and Zn are lower in the exposed group than in the control group. Again, the mean concentration of Hg, Pb, and Sb are higher in both hair and nail for the exposed group than the control group.

Determination of Trace Elements in Sediments Samples by Using Neutron Activation Analysis

The Juru River is a highly industrialized, urbanized, and agricultural catchment. This study aimed to investigate trace elements in Juru mangrove sediments, including geochemical baselines and enrichment. Sediment was collected from the mangrove in Juru, Penang, Malaysia. A total of eight target elements was examined. Instrumentation activation analysis (INAA) was used to determine the concentration of Fe, V, Cr, Zn and Co. Atomic absorption spectrometry (AAS) was used to determine the concentration of elements that not detectable by INAA (Cd, Pb, and As). In both methods, validated reference material studies were used for validation of the methodology. Metal pollution was estimated using the Enrichment Factor (EF), Geoaccumulation Index (Igeo), Contamination Factor (CF), and Pollutant Load Index (PLI). The EF, Igeo, and CF ranges from 0.45–7.96, -2.18 – 1.95, and 0.33–5.83 respectively. The order of accumulation of the elemental concentration found was Fe > Zn> Cr > V > Pb > As > Co >Cd. The computed mean value of PLI exceeds the unit (PLI > 1).

A simple method for glass analysis using total reflection X-ray fluorescence spectrometry

In this work, a simple and cost-effective method was developed for Na, Mg, Al, K, Ca, Ti, V, Cr, Mn, Ni, Cu, Zn, Rb, Sr, Ba and Pb determination in glass samples employing suspension sampling and total reflection X-ray fluorescence (TXRF). The experimental conditions were optimized using multivariate approach being the optimum conditions located by Derringer's desirability function. Proposed method was validated in accordance with the National Institute of Metrology, Quality and Technology (Inmetro, Brazil). Limit of detection (LD) and limit of quantification (LQ) were adequate for determination of trace elements in glass. The evaluation of the accuracy and precision was realized by analysis of standard reference materials of glass (NIST 612). For the majority of the elements, good agreement was achieved between the certified value and the value obtained in the NIST 612. The relative standard deviation (RSD%) was achieved between 3.6 and 10.3%. Moreover, no significant differences were observed between the proposed method compared to the ICP-MS. After the validation step, the method was applied to 31 glass samples and with aid of an exploratory principal component analysis (PCA), a perfect discrimination of the glass from originally manufactured smartphones was obtained. In addition, soda-lime glass could be reasonably distinguished from smartphone screens. The developed method is fast, consumes low amounts of reagents and allows the determination of many analytes simultaneously. Additionally, the method does not require calibration curves. Therefore, TXRF proved to be attractive and useful for routine analysis of glass.

Determination of Trace Elements in Biological Fluids by Arc Atomic Emission Spectrometry

Determination of Trace Elements in Biological Fluids by Arc Atomic Emission Spectrometry

Analytical potential of total reflection X-ray fluorescence (TXRF) instrumentation for simple determination of major and trace elements in milk powder samples

In this contribution, the analytical potential of total reflection X-ray fluorescence (TXRF) instrumentation has been evaluated for the determination of major and trace elements in milk powder. TXRF allows the possibility of direct analysis of solid suspensions without the need for a digestion process and therefore it can be a potential analytical candidate for simple and cost-effective analysis.A detailed study to select sample preparation and measurements conditions was carried out. Different quantification approaches (including internal standardization and empirical calibration) were also tested. Finally, the developed TXRF methods (W anode) were validated by a strict comparison with the data from the reference methods on a set of twenty-three samples using robust statistics. Results showed that acceptable results can be obtained for K, Ca, Fe and Zn determination if using adequate calibration approaches. Otherwise, only screening results can be obtained for light elements (P and Cl) in milk powder samples.

Occurrence of trace elements in Mediterranean mussels (Mytilus galloprovincialis Lamarck, 1819) from an experimental pilot farm in the Calich Lagoon (Sardinia, Italy).

The present study aimed to determine trace elements in Mediterranean mussels (Mytilus galloprovincialis) from an experimental pilot farm of the Calich Lagoon, a typical Sardinian brackish area (Italy). Two sampling sessions were scheduled in February and May 2019 and the occurrence of 24 metals (Hg, Ag, Al, As, Be, Bi, Cd, Co, Cr, Cu, Fe, Ga, In, Mg, Mn, Mo, Ni, Pb, Rb, Se, Sn, Ti, V, Zn) in bivalves was considered. Environmental conditions of water (temperature, salinity, pH, dissolved oxygen, and chlorophyll a) were also measured in situ. A high significant (P<0.001) difference was reported for temperature, pH, and dissolved oxygen. Our results showed a significant sessional variation of Mo (P<0.001); Cd, V (P<0.01); Ni, Pb and Co (P<0.05) in examined M. galloprovincialis samples; as all values were higher in February than those for May session samples, meanwhile the highest levels were reported for Mg (mean±s.d. 1151±263 mg kg-1 wet weight), Al (mean±s.d. 341±192 mg kg-1 w.w.), and Fe (mean±s.d. 212 ±75 mg kg-1 w.w.) in February samples. The European Union uppermost values (EC Reg. 1881/2006) for Cd, Hg, and Pb were never overpassed. The results confirmed the role of M. galloprovincialis as one of the most appropriate biological indexes to track the presence of trace elements in brackish environments. It could be concluded that the current ecology of the Calich Lagoon suggests that compatibly with the transitional ecosystem, the classification as a bivalves’ production area and the implementation of extensive shellfish farming can improve its production capacities. The knowledge of the lagoon ecology is an essential tool for its sustainable exploitation, preserving biodiversity, and mitigating the effects of anthropogenic activities on public health.