Measurement Of Trace Elements Research Articles

Petrogenesis of Montana, USA Sapphires Inferred from Oxygen Isotopes and Zircon Inclusions

Abstract Montana hosts the largest sapphire deposits in the US, but the genesis of and connection among the various secondary and primary sapphire occurrences remains cryptic. In situ SIMS measurements of oxygen isotopes in sapphires and zircon inclusions in sapphires provide an opportunity to study the isotope and trace element geochemistry in order to understand sapphire-forming protoliths (i.e., crustal setting and alteration). Sapphire from Montana was transported as xenocrysts in carrier (host) magmas that resorbed sapphire exteriors during transport. The timing and nature of sapphire genesis is elucidated by SIMS measurements of trace elements and U-Pb from discrete zones in zircon inclusions with rims that are interpreted to be syngenetic with host sapphire. Montana sapphires exhibit a large range of δ18O values, from -3 to +12‰ VSMOW. However, all but two anomalous crystals fall in the range of 0 to 8‰. There is significant crystal-to-crystal variability yet averages at most deposits are consistent with high-temperature equilibration with the mantle (δ18O(Crn) = 4.4 to 5.7‰), with the exception of the commercial sapphire deposits at Rock Creek that average 2.7‰. Ruby analyses are limited, but typically have lower δ18O values compared to sapphires from the same detrital localities. Homogeneity within individual crystals (avg. 2s = ±0.2‰) indicates the absence of isotopically distinct fluid or melt during crystallization. But intercrystalline δ18O ranges by up to 3‰ at a single locality, suggesting sapphire variability at a deposit reflects heterogeneity in the original protolith. Oxygen isotope fractionations between zircon rims and surrounding sapphire suggest comagmatic zircon inclusions and corundum equilibrated at high temperature. No correlation is seen for the degree of radiation damage and alteration of δ18O(Zrc) when zircon inclusions are surrounded and armored by sapphire. U-Pb ages and trace elements were measured in a small subset of syngenetic zircon inclusions in Dry Cottonwood Creek sapphires, revealing a Proterozoic (1778 ± 9 Ma) age for the protolith of sapphires at this locality and a likely polygenetic history. Previous work has suggested formation of these sapphires through partial melting of anorthosites and several anorthosites occur locally and match the age of zircon inclusion cores—the Boehls Butte anorthosite (~180 km NW of Rock Creek) and the Bitterroot anorthosite (~55 km W of Rock Creek) could correlate with Al-rich protoliths at depth. Proterozoic U-Pb ages of zircon from the Boehls Butte anorthosite (1787 ± 2 Ma) match well with the age of zircon inclusion cores in Dry Cottonwood Creek sapphires and suggest genesis in these or similar protoliths. Zircon rims with Tera-Wasserburg lower intercept ages of 110 ± 9 Ma are consistent with previous observations of a xenocrystic relationship to the ~50 Ma Eocene volcanic rocks. Corundum that formed over 50 Ma prior to being scavenged by Eocene magmas likely originated by the anatexis of Precambrian anorthosites and possibly other aluminum-rich rocks at depth.

Long-term deployment of commonly used DGT devices for trace element measurement across laboratory and field settings

Diffusive Gradients in Thin-films (DGT) technique is a promising passive sampling technique, which was used for the determination of lots of inorganic and organic pollutants. Although many DGT devices have not been extensively tested and verified in field, DGT device such as LSNP-NP, LSNT-NP, LSNZ-NP, and LSNM-NP DGT were widely employed for the assessment of various trace elements. However, the deployment time of these DGTs were much shorter than the theoretical time in the preexisting literature. Therefore, the performance of DGT for long-term application in different water bodies is not known. This investigation utilized the four DGTs for the assessment of various trace elements across extended periods both in controlled laboratory settings and natural field environments. Synthetic soft, hard, and seawater compositions served as media for laboratory deployments. Most elements can be measured accurately in 4–7 days in soft and hard water. Deployment durations in seawater exhibited a notable reduction compared to those in freshwater matrices. LSNZ-NP DGT excelling in oxyanion determination, while LSNT-NP DGT showcased superior efficacy in phosphorus quantification. Field deployments in rivers and sea affirmed the robustness of LSNZ-NP DGT, evidencing prolonged deployment capabilities for various elements, such as Mo, Se, As, Sb, and P, spanning 7–28 days. Assessment of pollution levels across four sampling sites revealed heightened concentrations of most elements in marine waters relative to riverine environments, except for phosphorus. Notably, all assessed elements, except for phosphorus, conformed to Class I water quality standards. This study demonstrated the difference between the theoretical application time and actual application time for the first time. It raises new questions for the application of DGT in nature water bodies. The mechanization of the difference between the theoretical and actual application time should be studied in the future research. The measures to extend the application time should be studied too.

Trace Elements in Hermann's Tortoises (Testudo hermanni) According to Sex, Season, and Sampling Region in Central Europe.

Some trace elements are essential for the health of vertebrates, but little is known about their function, the amounts required, and the factors influencing their metabolism in tortoises. The aim of this study was therefore to measure trace elements (chromium (Cr), cobalt (Co), copper (Cu), iron (Fe), magnesium (Mg), manganese (Mn), molybdenum (Mo), selenium (Se), zinc (Zn)) in heparinized blood plasma of Hermann's tortoises (Testudo hermanni) (n = 520) from March to September 2022 using inductively coupled plasma mass spectrometry (ICP-MS) and to establish specific reference intervals. Additionally, the influence of sex, season, and region of sample collection on the measured values were evaluated. Significant (p ≤ 0.05) sex-specific differences were found for Cu, Mg, and Mn; seasonal differences were found for Cr, Cu, Mn, Mo, and Se; and the region in which the tortoises were kept significantly impacted Cr, Cu, Fe, Mg, Mo, and Se levels. The results show that all of these factors should be consider when establishing and interpreting blood trace element levels in tortoises.

Association between the MTHFR (rs1801133) gene variation and serum trace elements levels (Copper and Zinc) in individuals diagnosed with neural tube defects

Background and AimsNeural tube defects (NTDs) occur when the neural tube fails to close within 28 days of human embryonic development. This results in central nervous system disorders like anencephaly, spina bifida, and encephalocele. Early diagnosis and treatment are crucial to minimize their impact on an individual’s health and well-being. The present study aims to define the association between prenatal exposure to trace elements (Cu and Zn) and the single nucleotide polymorphism (SNP) of the MTHFR gene involved in folate metabolism pathways in neural tube defects in children and their mothers. Material and MethodsA cross-sectional study involving 331 participants (90 NTD cases, 88 healthy mothers, 85 NTD children, and 68 healthy children) from antenatal check-ups in Obstetrics and Gynaecology and Pediatric Surgery for Neural Tube Defects in the Outpatient Department (OPD) and Inpatient Department (IPD). Assessed Cu and Zn concentrations and their associations. Genomic DNA was extracted, and real-time PCR was used to determine genotypes. Atomic absorption spectrophotometry measured trace elements. Statistical analyses included Chi-Square tests, odds ratios, and Mann-Whitney U tests. ResultsSignificant associations were found between MTHFR C677T genotypes and NTD risk in mothers (p = 0.0491) and children (p = 0.0297). Allelic frequency analysis indicated a T allele association with NTD risk in children (p = 0.0107). Recessive models showed significant associations in mothers (p = 0.0169) and children (p = 0.1678). Cu levels differed significantly between NTD cases and controls (p < 0.0001), with MTHFR genotypes influencing Cu levels. Zinc levels also varied significantly (p < 0.0001). ConclusionThis study reveals complex associations between MTHFR C677T genotypes, trace element concentrations, and NTD risk in mothers and children. This targeted approach allows healthcare providers to identify at-risk pregnancies early, enabling personalised interventions like folic acid supplementation and counselling to moderate neural tube defect (NTD) risk in a future pregnancy.

Quantitative source apportionment and health risk assessment of trace elements in surface soils around the Shazand chemical industrial district, northwestern of Iran

A comprehensive study aimed at measuring trace elements pollution in the Shazand chemical industrial district, located in northwestern Iran, was conducted. Employing principal component analysis (PCA) and positive matrix factorization (PMF), we identified sources of trace elements and assessed associated health risks for inhabitants. The results showed that the mean concentrations of Pb, Cd, Ni, Zn, and As of 190 topsoil samples exceeded the background values, except for Cu. The total noncancer risk values for adults and children were 0.72 and 7.95, respectively, and the total carcinogenic risks were 8.46 E – 05 and 2.69 E – 04, respectively. The noncarcinogenic risk for children was above the threshold level, but low for adults. The total potential carcinogenic health risks for children exceeded the threshold of 1 E – 04 indicating a high carcinogenic risk for them, whereas the risk for adults was considered acceptable. Furthermore, As was the primary hazardous metal to human health, followed by Cd and Ni. According to the results of the PMF model, four factors were extracted for trace elements, including natural source, transportation sources, industrial sources, and agricultural sources, which contributed about 27.9%, 17.51%, 29.15%, and 25.44% to pollution of the area, respectively. Anthropogenic sources contributed far more to the potential health risks posed to inhabitants of the study area. These findings can assist governmental agencies in implementing targeted control strategies to prevent the contamination of heavy metals.

Measurement of Trace Elements (Zinc, Copper, Magnesium, and Iron) in the Saliva of Horses: Validation Data and Changes in Equine Gastric Ulcer Syndrome (EGUS).

The objective of this study was to evaluate the possible use of spectrophotometric assays for the measurement of trace elements, including Zinc (Zn), Copper (Cu), Magnesium (Mg), and iron (Fe) in the saliva of horses and study their possible changes in equine gastric ulcer syndrome (EGUS). EGUS is a highly prevalent disease, with a current high incidence due to the increase in intensive management conditions. There are two EGUS diseases: equine squamous gastric disease (ESGD) and equine glandular gastric disease (EGGD), which can appear individually or together. For this purpose, automated spectrophotometric assays for measuring these analytes in horse saliva were analytically validated. Then, these analytes were measured in the saliva of horses with only ESGD, only EGGD, both ESGD and EGGD and a group of healthy horses. The methods used to measure the analytes were precise and accurate. Horses diagnosed with EGGD presented significantly lower levels of Zn and Mg. Fe concentrations were significantly lower in the saliva of horses with ESGD and EGGD. Overall, these results indicate that there are changes in trace elements in saliva in EGUS that could reflect the physiopathological mechanisms involved in this process and open the possibility of using trace elements as biomarkers of this syndrome.

Risk Assessment of Natural Radionuclides and Trace Elements of Industrial Activities in Suez Bay

ABSTRACT The study aims to assess the marine environmental hazards resulting from some industrial activities areas being found at the Suez Bay. The survey was done to select five industrial locations along the studied areas where different water and sediment samples were collected during September 2020. The study methods showed that different concentrations were measured in the collected water and sediment samples, such as; Al, Fe, Mn, Hg, Cd, Cr, Co, Mo, V, Pb, Ni, Cu, Zn, where the digested samples were measured by using Inductively Coupled Argon Plasma spectroscopy (ICAP 6500 Duo), while the natural radioactivity concentrations of the selected radio-nuclides such as 238U, 226Ra, 232Th, 40K, were measured in both water and sediments samples by using Hyper germanium detector, as the radiological risk assessment of different samples was detected by using ERICA modeling software. The study results showed that the concentrations of the measured trace elements in the selected five industrial sites were slightly higher than the standard limits, while the measured radioactivity concentrations of the selected radio-nuclides in both water and sediment samples were below the standard limits. The results showed that the calculated distribution coefficient of the selected trace elements was (Kd Metal Pollution Index < 3), which indicated that the measured trace elements were more dissolved in the aqueous than the sediment medium. The study used the mean probable effect Level (m-PEL-Q) for estimating the metal concentration hazards in the sediment samples at the selected sites, where these values were ranged from 0.04 to 0.1, indicating that the combined concentration effects for these metals were caused 9% toxic probability. The study showed that both the calculated quotient risk (QR) and dose rate values of the marine organisms which were being calculated by the ERICA model were below the recommended limits.

Evaluation of Antioxidant Effects and Estimation of Trace Minerals in Unripe Fruits of Capparis Zeylanica (Aadhandangai) – An Invitro Study.

Capparis zeylanica (Aadhandangai) is a 2- to 5-meter-tall shrub endemic to India and other Asian nations. The leaves are anti-inflammatory, anti-oxidant, and anti-helminthic. Several studies have been carried out to illustrate the medicinal and therapeutic properties of leaf extract. A careful examination of the literature identified no studies on unripe fruits, which are customarily eaten on the festival of Aadi Amavasya (new moon day of July-August). Capparis zeylanica, used for the study was recognised by a team of botanical experts and a marketing expert with an expertise of more than four decades. Unripe fruits were assessed for mineral content and antioxidant DPPH test. The phytochemical analyses were carried out using the procedures outlined. The Roche/Hitachi Cobas 6000 analyser series was used to measure trace elements and minerals such as phosphorus. The fruit showed the presence of antioxidants. The phytochemical studies also revealed proteins, amino acids, and saponins. The fruit was high in calcium and phosphorus (&gt; 48.0 mg/100 gm), but low in zinc and magnesium. It also had vitamin D and B12. The presence of trace minerals and vitamins with anti-oxidant action makes it a food; however, an excess of calcium with phosphorous may cause injury to a weak kidney, therefore an annual and infrequent consumption may have been advised. So far, there is no literature on the plant's immature fruit. This study is the first to demonstrate the utility of the customary practice of annual intake.

Trace Element Distribution and Arsenic Speciation in Toenails as Affected by External Contamination and Evaluation of a Cleaning Protocol.

Trace element concentrations in toenail clippings have increasingly been used to measure trace element exposure in epidemeological research. Conventional methods such as inductively coupled plasma mass spectrometry (ICP-MS) and high-performance liquid chromatography ICP-MS (HPLC-ICP-MS) are commonly used to measure trace elements and their speciation in toenails. However, the impact of the removal of external contamination on trace element quantification has not been thoroughly studied. In this work, the microdistribution of trace elements (As, Ca, Co, Cu, Fe, K, Mn, Ni, Rb, S, Sr, Ti, and Zn) in dirty and washed toenails and the speciation of As in situ in toenails were investigated using synchrotron X-ray fluorescence microscopy (XFM) and laterally resolved X-ray absorption near edge spectroscopy (XANES). XFM showed different distribution patterns for each trace element, consistent with their binding properties and nail structure. External (terrestrial) contamination was identified and distinguished from the endogenous accumulation of trace elements in toenails─contaminated areas were characterized by the co-occurrence of Co, Fe, and Mn with elements such as Ti and Rb (i.e., indicators of terrestrial contamination). The XANES spectra showed the presence of one As species in washed toenails, corresponding to As bound to sulfhydryl groups. In dirty specimens, a mixed speciation was found in localized areas, containing AsIII-S species and AsV species. ArsenicV is thought to be associated with surface contamination and exogenous As. These findings provide new insights into the speciation of arsenic in toenails, the microdistribution of trace elements, and the effectiveness of a cleaning protocol in removing external contamination.

The McClure Mountain Syenite Apatite as a Potential Age Control Reference Material for LA‐ICP‐MS AFT and U‐Pb Double Dating

Apatite fission track (AFT) dating is now routinely performed using LA‐ICP‐MS, and U‐Pb age data are often acquired at the same time, allowing double dating of individual grains. Furthermore, additional geochemical data, such as REE mass fractions are readily acquired during the analysis. It is therefore of practical interest to identify a single material as a quality control on ages and composition. Here we present AFT and U‐Pb data for the McClure Mountain Syenite (MMS) apatite, already widely used as an age reference material by the U‐Pb community. We performed double dating on 238 grains, in thirteen measurement sessions over two years. The AFT data show remarkable reproducibility with an overall central age of 254.1 ± 5.1 Ma. The U‐Pb results agree with the reference age for individual sessions (and for all data together). The results show that that the McClure Mountain apatite is a valid quality control material for double dating, allowing the use of the same material for both methods. We also propose to extend the quality control using MMS to trace element measurements performed in conjunction AFT and U‐Pb dating.

Review of melt inclusions in lunar rocks: constraints on melt and mantle composition and magmatic processes

Abstract. Mineral-hosted melt inclusions provide a window into magmatic processes and pre-eruptive liquid compositions. Because melt inclusions are small (typically &lt; 100 µm), the study of lunar melt inclusions is enabled by advancements of microbeam instrumental techniques. In the 1970s immediately following the Apollo and Luna missions, major and minor oxide concentrations of lunar melt inclusions were measured using electron microprobes. The data were used to understand magma evolution, and they revealed the immiscibility of two silicate liquids in the late stage of lunar magma evolution. More recently, the development of secondary ion mass spectrometry as well as laser ablation–inductively coupled plasma–mass spectrometry has enabled the measurement of key volatile elements and other trace elements in lunar melt inclusions, down to about the 0.1 ppm level. The applications of these instruments have ushered in a new wave of lunar melt inclusion studies. Recent advances have gone hand in hand with improved understanding of post-entrapment loss of volatiles. These studies have provided deep insights into pre-eruptive volatiles in lunar basalts, the abundance of volatiles in the lunar mantle, the isotopic ratios of some volatile elements, and the partition of trace elements between host olivine and melt inclusions. The recent studies of lunar melt inclusions have played a critical role in establishing a new paradigm of a fairly wet Moon with about 100 ppm H2O in the bulk silicate Moon (rather than a “bone-dry” Moon) and have been instrumental in developing an improved understanding of the origin and evolution of the Moon.

An Ocean of Particles Characterization of Particulate Trace Elements by the GEOTRACES Program

The GEOTRACES program has greatly expanded measurements of trace elements, which serve as key nutrients, harmful contaminants, and tracers of ocean processes and past conditions. Many elements tend to associate with particulate matter, and GEOTRACES has been particularly valuable for growing our understanding of this fraction. Focusing on the micronutrient iron as an example, GEOTRACES data demonstrate that the majority of iron in the ocean is particulate. Chemically labile particulate iron, likely available for biological use, is also often more abundant than dissolved forms, particularly near continents and in the deep sea. This highlights the need to consider the particulate fraction in conceptual and numeric ocean models. Direct comparisons of particle-sampling methods highlight both the abundance of small particles (&lt;0.45–0.8 μm), whose biogeochemical roles are still poorly known, and the difficulty in consistently capturing large, faster-sinking particles. In situ pumps with 0.8 μm filters often capture less small particulate iron than bottle-collected samples filtered onto 0.45 μm filters, but they can also capture more material near some sources. GEOTRACES datasets contain nearly sevenfold more dissolved than particulate iron measurements, and ongoing efforts to pair these measurements are needed in order to fully understand the cycles of iron and other important elements.

Trace element of small lake sediments sensitively recorded environmental changes in the watershed: Implications for mining history and urbanization

Lake sediments serve as a sink for trace elements and provide a record of watershed changes resulting from anthropogenic activities and natural processes. In this study, eight trace elements in the sediments of Lake Aha, an urban lake in Guiyang City, Southwest China, were investigated to reveal the effects of historical coal mining and rapid urbanization in the watershed. Results showed that the median contents of measured trace elements in order of Zn (220.00 mg/kg) > Ni (98.16 mg/kg) > Cr (70.26 mg/kg) > Cu (66.20 mg/kg) > As (58.14 mg/kg) > Co (41.66 mg/kg) > Pb (28.33 mg/kg) > Cd (1.39 mg/kg). Except for Cr and Pb, the median concentrations of Cd, As, Zn, Ni, Co, and Cu were 4.64, 2.33, 2.00, 1.92, 1.81, and 1.09 times higher than regional natural background values respectively. Trace element contents in sediments of the center of the lake were significantly higher than in the rest of the sediment cores, resulting from relatively stable hydrodynamic processes in the region. Vertical variation of trace elements indicated that the fluctuations in the intensity of coal mining activities in the tributaries were effectively tracked by variations of trace element levels in the middle layer sediments of the Youyu River and Baiyan River estuaries. The elevated concentrations of Pb in the surface sediments of the Jinzhong River estuary reflected the rapid urbanization in the basin over the past 20 years. PMF analysis demonstrated that As, Cd, and Pb in sediments were from a mixture of natural and urban activities, and Cu, Zn, Ni, and Co originated from coal mining. This study provides important information for comprehending the anthropogenic activities of small-scale lakes and historical environmental changes.

MGP‐1 Plagioclase: A Potential Element and Sr Isotope Reference Material for In Situ Microanalysis

Plagioclase, one of the most common rock‐forming minerals, can provide useful information on the crystallisation environment, magmatic evolution and thermal history of host rocks. Owing to matrix effects, trace element and Sr isotope in situ measurements in plagioclase have been hindered by a shortage of reference materials for quality control and method validation. A natural plagioclase sample from Madagascar was evaluated for its feasibility as a reference material for Sr isotope and element determination. Measurement results from EPMA, LA‐ICP‐MS and LA‐MC‐ICP‐MS indicate that MGP‐1 plagioclase is homogeneous at the μm–mm scale with respect to major elements (RSD &lt; 4%), most trace elements (RSD &lt; 15%), and 87Sr/86Sr ratio (2s = 0.00013). Major and trace elements were also determined using XRF and solution ICP‐MS, showing good agreement within 10% from in situ measurement results. The 87Sr/86Sr ratio obtained by TIMS ranged from 0.703441 to 0.703477, with a mean value of 0.703459 (2s = 0.000028), consistent with the LA‐MC‐ICP‐MS mean value. Reference values and uncertainties for major and trace elements and 87Sr/86Sr ratio are presented in this study. Consequently, the MGP‐1 plagioclase can be used as a reference material for in situ measurement of trace elements and 87Sr/86Sr ratios, contributing to research on the formation and evolution of micro‐zoned plagioclase and host rocks.

Determination of trace elements in ibuprofen drug products using microwave-assisted acid digestion and inductively coupled plasma-mass spectrometry

Trace elements are found in most drugs as a result of the drug formulation and drug production methods. An inductively coupled plasma-mass spectrometry method for the determination of 24 trace elements (Mg, Ti, V, Cr, Mn, Cu, Fe, Co, Ni, Zn, As, Se, Mo, Ru, Rh, Pd, Ag, Cd, Sb, Ba, Ir, Pt, Au, and Pb) in solid ibuprofen tablets was established in relation to the ICH Q3D(R1) guideline, to evaluate the possibility of linking trace elemental profiles to drug formulation strategies, and to differentiate between drug products based on the trace elemental profiles. Ten European ibuprofen drug products were evaluated (n=3). The sample preparation was performed by microwave-assisted acid digestion using only 10 mg of homogenized sample and 900 μL of a mix of 65% HNO3, 37% HCl, and 30% H2O2. Solid residuals primarily composed of insoluble SiO2 excipients were removed by centrifugation. Only concentrations of Mg, Fe, Ti, Mn, Cr, and Ni were detected above the limits of detection and did not exceed the ICH Q3D(R1) guideline permitted daily exposure limits. The trace elemental profiles were evaluated through principal component analysis. Three principal components describing 96% of the variance were useful in grouping the ibuprofen drug products, and the detected trace elemental remnants could be related to drug formulation and drug production strategies. An in-house quality control material was used in lack of certified reference materials and was in combination with spike recoveries used for method validation. Good spike recoveries (94–119%) were obtained for all measured trace elements except Mg. Mg showed acceptable spike recoveries (75–155%) for mid and high-spike concentrations, but poor recoveries (30–223%) were detected with low spike concentrations in spike matrices containing high amounts of Mg. Overall, the method is suggested applicable for solid drugs containing insoluble SiO2 excipients and drugs comparable to ibuprofen.

Direct and Indirect Linkages Between Trace Element Status and Health Indicators - a Multi-tissue Case-Study of Two Deer Species in Denmark

Measuring trace element concentrations in tissue can be a valuable approach to monitor animal health status. Temporal variation in the absorption, transport, and storage of elements between different tissues can, however, complicate the assessment of element-health relationships. Here, we measured concentrations of selected essential (copper (Cu), zinc (Zn), selenium (Se)) and non-essential (arsenic (As), cadmium (Cd), lead (Pb)) trace elements within blood, liver, kidney, and hair of fallow deer (Dama dama; N=20) and red deer (Cervus elaphus; N=21). Using multivariate regression and structural equation models, we estimated direct and indirect linkages between tissue-specific trace element profiles and long- (body condition) and short-term (serum protein biomarkers for acute inflammation, infection, and malnutrition) health indicators. Trace element concentrations varied markedly and were weakly correlated among tissues, with the exception of Se. After accounting for sex- and site-differences in trace element concentrations, body condition of red deer was directly, and positively, associated to trace element status in liver and hair, but not in kidney. For both deer species, trace element status in blood was directly linked to serum protein status with an indirect positive association to deer body condition. For fallow deer, no direct association between trace element status and body condition was detected in any of the tissues, possibly because of elemental homeostasis, and because all individuals were in good clinical health. This study shows that hair can serve as an effective, non-invasive, biomarker in deer health assessments, yet, to fully uncover trace element-health relationships a variety of sample matrices is preferred.

Controls of Tellurium enrichment in the rare earth elements and yttrium (REY) rich deep-sea sediments from the Central Indian Ocean Basin (CIOB)

As a potential Te reservoir for the global budget, the occurrence, material sources, migration and enrichment mechanism of Te in deep-sea sediments remain unclear. Based on the major and trace elements measurements of bulk sediments, this study proposed a procedure to quantify the contribution of Te by main host minerals, combining with TIMA and LA-ICP-MS in two cores (GC04 and GC11) from the Central Indian Ocean Basin (CIOB) and a core from east of the 90°E Ridge (GC03). Te shows the highest enrichment coefficient of 650 referred to UCC (Upper Continental Crust) in the REY (Rare Earth Elements and Yittrium) rich sediments in GC04, GC11 and GC02 (a core at the south of GC04 and GC11). Clinoptilolite-K and osumilite are indicated as the main host minerals, which correlates Te sources with volcanogenic materials and weathering products of terrigenous rocks. The inter elements correlation, cluster analysis and factors analysis further indicate distinct hydrothermal genetic Te. So, we put forward a hypothesis that Te is mainly sourced from the submarine volcanogenic hydrothermal activities, which are closely associated with local intraplate volcanism episodes from late Miocene with spatial and temporal differences. This study is the first attempt to quantify Te from different minerals and to reveal its geochemical behavior in the deep sea sediments, which will be benefit to the understanding of Te reservoir and cycle in deep sea and the comprehensive utilization of REY-rich deep-sea sediments. However, for the abundant presence of undetectable nanoscale minerals in these sediments, the contribution of Fe-Mn (oxyhydr) oxides and clay minerals of Te need more investigation.

New progress of a 2.45 GHz ECR ion source for carbon positive ion mass spectrometry

Positive ion mass spectrometry (PIMS) is a trace element measurement technique based on positive and negative ion conversion, which is contrary to conventional accelerator mass spectrometry (AMS). To precisely measure 14C, interference of molecular isobars (such as 12CH2 and 13CH) need to be suppressed in the ion source by generating multi-charged carbon ions, such as C2+ or C3+. At present, a high-frequency (> 7 GHz) electron cyclotron resonance (ECR) ion source is commonly used to generate C2+ or C3+ ions through CO2 discharge. At Peking University (PKU), we developed a compact permanent magnet 2.45 GHz ECR ion source attempting to produce C2+ ions. In this work, systematical experiments are performed to further improve the performance of the ion source for the application in PIMS. The results show that it can deliver 1.0 emA C2+ ions with an alumina ceramic liner, and its C consumption is about 10∼20 ng/s. Meanwhile, it is also proved that a certain proportion of He and CO2 mixing can improve the production efficiency of C2+ ions, and the consumption of C can be lower. Furthermore, results confirm that this ECR ion source with alumina liner has a lower memory effect, and the influence of original CO2 discharge can be eliminated by Ar plasma cleaning for several minutes. The experimental results show that the 2.45 GHz ECR ion source has the potential to be used in the PIMS system.

Rare Earth Elements Geochemistry and 234U/238U, 235U/238U Isotope Ratios of the Kanyakumari Beach Placer Deposits: Occurrence and Provenance

Geochemical studies of rare earth elements (REEs) as well as major and trace elements were conducted on the beach placer sands from the Kanyakumari coastal region, a well-known high background natural radiation area (HBNRA). For the first time, uranium isotope ratios (234U/238U and 235U/238U) were determined in the study area to investigate the provenance and leaching of U from the beach sands. Inductively coupled plasma mass spectrometry was used for the measurement of REEs and trace elements whereas thermal ionization mass spectrometry (TIMS) was used for the measurement of U isotope ratios. ∑REEs were found to be in the range of 778.93 to 15,007. 54 µg/g, whereas ∑Light REEs were in the range of 770.58 to 14,860.80 µg/g and ∑Heavy REEs varied from 8.35 to 146.74 µg/g. The enrichment factor showed the LREEs Th and U were extremely enriched in the Kanyakumari beach placer sands. The 235U/238U isotope ratios were similar to the natural terrestrial ratio value. The 234U/238U activity ratio varied from 0.995 to 1.071, and showed the prevailing secular equilibrium among them. The δ238U results could, to some extent, explain the U fractionation and source.

Measuring trace element fingerprinting for cereal bar authentication based on type and principal ingredient.

This paper introduces a method for determining the authenticity of commercial cereal bars based on trace element fingerprints. In this regard, 120 cereal bars were prepared using microwave-assisted acid digestion and the concentrations of Al, Ba, Bi, Cd, Co, Cr, Cu, Fe, Li, Mn, Mo, Ni, Pb, Rb, Se, Sn, Sr, V, and Zn were later measured by ICP-MS. Results confirmed the suitability of the analyzed samples for human consumption. Multielemental data underwent autoscaling preprocessing for then applying PCA, CART, and LDA to input data set. LDA model accomplished the highest classification modeling performance with a success rate of 92%, making it the suitable model for reliable cereal bar prediction. The proposed method demonstrates the potential of trace element fingerprints in distinguishing cereal bar samples according to their type (conventional and gluten-free) and principal ingredient (fruit, yogurt, chocolate), thereby contributing to global efforts for food authentication.