ICP-MS Analysis Research Articles

Nutritional Content, Phytochemical Profiling, and Physical Properties of Buckwheat (Fagopyrum esculentum) Seeds for Promotion of Dietary and Food Ingredient Biodiversity

The adoption of food crops as a source of dietary macro- and micro-nutrients is a sustainable way to promote diet biodiversity and health while being respectful to the environment. The aim of this work was to comprehensively characterize the nutrient and phytochemical content of buckwheat seeds (Fagopyrum esculentum) and assess their physical properties for the evaluation of their suitability as food ingredients. The buckwheat samples were found to be complete sources of amino acids (UPLC-TUV analysis), with a protein content between 11.71 ± 0.40% and 14.13 ± 0.50% (Vario Max CN analysis), and a source of insoluble fiber with 11.05 ± 0.25 %, in the UK hulled samples (GC analysis). The buckwheat samples were rich in phosphorus, manganese, molybdenum, zinc, magnesium, and selenium (ICP-MS analysis). A total of 196 plant metabolites were detected using HPLC and LCMS analysis, with anthocyanidins (pelargonidin and cyanidin) being the most abundant phenolic molecules that were measured in all the buckwheat samples. Removing the hull was beneficial for increasing the powder bulk density, whereas the hulled buckwheat samples were more easily rehydrated. The implementation of buckwheat as a staple food crop has enormous potential for the food industry, human nutrition, and diet diversification and could contribute towards meeting the daily recommendation for dietary fiber, essential amino acids, and minerals in Western-style diet countries such as the UK.

Influence of CeO2 and TiO2 Particles on Physicochemical Properties of Composite Nickel Coatings Electrodeposited at Ambient Temperature.

The Ni-TiO2 and Ni-CeO2 composite coatings with varying hydrophilic/hydrophobic characteristics were fabricated by the electrodeposition method from a tartrate electrolyte at ambient temperature. To meet the requirements of tight regulation by the European Chemicals Agency classifying H3BO3 as a substance of very high concern, Rochelle salt was utilized as a buffer solution instead. The novelty of this study was to implement a simple one-step galvanostatic electrodeposition from the low-temperature electrolyte based on a greener buffer compared to traditionally used, aiming to obtain new types of soft-matrix Ni, Ni-CeO2, and Ni-TiO2 coatings onto steel or copper substrates. The surface characteristics of electrodeposited nickel composites were evaluated by SEM, EDS, surface contact angle measurements, and XPS. Physiochemical properties of pure Ni, Ni-CeO2, and Ni-TiO2 composites, namely, wear resistance, microhardness, microroughness, and photocatalytic activity, were studied. Potentiodynamic polarization, EIS, and ICP-MS analyses were employed to study the long-term corrosion behavior of coatings in a 0.5 M NaCl solution. Superior photocatalytic degradation of methylene blue, 96.2% after 6 h of illumination, was achieved in the case of Ni-TiO2 composite, while no substantial change in the photocatalytic behavior of the Ni-CeO2 compared to pure Ni was observed. Both composites demonstrated higher hardness and wear resistance than pure Ni. This study investigates the feasibility of utilizing TiO2 as a photocatalytic hydrophilicity promoter in the fabrication of composite coatings for various applications.

Fluid origin and critical ore-forming processes for the giant gold mineralization in the Jiaodong Peninsula, China: Constraints from in situ elemental and oxygen isotopic compositions of quartz and LA–ICP–MS analysis of fluid inclusions

The Jiaodong Peninsula, China, is one of the largest gold provinces in the world. During a short time interval in the Early Cretaceous, over 5000 t of gold were accumulated there. The mechanisms controlling the focused Au deposition and the origins of massive amounts of auriferous fluids are still controversial. Quartz–sulfide lode mineralization (Linglong-type) and disseminated/stockwork mineralization (Jiaojia-type) are the two major mineralization styles in the Jiaodong Peninsula. Herein, we conducted in situ textural, elemental and oxygen isotopic analyses using scanning electron microscopy (SEM), laser ablation-inductively coupled plasma-mass spectrometry (LA–ICP–MS) and secondary ion mass spectrometry (SIMS) on quartz from different hydrothermal stages and depths for three representative Linglong-type (Linglong deposit) and Jiaojia-type (Xiadian and Jiangjiayao deposits) gold deposits in the northwestern Jiaodong Peninsula, with the aim to constrain the ore-forming processes. The LA–ICP–MS analysis of individual fluid inclusions was also conducted to unravel the origin of the auriferous fluids. The results show that from the pre-mineralization to the ore-forming stages in the Linglong-type mineralization, the homogenization temperatures and salinities of fluid inclusions and the δ18Oquartz values change slightly, but the Al concentrations of quartz decrease continuously. Combined with the coexistence of CO2- and H2O-rich fluid inclusion endmembers, these trends indicate the increase of pH induced by CO2 degassing (fluid–fluid unmixing), which led to focused Au deposition. The quartz grains from the Jiaojia-type mineralization typically show a homogeneous texture with well-correlated lithophile elements (e.g., K, Al and Rb), which are distinct from those of the Linglong-type that are characterized by oscillatory zoning with much higher Al concentrations and δ18Oquartz values. These phenomena indicate that enhanced fluid–rock interaction occurred in the Jiaojia-type mineralization. In addition, the δ18Oquartz values show an increase from deep to shallow depths. In combination with thermodynamic modelling, it suggests decreasing fluid–rock interaction with decreasing depth. The above results corroborate that multiple mechanisms led to the efficient Au deposition in the Jiaodong Peninsula. Fluid–fluid unmixing typically occurred in the Linglong-type mineralization, while fluid–rock interaction was dominant in the Jiaojia-type mineralization. The different mechanisms might render mining challenging due to the changeable locations of favorable Au unloading.The LA–ICP–MS results of fluid inclusions suggest that the ore-forming fluids are metamorphic fluids rather than magmatic–hydrothermal fluids. In combination with the isotopic compositions of ores showing considerable mantle affinities and large-scale mafic underplating occurring beneath the study region, we propose a new genetic model that accounts for the origin of the auriferous fluids. The new model invokes the devolatilization of previously emplaced H2O- and Au-rich amphibole cumulates through amphibolite- to granulite-facies metamorphism in the middle–lower crust. It suggests an alternative way to generate the ‘orogenic-like’ gold deposits.

Biosynthesis of silver nanoparticles using the aqueous extract of Rheum ribes, characterization and the evaluation of its toxicity on HUVECs and Artemia salina

This study describes an eco-friendly procedure to synthesize silver nanoparticles (AgNPs) using fresh and dried stem extract of Rheum ribes. AgNPs formation was confirmed using UV-vis spectrometry. The effects of parameters such as temperature, reaction time, pH, AgNO3 concentration, and plant extract/AgNO3 ratio on NP formation were evaluated. Morphology and structural features of the particles were characterized using SEM, TEM, XRD, and FTIR. The average size, polydispersity index, and zeta potential were determined using DLS. After characterization, among the two AgNP samples, selected one; AgNP sample synthesized by dried Rheum ribes stem extracts (d-AgNPs), which exhibited narrow size distribution and high surface plasmon resonance in the range of 435–445 nm for toxicity assessment. The cytotoxic effect of d-AgNPs on HUVECs cells was evaluated with MTT analysis. Accumulation measurements were made in three periods as 24, 48, and 72 h and elimination values were examined at +24 h using ICP-MS analysis

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.

The bromine mediated electrosynthesis of ethylene oxide from ethylene in continuous flow-through operation

In this work a reactor setup for the bromine mediated, electrochemical oxidation of ethylene oxide from ethylene was developed. This novel design featured a flow-through configuration for the ethylene feed to accommodate the in situ synthesis of the 2-bromoethanol intermediate, creating a low pH at the anolyte to selectively target the bromine evolution. The cell was characterized via chronopotentiometry in 0.5 M KBr electrolyte, using a (i) Pt or (ii) IrO2 coated gas diffusion anodes paired with a Ni foam cathode. Within a current density of 65 to 156 mA/cm2 for Pt and 65 to 133 mA/cm2 for IrO2, the productivity and selectivity of the reactor system was mapped. Throughout all conditions the reactor system retained a Faradaic efficiency of 80 to 90% towards ethylene oxide on both Pt and IrO2 coated gas diffusion anodes and exceeded an equivalent ethylene oxide production of 1 kg/hour/m2 at 156 mA/cm2. Furthermore, the reactor upheld identical selectivity and productivity for 4.5 h without any signs of fading performance. Analysis of the gaseous product phase at this highest current condition showed no CO2 or O2 side products, originating from hydrocarbon overoxidation or oxygen. Based on our findings, the bromine mediated pathway proves to be highly promising as the current best case of the chlorine mediated system achieves a 70% selectivity towards ethylene oxide. Additionally, the anodic catalyst stability was quantified by ICP-MS analysis and scanning electron microscopy coupled with energy dispersive X-ray analysis, which revealed IrO2 to be three orders of magnitude more dissolution resistant compared to Pt and confirm a homogeneous dispersion of the catalyst and binder material on the surface of the gas diffusion electrodes.

Concentrations of Zn, Mn and Al in wood chips from wood-based manufacturing industries

The elemental composition of wood chip samples manufactured in the wood industries at Batu Pahat were analyzed for their heavy metals composition. This study was aimed to prove that heavy metals can accumulate in wood and trees themselves without adding any wood treatment additives. ICP-MS analysis was conducted on the wastewater at the same manufacturing industry to evince the occurrence of the leaching process that causes the presence of heavy metals in the wastewater. The results of the experiments showed that Mn, Zn and Al were among the highest metal traces found in the wood chips. As a result, Mn concentrations in three different samples of wood chips were 83.6 mg/L, 88.1 mg/L, and 80.9 mg/L, whereas Zn amounts were 38.8 mg/L, 40.2 mg/L, and 37.7 mg/L. Furthermore, the amounts of Al traces in the three samples were 28.2 mg/L, 29.6 mg/L, and 30.7 mg/L, respectively. The study also found that the highest metal trace in wastewater shows a proportional value to the highest concentration of heavy metals in wood chips. Therefore, it can be concluded that, even though the whole chipping production process is considered to be a dry process, the wastewater generated after cleaning surfaces, storage tanks and machinery, causes heavy metal leaching and contributes to the presence of heavy metals in wastewater.

Challenges in Using Handheld XRFs for In Situ Estimation of Lead Contamination in Buildings

Lead in buildings can be found in certain materials such as paints or can be a result of contamination during the use stage. In situ methods for lead identification can be vital for the proper treatment of hazardous CDW (from repair works or selective demolition). A conventional handheld XRF (HHXRF) spectrometer can be used for this purpose, and this study analysed its reliability. A laboratory experiment was conducted to test different calibrations, and to establish a procedure for the conversion of the HHXRF lead concentrations into lead loadings. Model latex paint with a constant lead content was used on two types of surfaces (plasterboard and concrete). A field study was performed to identify and quantify the lead in paint on masonry walls in a public building. ICP-MS analysis was performed in order to verify the lead content. The coefficients of proportionality in the proposed model depend on various parameters: the contamination type, the layer thickness, the substrate, and the built-in calibrations. Despite the limitations of the HHXRF and the discrepancy of the mean lead loadings from the HHXRF and ICP-MS analysis, the HHXRF can be useful for the identification of lead in paint layers up to 1 mm, with a low limit of detection of the order of 0.01 mg/cm2 at worst.

A Qualitative and Quantitative Occupational Exposure Risk Assessment to Hazardous Substances during Powder-Bed Fusion Processes in Metal-Additive Manufacturing

Metal-additive manufacturing (AM), particularly the powder-bed fusion (PBF) technique, is undergoing a transition from the short-run production of components to higher-volume manufacturing. The industry’s increased production efficiency is paired with a growing awareness of the risks related to the inhalation of very fine metal powders during PBF and AM processes, and there is a pressing need for a ready-to-use approach to assess the risks and the occupational exposure to these very final metal powders. This article presents a study conducted in an AM facility, which was conducted with the aim to propose a solution to monitor incidental airborne particle emissions during metal AM by setting up an analytical network for a tailored approach to risk assessment. Quantitative data about the respirable and inhalable particle and metal content were obtained by gravimetric and ICP-MS analyses. In addition, the concentrations of airborne particles (10–300 nm) were investigated using a direct reading instrument. A qualitative approach for risk assessment was fulfilled using control banding Nanotool v2.0. The results show that the operations in the AM facility are in line with exposure limit levels for both micron-sized and nano-sized particles. The particulate observed in the working area contains metals, such as chromium, cobalt, and nickel; thus, biological monitoring is recommended. To manage the risk level observed for all of the tasks during the AM process, containment and the supervision of an occupational safety expert are recommended to manage the risk. This study represents a useful tool that can be used to carry out a static evaluation of the risk and exposure to potentially harmful very fine metal powders in AM; however, due to the continuous innovations in this field, a dynamic approach could represent an interesting future perspective for occupational safety.

Tomato (Solanum lycopersicum L.) accumulation and allergenicity in response to nickel stress

Vegetables represent a major source of Ni exposure. Environmental contamination and cultural practices can increase Ni amount in tomato posing significant risk for human health. This work assesses the tomato (Solanum lycopersicum L.) response to Ni on the agronomic yield of fruits and the related production of allergens. Two cultivars were grown in pots amended with Ni 0, 30, 60, 120, and 300 mg kg−1, respectively. XRF and ICP-MS analyses highlighted the direct increase of fruit Ni content compared to soil Ni, maintaining a stable biomass. Leaf water content increased at Ni 300 mg kg−1. Total protein content and individual allergenic components were investigated using biochemical (RP-HPLC and N-terminal amino acid sequencing) and immunological (inhibition tests of IgE binding by SPHIAa assay on the FABER testing system) methodologies. Ni affected the fruit tissue concentration of pathogenesis-related proteins and relevant allergens (LTP, profilin, Bet v 1-like protein and TLP). This study elucidates for the first time that tomato reacts to exogenous Ni, uptaking the metal while changing its allergenic profiles, with potential double increasing of exposure risks for consumers. This evidence highlighted the importance of adequate choice of low-Ni tomato cultivars and practices to reduce Ni uptake by potentially contaminated matrices.

Comparative Toxicity of Interferon Beta-1a Impurities of Heavy Metal Ions.

Background and Objectives: Providing a proper quality control of drugs is essential for efficient treatment of various diseases minimizing the possible side effects of pharmaceutical active substances and potential impurities. Recent in vitro and in vivo studies have shown that certain heavy metalloids and metals interfere with protein folding of nascent proteins in cells and their biological function can be altered. It is unknown whether the drug impurities including heavy metals may affect the tertiary protein structure. Materials and Methods: ReciGen and Rebif are pharmaceutical interferon beta-1a (IFNβ-1a) contained in preparations that are used for parenteral administration. Heavy metal impurities of these samples have been studied by gel electrophoresis, Fourier-transform infrared spectroscopy (FTIR) and inductively coupled plasma mass spectrometry analysis (ICP MS). The concentration of heavy metals including mercury, arsenic, nickel, chromium, iron, and aluminum did not exceed permitted levels established by International Council for Harmonisation guideline for elemental impurities. Results: The ICP MS analysis revealed the presence of heavy metals, moreover zeta potential was significantly different for IFNβ-1a, which can be an indirect indication of the difference in composition of ReciGen and Rebif samples, respectively. FTIR analysis revealed very similar amide I and II bonds at 1654 and 1560 cm−1 attributed to the peptide absorption peaks of IFNβ-1a in Rebif and ReciGen. Conclusions: It was hypothesized that the IFNβ-1a complex binds heavy metals affecting the tertiary protein structure and may lead to some side effects of drug administration. Further testing of IFNβ-1a bioequivalence for parenteral application is necessary.

Mobilization of Au and Ag during Supergene Processes in the Linglong Gold Deposit: Evidence from SEM and LA–ICP–MS Analyses of Sulfides

Precious metals can be mobilized during supergene processes, which are important for the formation of high-grade or high-purity ores. The world-class Linglong gold deposit has high-grade ores that have undergone supergene processes in the near-surface zone. Under which conditions the supergene modification occurred and how Au and Ag behaved during the supergene processes have been poorly studied in this deposit. Here, we performed scanning electron microscope (SEM) and laser ablation–inductively coupled plasma–mass spectrometry (LA–ICP–MS) analyses on samples from the supergene enrichment zone of the Linglong gold deposit. The results show that secondary minerals were formed sequentially from magnetite-goethite-limonite to marcasite-acanthite, and finally to siderite after the primary minerals of pyrite-pyrrhotite-chalcopyrite. These mineral assemblages and variations indicate that the supergene modification by groundwater occurred under oxidative and weakly acidic conditions in the near-surface zone and evolved to reductive and near neutral conditions in the supergene enrichment zone. The newly formed marcasite has much higher Au (0.003–23.5 ppm, mean of 1.33 ppm) and Ag (81.7–6021 ppm, mean of 1111 ppm) concentrations than those of the primary pyrite (Au of 0.004–0.029 ppm and Ag of 0.22–4.14 ppm), which together with the formation of independent Ag–S mineral (acanthite), indicates that Au and Ag were significantly mobilized and fractionated during the supergene processes. These processes improved the Au and Ag grades in the supergene enrichment zone and thus facilitate their extraction.

Label-Free Target Identification Reveals the Anticancer Mechanism of a Rhenium Isonitrile Complex

Elucidation of the molecular mechanism of therapeutic agents and potential candidates is in high demand. Interestingly, rhenium-based complexes have shown a highly selective anticancer effect, only on cancer cells, unlike platinum-based drugs, such as cisplatin and carboplatin. These differences might be attributed to their different molecular targets. We confirmed that the target of tricarbonyl rhenium isonitrile polypyridyl (TRIP) complex is a protein, not DNA, using ICP-MS analysis and identified heat shock protein 60 (HSP60) as its target protein using a label-free target identification method. The subsequent biological evaluation revealed that TRIP directly inhibits the chaperone function of HSP60 and induces the accumulation of misfolded proteins in mitochondria, thereby leading to the activation of mitochondrial unfolded protein response (mtUPR)-mediated JNK2/AP-1/CHOP apoptotic pathway.

Soil contamination by microplastics in relation to local agricultural development as revealed by FTIR, ICP-MS and pyrolysis-GC/MS

Plastic film mulching and use of wastewaters for irrigation have been common agricultural practices for over half a century in Tunisia, especially in arid regions, resulting in the undesired creation of a pathway for microplastics (MPs) to enter farmland soil. In order to assess the extent and characteristics of soil contamination by MPs in the Moknine province, an area of intensive agricultural practices, 16 farmland soil samples were collected and characterized. The total concentration of targeted MPs was 50–880 items/kg; among them, the most common MPs type being polypropylene (PP), mainly occurring as white/transparent fibers with small size (cross section <0.3 mm). SEM images of MPs surfaces revealed multiple features related to environmental exposure and degradation. ATR-FTIR spectroscopy and pyrolysis-GC/MS analyses enabled the accurate identification of MPs separated from the embedding soil micro- and macro-aggregates. Finally, contamination of the polymeric microparticles with a broad range of metals was found by ICP-MS analysis, suggesting that MPs can be vectors for transporting heavy metals in the soil and indicators of soil contamination as a result of mismanagement of industrial wastewaters.

Molybdenum accumulation in sediments: A quantitative indicator of hypoxic water conditions in Narragansett Bay, RI

Authigenic molybdenum (Mo) accumulation in marine sediments has often been used as a qualitative indicator of hypoxic bottom water. To investigate its use as a quantitative indicator of hypoxic exposure, sediment cores were collected from water quality monitoring sites in Narragansett Bay (RI, USA) that experience varying periods of hypoxia. Total Mo concentrations in surficial (0–1 cm) sediments were determined by total digestion and ICP-MS analysis. Lithogenic contributions to total Mo concentrations were estimated by multiplying measured concentrations of aluminum (Al) by the mean crustal Mo:Al ratio and subtracting them from the total concentrations to yield the authigenic fraction. 210Pb dating was used to determine sediment accumulation rates at each site. Mean annual periods of hypoxia in bottom waters were determined from continuous monitoring data for the years coinciding with the top 1 cm of sediment. Results indicated a linear relationship between authigenic Mo concentrations and frequency of hypoxia, although the relationships differed between different sampling periods. These results demonstrate the potential of sedimentary Mo as a tool for assessing the spatial and temporal extent of hypoxia in coastal waters.

Environmental geochemistry of heavy metals in coral reefs and sediments of Chabahar Bay

The amount of heavy metals in coral reefs and sediments and their impact on the marine environment is of great importance. The present study aimed to determine the quantity and quality, distribution, and origin of the elements introduced into the reefs and sediments of Chabahar Bay. In this research, specimens of coral reefs and sediments were collected from six stations in coral regions of Chabahar Bay. Then, standard grain size analysis was performed on the sediment sample. An ICP-MS analysis was done to identify heavy metals. The results indicate that the sediment type of coral regions of Chabahar Bay is gravelly sand, gravelly muddy sand, and muddy gravelly sand. Moreover, sediments have two clastic and biochemical origins, and their formation environment is a carbonate environment consisting of small and single reefs, often coral reefs. On the other hand, the concentrations of cadmium and lead in sediments as well as the concentrations of cadmium and cobalt in the coral reefs of Chabahar Bay are higher than concentrations of them in the earth's crust and global marine sediments. The highest contamination is associated with cadmium and lead, followed by aluminum and nickel (moderate contamination rate) and then, other elements (low contamination rate). Because of a significant/high correlation, the nickel and vanadium elements are the sources of oil pollution. Considering the maximum distribution of heavy metals, the breakwater and basin of Shahid Beheshti Port and the Great Sea are considered as the extremely contaminated places in the coral regions of Chabahar Bay, confirming the organic and human-induced origins of contaminations.

Transcriptome analysis provides new insights into plants responses under phosphate starvation in association with chilling stress

BackgroundChilling temperature reduces the rate of photosynthesis in plants, which is more pronounced in association with phosphate (Pi) starvation. Previous studies showed that Pi resupply improves recovery of the rate of photosynthesis in plants much better under combination of dual stresses than in non-chilled samples. However, the underlying mechanism remains poorly understood.Results In this study, RNA-seq analysis showed the expression level of 41 photosynthetic genes in plant roots increased under phosphate starvation associated with 4 °C (-P 4 °C) compared to -P 23 °C. Moreover, iron uptake increased significantly in the stem cell niche (SCN) of wild type (WT) roots in -P 4 °C. In contrast, lower iron concentrations were found in SCN of aluminum activated malate transporter 1 (almt1) and its transcription factor, sensitive to protein rhizotoxicity 1 (stop1) mutants under -P 4 °C. The Fe content examined by ICP-MS analysis in -P 4 °C treated almt1 was 98.5 ng/µg, which was only 17% of that of seedlings grown under -P 23 °C. Average plastid number in almt1 root cells under -P 4 °C was less than -P 23 °C. Furthermore, stop1 and almt1 single mutants both exhibited increased primary root elongation than WT under combined stresses. In addition, dark treatment blocked the root elongation phenotype of stop1 and almt1.ConclusionsInduction of photosynthetic gene expression and increased iron accumulation in roots is required for plant adjustment to chilling in association with phosphate starvation.

Seal meat enzymatic hydrolysates and its digests: A comparison on protein and minerals profiles

Seal meat is of high nutritive value but currently a by-product and waste from seal oil processing. Seal meat hydrolysates were generated from alcalase catalysis and were subjected to a soft dynamic digestion system to study their nutritional value and the health benefits. The total amino acid content was determined as 568.54 and 384.65 mg/g for seal meat hydrolysates and its intestinal digests, respectively, using UPLC, and both of the samples were rich in essential amino acids such as Leu and Lys. There were no harmful minerals observed by ICP-MS analyses. Both the gastric and intestinal digests revealed nutritive minerals, i.e., Ca, Fe, Mg, Zn, among which the contents of Fe were 548 and 602 mg/kg, respectively, higher than common meat products. The absorbable Fe2+ ions content remained almost the same during the gastric and intestinal digestion, while the content of undesirable Fe3+ ions declined drastically in intestinal digests. The change of Fe2+ and Fe3+ ions was probably due to the antioxidant activities of seal meat hydrolysates observed via scavenging of DPPH and hydroxyl radicals. This study provides knowledge on seal meat hydrolysates as healthy food supplement.

Copper deposition on metallic and non‐metallic single particles via impact electrochemistry

This study demonstrates the possibility of depositing metals onto low-metal content particles via impact electrochemistry, a technique used to measure transient current signals (electrochemical impacts) produced from the collision between particles moving under Brownian motion and a potentiostated interface (Rees, 2014; Markham et al., 2020; Zhang and Zhou, 2020). The deposition of copper onto the surface of fly-ash cenospheres via electrochemical impacts is reported, along with its deposition onto silver and gold nanoparticles. A comparison with linear sweep voltammetry confirmed that impact signals correlated with deposition potentials (bulk and underpotential deposition). Reductive impact events were observed at potentials negative of −0.3 V (for Ag) and −0.1 V (for Au) (vs. MSE), with evidence for a change in coverage of deposition from ca. 103% at −0.1 V to 261% at −0.8 V vs. MSE for Au. Cenospheres were shown to be sufficiently electrochemically active to facilitate copper deposition, either on modified electrodes or showing transient impact spikes indicating copper deposition, which was confirmed via SEM/EDX and ICP-MS analysis.

Determination of whole-rock trace-element compositions of siliceous rocks using MgO-diluted fused glass and LA–ICP–MS

The whole-rock trace-element compositions of igneous rocks provide primary geochemical information about their petrogenesis. Such compositions can be determined by LA–ICP–MS analysis of fused-glass samples as well as the conventional solution ICP–MS method. However, in contrast to basalt and andesite, the fused-glass method is not suitable for Si-rich rocks (granite and rhyolite) due to the difficulty of making homogeneous glasses. To extend the method to Si-rich rocks, we adopted an MgO dilution process to prepare fused glasses and evaluated the technique by analysis of granite and rhyolite reference materials. Dilution of 30 mg of powdered samples with 10 mg MgO facilitated the preparation of homogeneous fused-glass samples of felsic rocks. LA–ICP–MS analyses indicate that the fused glass is homogeneous in the contents of most incompatible elements considered in igneous petrology. The glass enables the analysis of these elements in felsic rocks within 20% deviation from reference data. The sample data are consistent with reference values for rhyolite although Zr and Hf data deviate significantly (by ~40%) from reference values for granitic rocks.