Inductively Coupled Plasma Mass Spectrometer Research Articles

Gas-Phase Reactivity of Actinides Monocations with NH3: ICP-MS Experiments Combined with a DFT Study.

The reactivity of actinide monocations (Th+, U+, Np+, Pu+, Am+, and Cm+) with NH3 gas was studied in the reaction cell of an inductively coupled plasma-mass spectrometer (ICP-MS). Only Th+, U+, Np+, and Cm+ react completely with NH3 to form AnNH+, contrary to Pu+ and Am+. Differences in reactivity are found between U+/Pu+, Pu+/Cm+, and Am+/Cm+, which could resolve isobaric interferences in ICP-MS. DFT calculations were performed across the first half of the actinide series. The calculated reaction energy between An+ and NH3 reproduces the experimental trends in reactivity with Th+ > Pa+ > U+ > Np+ > Ac+ > Cm+ > Pu+ > Am+. The reaction path involves the initial formation of an AnNH3+ adduct followed by N-H bond insertion with the formation of HAnNH2+ and H2AnNH+ intermediate species and subsequent H2 loss. The trend in reactivity across the actinides is largely due to the first energy barrier and formation of the HAnNH2+ intermediate species. This limiting step is energetically unfavorable for the Pu+ and Am+ cations. For these cations, the excitation energy required to achieve a reactive configuration with two non-f electrons available for bonding is too high.

Spatial analysis and soft computational modeling for hazard assessment of potential toxic elements in potable groundwater

Swiftly increasing population and industrial developments of urban areas has accelerated the worsening of the water quality in recent years. Groundwater samples from different locations of the Doon valley, Garhwal Himalaya were analyzed to measure concentrations of six potential toxic elements (PTEs) viz. chromium (Cr), nickel (Ni), arsenic (As), molybdenum (Mo), cadmium (Cd), and lead (Pb) using Inductively Coupled Plasma Mass Spectrometer (ICP-MS) with the aim to study the spatial distribution and associated hazards. In addition, machine learning algorithms have been used for prediction of water quality and identification of influencing PTEs. The results inferred that the mean values (in the units of µg L−1) of analyzed PTEs were observed in the order of Mo (1.066) > Ni (0.744) > Pb (0.337) > As (0.186) > Cr (0.180) > Cd (0.026). The levels and computed risks of PTEs were found below the safe limits. The radial basis function neural network (RBF-NN) algorithms showed high level of accuracy in the predictions of heavy metal pollution index (HPI), heavy metal evaluation index (HEI), non-carcinogenic (N-CR) and carcinogenic (CR) parameters with determination coefficient values ranged from 0.912 to 0.976. However, the modified heavy metal pollution index (m-HPI) and contamination index (CI) predictions showed comparatively lower coefficient values as 0.753 and 0.657, respectively. The multilayer perceptron neural network (MLP-NN) demonstrated fluctuation in precision with determination coefficient between 0.167 and 0.954 for the prediction of computed indices (HPI, HEI, CI, m-HPI). In contrast, the proficiency in forecasting of non-carcinogenic and carcinogenic hazards for both sub-groups showcased coefficient values ranged from 0.887 to 0.995. As compared to each other, the radial basis function (RBF) model indicated closer alignments between predicted and actual values for pollution indices, while multilayer perceptron (MLP) model portrayed greater precision in prediction of health risk indices.

Geochemical Characteristic of the Carbonaceous Sediments of the Upper Paleozoic Kuantan Group, Malaysia

The geochemical parameters discussed in this paper are based on an average values of twelve outcrop carbonaceous samples, mainly black shales, were determined using X-Ray Fluorescence (XRF) and Inductively Coupled Plasma-Mass Spectrometer (ICP-MS) techniques, representative of Charu, Sagor, and Permian formations.The aim of this study is to define and discuss their characteristics, the distribution abundance of major and minor elements, investigation the dominant mineralogical composition and reconstruct the depositional environment for these sediments.The bulk chemical result showed that, the average values of the major elements are 65.83%, 64.82 %, 71.4 % SiO2, 18.27 %, 22.2 %, 15.66 % Al2O3, 1.53 %, 0.99 %, 2.49 % Fe2O3. 4.06 %, 6.25 %, 3.66 % K2O , whereas in the case of the miner elements, the results read values of 524.4 ppm, 758.8 ppm, 446.3 ppm Ba , 366 ppm, 399.3 ppm, 257.3 ppm Rb, 88 ppm, 67.3 ppm, 47.3 ppm Sr , 308 ppm, 288.8 ppm, 327ppm Zr for the Charu, Sagor, and Permian formations respectively. The major oxides reflect the dominant mineralogical composition of quartz and other silicate minerals (e.g. illite, kaolinte, smectite) and deficiency in carbonates.The high Rb/K ratio suggests brackish marine environment or rapid depositions that prevent equilibrium between Rb and K in these study shales and marine environment. The high Rb/Sr ratios of 4.16, 5.89 and 5.44 for the Charu, Sagor, and Permian formations respectively possibly attributed to the lowest contents of Sr content due to reducing environment prevailing during deposition of these sediments.

2D geochemical imaging of biogenic marine carbonates using LA-TOF-ICP-MS at 1 and 2 μm pixel resolution

Many applications at the forefront of the study of the chemical composition of marine carbonates require in-situ micro-scale geochemical imaging. Such analyses are, however, challenging, requiring analytical techniques that are either expensive with limited accessibility (e.g. synchrotron X-Ray spectroscopy and secondary ion mass spectrometry), or time-consuming and able to only analyse a limited range of elements (e.g. electron microprobe). Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) as a tool for generating 2D images has grown in popularity, yet many analytical issues remain when generating high-spatial resolution geochemical images using this approach. Here we employ the imageGEO193 (ESL) fast wash-out laser ablation system coupled to the Nu Instruments Vitesse Time-of-Flight (TOF) ICP mass spectrometer, with its near-full mass spectra capabilities, to generate 2D geochemical images of a range of biogenic carbonates at ≤2 μm pixel resolution (pixel widths of either 1 or 2 μm) and at an unprecedented speed (200 pixels/s). We demonstrate sensitivity of ∼100 cps/μg g−1 at low mass rising to ∼1000 cps/μg g−1 at high mass based on analyses of reference materials JCp-1 (carbonate) and NIST SRM612 (silicate) with 1 μm wide square laser beams, and accuracy of ±7 % for elements present at concentrations >0.5 μg g−1 based on analyses of carbonate reference material JCt-1. By applying our quantitative method to a range of biogenic carbonates (coral skeletons, coralline algae, foraminifera), we demonstrate that considerable but coherent micron-scale compositional variability is the norm for nearly all quantified elements, including: Mg, Sr, Ba and U. This approach therefore has great potential to provide valuable insights into biomineralisation mechanisms and “vital effects”, ultimately facilitating more robust reconstructions of past environments.

B-164 Comparison of Analytical Performance of Two Processing Methods for Measurement of Zinc and Copper on Triple Quadrupole Inductively Coupled Plasma Mass Spectrometer

Abstract Background Copper (Cu) and zinc (Zn) are essential cofactors of enzymes involved in several metabolic processes required for the development of tissue structures and immune response, especially in pediatrics and pregnant women. Triple quadrupole inductively coupled plasma mass spectrometer (ICP-QQQ) enables simultaneous precise quantification of multiple elements with high throughput, sensitivity, and specificity. Samples are introduced into ICP-QQQ as a liquid and converted to fine aerosol with the help of a nebulizer and spray chamber. The precision and sensitivity of measured metals are dependent on the sample preparation thus, this study focuses on comparing the analytical performances between two sample preparations: 0.5% nitric acid (HNO3) as the only diluent (Diluent A) versus a combination of 0.5% HNO3 along with 1% ethanol, 0.5% Ammonium hydroxide, 0.02% TritonX-100, and 0.1% HNO3 (Diluent B) for Cu and Zn metal analysis in serum using ICP-QQQ. Methods Twenty deidentified randomly selected patient serum samples were prepared with either diluent A or diluent B and analyzed by ICP-QQQ (Agilent 8900). Data were analyzed using EP Evaluator. Bland-Altman analysis was used to determine the agreement between the two sample preparations. Deming regression analysis was used to determine other analytical performances, such as the proportional and constant bias of Zn and Cu concentration. Results There was a bias of -4.8 and -3.0 between the two sample preparation methods when analyzing Cu and Zn, respectively. The mean of Cu-Diluent B versus Cu—Diluent A was 125.2 ± 28.3 µg/dL and 120.4 ± 29.8 µg/dL, respectively, with a slope of 1.070. Conversely, the Zn comparison study shows a lower slope (0.769) with a mean of 71.0 ± 20.5 and 68.0 ± 16.1 µg/dL for Zn-Diluent B and Zn-Diluent A, respectively. Conclusions Samples prepared with nitric acid solution only (Diluent A) appeared to show negative bias compared to Diluent B solution containing triton-X for both metals. However, the bias is within the total allowable error for zinc and copper. Importantly, Zn-sample analysis with diluent A (HNO3 only) shows a 23% proportional bias, which is absent with copper sample analysis. A larger study is needed to further compare several methods of sample preparation in ICP-QQQ analysis while leveraging simple preparation without compromising analytical sensitivity. Overall, this study shows that both methods of sample preparation can be effectively used in the ICP-QQQ analysis of serum copper and zinc.

Assessing the Precision and Accuracy of Foraminifera Elemental Analysis at Low Ratios

AbstractThe minor and trace element compositions of biogenic carbonates such as foraminifera are important tools in paleoceanography research. However, most studies have focused primarily on samples with element to calcium (El/Ca) ratios higher than the El/Ca range often found in benthic foraminifera. Here, we systematically assess the precision and accuracy of foraminifera elemental analysis across a wide range of El/Ca especially at relatively low ratios, using a method on a Thermo Scientific iCAP Qc quadrupole Inductively Coupled Plasma Mass Spectrometer (ICP‐MS). We focus on two benthic foraminifera species, Hoeglundina elegans and Cibicidoides pachyderma, and prepared a suite of solution standards based on their typical El/Ca ranges to correct for signal drift and matrix effects during ICP‐MS analysis and to determine analytical precision. We observe comparable precisions with published studies at high El/Ca, and higher relative standard deviations for each element at lower El/Ca, as expected from counting statistics. The overall long‐term analytical precision (2σ) of the H. elegans‐like consistency standard solutions was 6.5%, 4.6%, 5.0%, for Li/Ca, Mg/Ca, Mg/Li, and 6.4%, 10.0%, 4.2% for B/Ca, Cd/Ca, Sr/Ca. The precision for H. elegans‐like Mg/Li is equivalent to a temperature uncertainty of 0.5–1.1°C. Measurement precisions were also assessed based on three international standards (one solution and two powder standards) and replicate measurements of H. elegans and C. pachyderma samples. We provide file templates and program scripts that can be used to design calibration and consistency standards, prepare run sequences, and convert the raw ICP‐MS data into molar ratios.

Determination of rare earth elements in ferrocarbonatite using ICP-AES and ICP-MS

AbstractA method has been developed for the determination of Rare Earth Elements (REEs) in ferrocarbonatite using Inductively Coupled Plasma—Atomic Emission Spectrometer (ICP-AES) and Inductively Coupled Plasma—Mass Spectrometer (ICP-MS). The conventional dissolution procedures are tedious, with large measurement uncertainty and are thus not suitable for certified reference material (CRM) production and exploration of REEs. The described method involves leaching of sample using 3 M HCl followed by dissolution of residue (silica and REEs) by HF then determined REEs using ICP-AES and ICP-MS. The leaching step prevents formation of fluoride precipitates of matrix (Ca, Mg, Ba and Al). The method has been validated using CRMs.

Toxicity assessment of heavy metals translocation in maize grown in the Ganges delta floodplain soils around the Payra power plant in Bangladesh

As a cereal crop, maize ranked third place after wheat and rice in terms of land area coverage for its cultivation, and in Bangladesh, it ranked second place after rice in its production. As the substitution of wheat products, maize has been used widely in baking for human consumption and animal fodder. However, maize grown in this soil around the coal-burning power plant may cause heavy metals uptake that poses a risk to humans. The study was conducted at the maize fields in the Ganges delta floodplain soils of Bangladesh to know the concentration of eight heavy metals (Ni, Cr, Cd, Mn, As, Cu, Zn, and Pb) in soil and maize samples using an inductively coupled plasma mass spectrometer (ICP-MS) and to estimate the risk of heavy metals in maize grains. Mean concentrations of heavy metals (mg/kg) in soil were in decreasing order of Zn (10.12) > Cu (10.02) > Mn (5.48) > Ni (4.95) > Cr (3.72) > As (0.51) > Pb (0.27) > Cd (0.23). The plant tissues showed the descending order of heavy metal concentration as roots > grains > stems > leaves. BCF values for As, Cd, Pb, and Mn in roots were higher than 1.0, indicating considerable accumulation of these elements in maize via roots. Total hazard quotient (ƩTHQ) of heavy metals through maize grain consumption was 3.7E+00 and 3.9E+00 for adults and children, respectively, indicating non-cancer risk to the consumers. Anthropogenic influences contributed to the heavy metals enrichment in the Ganges delta floodplain soils around the thermal plant, and potential risks (non-carcinogenic and carcinogenic) were observed due to the consumption of maize grain cultivated in the study area.

Effect of carbamide peroxide treatment on the ion release of different dental restorative materials

BackgroundTo predict the long-term performance of restorative materials in the oral environment, it is important to evaluate their resistance to chemical and mechanical degradation and to know the toxic potential of the type and amount of ions eluted from the filling material. In this study, home bleaching was applied to dental materials with different contents and it was aimed to determine the type and amount of ions released from these materials.MethodsIn this study, amalgam, posterior composite resin, anterior composite resin, bulk fill composite resin, indirect composite resin, hybrid ceramic and all-ceramic were used as restorative materials. 10 specimens of each material were prepared according to the manufacturer’s instructions. Each material group was divided into two subgroups as the bleached group and the control group. After bleaching, all specimens were stored in 1 ml of 75% ethanol/water solution. Solutions were renewed after 1, 14 and 28 days. The type and amount of ions released from the materials were determined using Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). Data were analyzed using the Friedman, Wilcoxon Signed Ranks, and Mann-Whitney U tests (α = 0.05).ResultsIt was determined that the amount of ions release from the restorative materials decreased over time (p < 0.05). According to the results of the Mann-Whitney U test, there was no difference between the bleaching and control groups in most of the restorative materials (p > 0.05).ConclusionWithin the limits of this study, home bleaching system does not have a significant effect on ion release from restorative materials.

The correlation between single and mixed trace elements exposure in systemic lupus erythematosus: A case-control study

BackgroundRecent studies have shown an association between trace elements and systemic lupus erythematosus (SLE), but the relationship between trace elements and SLE is still unclear. This study aims to determine the distribution of plasma trace elements in newly diagnosed SLE patients and the association between these essential and toxic element mixtures and SLE. MethodsIn total, 110 SLE patients and 110 healthy controls were included. Blood samples were collected. 15 plasma trace elements were quantified using an inductively coupled plasma mass spectrometer (ICP-MS). Multivariate logistic regression, restricted cubic spline (RCS), weighted quantile sum (WQS) regression, quantile g-computation (qgcomp), and Bayesian kernel machine regression (BKMR) are used to analyze the association between single and mixed exposure of elements and SLE. ResultsThe logistic regression model shows that, plasma lithium (Li) [OR (95 % CI): 1.963 (1.49–2.586)], vanadium (V) [OR (95 % CI): 2.617(1.645–4.166)] and lead (Pb) [OR (95 % CI): 1.603(1.197–2.145)] were positively correlated with SLE, while selenium (Se) [OR (95 % CI): 0.055(0.019–0.157)] and barium (Ba) [OR (95 % CI): 0.792(0.656–0.957)] had been identified as protective factors for SLE. RCS results showed a non-linear correlation between the elements Li, V, Ni, copper, Se, rubidium and SLE. In addition, WQS regression, qgcomp, and BKMR models consistently revealed significant positive effects of plasma Li and Pb on SLE, as well as significant negative effects of plasma Se. ConclusionsExposure to heavy metals such as Li and Pb is significantly positively correlated with SLE, but Se may be protective factors for SLE. In addition, there is a nonlinear correlation between the elements Li and Se and SLE, and there are complex interactions between the elements. In the future, larger populations and prospective studies are needed to confirm these associations.

Exposure assessment of pesticide residues, heavy metals, and veterinary drugs through consumption of Egyptian fish samples

Environmental contaminants may enter seafood products either through water and sediments or via feed and feed additives or may be introduced during fish processing and storage. The study focused on the nutritional and toxicological significance of heavy metals, antibiotics, and pesticide residues in 48 fish samples collected from the Kafr-ElSheikh governorate in Egypt. Various analytical instruments are used to determine and detect heavy metals, antibiotics, and pesticides. These include Liquid Chromatography Tandem Mass Spectrometer (LC-MS/MS), Inductively Coupled Plasma Mass Spectrometer (ICP-MS), and Gas Chromatography-Mass Spectrometer (GC-MS). The following metals were discovered in fish species: arsenic (As), cadmium (Cd), cobalt (Co), copper (Cu), iron (Fe), mercury (Hg), manganese (Mn), and zinc (Zn). Each of these metals was detected 47 times. Chromium (Cr) was detected 40 times, nickel (Ni) was detected 27 times, and lead (Pb) was detected 6 times. The mean concentrations of As, Cd, Cr, Co, Cu, Fe, Ni, Mn, Hg, Pb, and Zn were determined to be 0.025, 0.02, 0.501, 0.50, 0.81, 12.56, 0.5, 0.689, 0.051, 0.031, and 5.78 mg/kg, respectively. All levels of cadmium, mercury, and lead detected in fish samples were significantly lower than the maximum permissible limits set by Egyptian and European standards. Furthermore, in this study, antibiotics and pesticide residues were found to be not detected in all analyzed fish samples. Based on the estimated daily intake and hazard quotient values, the concentration levels of metals found in fish samples seem to pose no significant threat to public health.

Trace elements determination and health risk assessment of groundwater sources in Kumasi Metropolis, Ghana.

Trace element (TEs) contamination in groundwater is a key factor for health risk assessment and one of the environmental challenges linked with Ghana's sustainable development. This study aims to investigate TE concentrations in groundwater used for drinking and domestic purposes and their potential health risk in the Kumasi Metropolis using multivariate statistics. In the study, 23 groundwater samples were analyzed for 32 TEs using Perkin Elmer Nexion 2000 Inductively Coupled Plasma Mass Spectrometer (ICP-MS). Levels of TEs recorded in the study were in order of Na > Si > Ca > K > Mg > S > Ba > Cu > Zn > Al > Sr > Li > Mn > P > Fe > B > Pb > Ni > Co > Bi > Se > Sb > Cr > As > Ti > Be > V > U > C d > T l > Mo > Hg. The study revealed that the concentration of trace and toxic elements like Al, Cu, and Pb exceeded their corresponding WHO permissible standards. Hazard index (HI) values and total likely cancer risk (TLCR) values for non-carcinogenic and carcinogenic health risks indicate that 91.3% of the total sampling sites presented health concerns to adults and children. The mean TLCR values associated with exposure to carcinogenic metals via ingestion of groundwater samples were estimated to be 2.09 × 10-4 and 4.44 × 10-4 for adults and children respectively. Exposure through the ingestion pathway was found to be more risky compared to dermal contacts. Children are particularly vulnerable to these health hazards. Pearson correlation (PC) matrix, principal component analysis (PCA), and hierarchical cluster analysis (HCA) suggested that sources of TEs in the groundwater are attributed to both anthropogenic and geogenic factors.

Characterization of Nanoparticles in Drinking Water Using Field-Flow Fractionation Coupled with Multi-Angle Light Scattering and Inductively Coupled Plasma Mass Spectrometry

The current absence of well-established and standardized methods for characterizing submicrometer- and nano-sized particles in water samples presents a significant analytical challenge. With the increasing utilization of nanomaterials, the potential for unintended exposure escalates. The widespread and persistent pollution of water by micro- and nanoplastics globally is a concern that demands attention, not only to reduce pollution but also to develop methods for analyzing these pollutants. Additionally, the analysis of naturally occurring nano entities such as bubbles and colloidal matter poses challenges due to the lack of systematic and consistent methodologies. This study presents Asymmetric Flow Field-Flow Fractionation (AF4) separation coupled with a UV-VIS spectrometer followed by Multi-Angle Light Scattering (MALS) for detection and size characterization of nanometric entities. It is coupled with an Inductively Coupled Plasma Mass Spectrometer (ICP-MS) for elemental analysis. Water samples from different sources, such as untreated mountain spring water, groundwater, and bottled drinking water, were analyzed. The system was calibrated using pure particle standards of different metallic compositions. Our study demonstrates the capability of AF4-UV-MALS-ICP-MS to detect metals such as Al, Ba, Cu, and Zn in particles of around 200 nm diameter and Mg associated with very small particles between 1.5 and 10 nm in different drinking water samples.

Investigating the pH-Dependent Activity, Selectivity, and Dynamics of Metal Nitride Electrocatalysts for Fuel Cells and Electrolyzers

To mitigate climate change caused by the use of fossil fuel energy sources, there is an urgent need to decarbonize our energy systems. Developing fuel cell and water electrolysis technologies to support a green hydrogen infrastructure is a promising strategy for this transition. In both hydrogen fuel cells and water electrolyzers, platinum-group metal (PGM) materials such as Pt and IrOx are benchmark electrocatalysts, exhibiting high activity and stability for kinetically-hindered reactions including the oxygen reduction reaction (ORR), the oxygen evolution reaction (OER), and alcohol oxidation reactions (AOR; alternative anodic reactions to OER). Despite their remarkable performance, the high cost and low abundance of PGMs is a key factor limiting the widespread adoption of these technologies.Cobalt- and nickel-based metal and oxide catalysts have emerged in the literature as a promising PGM-alternative class of low-cost, high-performing ORR, OER and AOR catalysts. Substituting oxides with nitrides or other chalcogenides could be a favorable method to improve activity, selectivity, and stability; however, the material stability of these non-oxides as a function of reaction, potential window, and pH is not well-understood. Furthermore, the most active of these materials tend to be carbon-supported nanoparticles with complicated and heterogeneous active sites, which makes deconvoluting the role of the cobalt and secondary element(s) (e.g. N, C, etc.) difficult.With the goal of developing fundamental activity-stability relationships for non-precious metal-based electrocatalysts, we have developed a synthesis procedure for well-defined Co- and Ni-based thin film materials. Focusing on Co, using physical vapor deposition followed by thermal treatments with ammonia and an Sb-based precursor, we have synthesized CoxSbyNz thin films of varying compositions. These synthesis methods can be extended to synthesize a broad class of metallic (Co, Ni, Fe, etc.) or bimetallic X-ide (X = N, S, etc.) thin film materials. We evaluate ORR, OER, and AOR activity with cyclic voltammetry, demonstrating that activity depends on composition and electrolyte pH. Specifically, for Co-based thin films for ORR, we see improvement in activity with the incorporation of N, and improvement in acid-stability with the incorporation of Sb. In addition to ex situ post-characterization with x-ray photoelectron spectroscopy, we utilize in situ techniques to evaluate catalyst stability in real time. We monitor time- and potential-dependent cobalt dissolution with an on-line inductively coupled plasma mass spectrometer (ICP-MS) as well as nitride degradation with electrochemical mass spectrometry (EC-MS). In acidic media, the stability of CoxN is limited by Co dissolution, while in alkaline media stability appears to be limited by nitride degradation. With highly active non-oxide materials it is typically too complicated to disentangle the role of each individual element within an electrocatalyst. With our stepwise material synthesis platform and multifaceted characterization techniques we are able to individually probe the material stability and product-specific activity of each element. These results provide new insights to guide the strategic design of electrocatalysts across a range of reactions and applications.

(Invited) Degradation and Poisoning of Proton-Exchange Membrane Water Electrolyzer Anode Catalysts

Hydrogen production through water electrolysis is a crucial technology to enable the transition to a carbon neutral, hydrogen-based economy. One of the primary types of electrolyzers is the low-temperature proton-exchange membrane water electrolyzer (PEMWE). As with the analogous proton-exchange membrane fuel cells, platinum group metal electrocatalysts are utilized due to their activity and stability in acidic environment. Electrocatalysis R&D efforts for PEMWEs primarily focus on the oxygen evolution reaction (OER) since it is several orders of magnitude kinetically slower than the hydrogen evolution reaction (HER).1 Iridium-based metal oxides (IrOx) are regarded as the best PEM electrolyzer electrocatalysts as they balance activity and stability.2 However, improvements are needed in both areas to enable minimization of Ir loading to meet system cost targets while also meeting challenging performance and lifetime targets.3 An understanding of the factors affecting both the activity and stability of Ir-based OER catalysts is needed to develop strategies to enable both high OER activity and long-term stability of the PEMWE anode catalyst.This presentation will describe our studies of the effects of perfluorosulfonic acid (PFSA) binder on the OER kinetics and the factors influencing the stability of two commercial Ir-based OER catalysts, one comprised of IrOx only and the other also containing TiOx. Measurements of OER kinetics as a function of ionomer to catalyst ratio utilizing rotating disc electrode and cavity microelectrode methods in an acidic aqueous electrochemical environment will be described. Dissolution and loss of Ir under the operating conditions of the PEMWE anode is considered to be one of the main PEMWE anode degradation mechanisms.4 To understand the factors affecting this phenomenon, the potential and time-dependence of Ir (and Ti) were determined using an electrochemical flow cell system connected to an inductively-coupled plasma-mass spectrometer (ICP-MS) capable of detecting trace concentrations (<ppb) of dissolved elements in solution. The electrochemical data combined with the ICP-MS data have been used to evaluate the influence of various factors such as potential, potentiodynamic profile parameters (e.g., scan rate, upper and lower potential limits) on the dissolution processes in acidic aqueous electrolyte at room temperature.AcknowledgementsThis research is supported by the U.S. Department of Energy, Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office under the auspices of the H2NEW Consortium. Argonne National Laboratory is managed for the U.S Department of Energy by the University of Chicago Argonne, LLC, also under contract DE-AC-02-06CH11357.References A. Raveendran, M. Chandran, and R. Dhanusuraman, RSC Adv., 13 (2023) 3843.J. Ouimet, J.R. Glenn, D.D. Porcellinis, A.R. Motz, M. Carmo, K.E. Ayers, ACS Catalysis, 12 (2022) 6159."Technical Targets for Proton Exchange Membrane Electrolysis", U.S. Department of Energy, Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office, March, 2023.Zeng, R. Ouimet, L. Bonville, A. Niedzwiecki, C. Capuano, K. Ayers, A.P. Soleymani, J. Jankovic, H. Yu, R. Maric, et al., J. Electrochem. Soc., 169(5) (2022) 054536.

Investigating Corrosion Degradation of Porous Transport Layers for PEM Water Electrolyzers Using on-Line ICP-MS

The degradation of polymer electrolyte membrane water electrolyzer (PEMWE) is the net result of degradation phenomena across each component, which includes structural changes to the catalyst layer, deactivation of the electrolyte, loss of performance due to impurities in the feed water, and the corrosion and passivation of titanium-based bipolar plates (BPPs) and porous transport layers (PTLs).1, 2 This presentation will focus on PTL degradation, which has received relatively little attention compared to loss of performance related to catalyst and electrode degradation mechanisms. Generally, PTL degradation can be categorized into chemical/corrosion degradation and mechanical degradation. 3 In this work, we focus on corrosion degradation of the anode PTL. Titanium (Ti) is the state-of-the-art material for PTLs due to its stability and intrinsic electrical conductivity. Ti can however, develop an oxide layer in the harsh oxidizing conditions of the anode, thus reducing the effective electrical conductivity and cell performance. Coating the Ti parts with platinum group metals (Pt or Ir) is often used to protect against oxidation.4 An electrochemical flow cell system connected to an inductively-coupled plasma-mass spectrometer (ICP-MS) capable of detecting trace concentrations (<ppb) of dissolved elements in solution has been used to investigate the corrosion rates of the Ti-PTLs with and without coatings toward understanding factors influencing degradation mechanisms. The influence of various parameters such as potential, potentiodynamic profile parameters (e.g., scan rate, upper and lower potential limits), electrolyte type, and pH on the corrosion processes has been investigated. References Feng, X. Yuan, G. Liu, B. Wei, Z. Zhang, H. Li, H. Wang, J. Power Sources 2017, 366, 33.Babic, M. Suermann, F. N. Büchi, L. Gubler, T. J. Schmidt, J. Electrochem. Soc. 2017, 164, F387.Park, H. Oh, T. Ha, Y.I. Lee, K. Min, Appl. Energy 155 (2015) 866-880.Rakousky, U. Reimer, K. Wippermann, M. Carmo, W. Lueke, D. Stolten, J. Power Sources 326 (2016) 120–128. Acknowledgements This research is supported by the U.S. Department of Energy, Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office under the auspices of the H2NEW consortium. Argonne National Laboratory is managed for the U.S Department of Energy by the University of Chicago Argonne, LLC under contract DE-AC-02-06CH11357.

An insight into the origin of elemental chromium in the lacquer of Qin terracotta warriors

The origin of elemental chromium for the archaeological weapons from the pits of Qin terracotta warriors in China has been highly controversial. Although previous studies have highlighted that the chromium on the surface of weapon originated from the contamination of surrounding lacquer, the exact origin of chromium in the lacquer remains unclear. In this work, the measurement by inductively coupled plasma-mass spectrometer (ICP-MS) firstly confirmed that the elemental chromium was indeed contained in the archaeological Qin original lacquer. Nevertheless, the amount of elemental chromium in the Qin lacquer was as low as 0.0759 μg/mg, disclosing that it was impossible to artificially add extra refined chromium-containing substance to the lacquer in the preparation of the terracotta warriors. The soil from the archaeological site of Qin lacquer was found to have a chromium amount of 0.0660 μg/mg by ICP-MS. After the hygrothermal and soil-buried aging cycles for the lab-prepared lacquer, the surface and depth elemental analyses by time of flight-secondary ion mass spectrometer (TOF–SIMS) showed a gradient distribution of elemental chromium from the surface to interior of aged lacquer, indicating the migration and enrichment behavior of elemental chromium from the burial soil towards the lacquer. To explore the migration mechanism of elemental chromium, fluorescence imaging technique was employed in combination with Fourier transform infrared spectrometry (FT-IR) and X-ray photoelectron spectroscopy (XPS) characterizations. The results revealed that catechol-containing fragments were formed during hygrothermal and soil-buried aging of lacquer and consequently coordinated with chromium ions, inducing the migration of elemental chromium towards the lacquer.

Toxic element (As, Cd, Pb and Hg) biodistribution and blood biomarkers in Barbaresca sheep raised in Sicily: One Health preliminary study.

The health of humans, animals and the environment is interconnected. Adopting a One Health approach means intervening promptly to prevent the main diseases that affect animal health to guarantee the safety of livestock production. Exposure to toxic trace elements in sheep can lead to increased accumulation in different biological substrate, developing both acute and chronic diseases in humans and livestock. The aim of this study was to evaluate the bioaccumulation of arsenic (As), cadmium (Cd), lead (Pb) and mercury (Hg) in Sicilian Barbaresca sheep using the following biological substrates: milk, blood and fleece. An inductively coupled plasma mass spectrometer (ICP-MS) was used for As, Cd and Pb, and a direct mercury analyser (DMA-80) was used for Hg determination. In addition, the role of the haematological parameters as possible indicators of different biodistribution was evaluated. A statistically significant value was observed from our analysed metals in the substrates: arsenic (p < 0.001), cadmium (p < 0.01), lead (p < 0.001) and mercury (p < 0.0001). The correlation analysis showed a relationship between milk and blood for arsenic (p < 0.0001) and lead (p < 0.0001), and no correlation for the metals was observed between milk/blood and the haematological parameters analysed for the low concentration observed in the present study comforting the final consumer.

Optimization and validation of a simple extraction method coupled with ICP-MS for the determination of essential and toxic elements in liquid dietary supplement products

This study aimed to develop and validate a fast, easy, cost-effective, and accurate method for determining Mn, Co, Ni, Cr, Cu, Fe, Zn, As, Cd, Hg, Sb, and Pb in liquid dietary supplements using an inductively coupled plasma mass spectrometer (ICP-MS). Two sample preparation methods were compared: microwave acid digestion and direct analysis after dilution. Both methods provided acceptable recovery values (87.7–111 %), with RSD values up to 6.35 %. The microwave digestion method was validated using various certified reference materials (CRMs) and a proficiency test (PT). Additionally, 34 domestic dietary supplements were analyzed using both methods, and the results were similar. Only one sample exceeded the maximum allowable limit for arsenic, which is 150 mg/kg set by the United States Pharmacopeia (USP). Two products had high Fe and Zn levels exceeding the recommended daily allowance (RDA), according to the Food and Drug Administration (FDA). This study demonstrates the effectiveness and advantages of the direct analysis method for measuring essential and toxic elements in liquid dietary supplements. This method promotes green chemistry principles and provides valuable information for ensuring consumer safety and product quality.

Seasonal variability of trace elements bioaccumulation in Pacific Oysters (Crassostrea gigas) from an experimental pilot farm in the Calich Lagoon (Sardinia, Italy)

BackgroundMetals pollution is a worldwide environmental issue due to their persistence in the ecosystems, non-degradability, and bioaccumulation in marine biota. Pacific Oysters (Crassostrea gigas) are highly nutritious bivalve representing an important dietary constituent but may accumulate metals through feeding on suspended sediments from surrounding water, then represent a suitable tool for biomonitoring. Materials and methodsThe occurrence of trace elements (Al, As, Cd, Co, Cr, Cu, Fe, Mn, Mo, Ni, Pb, Rb, Se, Sn, V, Zn) was investigated in Pacific Oysters (Cassostrea gigas) collected from Calich Lagoon in each season of 2019. Samples were homogenized and subjected to microwave acid digestion before being analyzed by inductively coupled plasma-mass spectrometer (ICP-MS). ResultsThe results showed a significant seasonal variation for temperature, dissolved oxygen, chlorophyll, and pH. Moreover, high significant seasonal variation in concentrations of Cd, Mn, Ni, and V was recorded. The highest values were found for Fe (128 mg kg⁻1 w.w.), and Al (112 mg kg⁻1 w.w.) in October, for Zn (113 mg kg⁻1 w.w.) in March and May. ConclusionsPacific Oysters were confirmed as suitable bioindicators of the health status of coastal lagoons; trace elements concentrations were highly affected by season of collection, and according to literature the highest values were recorded in autumn and summer. The EU legal limits for Cd and Pb were not exceeded, then the farmed oysters were safe to consumers.