Secondary Ion Research Articles

Mapping active pharmaceutical ingredients Distributions in tablets using Time-of-Flight secondary ion mass spectrometry with multivariate curve resolution

This study introduces an advanced approach to identifying signals associated with indapamide, amlodipine, and perindopril in solid dosage form using time-of-flight secondary ion mass spectrometry (ToF-SIMS) combined with multivariate curve resolution (MCR). The primary objective was to obtain and characterize these signals through MCR factors, which then led to identifying unique signals specific to each active pharmaceutical ingredient (API). These unique signals were crucial for constructing detailed 2D and 3D images of the API distribution within the tablet. The results demonstrated that indapamide and amlodipine exhibited multiple unique peaks, while perindopril had only one. Additionally, the study revealed non-homogeneous distribution patterns of APIs and excipients, such as SiO2 and Mg stearate. This work highlights the significance of applying advanced analytical techniques such as ToF-SIMS and MCR in the pharmaceutical field to ensure consistent therapeutic efficacy through a better understanding of API distribution.

Design and Synthesis of Aggregation‐Caused Quenching Hydroxy‐Phenanthroimidazole Derivatives for Probing of Fe3+ Ions and as Potential Blue Light Emitters

AbstractFluorescence aggregated molecules tend to employ versatile opportunities in metal ion probe sensors and fluorescent lighting. To achieve this dual challenging task, currently synthesized three phenanthroimidazole‐naphthalene‐based compounds Pq‐tBu‐OH, Pq‐mF‐OH, and Pq‐pF‐OH are derived based on substitution at N1 position for better photophysical and electrochemical properties. Compared experimental and theoretical calculations define the highest bandgap to be 2.75 eV of Pq‐pF‐OH, and the same molecule expressed a higher (348 °C) thermal decomposition. The calculated singlet and triplet energies found in the range of 3.24–3.67 and 2.70–2.72 eV indicate well energy transfer from S1→S0 (quantum yield of 23.36 %, lifetime is 4.05 ns). Among the numerous morphologies, the solid form exhibited improved intensive deep blue emission (x=0.159, y=0.051), and its InGaN LED results demonstrated a strong deep blue emission at 418 nm. Moreover, the fluorophores were experimentally visualizing the aggregation‐caused quenching (ACQ) which enables the probing of Fe3+ ion. However, for the first time, the ACQ‐assisted concept is applied through synthesized molecules for Fe3+ ion probing via fluorescence spectra, Job's plot calculation, and 1H NMR results. In addition, the probe works excellently at a detection limit of 10 μM and it could also act as a potential competitor for lighting applications.

The Characteristics of Water-Soluble Inorganic Ions in PM1.0 and Their Impact on Visibility at a Typical Coastal Airport

Water-soluble inorganic ions (WSIIs) can increase the hygroscopicity of aerosols, which will transform aerosols into larger sizes and reduce visibility by enhancing light scattering. To explore the characteristics of WSII concentrations and their impacts on visibility in a coastal airport, in this study, PM1.0 samples at two monitoring sites (including airport site and background site) were collect in spring and summer, and 12 species of ions were detected. In general, secondary water-soluble inorganic ions (SNA, including SO42−, NO3− and NH4+) and Ca2+ were the dominant WSIIs in PM1.0, contributing about 89% to 95% of the total measured ions. The continental contributions of SO42−, K+, and Ca2+ accounted for more than 60% during the whole period, while Na+ and Cl− were mainly from marine sources. The source identification showed that airport emissions were a major source at the sampling site and significantly contributed to the levels of sulfate, nitrate, and ammonium. Agricultural activities were the dominant sources impacting visibility in spring, while airport emissions and secondary inorganic aerosols were the main components affecting visibility in summer. Therefore, improving atmospheric visibility in coastal airport areas should focus on reducing the precursors of secondary particulates and reducing biomass-burning activities.

Urea assimilation and oxidation support activity of phylogenetically diverse microbial communities of the dark ocean.

Urea is hypothesized to be an important source of nitrogen and chemical energy to microorganisms in the deep sea; however, direct evidence for urea use below the epipelagic ocean is lacking. Here, we explore urea utilization from 50 to 4000 meters depth in the northeastern Pacific Ocean using metagenomics, nitrification rates, and single-cell stable-isotope-uptake measurements with nanoscale secondary ion mass spectrometry. We find that on average 25% of deep-sea cells assimilated urea-derived N (60% of detectably active cells), and that cell-specific nitrogen-incorporation rates from urea were higher than that from ammonium. Both urea concentrations and assimilation rates relative to ammonium generally increased below the euphotic zone. We detected ammonia- and urea-based nitrification at all depths at one of two sites analyzed, demonstrating their potential to support chemoautotrophy in the mesopelagic and bathypelagic regions. Using newly generated metagenomes we find that the ureC gene, encoding the catalytic subunit of urease, is found within 39% of deep-sea cells in this region, including the Nitrososphaeria (syn., Thaumarchaeota; likely for nitrification) as well as members of thirteen other phyla such as Proteobacteria, Verrucomicrobia, Plantomycetota, Nitrospinota, and Chloroflexota (likely for assimilation). Analysis of public metagenomes estimated ureC within 10-46% of deep-sea cells around the world, with higher prevalence below the photic zone, suggesting urea is widely available to the deep-sea microbiome globally. Our results demonstrate that urea is a nitrogen source to abundant and diverse microorganisms in the dark ocean, as well as a significant contributor to deep-sea nitrification and therefore fuel for chemoautotrophy.

Au‐Free Ti/Al/Ni/TiN Ohmic Contact to AlGaN/GaN Heterostructure: Ti/Al Thicknesses at an Optimized Ratio

Although a few studies report that tuning Ti/Al thicknesses at a fixed ratio can further improve the Ohmic contact to AlGaN/GaN heterostructure, systematic physical mechanisms have not been reported. In this work, after determining the optimal Ti/Al ratio of 1/4, two metal stacks with varying Ti/Al thicknesses and fixed Ni/TiN thicknesses are deposited to investigate how tuning Ti/Al thicknesses at an optimized ratio enhances the Ohmic contact performance. At the optimal annealing condition (950 °C, 45 s) of samples with Ti/Al thicknesses of 20/80 nm, samples with Ti/Al thicknesses of 35/140 nm exhibit a reduction of 48% in contact resistance and 70% in specific contact resistivity (ρc). By correlating the results from ρc–T measurements, time‐of‐flight secondary ion mass spectrometry, and high‐resolution X‐ray diffraction, it has been determined that this method effectively enables N‐vacancies doping into the heterostructure, thereby increasing the carrier concentration and reducing both the height and width of the interfacial potential barrier, achieving a more efficient carrier transport. By avoiding the use of Au with high solubility and ductility, this approach significantly improves contact performance without adversely affecting the electrode surface morphology, demonstrating good adaptability for optimizing Au‐free Ohmic contacts.

Presolar Grains as Probes of Supernova Nucleosynthesis.

We provide an overview of the isotopic signatures of presolar supernova grains, specifically focusing on 44Ti-containing grains with robustly inferred supernova origins and their implications for nucleosynthesis and mixing mechanisms in supernovae. Recent technique advancements have enabled the differentiation between radiogenic (from 44Ti decay) and nonradiogenic 44Ca excesses in presolar grains, made possible by enhanced spatial resolution of Ca-Ti isotope analyses with the Cameca NanoSIMS (Nano-scale Secondary Ion Mass Spectrometer) instrument. Within the context of presolar supernova grain data, we discuss (i) the production of 44Ti in supernovae and the impact of interstellar medium heterogeneities on the galactic chemical evolution of 44Ca/40Ca, (ii) the nucleosynthesis processes of neutron bursts and explosive H-burning in Type II supernovae, and (iii) challenges in identifying the progenitor supernovae for 54Cr-rich presolar nanospinel grains. Drawing on constraints and insights derived from presolar supernova grain data, we also provide an overview of our current understanding of the roles played by various supernova types- including Type II, Type Ia, and electron capture supernovae- in accounting for the diverse array of nucleosynthetic isotopic variations identified in bulk meteorites and meteoritic components. We briefly overview the potential mechanisms that have been proposed to explain these nucleosynthetic variations by describing the transport and distribution of presolar dust carriers in the protoplanetary disk. We highlight existing controversies in the interpretation of presolar grain data and meteoritic nucleosynthetic isotopic variations, while also outlining potential directions for future research.

Evaluation of Ocean Plastic Using Time-of-flight Secondary Ion Mass Spectrometry with Tandem Mass Spectrometer and Machine Learning

Evaluation of Ocean Plastic Using Time-of-flight Secondary Ion Mass Spectrometry with Tandem Mass Spectrometer and Machine Learning

Biomimetics through bioconjugation of 16-methylheptadecanoic acid to damaged hair for hair barrier recovery

The primary component of the lipid barrier on human hair, which is essential for defense against aging and environmental stresses, is 18-methyleicosanoic acid (18-MEA), which provides hydrophobic properties and protective benefits. Since 18-MEA cannot be regenerated once damaged, developing technology that can permanently bind alternative materials to hair is critical. Once 18-MEA was removed from hair via X-ray photoelectron spectroscopy (XPS), pentaerythritol tetraisoosterate (PTIS) was hydrolyzed and observed via gas chromatography/mass spectrometry (GC/MS) to confirm that it mimicked 18-MEA, and 16-methylheptadecanoic acid (16-MHA) was obtained at pH 4 or lower. 16-MHA was bioconjugated to damaged hair from which 18-MEA was removed via a carbodiimide reaction using polycarbodiimide. Time-of-flight secondary ion mass spectrometry (TOF-SIMS) confirmed that 16-MHA remained on the surface of the bioconjugated hair even after washing. Observation of the endothermic reaction of moisture in hair via a differential scanning calorimetry (DSC) and evaluation of the moisture content confirmed that the physical properties of hair enriched with 16-MHA were similar to those of virgin hair. This biomimetic approach has been shown to restore both external structural integrity and internal moisture homeostasis.

Peak-Based Machine Learning for Plastic Type Classification in Time-of-Flight Secondary Ion Mass Spectrometry.

Time-of-flight secondary ion mass spectrometry (ToF-SIMS) measurement data and machine learning were used in this work to classify six different types of plastics. In order to take into account the characteristics of the measurement data, the local maxima of the measurement data were first examined in a preprocessing step. Several machine learning methods were then implemented to create a model that could successfully classify the plastics. To visualize the data distribution, we applied a dimensionality reduction method, namely, principal component analysis. Finally, to distinguish between the six types of plastics, we conducted an ensemble analysis using four tree-based algorithms: decision tree, random forest, gradient boosting, and LIGHTGBM. This approach can identify the feature importance of plastic samples and allow the inference of the chemical properties of each plastic type. In this way, ToF-SIMS data could be utilized to successfully classify plastics and enhance explainability.

Gradient variations of formation mechanisms and sources of PM1 at the steep slope from western SiChuan Basin to eastern Tibetan Plateau

Vertical distributions of chemical components of particulate matter (PM) are essential for better understanding the climate, environmental and health effects. The steep slope from western SiChuan Basin (SCB) to eastern Tibetan Plateau (TP) provides a good platform for obtaining the gradient variations of PM chemical components. Daytime and nighttime PM1 (particulate matter smaller than 1 μm) samples were collected with the medium-volume sampler at six sites with elevation ranging from 500 m to 3500 m (Chengdu, Sanbacun, Wenchuan, Lixian, Maerkang and Hongyuan). The secondary inorganic ions and carbonaceous aerosols were the largest contributor to PM1 concentrations. The chemical components from the anthropogenic sources existed strong stratification with high concentrations inside the basin, while primary natural ions showed little discrepancy among the sites. The concentrations of primary inorganic ions from anthropogenic sources were much higher at nighttime than daytime, which was contrary to the diurnal cycle of secondary inorganic ions. Spatial heterogeneity of PM chemical components was large between basin and plateau sites, especially for NO3− and NH4+, large depending on season and daylight. The excess NH4+ concentrations existed in spring, summer and fall, while SO42− and NO3− cannot be completely neutralized by NH4+ in winter. The proportion of secondary formation in all sources significantly increased from about 10 % to 30 %–40 % with the increased elevation, while the contribution of motor vehicles declined from western SCB to eastern TP. This study will fill the scarce observations of PM chemical components at the sloped terrain and deepen the understanding of formation mechanism of heavy pollution inside the basin.

Ion Chemistry in Dielectric Barrier Discharge Ionization: Recent Advances in Direct Gas Phase Analyses.

Dielectric barrier discharge ionization (DBDI) sources, employing low-temperature plasma, have emerged as sensitive and efficient ionization tools with various atmospheric pressure ionization processes. In this review, we summarize a historical overview of the development of DBDI, highlighting key principles of gas-phase ion chemistry and the mechanisms underlying the ionization processes within the DBDI source. These processes start with the formation of reagent ions or metastable atoms from the discharge gas, which depends on the nature of the gas (helium, nitrogen, air) and on the presence of water vapor or other compounds or dopants. The processes of ionizing the analyte molecules are summarized, including Penning ionization, electron transfer, proton transfer and ligand switching from secondary hydrated hydronium ions. Presently, the DBDI-MS methods face a challenge in the accurate quantification of gaseous analytes, limiting its broader application in biological, environmental, and medical realms where relative quantification using standards is inherently complex for gaseous matrices. Finally, we propose future avenues of research to enhance the analytical capabilities of DBDI-MS.

Direct observation of nanometer size hydride precipitations in superconducting niobium.

Superconducting niobium serves as a key enabling material for superconducting radio frequency (SRF) technology as well as quantum computing devices. Niobium has a high propensity for the uptake of hydrogen. At room temperature, hydrogen commonly occupies tetragonal sites in the Nb lattice as the metal (M)-gas (H) phase. When the temperature is decreased, however, a solid solution of Nb-H begins to precipitate. In this study, we show the first identified topographical features associated with nanometer-size hydride phase (Nb1-xHx) precipitates on the surface of the metallic superconducting niobium using cryogenic-atomic force microscopy (AFM). Further, high energy grazing incidence X-ray diffraction reveals information regarding the structure and stoichiometry of these precipitates. Finally, through time-of-flight secondary ion mass spectroscopy (ToF-SIMS), we locate atomic hydrogen sources near the top surface. This systematic study clarifies nanometer scale hydrides precipitated on the surface of the SRF Nb cavity that exhibit performance degradation at a high accelerating field regime.

Genome-guided isolation of the hyperthermophilic aerobe Fervidibacter sacchari reveals conserved polysaccharide metabolism in the Armatimonadota

Few aerobic hyperthermophilic microorganisms degrade polysaccharides. Here, we describe the genome-enabled enrichment and optical tweezer-based isolation of an aerobic polysaccharide-degrading hyperthermophile, Fervidibacter sacchari, previously ascribed to candidate phylum Fervidibacteria. F. sacchari uses polysaccharides and monosaccharides for growth at 65–87.5 °C and expresses 191 carbohydrate-active enzymes (CAZymes) according to RNA-Seq and proteomics, including 31 with unusual glycoside hydrolase domains (GH109, GH177, GH179). Fluorescence in-situ hybridization and nanoscale secondary ion mass spectrometry confirmed rapid assimilation of 13C-starch in spring sediments. Purified GHs were optimally active at 80–100 °C on ten different polysaccharides. Finally, we propose reassigning Fervidibacteria as a class within phylum Armatimonadota, along with 18 other species, and show that a high number and diversity of CAZymes is a hallmark of the phylum, in both aerobic and anaerobic lineages. Our study establishes Fervidibacteria as hyperthermophilic polysaccharide degraders in terrestrial geothermal springs and suggests a broad role for Armatimonadota in polysaccharide catabolism.

Effect of Confinement on the Structure-Conductivity Relationship in PEO/LiTFSI Electrolytes in 3D Microporous Scaffolds.

Because 3D batteries comprise solid polymer electrolytes (SPEs) confined to porous scaffolds with high surface areas, the interplay between polymer confinement and interfacial interactions on SPE total ionic conductivity must be understood. This paper investigates contributions to the structure-conductivity relationship in poly(ethylene oxide) (PEO)-lithium bis(trifluorosulfonylimide) (LiTFSI) complexes confined to microporous nickel scaffolds. For bulk and confined conditions, PEO crystallinity decreases as the salt concentration (Li+:EO (r) = 0.0125, 0.0167, 0.025, 0.05) increases. For pure PEO and all r values except 0.05, PEO crystallinity under confinement is lower than in the bulk, whereas the glass transition temperature remains statistically invariant. At 298 K (semicrystalline), total ionic conductivity under confinement is higher than in the bulk at r = 0.0167 but remains invariant at r = 0.05; however, at 350 K (amorphous), total ionic conductivity in confinement is lower than in the bulk for both salt concentrations. Time-of-flight secondary ion mass spectrometry indicates selective migration of ions toward the polymer-scaffold interface. In summary, for the 3D structure studied, polymer crystallinity, interfacial segregation, and tortuosity play important roles in determining total ionic conductivity and, ultimately, the emergence of 3D SPEs as energy storage materials.

Longitudinal Piezoelectricity and Polarization-Insensitive Oxidation in Janus vdWs Nb3SeI7.

As a newly discovered Janus van der Waals (vdW) material, semiconducting Nb3SeI7 offers several notable advantages, including spontaneous out-of-plane polarization, facile exfoliation to the monolayer limit, and significant out-of-plane emission dipole in second harmonic generation. These properties make it a promising candidate for piezoelectric and piezophototronic applications in highly efficient energy conversion. However, Nb3SeI7 is prone to oxidation when exposed to oxygen, which can severely limit the exploration and utilization of these intriguing physical properties. Therefore, understanding the oxidation mechanism of pristine Nb3SeI7 and its correlation with electrical polarization-an area that remains largely unexplored-is highly significant. In this study, the out-of-plane piezoelectricity of Nb3SeI7 is experimentally demonstrated, with a piezoelectric coefficient (|d33 eff|) of 0.76nmV-1. Furthermore, by combining near ambient-pressure X-ray photoelectron spectroscopy (NAP-XPS), Time-of-Flight secondary ion mass spectrometry (ToF-SIMS), and Density functional theory (DFT)calculations, it is revealed that the oxidation of Nb3SeI7 is self-limiting and independent of its electrical polarization, owing to the similar defect formation energies of Se and I atoms. This self-limiting and polarization-insensitive oxidation provides valuable insights into the stabilization mechanisms and expands the potential applications of out-of-plane piezoelectricity and other intriguing physical properties in Janus vdW Nb3SeI7.

Enhancing Counterfeit Banknote Analysis: Case Studies Using TOF-SIMS

Counterfeiting banknotes poses a significant threat to economies worldwide, particularly in developing countries where cash transactions remain predominant. Despite advancements in security features, counterfeiters continue to adapt, necessitating more sophisticated analysis methods. Time of flight Secondary Ion Mass Spectrometry (TOF-SIMS) offers a powerful approach to surface chemical imaging and depth profiling of counterfeit currencies. Real cases of five different counterfeit Lebanese banknotes are studied, using TOF-SIMS to address specific questions regarding the composition and placement of replicated security features, gaining insights into counterfeit banknote production and the raw materials used. The findings provide essential information to decision-makers at the national bank, supporting the design of future currencies through the selection of security features best suited to the local market, thereby enhancing protection against financial fraud..

High-Sensitivity Detection of Copper Ions in Water via Cellulose Nanomaterial Nano-Antennas and DFT studies

The widespread occurrence of copper in water presents serious health hazards, requiring improvement of a method to monitor and remove copper ions in the field. In this study, a fresh approach is introduced that incorporates Cellulose Nanomaterials (CNMs) with a unique rod-like structure, offering a large surface area that is perfect for adsorbing cupral, a Cu(II) ion probe. By using this arrangement, toxic copper can be rapidly and visibly detected. Without any special tools, it's easy to see the color change from off-white to brown. The copper nano-antenna (CNA) has an impressively high sensitivity, detecting as low as 2.5 × 10-7 M through image analysis and 4.3 × 10-8 M with spectrophotometric methods. The values fall significantly below the WHO drinking water guidelines of 2 ppm. The CNA's ability to detect at low thresholds and be easily regenerated makes it an effective tool for initial water testing. According to the findings, the CNA could be a promising solution for enhancing safety in drinking water by allowing real-time visualization of copper ions, with only 5 mg required for measurements. Computational analysis has been conducted to study the structural properties of copper and its copper complex (Cu(CNA)2). There is a significant-close agreement between the theoretical and experimental results. The developed CNA material was tested in various environmental and real samples for detecting Cu2+ ions, especially in water and whitening cream samples showing the material application for real-world applications.

Molecular mechanisms of iron nanominerals formation in fungal extracellular polymeric substances (EPS) layers during fungus-mineral interactions

Extracellular polymeric substances (EPS), which envelop on fungal hyphae surface, interact strongly with minerals and play a crucial role in the formation of nanoscale minerals during biomineralization in nature environments. However, it remains poorly understood about the molecular mechanisms of nanominerals (i.e., iron nanominerals) formation in fungal EPS halos during fungus-mineral interactions. This process is vital because fungi typically grow attached to various mineral surfaces in nature. According to the changes of thickness of the fungal cell and EPS layers during the Trichoderma guizhouense NJAU 4742 and hematite cultivation experiments, we found that fungal biomineralization could trigger the formation of EPS layers. Fe-dominated nanominerals, aromatic C (283-286.1 eV), alkyl C (287.6-288.3 eV), and carboxylic C (288.4-289.1 eV) were the dominant chemical groups on the EPS layers, as determined by nanoscale secondary ion mass spectrometry (NanoSIMS), high-resolution transmission electron microscope (HRTEM), and carbon 1s near-edge X-ray absorption fine structure (NEXAFS) spectroscopy. Further, evidence from Fe K-edge X-ray absorption near-edge structure (XANES) and X-ray photoelectron spectroscopy (XPS) spectra indicated that oxygen vacancy (OV) was formed on the Fe-dominated nanomineral surface during fungus-mineral interactions, which played an important role in catalyzing H2O2 decomposition and HO∗ production. Taken together, the intrinsic peroxidase-like activity by reactive oxygen species (ROS) could modulate the Fe-dominated nanominerals formation in EPS layers to newly form a physical barrier between the cell and the external environments around hyphae, providing novel insights into the effects of ROS-mediated fungal-mineral interactions on fungal nutrient recycling, attenuation of contaminants, and biological control in nature environments.

Microstructure evolution and hydrogen absorption characteristics of gradient-hydrogenated Ti-4.5Al-3V-2Mo-2Fe alloys

Ti-4.5Al-3V-2Mo-2Fe rolled material is a dual-phase titanium alloy with an average grain size of less than 3 μm; its optimal superplastic forming temperature of 760 °C is at least 50 °C lower than the temperature required for diffusion bonding, making it challenging to carry out superplastic forming/diffusion bonding within a process window. The promotion of hydrogen on the low-temperature diffusion bonding of the alloy was verified through thermohydrogen processing, and the absorption characteristics of hydrogen in the alloy at various temperatures, holding times, and pressures were investigated. Subsequently, a mathematical model for achieving standardized hydrogen content was developed. X-ray polycrystalline diffractometer (XRD) analysis was utilized to preliminarily explore phase differences in samples with varying levels of hydrogen content. Furthermore, scanning electron microscopy (SEM), transmission electron microscopy (TEM), electron back scatter diffraction (EBSD) and time of flight secondary ion mass spectrometry (TOF-SIMS) were employed to analyze microstructure changes and hydrogen distribution in both the surface and core regions of the titanium alloy following hydrogenation, demonstrating its feasibility for surface hydrogenation treatment of titanium alloy sheets.

Matrix Corrected SIMS In Situ Oxygen Isotope Analyses of Marine Shell Aragonite for High Resolution Seawater Temperature Reconstructions

AbstractMarine shells incorporate oxygen isotope signatures during growth, creating valuable records of seawater temperature and marine oxygen isotopic compositions. Secondary ion mass spectrometry (SIMS) measures these compositions in situ at finer length‐scales than traditional stable isotope analyses. However, determining oxygen isotope ratios in aragonite, the most common shell mineral, is hampered by a lack of ideal reference materials, limiting the accuracy of SIMS‐based seawater temperature reconstructions. Here, we tested the capability of SIMS to produce seawater temperature reconstructions despite the matrix calibration challenges associated with aragonite. We cultured Anadara trapezia bivalves at four controlled seawater temperatures (13–28°C) and used strontium labeling to mark the start of the temperature‐controlled shell increment, allowing for more spatially precise SIMS analysis. An improved matrix calibration was developed to ensure more accurate bio‐aragonite analyses that addressed matrix differences between the pure abiotic reference materials and the bio‐aragonite samples with intricate mineral‐organic architectures and distinct minor and trace element compositions. We regressed SIMS‐IRMS biases of abiotic and biogenic aragonites that account for their systematic differences in major, minor, and trace elements, allowing for more accurate SIMS analyses of the temperature‐controlled shell increment. The thorough matrix calibration allowed us to provide a SIMS‐based seawater‐corrected oxygen isotope thermometer of T(°C) = 23.05 ± 0.36 − 4.48 · (δ18Oaragonite [‰ VPDB] − δ18Oseawater [‰ VSMOW] ± 0.25) and 103lnαaragonite‐seawater = (17.78 ± 0.88) · 103/T (K) − (29.44 ± 2.40) that agrees with existing aragonitic IRMS‐based thermometer relationships and improves the applicability of SIMS‐based paleo‐environmental reconstructions of marine bio‐aragonites.