Cross-instrument coal quality spectral analysis via a PDS-assisted fine-tuning calibration transfer method.

This study evaluated the feasibility of portable X-ray fluorescence spectroscopy (pXRF) as a rapid, non-destructive comparative screening tool for differentiating genuine and counterfeit luxury handbags distributed in the Korean domestic second-hand market through the analysis of metallic hardware components. A total of 100 type 1 handbag samples were examined using a silicon drift detector-based handheld pXRF instrument under rapid measurement conditions, with spot sizes of 3-5 mm and acquisition times of 2-3 s. Reproducible multi-element spectral patterns were obtained from curved metallic regions without destructive sample preparation. Within the analysed type 1 handbag category, counterfeit items consistently showed Cu- and Zn-enriched signatures, whereas genuine items showed relatively higher Ni- and/or Fe-related signals depending on the product group. Representative Cu concentrations ranged from 0.4-43 wt% in authentic Re-nylon bucket bag samples and 60-83 wt% in counterfeit samples, while Zn was predominantly below the detection limit in authentic samples but was detected at 1.2-20 wt% in counterfeit samples. Short-term repeatability under the present rapid-screening conditions showed relative standard deviations of 0.30%, 2.72%, 6.23%, and 33.97% for Cu, Ni, Zn, and Fe, respectively; the high Fe variability was attributed to near-LOD measurements. Reference LOD/LOQ ranges for Cu, Zn, Ni, and Fe were estimated from the manufacturer's published alloy-mode specifications to aid interpretation of <LOD and <LOQ entries. However, accuracy was not independently evaluated using matrix-matched certified reference materials or destructive metallurgical confirmation. Principal component analysis (PCA) of the fluorescence intensity matrix provided clear exploratory separation between genuine and counterfeit samples, with Cu and Zn contributing primarily to class separation and Ni/Fe contributing to secondary variance. The proposed approach offers practical advantages including rapid measurement, portability, non-destructive analysis, and applicability to irregular metallic hardware; however, it remains limited by surface and plating effects, the absence of independent matrix-matched validation, and the restricted type 1 dataset. Therefore, the results should be interpreted as a feasibility-oriented comparative screening result rather than a fully validated analytical authentication method.

The contamination of aquatic environments by pharmaceuticals is a critical global concern, as a consequence of their persistence, bioaccumulation, and adverse effects on ecosystems and public health. To effectively mitigate this issue, it is essential to adopt a preventive approach based on regular monitoring of contaminants. Hence, this study reports the optimization of a green synthesis of silver selenide (AgxSe) quantum dots (QDs) as efficient signal amplifiers via surface-enhanced infrared absorption (SEIRA) spectroscopy. The QDs synthesis was performed in water using glutathione (GSH) and ascorbic acid as the stabilizing and reducing agent, respectively. The synthesis procedure was optimized using a Box-Behnken multivariate design approach, identifying critical parameters that influence the resulting optical response. AgxSe-GSH QDs exhibited an emission maximum around 700nm and an average diameter of 6nm. Total reflection X-ray fluorescence (TXRF) confirmed the expected presence and molar proportion of Ag and Se in the non-stoichiometric molar ratio of Ag:Se 7:1. Venlafaxine (VEN) was selected as a model pharmaceutical to evaluate QDs performance in SEIRA following two deposition strategies: (i) layered deposition (LD) and (ii) mixed deposition (MD). The following SEIRA experiments comparing MD and LD QDs resulted in more repeatable signals for the MD-QDs with IR signal amplification of up to 38-fold. The lowest detectable VEN concentration via SEIRA was 0.113mmolL-1, demonstrating the potential of SEIRA, augmented by AgxSe QDs, for monitoring pharmaceutical contaminants in aqueous matrices.

A novel AgNPs spongy trap coupled with portable XRF: a field-ready strategy for sensitive mercury analysis in soils.

This study represents the first feasibility demonstration of hyperspectral X-ray absorption near-edge structure (XANES) mapping performed using a full-field fluorescence imaging approach. This method may be useful in many research fields for determining the spatial distributions of the different oxidation states of an element present at low concentration in X-ray beam-sensitive samples. It was demonstrated that this approach could be easily performed using a full-field imaging method where a Fresnel zone plate (FZP) was employed as a coded aperture, which represented a practical, fast and dose-efficient alternative to the raster-scanning technique, when these two approaches were tested at a beamline not dedicated to X-ray imaging. The basic form of the reconstruction algorithm, which was derived from inline holography, was optimized. This enabled the spatial resolution and overall quality of the reconstructed image to be improved. The ∼62 µm spatial resolution experimentally achieved may be further optimized to about 5 µm using a smaller FZP and larger detector than those used in this investigation. The XANES spectra corresponding to the main chemical species present in the sample, obtained from the tested hyperspectral spectroscopy approach, did not exactly match those expected, as they depended on several empirical processing steps. While these results can be further improved by optimizing the linearity of the detector output via pile-up corrections, further work is needed to establish robustness against variations in masking, background treatment, and intensity-correction choices, especially for studying diluted specimens whose corresponding pixel intensities are similar to those of the background.

Scanning fluorescence X-ray microscopy is widely used for quantitative mapping of elemental concentrations, including in studies of essential but low-concentration metals in cells, tissues, and organs. Practical studies often use a single incident photon energy to excite fluorescence from many elements. We present calculations of the number of incident photons per pixel required to detect a specified areal concentration of an element in the case of far-from-threshold excitation, along with the calculated radiation dose consequently imparted in a simple model tissue. We also show how certain approximations can lead to less accurate estimates. These calculations are not specific to one particular experiment, though we also provide a comparison with one experimental result. These results can be used to guide experimental planning for studies of the role of low-concentration elements in biological tissues.

A Bayesian optimization stacked ensemble learning method: Predicting ash content in flotation cleaned coal using X-ray fluorescence oxides data

Metals are key toxic components of PM2.5, but their personal exposure levels and health effects remain unclear, due to their high spatiotemporal heterogeneity and large differences in individual behaviors. This study proposed a "personal PM2.5-bound metal exposome" framework to (1) systematically characterize personal metal exposure profiles and their variability, (2) comprehensively evaluate the health effects of multimetal exposures, and (3) explore interactions among metals. Using data from the SCOPE (Study Comparing the cardiO-metabolic and respiratory effects of air Pollution Exposure) panel study, we analyzed personal samples and data from 588 follow-up visits of 120 elders in Beijing, China. Personal 23.5-h PM2.5 samples were collected using portable devices, and concentrations of 15 metals were quantified by micro-synchrotron radiation X-ray fluorescence (μ-SRXRF). Linear mixed-effects models were applied to assess the impacts of transportation modes and personal exposure sources on personal PM2.5-bound metal exposure profiles. A Bayesian Kernel Machine Regression (BKMR) model was applied to examine the associations between metals and inflammatory biomarkers and evaluate interactions among metals. The results indicated that participants exposed to the subway microenvironment had elevated exposure levels of iron (Fe), manganese (Mn), and copper (Cu). This suggests that even when metal exposure is accumulated over only a short period in the subway, the enclosed environment may still lead to potentially pronounced health impacts. An interquartile range increase in arsenic (As) was associated with an increase of 6.2% in IFNγ (95% CI: 0.0-12.4%), 20.2% in sCD40L (95% CI: 7.1-33.3%), 2.9% in MCP-1 (95%CI: 1.0-5.5%), 1.8% in white blood cells (95% CI: 0.3-3.2%), and 3.3% in monocytes (95% CI: 1.0-5.4%). Suggestive evidence indicated that transition metals (Fe, Cu, Mn) may have synergistic pro-inflammatory effects. Based on a "personal PM2.5-bound metal exposome" analytical framework, this study has improved scientific understanding of personal metal exposure profiles and their health effects.

Systematically exploring the multidimensional parameter space of metal-organic framework (MOF) crystallization remains challenging due to limited adoption of high-throughput (HT), automated experimental workflows. MOF development is dominated by manual synthesis and characterization methods and a trial-and-error approach, and the integration of HT MOF synthesis with HT characterization and analysis is uncommon. Here, we present a practical HT MOF discovery workflow that combines automated solvothermal synthesis with three scalable characterization methods. First, we characterize bulk structure using HT powder X-ray diffraction (PXRD) and rapid matching of PXRD data to reported MOF crystal structures. We also employ a custom machine-learning based computer vision (CV) model to identify MOF formation rates from images of sample vials. Finally, we develop a HT X-ray fluorescence (XRF) method to quantify elemental ratios in bimetallic MOF samples. As a case study, we investigate the crystallization of rare earth (RE) MOFs, systematically probing the effects of reaction conditions such as metal identity, linker structure, temperature, and acid concentration. We then leverage these insights to demonstrate a proof-of-concept selective crystallization from a mixed RE solution. Using our HT workflow, we performed 1488 unique MOF crystallization reactions and characterized the resulting samples through the collection of >800 PXRD patterns, CV analysis of >13 000 images, and elemental analysis measurements of 144 bimetallic crystallization reactions. We identified 5 previously unreported rare earth MOFs (NU-2501-NU-2505) and characterized their structures with single-crystal X-ray diffraction (SCXRD) and microcrystal electron diffraction (MicroED). Our HT approach enabled us to construct phase diagrams mapping out the crystallization preferences and formation kinetics for 18 distinct RE-MOF products. By unifying automated MOF synthesis with multimodal characterization, we demonstrate the efficient exploration of a complex synthetic landscape, generating insights into MOF structure, crystallization kinetics, and composition.

Iron (Fe) and zinc (Zn) deficiencies severely threaten global human health. Thus, rice biofortification to enhance intrinsic Fe and Zn levels in grains represents an effective strategy to alleviate human Fe and Zn deficiencies. Several biofortification strategies have successfully increased Fe and Zn concentrations in the rice endosperm, with multigene approaches demonstrating synergistic micronutrient accumulation. To enhance Fe and Zn accumulation in rice endosperm, we designed a transformation construct (NYFN) in which OsNRAMP7 and OsNAS2 were driven by the 35S promoter, OsYSL2 by the OsSUT1 promoter, and OsFER2 by the endosperm-specific OsGluA2 promoter. Multi-year field trials were conducted at two locations to evaluate Fe and Zn accumulation in transgenic NYFN rice plants derived from Nipponbare (NB) and commercial cultivar Huaidao 5 (HD5) genetic backgrounds. The results showed that transgenic NB lines exhibited 10.93-14.72 μg/g DW Fe and 33.01-48.33 μg/g DW Zn in polished grains, representing 4.9- to 6.3-fold increases in Fe and 2- to 2.7-fold increases in Zn compared to the NB control. Polished grains of HD5 transformants contained 10.24-13.35 μg/g DW Fe and 32.17-50.33 μg/g DW Zn, corresponding to 4- to 7.4-fold elevations in Fe and 2- to 2.3-fold elevations in Zn relative to the HD5 control. X-ray fluorescence spectroscopy (µ-XRF) and Perls' Prussian blue staining analyses confirmed the significantly enhanced Fe and Zn accumulation in transgenic grains. Transgenic NB lines exhibited significant changes in certain agronomic traits, including reduced 1000-grain weight, grain size, and grain filling rate, whereas transgenic HD5 lines showed no significant agronomic differences relative to the wild type. Total grain weight per plant remained unchanged in both the transgenic NB and HD5 lines compared to the wild type. The results demonstrate that the NYFN strategy enables sustainable Fe and Zn biofortification, representing a promising solution to the global challenge of human Fe and Zn deficiency.

A series of multicharged surfactants with magnetic counterions (Mag-D-Surfs) containing one hydrophobic tail and two hydrophilic groupings, and comprising exclusively carbon atoms in the hydrophobic part, i.e., 2-alkyl-N,N,N,N',N',N'-hexamethylpropan-1,3-ammonium salts (ferrates; alkyl: decyl, dodecyl, and tetradecyl, abbreviated, respectively, as C10-DCMe3Mag, C12-DCNMe3Mag, and C14-DCNMe3Mag), were first synthesized and characterized by FT-IR, Raman, X-ray fluorescence (XRF), and FIR spectra as well as elemental analyses. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC), supported by optical polarization microscopy, showed that the coexistence of isotropic and anisotropic subphases depended on cooling rates. Surface activity of Cn-DCNMe3Mag at the air/water interface was evaluated by measuring the surface tension of their solutions by the pendant drop technique and compared with surfactants without magnetic function. Moreover, surface tensiometry in a magnetic field demonstrated that the studied Mag-D-Surfs exhibited magnetically induced changes in the drop shape. Their magnetic behavior in the solid state was determined by superconducting quantum interference device magnetometry (SQUID). All findings related to the aforementioned double-headed Mag-D-Surfs were compared to linear magnetic ionic liquids surfactants (MILSs), i.e., alkyltrimethylammonium halogenoferrates (alkyl: dodecyl [DTA][FeClxBr4-x-], tetradecyl [TTA][FeClxBr4-x-], and cetyl [CTA][FeClxBr4-x-]). Magnetic tests confirm the paramagnetic nature of the studied compounds and the 1:1 molar ratio (surface active cation:Fe3+) for all the studied surfactants. Their unique physicochemical properties demonstrate exceptional performance, particularly in the development of new stimuli-responsive materials.

Clayey sediments in aquitards are considered primary sources of endogenous iodine in groundwater of coastal areas. Aquitard compaction was assumed to elevate iodine concentrations in groundwater beneath. Nonetheless, the mechanisms governing iodine migration during compaction remain poorly understood. Field-simulated compaction experiments with pristine clayey sediments from the Pearl River Delta were conducted to elucidate iodine mobilization dynamics during aquitard compaction. The results reveal that a substantial amount of authigenic pyrite occurred in the clayey sediments and carried approximately 30% of total iodine. With intensifying sediment compaction, iodine was continuously released primarily as I-, resulting in high iodine concentrations (>100 μg/L) in the expelled porewater. Combined sequential chemical extraction, micro-X-ray fluorescence (μ-XRF), and scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDS) analyses suggest that, as compaction pressure increased, progressive pyrite fragmentation and formation of surface Fe oxide minerals (hematite) led to a marked decrease of pyrite-bound iodine and IO3- reduction. Concurrently, dynamic transformation of iodine species among IO3-, I-, and organic iodine occurred in the porewater, with I- being the dominant species finally. In summary, structural changes of iodine-bound pyrite play a critical role in iodine transformation and mobilization within compacting aquitards, exerting overlooked implications for the genesis of high-iodine groundwater in coastal areas.

Wastewater-derived struvite (MgNH4PO4·6H2O) microcrystals could replace a significant fraction of traditional nitrogen and phosphorus fertilizers, supporting nutrient recycling and sustainability while mitigating environmental impacts such as water eutrophication and atmospheric pollution. However, phosphorus recovery is often hindered by iron interference, as iron (Fe) can strongly bind phosphate to form insoluble iron phosphate minerals, such as vivianite, through pH, redox, and organic matter dependent processes. These Fe-containing anthropogenic solids represent an unexplored source of anthropogenic iron flux into the environment. This study investigates the influence of Fe concentration on struvite formation using magnesium carbonate (MgCO3) as a naturally abundant magnesium (Mg) source in simulated wastewater containing up to 500 ppm of Fe3+. Iron-containing struvite (Fe-struvite) microcrystals were successfully synthesized and characterized using complementary structural and spectroscopic techniques. Up to 150 ppm Fe3+ precursor concentration yielded well-defined crystalline Fe-struvite, whereas higher levels resulted in amorphous phases. Low Fe3+ levels (up to 10 ppm) caused a lattice contraction in struvite due to limited magnesium substitution. Raman micro-spectroscopy revealed that low Fe3+ concentrations (<10 ppm) allowed coexistence of hydromagnesite (Mg5(CO3)4(OH)2·4H2O) with struvite, whereas at >150 ppm Fe3+, only amorphous phosphate was present. Ion chromatography showed equilibrium aqueous phosphate (PO43-) concentrations decreasing from 235 ppm to 38 ppm with increasing Fe3+, while ammonium removal from solution was inhibited. X-ray fluorescence analysis indicated that at >150 ppm Fe3+, an iron-rich amorphous phase with Fe : P ≈ 1 : 1.75 was produced. The findings indicate that recovered Fe-struvite can serve as an anthropogenic iron source to the environment.

Barium ferrite has been modified by the addition of titanium and lanthanum ions, following the formula LayBa1-yTixFe12-xO19. Samples were obtained by ball-milling and annealing the powder precursors, and the resulting powders were then pressed into ceramic pellets. The value ofxwas fixed at 0.1, while the values ofywere 0.01, 0.03, and 0.05, respectively. Structural characterization of the samples was performed using x-ray diffraction (XRD), and scanning electron microscopy was employed to observe the morphology and estimate particle size. The presence of titanium and lanthanum was confirmed through x-ray fluorescence. The magnetic properties of the compound were characterized by magnetic hysteresis loop analysis, thermal magnetization analysis, and Curie temperature estimation. Analysis of XRD diffractograms confirms that the majority phase of barium ferrite is hexagonal in all samples. Additionally, Ti-Kα and La-Kαpeaks were observed in the samples modified with Ti and La ions. The saturation magnetization values observed in the hysteresis loops of the samples withy= 0.00, 0.01, and 0.03 are above 60 emu g-1and close to the reference value. In contrast, fory= 0.05, a significant drop of approximately 8% is observed. Thermal scanning of the dielectric permittivity reveals a substantial increase of at least 100% in the dielectric constant compared to the unmodified sample, along with a paraelectric-like transition between 0 °C and 50 °C induced by the addition of titanium and lanthanum.

ABSTRACT Mineralogical and geochemical investigations have been carried out on organic-rich and inorganic-rich fractions of Ib Valley coal to understand the association and distribution of macerals, minerals, and the occurrence of major, minor, trace, and rare earth elements. Density fractionation was performed using heavy liquids of relative density 2.0 g/ml to generate organic-rich and inorganic-rich fractions, followed by detailed petrography, mineralogy, and geochemical analyses using X-ray diffraction (XRD), X-ray fluorescence (XRF), scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS), and inductively coupled plasma optical emission spectroscopy (ICP-OES). The results revealed significant differences in mineralogical composition and elemental associations between the two fractions. The inorganic-rich fraction contained mainly pyrite, siderite, hematite, and some minor sulfides minerals such as chalcopyrite, sphalerite, and galena, with enrichment of trace elements such as Mn, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Sn, and Pb. The organic-rich fraction is found to host quartz, clay minerals, apatite, and Ti-oxide with elevated concentrations of Li, Sc, V, Cr, Ge, Ga, Sr, Zr, Nb, Sb, Ba, and W. The rare earth elements, including yttrium (REY), concentration of Ib Valley coal ash is higher than the average REY of global coal ash. In density separation, the REY are found to be enriched in the organic-rich fraction, suggesting their association with aluminosilicates, phosphates, and the oxide bearing phases. These findings provide insights into the mineralogical control on elemental partitioning of Ib Valley coal, with implications for its utilization, environmental impact, and resource management.

From morphology to nanoscale chemistry: resolving drivers of shell alteration in marine gastropods.

Background and Aim: Rapid urbanization, post-conflict reconstruction, demolition activities, traffic emissions, and informal industrial practices have increased heavy metal accumulation in urban soils, creating environmental and public health concerns. This study assessed the spatial distribution, contamination levels, and human health risks of selected heavy metal oxides in surface soils from urban districts on the right side of Mosul City, Iraq, using X-ray fluorescence analysis. Methods: A cross-sectional environmental assessment was conducted from January to June 2025 across ten urban districts using purposive site selection. Surface soil samples were collected, air-dried, sieved, homogenized, and analyzed with a portable X-ray fluorescence spectrometer. Six metal oxides were measured in ppm: V₂O₅, ZrO₂, CuO, Ga₂O₃, Tl₂O, and PbO. Data were analyzed using SPSS version 26.0. Descriptive statistics, Shapiro–Wilk tests, Pearson correlation, pollution indices, and USEPA-based Hazard Quotient/Hazard Index calculations were performed for adults and children. A composite Site Environmental Vulnerability Index was also developed. Results: CuO showed marked spatial variability, ranging from 24.50 to 288.11 ppm. Tl₂O reached Moderate geoaccumulation levels at all sites and Moderate–Heavy contamination at Wadi Hajar. A strong positive correlation was found between CuO and PbO, suggesting shared anthropogenic sources. The pediatric Hazard Index exceeded 1 at all sites, with Wadi Hajar showing the highest risk. The vulnerability index ranked Wadi Hajar and Wadi Akab as Very High-risk districts, while Al-Aamil was the least contaminated site. Conclusion: Heavy metal contamination in right-side Mosul soils is spatially heterogeneous, with thallium and copper posing the greatest concern, especially for children. District-level remediation, biomonitoring, and routine surveillance are urgently recommended.

Occupational exposure to commercial cooking emissions has not been comprehensively studied, particularly in a Western context. This investigation measured the concentration and composition of volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), particulate matter (PM), carbon monoxide (CO), and black carbon (BC) in 18 New York City restaurants. Eight-hour gravimetric PM1,2.5,10 mass concentrations were measured in kitchen and dining areas, and PM1 was speciated using X-ray fluorescence. Evacuated canisters and XAD-2 sorbent tubes collected VOCs and PAHs, respectively, and were speciated using gas chromatography/mass spectrometry (GC/MS). Lastly, spatial concentration gradients for PM2.5 and day-of-the-week effects were considered in eight additional restaurants. A median PM2.5 concentration of 79.6 μg/m3 was found in kitchens, with real-time values spiking into the thousands of micrograms per cubic meter in some restaurants─values below the Occupational Safety and Health Administration 8 h permissible exposure limit of 5 mg/m3 for particles not otherwise regulated (respirable fraction), but well above the 24 h World Health Organization recommended ambient exposure limit of 15 μg/m3 for 2021. Benzene, a known carcinogen, was frequently detected in the kitchen areas, while PAHs were often undetected. These data warrant further investigation into the cardiopulmonary health of restaurant workers.

Road dust resuspension represents a significant yet inadequately quantified contributor to urban particulate matter (PM) pollution in Indian non-attainment cities. This study aims to quantify road dust emissions and characterize the elemental composition of road dust in Ujjain, Madhya Pradesh-a city designated as non-attainment under India's National Clean Air Programme (NCAP), through systematic field measurements, traffic surveys, and chemical characterization. During October 2023, road dust samples were collected at 11 strategically chosen sites that represent a variety of traffic densities with the help of the U.S. EPA-standardized protocols. The silt loading values showed that there was significant spatial heterogeneity of 4.3g/m2 at Malkhamba Statue and 15.2g/m2 at Piplinaka Chauraha with a city average of 8.4 ± 3.6g/m2 (coefficient of variation (CV) = 43%). Extensive traffic surveys were recorded in terms of vehicle make-up in five categories with daily traffic volumes of 15,800 to 57,655 vehicles. The bcity-wide estimates of 132.37 tons/day PM10 and 32.03 tons/day PM2.5 were found by the use of the U.S. EPA AP-42 emission methodology. Ujjain Ring Road was the largest emitter of the total measured emissions 41.34 tons/day PM10. Wavelength dispersive X-ray fluorescence (WD-XRF) analysis revealed a dual-source structure: predominant crustal elements (Fe: 19.21%, Si: 14.2%) from soil and agricultural dust and traffic-related heavy metals (Zn, Cu, Ni, Cr, V) from non-exhaust vehicle emissions. Three high-emission hotspots Ujjain Ring Road, Aagar Naka, and Hari Fatak collectively account for 59.7% of the collected city-wide road dust emissions, underscoring the importance of spatially targeted mitigation strategies for air quality management in non-attainment cities.

Abstract Organic-rich mixed carbonate–siliciclastic unconventional successions commonly exhibit centimeter- to decimeter-scale mineralogical and geochemical heterogeneity that complicates stratigraphic interpretation and reservoir characterization. Although handheld X-ray fluorescence (HHXRF) resolves this variability at high resolution, multielement profiles are high-dimensional and strongly correlated, limiting reproducible translation of coupled elemental behavior into stratigraphically coherent chemofacies. Here, we present a reproducible informatics workflow for chemofacies delineation and interpretation using 20-element core HHXRF data (interpreted in terms of relative downcore variability) from two subsurface cores spanning the Upper Ordovician Trenton/Lexington, Point Pleasant, and Utica interval in Ohio, USA. Principal component analysis (PCA) reduces redundancy and provides a stable feature space for distance-based classification. K-means clustering of retained PCA scores delineates five chemofacies: (i) Detrital Dolomitic, (ii) Siliceous Argillaceous, (iii) Mixed Silica–Argillaceous, (iv) Carbonate-Dominated, and (v) a localized Mo-enriched anoxic end-member that marks extreme conditions over a short stratigraphic thickness. Exploratory factor analysis (EFA) extracts three interpretable latent factors representing terrigenous/siliciclastic influence, redox-sensitive trace-metal enrichment, and anoxia/sulfidic conditions. Median factor scores and Kruskal–Wallis tests ( p &lt; 0.00001) provide statistical support for overall differentiation among chemofacies in factor-expression space. The workflow is transferable to other core-based geochemical datasets and reduces subjectivity in facies-based chemostratigraphic interpretation.