Spectrochimica Acta Part B: Atomic Spectroscopy最新文献

{"title":"Relativistic and semi-theoretical calculations of K-shell to L-shell/subshell vacancy transfer probabilities","authors":"Boualem Berkani ,&nbsp;Abdelhalim Kahoul ,&nbsp;Jorge Miguel Sampaio ,&nbsp;Salim Daoudi ,&nbsp;José Pires Marques ,&nbsp;Fernando Parente ,&nbsp;Assala Hamidani ,&nbsp;Stephen Croft ,&nbsp;Andrea Favalli ,&nbsp;Yazid Kasri ,&nbsp;Amina Zidi ,&nbsp;Kahina Amari","doi":"10.1016/j.sab.2024.107089","DOIUrl":"10.1016/j.sab.2024.107089","url":null,"abstract":"<div><div>In this study, we use the relativistic multiconfiguration Dirac–Fock method (MCFD) to compute the probabilities of radiative and radiationless vacancy transfer from K- to L₁-, L₂-, and L₃₋ subshells in ₁₆S, ₁₈Ar, ₂₂Ti, ₂₉Cu, ₃₀Zn, ₃₂Ge, ₃₃As, ₃₄Se, ₃₆Kr, ₄₀Zr, ₄₈Cd, ₅₀Sn, ₅₂Te, ₈₀Hg, ₈₃Bi, and ₈₆Rn atoms. Semi-theoretical calculations for elements within the atomic range of 18 ≤ <em>Z</em> ≤ 96 (₁₈Ar to ₉₆Cm) were also conducted, leveraging available data on radiative and radiationless transitions from the scientific literature. The theoretical calculation results aligned well with the values calculated semi-theoretically and with other published works. However, some notable differences were identified.</div></div>","PeriodicalId":21890,"journal":{"name":"Spectrochimica Acta Part B: Atomic Spectroscopy","volume":"224 ","pages":"Article 107089"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094307","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Study on ablation behavior and mechanism for accurate determination of rare earth elements in CaF2 crystals by UV-LA-ICP-MS","authors":"Yuqiu Ke ,&nbsp;Hui Hu ,&nbsp;Jianzong Zhou ,&nbsp;Haitao Li ,&nbsp;Yu Zhang ,&nbsp;Chaoyang Tu ,&nbsp;Herui Wen ,&nbsp;Yijian Sun","doi":"10.1016/j.sab.2024.107091","DOIUrl":"10.1016/j.sab.2024.107091","url":null,"abstract":"<div><div>Catastrophic ablation of CaF₂ crystals is often observed in ultraviolet-laser ablation-inductively coupled plasma-mass spectrometry (UV-LA-ICP-MS) analysis, leading to variations in the volume of ablated material and resulting analytical errors in LA-ICP-MS microanalysis. Therefore, it is essential to understand the ablation behavior and the interaction mechanisms between the laser and CaF₂ crystals. In this study, we examined the effects of crystal surface roughness and laser fluence on ablation behavior. The CaF₂ crystal polished with 1500 mesh abrasive paper exhibited a stable signal profile, a regular ablation crater, and the formation of nanoparticles, which align with predictions from the thermo-mechanical coupling model. Both higher and lower roughness resulted in either unstable ablation or uncontrolled ejection of fragments; the latter occurred when the thermal stress from accumulated light energy significantly exceeded the compressive strength of CaF₂. Consequently, a roughness of 1500 mesh at the bottom of the ablation craters was deduced. We also identified a laser fluence of 14 J·cm⁻² as the threshold for effective LA-ICP-MS analysis of CaF₂ crystals, based on consistent signal profiles, elemental fractionation index (EFI), and crater morphology as revealed by LA-ICP-MS and scanning electron microscope (SEM) analyses, along with theoretical calculations from the thermo-mechanical coupling model. The optimal roughness (1500 mesh) and fluence (14 J·cm⁻²), together with the thermo-mechanical coupling model, can serve as guidelines for UV-LA-ICP-MS settings in further quantitative analyses of CaF₂ crystals.</div></div>","PeriodicalId":21890,"journal":{"name":"Spectrochimica Acta Part B: Atomic Spectroscopy","volume":"224 ","pages":"Article 107091"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Surface and in-depth characterization of commercial papers by LIBS technique: Parameters and features for their classification, and complementary information from Raman spectroscopy","authors":"Flavio Cicconi ,&nbsp;Violeta Lazic","doi":"10.1016/j.sab.2024.107112","DOIUrl":"10.1016/j.sab.2024.107112","url":null,"abstract":"<div><div>In examination of documents by LIBS technique, the paper material is usually probed by surface scanning and the averaged spectra are processed by chemometric methods. The scope of this work is to have insight into LIBS analysis of common writing/printing papers, considering both the laser depth profiling and surface measurements. The sample set consisted in 14 papers (copy, notebook and envelope papers), some of them made of recycled materials. Examination of the laser induced craters showed a preferential ablation of paper fillers while the cellulose fibres were displaced at surface and swallowed around the centre of laser spot. Beside material inclusions, found both on the paper surface and in depth, the not uniform ablation also contributes to large intensity fluctuations of the element's line intensities, which standard deviations differ from one sample to another. By studying correlations between the line intensities from different elements at paper surface and in depth, it was possible to distinguish some top coatings (e.g., kaolinite) from bulk fillers (e.g., containing alumina-silicates), to hypothesize the use of NaOH in the industrial processing, as well as to exclude presence of certain types of fillers or coatings. Raman spectroscopy was performed both on sample surfaces and inside the laser induced craters (bulk material), showing the differences among papers regarding relative contents of CaCO₃ filler, lignin, and cellulose. We tested different chemometric models based on the LIBS measured composition of paper bulk or surface, obtaining up to 100 % correct classification for six similar copy papers of Italian manufacture.</div></div>","PeriodicalId":21890,"journal":{"name":"Spectrochimica Acta Part B: Atomic Spectroscopy","volume":"224 ","pages":"Article 107112"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143103860","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancement mechanisms analysis using microwave plasma torch-assisted laser-induced breakdown spectroscopy","authors":"Shujia Wu ,&nbsp;Zhihang Lai ,&nbsp;Chen Yang ,&nbsp;Juhao Yue ,&nbsp;Xiyan Duan ,&nbsp;Lei Li ,&nbsp;Zhihang Cui ,&nbsp;Bingyu Wei ,&nbsp;Shaohua Sun ,&nbsp;Bitao Hu ,&nbsp;Zuoye Liu","doi":"10.1016/j.sab.2024.107110","DOIUrl":"10.1016/j.sab.2024.107110","url":null,"abstract":"<div><div>Laser-induced breakdown spectroscopy (LIBS) has been extensively applied across various fields for elemental analysis, due to its rapid, in-situ, and multi-element detection capabilities. However, its application is often constrained by matrix effects and the weak signal intensity of emission spectra, particularly in the detection of irregular targets and (ultra-)trace elements. To address these challenges, this study introduces an approach to enhance LIBS spectral signal intensity through the assistance of a microwave plasma torch (MPT). Using a pure silicon target, the research systematically examines the primary mechanisms by which MPT influences laser-induced plasma under different laser energy conditions and identifies the sources of signal enhancement, resulting in significant improvements in LIBS spectral intensity. The MPT-assisted enhancement was further validated using an aluminum alloy target, confirming that the effect is non-selective and can significantly improve the LIBS signals for both metallic and non-metallic targets. Overall, by creating an environment that combines the benefits of flame, microwave, and argon gas (Ar), MPT effectively reduces the demands on target surface quality and minimizes target damage during LIBS analysis. This approach offers superior signal enhancement compared to single enhancement methods, positioning MPT as a promising re-excitation strategy in LIBS applications. This capability makes it possible to integrate MPT with compact laser systems, thereby advancing the use of LIBS technology for in-situ and online detection in field or harsh environments.</div></div>","PeriodicalId":21890,"journal":{"name":"Spectrochimica Acta Part B: Atomic Spectroscopy","volume":"224 ","pages":"Article 107110"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143103862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Selective extraction and determination of trace metals by magnetic covalent organic frameworks with abundant thione and secondary amine groups coupled with ICP-MS","authors":"Yinzhong Gao ,&nbsp;Heping Jiao ,&nbsp;Zhenhua Wang ,&nbsp;Jingbo Chao ,&nbsp;Jian Li ,&nbsp;Ligang Hu ,&nbsp;Shengxiao Zhang ,&nbsp;Jing Sun","doi":"10.1016/j.sab.2024.107115","DOIUrl":"10.1016/j.sab.2024.107115","url":null,"abstract":"<div><div>A core-shell magnetic covalent organic frameworks (MCOF-SN) nanocomposite with high adsorption capacity was prepared by simply and directly coating covalent organic frameworks with abundant thione and secondary amine groups on the surface of magnetic nanoparticles, which were used to selectively extract copper (Cu²⁺), cadmium (Cd²⁺), lead (Pb²⁺), cobalt (Co²⁺) and nickel (Ni²⁺) ions prior to the detection by ICP-MS. The prepared magnetic covalent organic frameworks have high adsorption capacity of 52, 65, 162, 34 and 42 mg g⁻¹ for Cu²⁺, Cd²⁺, Pb²⁺, Co²⁺ and Ni²⁺ ions, respectively. The analytical parameters affecting magnetic solid-phase extraction (MSPE) of metal ions were optimized. They were pH of sample, 4–5; eluent, 1 mL of 1 % (<em>v</em>/v) HNO₃; amount of adsorbent, 15 mg; and sample volume, 200 mL. Under optimal experimental conditions, the limits of detection (LODs) of Cu²⁺, Cd²⁺, Pb²⁺, Co²⁺ and Ni²⁺ ions for water are 0.26, 0.16, 0.25, 0.08 and 0.17 ng L⁻¹ with enrichment factors of 192, 191, 196, 188 and 190, and their relative standard deviations (RSD) were less than 5 % (20 ng L⁻¹, <em>n</em> = 3), respectively. The LODs for Chinese herbal medicine samples were 0.52, 0.32, 0.50, 0.16 and 0.34 μg kg⁻¹ based on 0.100 g sample, respectively. The proposed MSPE-inductively coupled plasma mass spectrometry (MSPE-ICP-MS) method with simple operation, high sensitivity and high anti-matrix interference ability has been successfully applied to the samples with complicated matrices, such as water and Chinese herbal medicine.</div></div>","PeriodicalId":21890,"journal":{"name":"Spectrochimica Acta Part B: Atomic Spectroscopy","volume":"224 ","pages":"Article 107115"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143103865","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An accurate interface detection of TBCs coated blades by double pulse femtosecond laser-induced breakdown spectroscopy","authors":"Zhao Xu,&nbsp;Lan Jiang,&nbsp;Sumei Wang,&nbsp;Jiaxin Sun,&nbsp;Jie Zhan,&nbsp;Weihua Zhu","doi":"10.1016/j.sab.2024.107088","DOIUrl":"10.1016/j.sab.2024.107088","url":null,"abstract":"<div><div>To control the laser machining process of cooling holes on thermal barrier coatings (TBCs) deposited on turbine blades, we implemented interface detection in the depth direction by employing femtosecond-laser-induced breakdown spectroscopy (fs-LIBS). With the plasma reheating and reionization effects of double pulses, a maximum spectral enhancement factors of 12.5 was obtained. The signal-to-noise ratio of the spectrum was improved with decreasing the ablation volume. As a result, accurate detection of the interfaces between the yttria-stabilized zirconia (YSZ) coating, Ni-based superalloy substrate and glass slide was achieved. The comparison of the LIBS results with the energy-dispersive X-ray spectroscopy (EDS) confirmed the effectiveness of the detection method, which exhibited a minimum ablation rate of 255 nm per pulse. Furthermore, a practical online detection approach was proposed for depth profiling and breakdown detection during the machining process of multilayer materials with a maximum detection depth of 273 μm.</div></div>","PeriodicalId":21890,"journal":{"name":"Spectrochimica Acta Part B: Atomic Spectroscopy","volume":"224 ","pages":"Article 107088"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Machine learning-based novel approach of image analysis in LIBS elemental mapping for discriminating archeological human bone","authors":"Doaa Youssef ,&nbsp;Vincent Motto-Ros ,&nbsp;Mohamed Abdel-Harith","doi":"10.1016/j.sab.2024.107108","DOIUrl":"10.1016/j.sab.2024.107108","url":null,"abstract":"<div><div>Recovering individuals from commingled remains is a common issue for bioarcheologists and human paleontologists. Human bones and teeth are the most durable and well-preserved remains in mass graves. They contain major, minor, and trace elements related to dietary habits, diseases, and environment. However, due to postmortem and burial conditions, archaeological bones lose some of their tensile strength and organic constituents and are impacted by diagenesis. Moreover, the elements' distribution and concentration vary within a single bone. This study introduces a novel non-destructive method for characterizing and classifying commingled human bone remains of individuals from different ancient Egyptian dynasties using multi-elemental laser-induced breakdown spectroscopy (LIBS) mapping. The LIBS maps are constructed from fresh spots on the bone surface on a 100 × 300 matrix with 25 μm spatial resolution for elements related to biogenic signals with no influence from postmortem alterations. Then, we address the minimum number of pixel-to-pixel LIBS measurements needed to compensate for the heterogeneous nature of the bone samples by conducting various experiments. A new image analysis methodology is also proposed to capture the statistical information of the LIBS maps. This method combines LIBS maps with a stationary wavelet transform to generate a more informative composite image. Then, a set of spatial and texture-based features are extracted from the LIBS fusion images and fed to different machine learning algorithms like support vector machine (SVM), k-nearest neighbor (kNN) motivated by ensemble learning, and corrective boosting (TotalBoost) to develop the classification models. The results indicate, for the first time, the capability of the LIBS mapping-based image analysis technology to identify individuals from commingled human remains that show promise for the bioarchaeology and forensic osteology domains.</div></div>","PeriodicalId":21890,"journal":{"name":"Spectrochimica Acta Part B: Atomic Spectroscopy","volume":"224 ","pages":"Article 107108"},"PeriodicalIF":3.2,"publicationDate":"2025-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143094318","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Applicability of high sensitivity cone combination for precise measurement of 87Sr/86Sr and δ88/86Sr using MC-ICP-MS","authors":"Tomoko Ariga ,&nbsp;Ki-Cheol Shin ,&nbsp;Tomohiro Narukawa","doi":"10.1016/j.sab.2025.107134","DOIUrl":"10.1016/j.sab.2025.107134","url":null,"abstract":"<div><div>The applicability of a high sensitivity cone combination (Jet sample and X skimmer cones; hereafter “Jet/X”) for high-precision measurements of Sr isotope ratios was evaluated via a Neptune Plus multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) system (Thermo Fisher Scientific Inc.) under wet plasma conditions. Although Jet/X has effectively achieved highly precise and sensitive measurements of isotope ratios for various elements (e.g., Li, B, Cu, Hf, and U), its applicability for Sr has not been adequately evaluated. In this study, the sensitivity, accuracy, and precision of measurements, the extent of mass fractionation that occurs in MC-ICP-MS, and the behavior of spectral interference from a concomitant element (i.e., Ca) in ⁸⁷Sr/⁸⁶Sr and δ⁸⁸/⁸⁶Sr measurements using Jet/X were compared with those of a conventional cone combination (standard sample and H skimmer cones; hereafter “Standard/H”). Jet/X improved the signal sensitivity of ⁸⁸Sr by a factor of four, which enabled measurements at lower Sr concentrations (i.e., 50 μg kg⁻¹) with comparable reproducibility to that of measurements of 200 μg kg⁻¹ Sr using Standard/H. Measured ⁸⁷Sr/⁸⁶Sr and δ⁸⁸/⁸⁶Sr of the Sr isotopic standard (i.e., NIST SRM 987) using Jet/X were consistent with those using Standard/H, literature data, and theoretical values. With Jet/X, the magnitude of mass-dependent fractionation within MC-ICP-MS was smaller than that with Standard/H. No significant difference in the magnitude of Ca-induced spectral interference was observed between Jet/X and Standard/H at Ca/Sr concentration ratios of ≤10. Finally, the applicability of Jet/X to matrix-type samples was confirmed by measuring the ⁸⁷Sr/⁸⁶Sr and δ⁸⁸/⁸⁶Sr of standard reference materials, JCp-1 and FEBS-1.</div></div>","PeriodicalId":21890,"journal":{"name":"Spectrochimica Acta Part B: Atomic Spectroscopy","volume":"225 ","pages":"Article 107134"},"PeriodicalIF":3.2,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143369656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ensemble-learning for pressure prediction in vacuum circuit breaker using feature fusion of laser-induced plasma spectra and images","authors":"Wei Ke ,&nbsp;Jianbin Pan ,&nbsp;Huan Yuan ,&nbsp;Xiaohua Wang ,&nbsp;Dongzhi Zhang ,&nbsp;Mingzhe Rong","doi":"10.1016/j.sab.2025.107137","DOIUrl":"10.1016/j.sab.2025.107137","url":null,"abstract":"<div><div>The detection of vacuum level using laser-induced plasma shows a great potential for safe and reliable online monitoring of vacuum level on vacuum interrupter. However, traditional methods often rely on a single type of plasma signal (spectra or image), which leads to relatively low accuracy. To tackle it, this paper employs ensemble learning to fuse plasma spectra and images to construct a regression model using Gradient Boosting Regression (GBR), Multilayer Perceptron Regression (MLP), Support Vector Regression with Radial Basis Function (SVR-RBF), and Linear Regression (LR). The model consists of <strong><em>Image prediction module</em></strong>, <strong><em>Spectra prediction module</em></strong>, and <strong><em>Ensemble learning module</em></strong>. In the first two modules, the base models predict pressure based on images and spectra, respectively. The predictions are then stacked in <strong><em>Ensemble learning module</em></strong> and fed into LR for final pressure prediction. The results indicate that the base models within the <strong><em>Image prediction module</em></strong> and <strong><em>Spectra prediction modules</em></strong> can predict pressure; however, their prediction errors are significantly greater than those of <strong><em>Ensemble learning module</em></strong>. The prediction errors and evaluation parameters reveal that ensemble learning, in combination with feature fusion, effectively reduce the prediction errors, and significantly enhance predictive performance of model. More importantly, the Limit of Quantification (LOQ) of this method reaches 10⁻⁵–10⁻⁴ Pa, meeting the requirements of the electric power industry standards. A beneficial exploration has been conducted on the application of vacuum level detection based on laser-induced plasma.</div></div>","PeriodicalId":21890,"journal":{"name":"Spectrochimica Acta Part B: Atomic Spectroscopy","volume":"226 ","pages":"Article 107137"},"PeriodicalIF":3.2,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143377706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Exploring the boundaries of double excitation in TXRF","authors":"Heiko S. Till ,&nbsp;Armin Gross ,&nbsp;Ursula E.A. Fittschen","doi":"10.1016/j.sab.2025.107138","DOIUrl":"10.1016/j.sab.2025.107138","url":null,"abstract":"<div><div>Double excitation is an established concept in <strong>T</strong>otal-Reflection <strong>X</strong>-<strong>R</strong>ay <strong>F</strong>luorescence Analysis (TXRF) and one of the key advantages of TXRF over common XRF methods. It is realized by setting the incident angle of the excitation beam to an angle below the critical angle of total reflection of the reflector material (<em>e.g.</em> Si wafers or quartz glass), external total reflection can take place. Consequently, the excitation beam can excite the sample prepared on the reflector twice: once by the incoming beam, and once by the reflected beam. Are there boundaries to this concept however? One obvious boundary is the realm of the <strong>X</strong>-Ray <strong>S</strong>tanding <strong>W</strong>ave Field (XSW) that leads to oscillating excitation conditions in the nanometer range above the reflector surface, this may be identified as a “lower” boundary. Here however, the authors study an “upper” boundary for specimens in the micrometer range. This “upper” boundary was probed with binary mixtures of Ni and Ga with metal masses between 300 and 10,000 ng. These sample masses translate into dried sample residues with heights of about 5 to 100 μm and widths of up to several hundred μm. Using laboratory based angle-resolved (T)XRF two distinct deviations from the angle dependent double excitation were observed. A fundamental parameter model was created to give comprehensive insights into the why and wherefore of this “upper” boundary. This includes the approximation of the sample 3D shape, excitation geometry, reflectivity of the sample carrier and matrix effects. The model suggests that sample widths of several hundred micrometers induce a dampening of double excitation, <em>i.e.</em> only a relative signal intensity of <em>approx.</em> 1.75 is observed below the critical angle instead of twice the intensity (both relative to large angles above the critical angle). Furthermore, heights above several ten micrometers lead to an angle-dependency of the signal intensity with a maximum just below the critical angle, due to insufficient illumination of the sample by the reflected beam.</div></div>","PeriodicalId":21890,"journal":{"name":"Spectrochimica Acta Part B: Atomic Spectroscopy","volume":"225 ","pages":"Article 107138"},"PeriodicalIF":3.2,"publicationDate":"2025-01-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143369595","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}