Journal of Analytical Atomic Spectrometry最新文献

This study presents a new procedure for high-precision Sm isotope analysis by thermal ionisation mass spectrometry (TIMS) for geological samples. A four-step chemical separation scheme results in sharp separation of Sm and Nd from the same sample aliquot. The first step utilises anion exchange resin to remove Fe from the sample solution. Two different liquid–liquid extraction resins are then used to isolate rare-earth elements (TRU-Spec) and purify Sm from Nd (DGA). Fractionation occurs on the DGA resin due to the nuclear field shift effect, but this is negligible if yields greater than 70% are achieved. Different analytical setups were tested to ascertain their ionisation efficiencies on TIMS. The effect of activators composed of Pt and Ta was tested on single Re filaments but the conventional double Re filament assembly provided efficient ionisation and more stable ion beams. The determination of nucleosynthetic isotope variations requires high precision for all Sm isotope ratios. We aimed to improve the precision on the scarce ¹⁴⁴Sm isotope (3% of all Sm). Static, multistatic and dynamic methods were tested. Isotope ratios were normalised to both ¹⁴⁷Sm/¹⁵²Sm and ¹⁵²Sm/¹⁴⁸Sm for comparison. The dynamic methods failed to provide better precision on ratios involving ¹⁴⁴Sm, whereas the multistatic method yielded improved precisions between 13 and 22 ppm (twice the standard deviation, 2 SD) on the ¹⁴⁴Sm/¹⁵²Sm ratio. Synthetic standards have variable Sm isotope compositions, thus requiring systematic and precise characterisation against terrestrial samples. Analyses conducted using this new procedure yielded high-precision values which were consistent with literature data for an array of terrestrial rock standards and the meteorite Allende.

Wall paintings from the world heritage site Petra-Jordan contain gilding remnants, which show various types of degradation. To investigate the deterioration processes as well as assess the conservation treatment, non-destructive (ND) and non-invasive (NI) analyses of the chemical species of gold are mandatory. In this work, simultaneous multi-angle angle-resolved X-ray absorption near-edge spectroscopy (AR-XANES) measurements were performed to assess gold species variations in depth. Experimental validation proved the method to be successful in differentiating between gold species in nanolayered structures. Technical advantages and limitations of the method are discussed. The application of a conservation material containing Nano Gold Gel (NGG) applied underneath a gold layer to regenerate adhesion with its support layer was also examined.

Single particle inductively coupled plasma-mass spectrometry (SP ICP-MS) has evolved into one of the most powerful techniques for the bottom-up characterisation of nanoparticle suspensions. The latest generation of time-of-flight mass analysers offers new perspectives on single particles by rapidly collecting full mass spectra and providing information on particle composition and abundances, even in unknown samples. However, SP ICP-TOFMS is associated with vast and complex data, which can hamper its applicability and the interrogation of specific particle features. Unlocking the full potential of SP ICP-TOFMS requires dedicated, easy-to-use software solutions to navigate through data sets and promote transparent, efficient and precise processing. SPCal is an open-source SP data processing platform, which we have previously released for quadrupole-based data. In this work, we expand its reach by additionally enabling the analysis of TOF-based SP data sets. We have incorporated various tools to facilitate the handling, manipulation and calibration of large data sets and provide the required statistical fundament and models to promote accurate thresholding. Non-target screening tools are integrated to pinpoint particulate elements in unknown samples without the requirement for a priori investigations or modelling. Next to basic functions like the calibration of size and mass distributions, methods to carry out cluster analysis (PCA, HAC) provide the means to study groups of particles based on their composition and conditional data filtering allows the interrogation of particle populations by selectecting specific features.

To gain a deeper understanding of how the size of the nanoparticles synthesized by Electric Field-Assisted Laser Ablation in Liquids (EFLAL) changes with the applied electric field, we use Laser-Induced Breakdown Spectroscopy (LIBS) and a Beam Deflection Set-up (BDS). These tools help us examine how the electric field strength affects the plasma parameters and the bubble dynamics. The findings show that the electron density and plasma temperature are perturbed as the electric field strength can alter the interaction region. The strength of the electric field can cause the bubble size to increase, which also elevates its pressure and temperature. These alterations at the breakdown region lead to changes in the size, properties, and production of the Mn₂O₃ nanoparticles. Thus, the interplay of laser plasma and fluid-assisted bubble phenomena in the presence of an electric field is probed for Mn₂O₃ nanoparticles thereby optimizing as UV emitters.

Safe operation of next-generation nuclear reactors is contingent on developing and effectively operating new diagnostics methods. For helium-cooled fast reactors, one important safety concern is the onset of fuel-cladding failure, which could be detected from the increased concentration of mobile fission fragments such as xenon in the helium coolant. In a previous study [Burger et al., JAAS, 2021, 36, 824], we demonstrated that laser-induced breakdown spectroscopy (LIBS) is a viable candidate for sensitive xenon detection in helium, offering a limit of detection on the order of 0.2 μmol mol⁻¹ for 10⁴ laser shots. Here, we demonstrate that double-pulse LIBS enhances the xenon signal by approximately 14× at a concentration of 1 μmol mol⁻¹ in an ambient helium environment, which results in significantly improved sensitivity. Additionally, we examine the effect of relative energy in two laser pulses, interpulse delay, and laser polarization on the xenon signal enhancement. These results further motivate the development of LIBS sensors for this application.

Previous studies have reported that even low concentrations of Sn can lead to biased Cd isotopic measurements using MC-ICP-MS. In this paper, we propose a novel method of Cd isotopic analysis involving use of a ¹⁰⁶Cd–¹¹¹Cd double spike. To eliminate isobaric interference from ¹¹⁴Sn, we use ¹¹³Cd together with ¹⁰⁶Cd, ¹¹⁰Cd, and ¹¹¹Cd to obtain δ^113/110Cd, and then calculate δ^114/110Cd as 1.33 × δ^113/110Cd. We find that when Sn/Cd is ≤2.5 in sample solutions, δ^114/110Cd values are not affected by Sn, which behaves as a matrix element rather than causing isobaric interference. Cd isotopic measurements are not sensitive to the molarities of diluted HNO₃ or the Cd concentration. Additionally, when Mo/Cd, Ni/Cd, and Se/Cd are ≤1 in sample solutions, Cd isotopic measurements are not significantly affected. Instead, when Zn/Cd is >0.1, In/Cd > 0.05, and Pd/Cd > 5 × 10⁻³, the measured δ^114/110Cd values deviate significantly from zero. However, Zn and In can be eliminated completely, and Pd was not detected in any Cd eluents. The δ^114/110Cd values of three standard solutions (Spex-CUGB, BAM I012, and Münster) and four geochemical reference materials (SGR-1b, BCR-2, GSD-7a, and NIST 2711a) were measured and found to be in close agreement with published results (with 2SD and ranges for all data of less than 0.090 and 0.120, respectively). This indicates that the data obtained by our double spike method are precise and reliable. Additionally, our new technique can help to simplify separation procedures, thus saving time and reducing the quantities of acid required.

Laser-Induced Breakdown Spectroscopy (LIBS) is a versatile and powerful analytical technique widely used for rapid, in situ elemental analysis across various fields, from industrial quality control to planetary exploration. This review addresses the critical aspects and emerging trends in LIBS, focusing on calibration challenges, integrating complementary techniques (data fusion), and applying data science for spectral analysis. Calibration is a fundamental challenge in LIBS due to matrix effects, signal drift, and variations in experimental conditions. Recent advancements aim to develop matrix-independent calibration models and employ machine learning algorithms to improve calibration accuracy and robustness. LIBS has also proven invaluable in space exploration, particularly on Mars. Instruments like ChemCam and SuperCam have successfully utilized LIBS to perform real-time chemical analysis of the Martian surface, providing critical insights into its composition and history. The review further explores the advancements in multivariate calibration techniques for handling complex and multi-component systems. Techniques such as Partial Least Squares (PLS) regression and Principal Component Analysis (PCA) are increasingly employed to address the high dimensionality of LIBS data, enhancing the precision and reliability of the analysis. In addition, combining LIBS with other instrumental analytical techniques expands its analytical capabilities. Data fusion strategies integrating LIBS with techniques like Raman spectroscopy, X-ray fluorescence (XRF), and hyperspectral imaging provide a more comprehensive understanding of material composition. These integrated systems, supported by sophisticated data fusion algorithms, offer unprecedented insights and accuracy. Finally, applying data science in LIBS transforms spectral inspection and analysis. Machine learning and deep learning methods are being adopted to automate and enhance the processing and interpretation of LIBS spectra, uncovering complex patterns and improving analysis accuracy. The future lies in leveraging big data analytics and real-time processing to address more complex analytical challenges. In conclusion, LIBS is evolving rapidly, driven by advancements in calibration methods, techniques integration, and data science. This review highlights the potential of LIBS to continue pushing the boundaries of material analysis and its significant contributions to diverse scientific and industrial fields.

The iodine-to-calcium ratio (I/Ca) in carbonate rocks has been extensively used to indicate marine oxidation states. However, the low-iodine and high-calcium characteristics of carbonate samples pose challenges in achieving rapid and accurate determination of I/Ca. In this study, we have developed a solution cathode glow discharge (SCGD) sampling technique coupled with inductively coupled plasma mass spectrometry (ICP-MS) for highly sensitive and accurate determination of I/Ca in low-iodine carbonate samples. The proposed method takes full advantage of the high-efficiency vapor generation of iodine and the inefficient introduction of calcium by SCGD, thereby significantly enhancing the sensitivity for iodine measurement and reducing matrix interference. In addition, it enables the simultaneous determination of I and Ca even in high-calcium samples. Compared to conventional pneumatic nebulization sampling, the SCGD sampling method demonstrated a 100-fold sensitivity improvement for iodine determination, while Ca sensitivity was reduced by a factor of 70. The effect of operating parameters and reaction conditions on the signal intensities was investigated. Under optimized conditions, the iodine detection limit was as low as 0.9 pg g⁻¹ for carbonate samples. Finally, the validity of the method was verified through the analysis of standard reference samples, actual carbonate rocks, and simulated samples. The results conclusively demonstrate that our developed method offers a simple, sensitive, and rapid approach for accurately measuring the I/Ca ratio in carbonate rocks, thereby facilitating broader application of the I/Ca indicator.

Soil is a vital resource for human survival. In particular, aluminum (Al) and iron (Fe) metal elements in soil play significant roles in stabilizing soil organic matter. Therefore, the rapid and effective detection of Al and Fe elements in soil is imperative. Compared with conventional elemental detection techniques, laser-induced breakdown spectroscopy (LIBS) has emerged as a pivotal method for soil detection because of the advantages of simultaneous detection of multiple elements, rapidity and environmental friendliness. However, the LIBS signal of trace metal elements remains to be enhanced due to some influencing factors like the soil matrix effect. Hence, this study introduces a magneto-electrical fusion soil LIBS signal enhancement device, through an investigation into the impacts of magnetic field strength, energization, and magneto-electric fusion on the LIBS signals of Al and Fe in soil. Examining the single-factor effects of magnetic field strength and energization on soil LIBS signals, enhancements were observed in the spectral intensity (SI), signal to background ratio (SBR), plasma electronic temperature (PET), and plasma electronic density (PED) for soil Al and Fe elements compared to those observed with the unenhanced LIBS technique. According to the results of two-factor analysis of variance (ANOVA), the cost of the study and the safety of use, the appropriate magnetic field strength and energizing voltage were selected, respectively, to be 110 mT and 12 V. The magneto-electrical fusion LIBS signal enhancement device was designed based on the above results of the study in terms of operational reliability, ease of operation, safety and economy. It mainly included a base module, a support module and an enhancement module. For the designed device performance, validation was carried out in terms of parameters and applications, respectively. For parameter validation, the fusion enhancement device realized the enhancement of soil LIBS signals in 4 different areas. For application validation, the soils originating from 4 different regions were subjected to discriminant analysis. Comparative analysis with the original LIBS technique revealed significant enhancement in the performance of the soil origin discrimination model facilitated by the fusion enhancement device. This study provides support for the development of efficient techniques and equipment for soil element detection in farmland, as well as a theoretical basis for high-quality agricultural production.

The use of microjoule high pulse repetition frequency (PRF) lasers as excitation sources is an important direction in the miniaturisation of laser-induced breakdown spectroscopy (LIBS) instruments. However, high PRF LIBS is sensitive to experimental parameters, and the relationship between the experimental parameters and the spectral intensity of high PRF LIBS is less studied. In this work, we present a model based on Gaussian spot overlapping ablation with aluminium alloys as samples. After the index values have been collected in the non-motion state, the model derivation formula can be used to calculate the intensity of the spectral peaks under any proposed experimental parameters in the motion state. The experimental results show that the mean relative error (MRE) between the measured and predicted values of spectral peak intensity is ≤0.15 under different experimental parameters, and this result proves the validity of the model in predicting the spectral peak intensity. Meanwhile, we used 5 standard aluminium alloy samples to construct the standard curves of measured and predicted values under different experimental parameters. The experimental results show that the MRE between the measured and predicted values is ≤0.15, and the two standard curves fitted with the measured and predicted values have a high similarity with an average R² ≥ 0.85. This study is expected to provide a universally applicable and efficient method for the quantitative analysis of high PRF LIBS in different application scenarios.