• Editor in Chief:
    Prof. Xian-Hua Li
  • Executive Editor:
    Prof. Wei Guo
  • Associate Editors:
    Prof. Michael Dürr
    Prof. Wei Hang
    Prof. Zhaochu Hu

    Print ISSN:0195-5373
    Online ISSN: 2708-521X
    2023 SCIE IF: 3.4 (JCR, Q1)

          The ATOMIC SPECTROSCOPY is a peer-reviewed journal started in 1962 for PerkinElmer by Dr. Walter Slavin and now is published by Atomic Spectroscopy Press Limited (ASPL), Hongkong, P.R. China. It is intended for the rapid publication of both original paper and reviews in the fields of AAS, AFS, XRF, LIBS, ICP-OES, ICP-MS, GD-MS, TIMS, SIMS, AMS, electron microscopy and energy spectroscopy related microbeam analysis techniques, and Synchrotron radiation related technology,etc. Manuscripts dealing with (i) fundamentals & instrumentation development, (ii) novel methodology development & applications, (iii) sample preparation related technology, and (iv) standard reference materials development, can be submitted for publication. All published papers can be downloaded freely from the journal official website (www.at-spectrosc.com), and authors are not required to pay any publication fees (or APC).

     

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      Abstract:
      Achondrites are igneous rocks originating from terrestrial planets or differentiated asteroids, and they preserve crucial insights into planetary differentiation and evolution. However, distinguishing achondrites from terrestrial igneous rocks remains challenging due to their striking similarities. Developing a convenient, non-destructive identification technique is essential for improving the efficiency and accuracy of field meteorite searches and museum curation. This study utilizes 64 meteorite samples analyzed by handheld energy-dispersive X-ray fluorescence (HH-ED-XRF) and 1532 datasets from the literature to train a model that effectively differentiates Vesta, Martian, Lunar, and angrite meteorites from terrestrial rocks. Key parameters, including bulk rock major element compositions, Fe/Mn ratios, and Al?O?/(FeO+MgO) ratios, were used in the training process with Subspace K-Nearest Neighbor algorithm. The model achieved an overall accuracy of 95%. This technique provides intelligent and non-destructive identification of achondrites in the field, significantly enhancing the efficiency and accuracy of meteorite searches. Its applications extend from museum meteorite collection curation to field searches of meteorites in hot and cold deserts.
      2025,46(2),99-108
      DOI: 10.46770/AS.2024.286
      Abstract:
      A rapid bioassay method for transuranium radionuclides (Np, Pu, Am and Cm) in urine is needed to quickly assess the potential internal contamination in a radiological and nuclear emergency event. In this work, an automated analytical method in combination with the tandem quadrupole inductively coupled plasma-mass spectrometry (ICP-MS/MS) and sequential chromatographic separation by TK200 resin and DGA resin was developed. The chemical behaviors of Np and Pu on TK200 resin and those of Am and Cm on DGA resin using the column of Φ 0.4 × 8 cm were very consistent in 8 mol/L HNO3 + 0.02 mol/L NaNO2 media. The high U decontamination factor of 2.51 × 105 was achieved by using a single TK200 columns. The sensitivity of transuranium radionuclides was improved and the interferences from matrix elements (U, Bi, Pb, Hg and Tl) can be efficiently eliminated in He-O2 mode even if the eluate was directly measured by ICP-MS/MS. The elimination efficiency of 238U+ tailing (<1 × 10-9) and 238UHO2+/238UO2+ of <1 × 10-7 were achieved using 11.0 mL/min He?0.4 mL/min O2. The detection limits for all transuranium radionuclides were at femtogram level in 50 mL urine sample, and the analytical results for spiked samples showed a good agreement with the expected values, thereby demonstrating its feasibility of the ICP-MS/MS for rapid transuranium radionuclides analysis at femtogram levels in urine.
      2025,46(2),109-118
      DOI: 10.46770/AS.2025.005
      Abstract:
      Before LIBS can be applied to analysis at mine sites under normal weather conditions, a number of practical issues need to be addressed. One of these is the moisture content of rock samples taken directly in the field. To assess the effect of rock moisture content on LIBS measurements, we studied its temporal evolution as the rock dried under ambient laboratory conditions using a series of 1080 laser shots (18 rows × 60 columns) at 2 Hz (8 ns pulse duration, 1064 nm wavelength, with a fluence of ~4 kJ cm-2). At maximum moisture, the LIBS spectra are weak, with only a few strong lines emerging from the background noise, while a richer spectrum appears as the rock dries. Color maps of LIBS spectra averaged over wavelength (white light) from the rock surface and net Hα line intensity from the water layer form complex, weakly correlated mosaics whose components depend on local rock properties (e.g., composition, porosity, asperities). However, the time evolution of their average over each of the 18 rows correlates well with that of the rock weight and microwave moisture measurements. Using the Hα line broadening and the ratio between the Mg II 280.27 nm and Mg I 285.21 nm line, the space and time averaged plasma produced in both the dry and wet rock areas is characterized by an electron number density in the range of 1017 cm-3 and an ionization temperature close to 1 eV. The physical mechanisms involved are discussed. This study highlights the importance of controlling the moisture of the rock at the mining site before starting LIBS measurements, as it has a significant impact on the accuracy of the results obtained.
      2025,46(2),119-131
      DOI: 10.46770/AS.2025.055
      Abstract:
      Lunar impact glass beads are the products of meteorite impacts into lunar surface materials. While most beads exhibit compositions matching local regolith, some display significant geochemical anomalies, traditionally attributed to either ballistic transport of exotic materials or excavation of underlying rocks. However, such explanation neglects potential compositional biases introduced during the formation of impact glass beads. Incomplete homogenization of impact melt prior to ejection could induce larger deviations from bulk melt chemistry in smaller droplets, thereby leading to increased chemical variability in smaller beads. In this study, the major-element compositions and sizes of 635 homogeneous glass beads, along with trace-element compositions of 56 beads from the Chang’e-5 (CE-5) soil, were determined. The Kullback-Leibler divergence (KLD) was employed to quantify the dissimilarity between the compositional distributions of individual glass beads and the CE-5 regolith. KLD analysis of CE-5 basalt fragments and individual minerals relative to the CE-5 regolith reveal those materials with KLD > 0.1 exhibit significant chemical composition differences from CE-5 regolith. Glass beads with diameters > 100 μm and KLD < 0.1 have the major- and rare earth- element compositions similar to the local CE-5 regolith. Of the 4 glass beads with diameters > 100 μm and KLD > 0.1, three are interpreted as being exotic to the CE-5 region and one was derived from impact melting of underlying cumulates near the base of the local basaltic lava flows. In contrast, glass beads with diameters < 100 μm exhibit a large range of chemical compositions. Among the 32 glass beads with diameters < 100 μm and KLD > 0.1, 9 originated from the impact melting of single-mineral-enriched components in local regolith, including 5 primarily composed of pyroxene, two of ilmenite, one of plagioclase, and one primarily of mesostasis assemblage. Only 14 were identified as exotic glass beads in these 32 glass beads. These results indicate that smaller impact glass beads exhibiting significant compositional deviations from local regolith are not necessarily from exotic sources, as sampling bias. The sizes of impact glass beads should be considered when using their chemical compositions to infer local and regional characteristics of the Moon.
      2025,46(2),132-141
      DOI: 10.46770/AS.2025.008
      Abstract:
      Energy dispersive X-ray fluorescence spectrometry has been widely used for the analysis of trace and minor elements in applications that extend from biomedical to environmental assessment, due to its non-destructive nature, rapid analysis and suitable detection limits. However, EDXRF quantification is frequently hampered by matrix effects, introducing significant inaccuracies in the obtained results. In this work, we present an automated methodology for sample matrix determination using EDXRF spectra, leveraging on the analysis of the Compton and Rayleigh peaks of the characteristic lines of the X-ray tube anode. First, a model was created to fit these scattering peaks, allowing the plotting of a calibration curve that correlated the Compton-to-Rayleigh ratio with the average atomic number (Z) of the sample. Matrix composition was quantified using a developed algorithm combining support vector regression (SVR) and bootstrapping to optimize the determination of the best matrix composition. SVR with a Radial Basis Function kernel was applied to handle non-linear data, and Bootstrapping was utilized to train the algorithm, enhancing model generalization. The study demonstrates that the developed algorithm and matrix-based approach effectively quantified elemental compositions across various certified reference materials (CRMs). The chosen Matrix provided more accurate results, especially for heavier elements like Fe, Cu, and Zn, while deviations of around 20% were observed for lighter elements in biological matrices. In geological samples like phosphate rock and clay, heavier elements aligned well with reference values, but trace elements like Cu and Ni showed larger deviations due to low concentrations. Despite discrepancies for some elements like Pb in wood, the methodology proved effective, particularly for elements like Cr with minimal deviation, highlighting its versatility across diverse matrices. The methodology successfully integrated computational tools and open-source libraries to establish a reliable, efficient workflow for average atomic number determination and spectral analysis, achieving strong agreement with reference materials.
      2025,46(2),142-150
      DOI: 10.46770/AS.2025.018
      Abstract:
      Accurate quantification of total soil carbon (C) is challenging because of the complex composition of soil samples, which include varying levels of organic matter, oxides of Al and Fe, and diverse soil textures. These factors introduce variability and spectral interference, which hinder the measurement accuracy. In laser-induced breakdown spectroscopy (LIBS), the key C emission lines often overlap with those of Al and Fe, complicating the development of reliable calibration models. This study presents a comprehensive machine learning approach for total C quantification using LIBS data. It integrates emission lines identified through the SHapley Additive exPlanations (SHAP) algorithm and literature insights with spectral preprocessing techniques such as baseline correction, peak fitting, and peak area calculations. Although the SHAP algorithm effectively identified crucial emission lines, expert knowledge was vital in refining variable selection and excluding irrelevant data. Two datasets were utilized: one containing 1019 Brazilian soil samples representing various soil types and textures, and another containing 387 samples collected later that served as an external test set. The first dataset was divided into 713 samples for model training and 306 samples for validation. The external test set was used to evaluate the reproducibility and stability of the model. The integration of expert knowledge and machine learning produced a highly efficient model that reduced the number of variables without compromising accuracy. Among the tested algorithms, the Extra Trees regression model excelled, achieving R2 values of 0.74, 0.74, and 0.72 for the training, validation, and external test sets, respectively, with root mean square error values of 5.1, 5.1, and 5.0 g kg?1 of total C. This approach outperformed previous machine learning models in terms of accuracy and adaptability, demonstrating its potential applicability beyond soil analysis. This study highlights a pathway for creating robust predictive models across various domains by combining machine learning, spectral processing, and expert insights.
      2025,46(2),151-160
      DOI: 10.46770/AS.2025.054
      Abstract:
      In-situ microanalytical lithium isotope techniques like laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) are powerful geochemical tools that help study crust-mantle material cycling, silicate weathering, and crustal hydrothermal processes. This work enhances lithium isotope measurement methods in lepidolite by developing a matrix-matched reference material. Natural lepidolite powders were first ground into ultra-fine particles using a planetary ball mill and then rapidly sintered at 700°C and 50 MPa for 10 minutes using the fast hot pressing (FHP) technology. The synthesized lepidolite (NWU-LPD) has a smooth surface and dense structure suitable for laser ablation analysis. To assess its isotopic homogeneity, 285 spot analyses using LA-MC-ICP-MS yielded consistent values with an average δ?Li value of 8.74 ± 0.46‰ (2SD). This uniform lithium isotopic composition in NWU-LPD demonstrates its potential as a matrix-matched reference material for in-situ lithium isotope analysis in natural lepidolite. We also optimized laser settings and established a standard LA-MC-ICP-MS protocol using matrix-matched reference materials in lithium isotope analysis. Finally, solution-based MC-ICP-MS analyses determine a recommended reference δ?Li value of 8.70 ± 0.28‰ (2SD, n = 5) for NWU-LPD.
      2025(2),161-170
      DOI: 10.46770/AS.2025.015
      Abstract:
      Garnet has become a crucial mineral for constraining the timing of metamorphic and magmatic events due to its variable uranium content, low common Pb characteristics, and high U–Pb system closure temperature (> 850°C). Although Laser ablation multi-collector inductively coupled plasma mass spectrometry (LA-MC-ICP-MS) has been carried out on garnet U–Pb dating, its measurement accuracy remains constrained by matrix effects. This study introduces water vapor into garnet U–Pb dating and conducted comparative test under different laser spot sizes (15-50 μm), yielding the following findings: 1) The introduction of water vapor reduced signal intensity during U–Pb analysis of LA-MC-ICP-MS; 2) Under small spot sizes conditions (15 and 23 μm), water vapor significantly reduces Pb/U down-hole fractionation and enhances signal stability; 3) Normal ablation conditions with large spot size (50 μm) effectively overcome matrix effects, achieving optimal age dates deviation of ~ 3%; 4) Water vapor-assisted small spot sizes (15 and 23 μm) can also suppress matrix effects, yielding age dates deviation of ~ 4%. This study develops a water vapor-spot size synergistic method that enhances garnet non-matrix-matched calibration and enables micro-scale high-precision garnet U–Pb dating.
      2025,46(2),171-184
      DOI: 10.46770/AS.2025.009
      Abstract:
      Highly enriched 233U reference material is one of the most widely used isotopic spikes to measure uranium content by isotope dilution mass spectrometry (IDMS). Herein, the property values, uranium molarity and isotopic abundances, of a newly prepared highly-enriched 233U candidate reference material (n(233U)/n(U)>99%) were characterized according to ISO 33405:2024. The traceable IDMS method was applied to characterize uranium molarity in the 233U candidate reference material using a homemade 238U reverse spike, whose uranium molarity and isotopic abundances had been well-characterized and were traceable. Uranium isotope ratios were measured by thermal ionization mass spectrometry using the total evaporation method and corrected using a uranium isotopic certified reference material. The uncertainty budgets were performed based on ISO GUM guidelines. Relative expanded uncertainties (k=2) of 0.18% and 0.00061% for uranium molarity and isotopic abundance of 233U were achieved, comparable to those of some existing 233U certified reference materials. This characterization strategy with the IDMS method using a homemade traceable reverse spike has the advantages of less sample consumption and no requirement of a certified reverse spike. It is applicable to the precise and traceable characterization of 233U spikes with relatively low uranium concentration, which is beneficial for producing isotopic spikes with lower cost, shorter period, and lower radioactive waste production.
      2025,46(2),185-197
      DOI: 10.46770/AS.2025.012
      Abstract:
      The high background of Chlorine (Cl) signals in the carrier gas and the influence of apparent halogen signals have posed challenges for determining Cl content in apatite using Laser Ablation Inductively Coupled Plasma (quadrupole) Mass Spectrometry (LA-(Q)ICP-MS), which hinder simultaneous determination of U-Pb ages, trace element in apatite. In this contribution, we present an enhanced Cl content calibration method using Iolite software 3D Trace elements DRS. We analyzed six reference materials (RMs) at spot sizes of 44 μm, 32 μm, and 24 μm. The U-Pb ages (corrected against Madagascar apatite), and the trace element concentrations (calibrated using NIST SRM 610), respectively, were consistent with the recommended values. We thus compared two methods for calibrating Cl content: (1) using a single RM (Durango with analyzed Cl content) and (2) employing multiple RMs (Madagascar, Mud Tank, Durango, Otter Lake with Slyudyanka as monitor). The former method yielded Cl contents that deviated from Electron probe microanalyzer analysis (EPMA) results due to the "apparent halogen signal," while the latter provided consistent results across all spot sizes. As analytical uncertainties increase with smaller spot sizes, we recommend ≥44 μm spot size for routine analysis. Our findings suggest that combinations of Madagascar, Mud Tank, Durango, Otter Lake and NIST SRM 610 can be used to determine U-Pb ages, trace element concentrations, and Cl contents simultaneously using LA-(Q)ICP-MS, where Madagascar and NIST SRM 610 are recommend to corrected U-Pb age and calibrate trace element contents, respectively.
      2025,46(2),198-208
      DOI: 10.46770/AS.2025.051
      Abstract:
      The classification and recycling of alloys hold strategic significance in promoting sustainable development. Traditional LIBS technology has been widely used in factories for online analytical detection. However, most miniaturized handheld LIBS instruments, which are more suitable for factory applications, employ high pulse repetition frequency lasers. Nevertheless, due to its high sensitivity to operational parameters, this poses significant challenges to industrial production. This research tackles three critical challenges in high-speed LIBS analysis: speed-dependent intensity variations, overlapping alloy spectra, and rigid algorithmic processing. Our solution combines adaptive neural networks with spectral focusing mechanisms, tested on 21 industrial alloys (Cu, Al, Fe). Key findings show that faster scanning speeds (4 vs. 1 mm/s) intensify spectral signals through reduced laser defocusing, yet degrade traditional neural network accuracy to 78.00%. The developed dual-focus network maintains 93.95% classification accuracy at high speeds by learning speed-independent patterns and prioritizing critical emission lines, Ssuch as Mg I 285.2 nm and Fe Ⅱ 275.6 nm. Compared to conventional methods, this approach reduces prediction inconsistencies in high PRF LIBS spectra acquired at handheld-device movement speeds by 42.3%, while maintaining over 90% accuracy within the operational speed range of handheld devices used in practical industrial applications. This effectively addresses the challenges of identifying copper, aluminum, and iron alloys in dynamic LIBS environments.
      2025,46(2),209-220
      DOI: 10.46770/AS.2024.287
      Abstract:
      The δ98/95Mo values relative to NIST SRM 3134 and the molybdenum (Mo) mass fractions were determined for eleven rock and soil reference materials. Among them, GBW07109 (syenite), GBW07110 (trachyte), GBW07111 (granodiorite), GBW07113 (rhyolite), GBW07122 (amphibolite) and three soil reference materials GBW07401a, GBW07405a and GBW07407 were reported for the first time. A modified chemical separation method was employed, and isotopic measurements were conducted using MC-ICP-MS with a 97Mo-100Mo double spike for mass bias correction. Long-term reproducibility for NIST SRM 3134 was ±0.06‰ (2SD, n = 790), while the seawater standard (NASS-7) processed alongside samples showed a long-term external reproducibility of 0.05‰ (2SD, n = 64) over 18 months. The δ98/95Mo values ranged from -0.54‰ to +0.01‰ for igneous rocks,
      Abstract:
      On-line chemical vapor generation atomic fluorescence spectrometry (CVG-AFS) was, for the first time, used to determine trace copper in biological samples by merging acidified sample solution with potassium tetrahydroborate aqueous solution in the presence of micro-amounts of 1,10-phenanthroline. Nitric acid, for both sample digestion and chemical vapor generation, was used as the acid medium. CVG conditions and instrumental parameters were optimized for the best CVG efficiency, good gas/liquid separation, and efficient atomization/excitation. Under the optimized conditions, a limit of detection of 4 ng mL(-1) was obtained for copper, with a linear dynamic range of over three orders of magnitude. The proposed method was successfully applied to the determination of copper in biological certified reference materials.
      Abstract:
      A rapid, sensitive, and cost-effective method was developed for the determination of trace mercury in water samples by on-line coupling of flow injection (FI) sorption preconcentration with oxidative elution to cold vapor atomic fluorescence spectrometry (CV-AFS). race Hg(II) in aqueous solution was preconcentrated by on-line formation of mercury diethyldithiocarbamate complex (Hg-DDTC) and adsorption of the resulting neutral complex on the inner walls of a PTFE knotted reactor (KR). A mixture of 16% (v/v) HCl and 10% (v/v) H2O2 was used as the eluent to remove the adsorbed Hg-DDTC from the KR, then convert on-line the Hg-DDTC into Hg(II) prior to its reduction to elemental mercury by KBH4 for subsequent on-line CV-AFS detection. The tolerable concentrations of Cd(II) As(Ill) Se(IV) Fe(III), Co(II), Ni(II), and Cu(II) and Cu(II) for the determination of 0.1 mug L-I Hg(II) were 0.1, 10, 0.1, 0.1, 0.7, 1, 0.3, and 0.2 mg L-1, respectively. With a sample loading flow rate of 3.1 mL, min(-1) for a 60-s preconcentration, a detection limit (3sigma) of 4.4 ng L-I was achieved at a sample throughput of 36 samples h(-1). The precision (RSD, n = 11) was 1.7% at the 1 0, 1-mug L-1 Hg (11) level. The method was successfully applied to the determination of mercury in a certified reference material, GBW(E) 080392, and a number of local natural water samples.
      Abstract:
      A method based on?cloud?point?extraction?was developed to determine?cadmium?at?the?nanogram?per?liter?level?in?sea-water?by?graphite?furnace?atomic absorption spectrometry. Diethyldithiocarbamate (DDTC) was used as?the?chelating reagent to form Cd-DDTC complex; Triton X-114 was added as?the?surfactant.?The?parameters affecting sensitivity and?extraction?efficiency (i.e., pH?of?the?solution, concentration?of?DDTC and Triton X-114, equilibration temperature, and centrifugation time) were evaluated and optimized. Under?the?optimum conditions, a preconcentration factor?of?51.6 was obtained for a 20-ml, water sample.?The?detection limit was as low as 2.0 ng L-1 and?the?analytical curve was linear?in?the?10.0-200.0 ng L-1 range with satisfactory precision (RSD < 4.7%).?The?proposed method was successfully applied to?the?trace?determination?of?cadmium?in?seawater.
      Abstract:
      The analytical procedure for the determination of trace rare earth impurities in high purity neodymium oxide (Nd2O3) by ICP-MS is described. The effect of ICP-MS operating parameters on the REO(H)(+)/RE+ production ratio was studied in detail, and the optimal ICP operating conditions were established. In this context, the relationship between REO(H)(+)/RE+ production ratio and the bond strength of the rare earth oxides is also discussed briefly. For the correction of the spectral interference induced by the matrix (neodymium), a simple correction equation was used for correcting the interferences of the polyatomic ions NdO+ and NdOH+ with Tb-159 and Ho-165. The proposed method was applied to the determination of trace rare earth impurities in high purity Nd2O3\, and the analytical results were in good agreement with the recommended reference values.
      Abstract:
      A powerful multielement analytical technique using laser ablation Inductively coupled plasma source mass spectrometry (LA-ICP-MS) for the sensitive determination of trace impurities in thin glass filaments, used as reinforcing material in the construction industry, was developed. The trace analysis was carried out directly on very thin solid strands (without any sample preparation steps) by LA-ICP-MS whereby a bundle of thin glass fibers (with a filament diameter of about 10 - 20 mum) was fixed on a thin, special tape of a target holder. The fibers were ablated in the ablation chamber with the aid of a commercial laser ablation system using a Nd-YAG laser at a wavelength of 266 nm). In order to verify the trace analytical data, the ablated T-glass fibers were analyzed using a quadrupole (LA-ICP-QMS) and double-focusing sector field mass spectrometer (LA-ICP-SFMS). The detection limits of the trace elements in glass fibers using the LA-ICP-MS with a quadrupole analyzer were in the sub mug g(-1) range, whereas using a sector,field mass spectrometer (LA-ICP-SFMS) the detection limits could be Improved by 3-4 orders of magnitude down to the low and sub ng g(-1) range. The multielement trace analytical method, developed for high-purity glass fibers, was applied to the determination of chemical composition on thin alkati-resistant glass and basalt fibers with finishing additives used in fine concrete for the building industry. The analytical results were quantified using standard reference materials (SRMs) of glass matrix, such as the NIST 612 glass SRM and the basalt geological reference glasses, KL-2G and ML3B-G, for the trace analysis of basalt glass fibers. The experimentally determined relative sensitivity coefficients (RSC) in LA-ICP-MS for both SRMs varied between 0.2 and 3 for most of the elements. An increase of the relative sensitivity coefficients was observed with increasing mass. The relative standard deviation (RSD) of most elements (N = 3) was T between 2 and 10%. The results of the trace element concentrations by LA-ICP-MS using different instrumentation are in good agreement.
      Abstract:
      A?sequential?injection?system?for?on-line?ion exchange separation and?preconcentration?of trace level amounts of metal ions with ensuing detection by electrothermal atomic absorption spectrometry (ETAAS) is described. Based on the use of?a?renewable microcolumn incorporated within an integrated lab-on-valve microsystem, the?column?is initially loaded with?a?defined volume of beads of an SP Sephadex C-25 cation exchange resin. After having been exposed to?a?metered amount of sample solution, the loaded bead suspension is precisely manipulated within the valve to allow reproducible elution of the retained analyte by 30 muL nitric acid (1: 16,v/v) which, via air segmentation, are then transported into the graphite tube for quantification. The content of the used?column?is afterwards discarded and new?column?material is aspirated for the next run. The ETAAS determination is performed in parallel with the?preconcentration?process of the ensuing sample. The performance of the?system?is demonstrated for the determination of bismuth. With 2.4-mL sample loading, an enrichment factor of 33.4,?a?detection limit of 27 ng 1:1, along with?a?sampling frequency of 10 h(-1) was obtained. The relative standard deviation was 2.3% for the determination of 2.0 mg 1:1 Bi (n = 7). The procedure was validated by determination of bismuth in?a?certified reference material CRM 320 (river sediment) and by bismuth spike recoveries in two human urine samples.
      Abstract:
      A?sequential?injection?system?for?on-line?sorbent extraction?preconcentration?in electrothermal atomic absorption spectroscopy was developed for the determination of trace thallium in geochemical samples. The TlBr4-1 complex was adsorbed on?a?20-mu L micro-column?(located at the tip of the furnace sampling probe) packed with XAD-8 resin. After sequentially aspirating separate zones of acetone, rinsing acid, and sample (pretreated with bromine) into?a?2.5-m long, 1-mm i.d. holding coil, the flow was reversed and directed to the?column. Sample loading, analyte adsorption,?column?rinsing and analyte elution were achieved within?a?single reversed syringe stroke. The adsorbed analyte was eluted into the furnace with 50 mu L acetone. Mutual mixing between sample, rinsing acid, and eluent were prevented by separating the zones with small air segments during metering. Tightening of?column?packing was avoided by?a?slight back-suction through the?column?after each operational cycle. With 1-mL sample loading, an enrichment factor of 15 was obtained with?a?detection limit of 18 ng/L thallium (3 sigma).?A?precision of 2.4% RSD (n=11, 4 μ g/L) and?a?sampling frequency of 11/hour were achieved. The method was applied to the analysis of geochemical samples. The results were in good agreement with the certified values of standard reference geochemical materials.
      Abstract:
      The metal content in several TCM drugs was determined by ICP-MS. The efficiencies of different sample digestion methods were compared. Since one of the products studied is known to contain arsenic sulfides as a main ingredient, a solvent fractionation scheme was developed and applied to speciate As in the product. The metal content in the same TCM drug produced by different manufacturers was compared. The concentration of some metals such as Pb and Cd differs widely with different manufacturers, suggesting that their origin is primarily from external contamination. The high sensitivity and precision of the ICP-MS technique offers considerable advantages over conventional ICP-OES techniques for the analysis of complex samples such as TCM materials. Standardized analytic protocols based on ICP-MS are being developed fur the determination and characterization of metals and trace elements in TCM materials for product quality assessment.
      Abstract:
      Theory, design, and operation of a dynamic reaction cell for ICP-MS

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