Most view articles

  • Display Type:
  • Text List
  • Abstract List
  • 1  In situ Investigation of the Valence States of Iron-bearing Phases in Chang’E-5 Lunar Soil using FIB, AES, and TEM-EELS Techniques
    Bing Mo Zhuang Guo Yang Li Dan Zhu Xiaojia Zeng Xiongyao Li Jianzhong Liu Yanxue Wu
    2022, 43(1):53-59. DOI: 10.46770/AS.2022.014
    [Abstract](625) [HTML](0) [PDF 4.58 M](6288)
    Abstract:
    Nanophase iron (np-Fe0) is a major product of space weathering and its presence significantly alters the reflectance spectral characteristics of lunar soil. Previous studies have established that the np-Fe0 particles originate from the reduction of ferrous ions in the plasma, in-situ decomposition of olivine and pyroxene, and disproportionation of ferrous ions in solid ferrosilicates. In this study, sample charging effects were eliminated and in situ nanoscale valence state analysis of iron-bearing phases in Chang’E-5 lunar soil was conducted by combining focused ion beam (FIB) microscopy, Auger electron spectroscopy (AES), and transmission electron microscopy-electron energy loss spectroscopy (TEM-EELS) techniques. The results indicate that the contents and valence states of iron in the np-Fe0 particles, amorphous matrix, and ferrosilicates differ. The np-Fe0 particles were found to be composed of pure metallic iron, whereas ferrous and ferric iron ions were present in olivine crystals and the amorphous matrix, respectively. The discovery of both metallic and ferric iron in the amorphous matrix of Chang’E-5 lunar soil offers new insights regarding the disproportionation reaction of Fe2+ on the lunar surface. This study demonstrates that the combination of FIB, AES, and TEM-EELS is an effective and precise approach for analyzing the valence states of iron-bearing phases in lunar soil, which can be extended to other extraterrestrial samples and other multivalent elements.
    2  Design, Function, and Implementation of China's First LIBS Instrument (MarSCoDe) on the Zhurong Mars Rover
    Xiong Wan Chenhong Li Hongpeng Wang Weiming Xu Jianjun Jia Yingjian Xin Huanzhen Ma Peipei Fang Zongcheng Ling
    2021, 42(6):294-298. DOI: 10.46770/AS.2021.608
    [Abstract](579) [HTML](0) [PDF 14.32 M](7111)
    Abstract:
    MarSCoDe (Mars Surface Composition Detector) is China's first instrument for Mars material analysis, which accompanies the Zhurong Mars rover landing on Utopia Planitia and will detect interested Martian rock and soil targets based on laser-induced breakdown spectroscopy (LIBS) technique. MarSCoDe consists of a bioxial pointing mirror (BPM), an optical head, a calibration targets assembly (CTA), a spectrometer module (SM) and a payload controller. The MarSCoDe is scheduled to analyze twelve major elements. To achieve accurate quantitative analysis and classification of Mars targets, a PSO (particle swarm optimization)-based calibration scheme is adopted to correct the spectral shift due to the temperature change on Mars, and then a convolutional neural network (CNN) was proposed to implement the analysis of elements. Finally, the mineral types of Martian objects will be identified according to the alkali silica ratio. The detection results of the MarSCoDe will provide further information about the evolution of Mars.
    3  Fast Quantification and Speciation of Selenium in Dietary Supplements through Handheld XRF and Synchrotron Radiation XAS
    Yunyun Li Jiating Zhao Lina He Liming Wang Liwei Cui Bai Li Yu-Feng Li
    2020, 41(3):127-131. DOI: 10.46770/AS.2020.03.005
    [Abstract](450) [HTML](0) [PDF 731.58 K](2120)
    Abstract:
    The handheld X-ray fluorescence spectrometer (XRF) has the advantages of being easy to carry, simple in operation, non-destructive, and offers fast and relatively accurate detection, while synchrotron radiation X-ray absorption spectroscopy (XAS) has been used for the selenium (Se) speciation of Se-enriched yeast and Se hyperaccumulators. In this study, we propose the application of a handheld XRF in combination with XAS for the fast quantification and speciation of Se in commercially available dietary supplements. The results of total Se determined by handheld XRF were in good agreement with ICP-MS data, which was also consistent with the labeled value of Se dietary supplements. The XAS analysis of the tested samples showed that Se was mainly present in the form of organic Se. The proposed method is practical and simple for high throughput label verification and quality control of Se dietary supplements. It can, therefore, be a useful method not only for researchers but also for regulators and producers in the analysis of Se dietary supplements.
    4  Multielement Analysis of Alkaline-Resistant Glass and Basalt Glass Fibers Using Laser Ablation ICP-MS: A Useful Tool in Technical Textile Quality Control
    J. Su. Becker C. Pickhardt N. Hoffmann H. H?cker J. Sa. Becker
    2002, 23(1):1-6. DOI: 10.46770/AS.2002.01.001
    [Abstract](432) [HTML](0) [PDF 135.56 K](3429)
    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.
    5  Simultaneous or Sequential Multi-element Graphite Furnace Atomic Absorption Spectrometry Techniques: Advances Within the Last 20 Years
    Ioannis N. Pasias Nikolaos I. Rousis Aikaterini K. Psoma Nikolaos S. Thomaidis
    2021, 42(6):310-327. DOI: 10.46770/AS.2021.707
    [Abstract](392) [HTML](0) [PDF 1.65 M](2752)
    Abstract:
    Electrothermal or graphite furnace atomic absorption spectrometry (ETAAS or GFAAS) is one of the most widely used techniques for determining elements in different matrices (e.g., foodstuffs, pharmaceuticals, biological specimens, nanomaterials, polymers, fuels and environmental media). Numerous elements can be simply and quickly determined with high precision and accuracy, low detection limits, and at moderate cost. The technique is also suitable for direct solid and slurry sample analysis. A crucial feature of this technique is that it can perform simultaneous or sequential multi-element analysis. Over the years, many instruments have come on the market for multi-elemental analysis using mostly line source (LS) GFAAS and high-resolution continuum source (HR-CS) GFAAS. This review covers publications from 2000 to 2020 related to the simultaneous or sequential multi-elemental analysis by LS-GFAAS and HR-CS-GFAAS. Mainly the applications, the limits of detection, the use of internal standardization and other aspects regarding the matrix, pyrolysis and atomization temperatures and modifiers are discussed. Finally, a critical comparison is made between the LS-GFAAS and HR-CS-GFAAS techniques.
    6  Quantitative Analysis of Gold Nanoparticles in Single Cells with Time-resolved ICP-MS
    Jinhui Liu Lingna Zheng Junwen Shi Xing Wei Xue Li Mingli Chen Meng Wang Jianhua Wang Weiyue Feng
    2021, 42(3):114-119. DOI: 10.46770/AS.2021.102
    [Abstract](385) [HTML](0) [PDF 4.24 M](7599)
    Abstract:
    Single-cell inductively coupled plasma mass spectrometry (SC-ICP-MS) has been introduced for the analysis of intracellular essential elements and nanoparticles (NPs) at the single cell level. However, it is still quite challenging for accurate and reliable determination. In this work, a high-efficiency sample introduction system was used for single cell analysis with ICP-MS. The system includes a microconcentric nebulizer, a low-volume single pass spray chamber, and a syringe pump. The transport efficiency of single cells was greatly improved to ~12%. In addition, 197Au signals in individual HepG2 cells, after incubation with gold nanoparticles (AuNPs) at the concentrations of 0.1, 0.5, and 1 μM for 12 h, were analyzed by time-resolved ICP-MS with dwell times of 100 μs and 5 ms, respectively. The 197Au signal-to-background ratio (S/B) at 100 μs dwell time was much higher than at 5 ms. For quantitative analysis, AuNP standard reference materials were used for calibration. The SC-ICP-MS data using NP calibration were in good agreement with those using solution ICP-MS analysis, validating the developed SC-ICP-MS method.
    7  Determination of Trace Copper in Biological Samples by On-line Chemical Vapor Generation-Atomic Fluorescence Spectrometry
    Liang He Xiaofan Zhu Li Wu Xiandeng Hou
    2008, 29(3):93-98. DOI: 10.46770/AS.2008.03.004
    [Abstract](369) [HTML](0) [PDF 146.88 K](2983)
    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.
    8  Trace Metals in Traditional Chinese Medicine: A Preliminary Study Using ICP-MS for Metal Determination and As Speciation
    Xiaoru Wang Zhixia Zhuang Dahai Sun Jiangxing Hong Xihong Wu
    1999, 20(3):86-91. DOI: 10.46770/AS.1999.03.002
    [Abstract](365) [HTML](0) [PDF 283.26 K](3087)
    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.
    9  Determination of Cadmium at the Nanogram per Liter Level in Seawater by Graphite Furnace AAS Using Cloud Point Extraction
    Chun-gang Yuan Gui-bin Jiang Ya-qi Cai Bin He Jing-fu Liu
    2004, 25(4):170-176. DOI: 10.46770/AS.2004.04.003
    [Abstract](331) [HTML](0) [PDF 99.16 K](3198)
    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.
    10  Rapid Determination of Chemical Oxygen Demand by Flame AAS Based on Flow Injection On-line Ultrasound- assisted Digestion and Manganese Speciation Separation
    Zhi-Qi Zhang Hong-Tao Yan Lin Yue
    2004, 25(4):191-196. DOI: 10.46770/AS.2004.04.006
    [Abstract](331) [HTML](0) [PDF 86.02 K](2937)
    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.
    11  Estimation of Isotopic Reference Values for Pure Materials and Geological Reference Materials
    Wen Zhang Zhaochu Hu
    2020, 41(3):93-102. DOI: 10.46770/AS.2020.03.001
    [Abstract](330) [HTML](0) [PDF 1.73 M](3519)
    Abstract:
    Reference materials (RMs) are the foundation in isotopic analysis, and the assignment of reference values of isotope ratios in RMs is a complex process. In this study, we established new isotopic reference values and its uncertainties for the Sr, Nd, Hf and Pb isotope ratios in 18 commonly used pure materials and rock RMs, and for Hf and O isotope ratios in five zircon RMs, following the ISO guidelines and procedures in the IAG Certification Protocol. The original data were collected from the geochemical database “GeoReM”. An estimation method for generating reference values of isotope ratios was developed, including a data filter process, technical criteria assessment and robust statistical calculation. The generated analytical results demonstrate the same instrumental performance with both TIMS and MC-ICP-MS for Sr and Nd isotopic analysis. However, significant discrete data for the Pb isotope ratios obtained by TIMS and MC-ICP-MS are evident, indicating existing challenges for accurate Pb isotopic analysis. It was found that 91500 is not a suitable Hf isotopic RM for micro-analysis due to the heterogeneous Hf isotopic composition and the Ple?ovice zircon may be a more ideal alternative. This study provides a powerful protocol and practical examples for estimating reference values of isotope ratios in frequently used RMs.
    12  Simultaneous in-situ determination of major, trace elements and Fe3+/∑Fe in spinel using EPMA
    Lihui Jia Yi Chen Qian Mao Di Zhang Jiangyan Yuan Xiaoguang Li Shitou Wu Danping Zhang
    2022, 43(1):42-52. DOI: 10.46770/AS.2022.002
    [Abstract](324) [HTML](0) [PDF 5.44 M](5493)
    Abstract:
    Spinel, an important mineral in basalts and ultramafic rocks on Earth, Mars, and the Moon, is sensitive to petrologic and geochemical processes, and redox evolution. Due to the small grain size of extraterrestrial samples, investigations on the composition of spinel samples including presence of trace elements and ferric iron have been hindered by the lack of appropriate in-situ analytical techniques with high spatial resolution and the shortage of reference materials. This paper presents a combined method of simultaneously measuring the major and trace elements, and Fe3+/∑Fe ratio in spinel samples using electron probe microanalysis (EPMA). Our new EPMA method is performed under double beam condition at a beam current of 200 nA for trace elements (Ti, V, Mn, Co, Ni, and Zn) and 60 nA for major elements (Mg, Fe, Al, and Cr) with an acceleration voltage of 25 kV. In addition, large analyzing crystals and peak overlap corrections were applied to reduce the detection limits and improve the analytical precision. The detection limits of 16–55 μg/g (3σ) for trace elements were achieved, and the estimated accuracies for the major elements and trace elements were within ± 2 and ± 6% (1σ), respectively. We selected seven spinel samples from the Luobusha and Stillwater intrusions to evaluate the validity of our method. They were sufficiently homogeneous with a relative standard deviation (RSD) of ± 2.0% (1σ) for the major elements (except MgO in 16SW3-9) and ± 7.0% (1σ) for the trace elements. The EPMA results obtained for the major and trace elements of the most homogeneous spinel LBS13-04 were compared with those measured using X-ray fluorescence and laser ablation inductively coupled plasma mass spectrometry. These values were in good agreement with the uncertainty of the methods. Thus, this spinel is highly suitable as a reference material for in situ microanalysis. The Fe3+/ΣFe ratios of high Cr# (57.7-79.1) spinel standards determined using M?ssbauer spectroscopy varied from 0.07 to 0.27, which were used for secondary standard calibration method to determine the spinel Fe3+/ΣFe ratio with an accuracy of < ± 0.04 (2σ). Our results offer a high-precision EPMA method that can simultaneously determine the major and trace elements together with the Fe3+/ΣFe ratio in spinel. This method provides robust and precise data on spinel for small, precious, and rare terrestrial or extraterrestrial samples, which can be used to understand the formation and evolution of rocky planets.
    13  Chemical Characterization of Coal Fly Ash Samples by ICP-AES and ICP-MS With Focus on Trace Level Toxic Elements
    V. Padmasubashini G. Chakrapani
    2016, 37(6):229-237. DOI: 10.46770/AS.2016.06.003
    [Abstract](320) [HTML](0) [PDF 109.38 K](597)
    Abstract:
    Coal fly ash contains several trace elements some of which are toxic such as As, Cr, Pb, etc. Coal ash also contains relatively high amounts of rare earth ele- ments whose recovery from coal ash could be an alternate source for their supply. Although ura- nium and thorium are less chemi- cally toxic than other constituent elements such as arsenic, ques- tions have been raised concern- ing the possible risk from radiation. Hence, the concentration levels of all of these trace toxic elements in fly ash samples have to be assessed to determine whether the ash is hazardous or not, and also to decide the place and method of its disposal or re- utilization. In this study, multi- elemental analysis of some coal ash samples originating from two thermal power plants in southern India has been carried out, employ- ing inductively coupled plasma atomic emission spectrometry (ICP-AES) and inductively cou- pled plasma mass spectrometry (ICP-MS), with the focus on some trace toxic elements. The meth- ods employed were validated by analayzing international certified fly ash reference materials. The concentrations of trace-toxic ele- ments in the samples analyzed were: 20-82 μg/g for As, 45-281 μg/g for Cr, 31-607 μg/g for Ba, 21- 865 μg/g for Sr, 8-39 μg/g for Ge, <5-80 μg/g for Ga, <5-100 μg/g for Cu, 19-50 μg/g for Co, 58-258 μg/g for Ni, 8-73 μg/g for Pb, 44-260 μg/g for Zn, 0.6-8.6 μg/g for U, 1-30 μg/g for Th, 6-196 μg/g for La, 14-528 μg/g for Ce, 5-196 μg/g for Y. These results were compared with trace-toxic element concentra- tions in coal ash samples as reported in the literature.
    14  A Novel Synergetic Salt- and Acid-induced Ligandless Mixed Micelle Cloud Point Extraction of Ultratrace Levels of Cd, Hg, Bi, and Tl From Petrochemical Effluents Followed by ETAAS Determination
    K. Ravi Kumar K. Madhavi P. Shyamala N.N. Meeravali Sunil Jai Kumar
    2018, 39(3):118-125. DOI: 10.46770/AS.2018.03.005
    [Abstract](317) [HTML](0) [PDF 176.31 K](1447)
    Abstract:
    A new synergetic salt- and acid-induced ligandless mixed micelle cloud point extraction procedure was developed for the simultaneous separation and preconcentration of Cd, Hg, Bi, and Tl from petrochemical effluents and groundwater samples. The cationic mixed micelles are formed by the micelle-micelle interaction of cationic cetylpyridinium ammonium bromide (CPAB) and nonionic Triton? X-114 micelles, which act as an ion pair and extracting agent. Due to the synergetic effect of potassium iodide and sulfuric acid, the hydrophilic anionic Cd, Hg, Bi, and Tl iodide species are formed. These also induce the clouding phenomenon in cationic mixed micelles. The strong electrostatic interaction between the mixed micelles head groups and the anionic iodide species form the hydrophobic ion pairs which are separated from the bulk aqueous phase into a small mixed micelle-rich phase, thus avoiding the addition of an external chelating agent. Under the optimized conditions, a pre-concentration factor of nearly 20 times was obtained for all of the elements. The limits of detection obtained were 0.0005, 0.2, 0.04, and 0.05 ng mL-1 for Cd, Hg, Bi, and Tl, respectively. The recoveries were in the range of 93–102% at 0.1 to 10 ng mL-1 with a relative standard deviation of 2–10%. The accuracy of the method was validated by analysis of certified reference materials BCR 714 Initial Influent, BCR 715 Industrial Effluent, BCR 610 Groundwater, and NIST 1643e, 1643f, and 1642b Trace Elements in Water. The method was also applied to real samples of petrochemical effluents and groundwater collected locally. A continuum source electrothermal atomic absorption spectrometer (CS-ETAAS) was used for the determination of the elements.
    15  Development and Validation Method for the Determination of Rare Earth Impurities in High Purity Neodymium Oxide by ICP-MS
    Man He Bin Hu Zucheng Jiang Yan Zeng
    2004, 25(1):13-20. DOI: 10.46770/AS.2004.01.002
    [Abstract](313) [HTML](0) [PDF 154.90 K](2996)
    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.
    16  Further Evaluation for High-precision Isotopic Measurement of 205Pb-spiked Pb by Dynamic Multiple Ion Counting
    Zhu-Yin Chu Chao-Feng Li Wen-Gui Liu Wei Wang Jing-Hui Guo
    2020, 41(4):148-153. DOI: 10.46770/AS.2020.04.002
    [Abstract](312) [HTML](0) [PDF 2.37 M](2315)
    Abstract:
    A high-precision MIC-ID-TIMS (multiple ion counting-isotope dilution-thermal ionization mass spectrometry) Pb isotope ratio measurement method (using 205Pb as spike) with a TRITON Plus TIMS, which is equipped with a 205Pb-Pb MIC array, using a two-line multi-dynamic data collection method, was thoroughly re-set and re-evaluated, based on our previous work.1 After some vital modifications, better than 0.01% RSE internal precision on 207Pb/206Pb for a 205Pb-spiked NIST981 with ~ 50 pg of Pb load was achieved with a measurement time of about 100 min. This is more precise compared to the traditional isotopic measurement method for the 205Pb-spiked Pb, using a single secondary electron multiplier (SEM) with five peak jumps, provided with similar ion beam intensities and measurement time. The external precision on 207Pb/206Pb was better than 0.1% (2RSD, n = 24), which is much better than that achieved by the static MIC method as previously reported1, 2. The present work indicates that the 205Pb-Pb MIC array of the TRITON Plus TIMS can be successfully used for zircon ID-TIMS U-Pb dating with high precision, particularly is useful for samples containing extremely small amounts of Pb (down to several pico-grams).
    17  Determination of Elemental Impurities in Iron-nickel-based Superalloys by Glow Discharge Mass Spectrometry
    F. F. Hu C. H. Wang J. D. Li P. Y. Liu H. Liu L. Zhang
    2021, 42(1):25-31. DOI: 10.46770/AS.2020.215
    [Abstract](311) [HTML](0) [PDF 669.52 K](2000)
    Abstract:
    A method for the determination of impurities in iron-nickel-based superalloys by high-resolution glow discharge mass spectrometry is described. The optimum discharge conditions were investigated to obtain stable discharge and good sensitivity. The interference was separated in high resolution mode of the instrument. The calibration relative sensitivity factors (RSF) for 12 elements were obtained with the matrix-matched certified reference material, IARM Ni909-18. The reference material was analyzed by using the calibration RSFs. The relative error of the measured value was within 16.4% compared with the certified value, and the relative standard deviation (RSD) was less than 7.0%. The 12 elements in the iron-nickel-based superalloy were determined using the calibration RSFs (quantitative analysis) and the standard RSFs (semi-quantitative analysis) in the instrument, including C, N, O and S. The results of the verification methods, such as inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), high frequency combustion infrared absorption and inert gas pulse infrared thermal conductivity, were closer to quantitative analysis results. The elements without certified values in the reference material were determined by using the standard RSFs. There was no significant difference between the results of GDMS and the verification by ICP-MS. The validation revealed that the proposed analytical approach achieves reliable results for the rapid determination of several impurities, such as metals as well as non-metals, even the gas elements C, N, O and S.
    18  Non-matrix-matched 9 micron U-Pb Dating of Zircon Using Excimer Laser Ablation ICP-MS
    Nan Lv Kaiyun Chen Zhian Bao Kai Wu Danbo Lei Honglin Yuan
    2021, 42(2):51-61. DOI: 10.46770/AS.2021.010
    [Abstract](306) [HTML](0) [PDF 5.18 M](2190)
    Abstract:
    U-Pb dating geochronology by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been widely applied in geological research as a low-cost and high-efficient in situ micro-analytical tool. Currently, quantitative analysis using LA-ICP-MS requires matrix-matched external standards to correct for elemental fractionation. Since natural standard minerals are often limited in supply or not available, non-matrix-matched calibration methods using synthetic glasses as the calibration standards have attracted attention. In addition, access to a higher spatial resolution capability of <10 μm spot size has been driven by the interest in studying the temporal records of fine mineral grains or rims compared to the conventional >20 μm laser ablation spots used in most LA-ICP-MS laboratories for zircon dating. In this study, we present an LA-ICP-MS analytical procedure for non-matrix-matched U-Pb zircon dating using a 9 μm laser ablation spot size and a synthetic silicate glass (NIST SRM 610) as the external standard. The elemental fractionation between the NIST SRM 610 glass and zircons can be significantly reduced by using a low laser frequency (2 Hz) and energy density (3 J/cm2). To minimize the matrix effect on matrix-mismatched calibration between samples and standards, the effect of adding a small amount of water vapor or hydrogen into the carrier gas was investigated. A small amount (about 1.9 μL/min) of water vapor added into the sample cell can reduce the Pb/U ratios of the NIST SRM 610 up to 14% during a 40 s ablation time at a small spot size. However, by adding water vapor after the sample cell can achieve an accuracy and precision of better than 2.3% for the weighted average 206Pb/238U ages using a 9 μm spot size. In addition, the laser-ablated crater depth needs to be less than 4.3 μm to control the down-hole fractionation during laser ablation.
    19  Review: Application of LIBS to Elemental Analysis and Mapping of Plant Samples
    Vivek K. Singh Neha Sharma Onkar N. Verma Virendra K. Singh Durgesh K. Tripathi Yonghoon Lee Sandeep Kumar Piyush K. Rai M.A. Gondal
    2021, 42(2):99-113. DOI: 10.46770/AS.2020.201
    [Abstract](304) [HTML](0) [PDF 2.06 M](2412)
    Abstract:
    Trace minerals and metallic elements play a key role in plant metabolism and function. Therefore, it is important to understand the movement and distribution of trace minerals within various parts of plants in order to understand their metabolic pathways. Information on the localization of minerals can be utilized in the fields of plant science, agriculture, and food technologies. In this context, herein, we review the feasibility of application of laser-induced breakdown spectroscopy (LIBS) as a technique for trace element detection and mapping in different plant matrices. LIBS is a well-established technique that can be used to perform rapid multi-elemental detection in various types of samples, including plants. Owing to the unique capabilities of LIBS, its field applications are growing rapidly, particularly in the area of plant science. Here, our primary emphasis is on the quantitative and qualitative elemental imaging of different varieties of plant species that are of importance as medicines and foodstuffs. In this review article, we present an exhaustive survey of recent developments, including technical advances and recent work involving the detection of nanoparticles in plant samples and in the monitoring of soil content. The future potential of LIBS and the viability of its possible applications to the detection of essential minerals and heavy metals in plants used as foods or of medicinal importance are also discussed.
    20  Estimating the Aging Grade of Heat-resistant Steel by Using Portable Laser-induced Breakdown Spectroscopy
    Junbin Cai Meirong Dong Yongsheng Zhang Yixiang Chen Hongjie Chen Youcai Liang Weijie Li Jidong Lu
    2021, 42(2):43-50. DOI: 10.46770/AS.2020.217
    [Abstract](303) [HTML](0) [PDF 4.26 M](2079)
    Abstract:
    Heat-resistant steel is widely used in the construction of various types of industrial pressure-bearing equipment. In this work, laser-induced breakdown spectroscopy (LIBS) was applied to evaluate the aging grade of actual industrial pipe heating surfaces (made by T91 steel) via a self-developed portable LIBS device. First, the pretreatment effect of wavelet threshold denoising (WTD) and multiple scattering correction (MSC) on the LIBS spectrum is discussed. Based on the K-fold-support vector machine-recursive feature elimination (K-SVM-RFE) and support vector machine (SVM), the aging grade model is established using the spectral data of the T91 artificial specimens and of the industrial pipe slices at different aging grades. The influence of the denoising of WTD and the transformation of MSC in the selection of optimal feature subsets using K-SVM-RFE are discussed along with the model's performance. Second, the spectral characteristics of the actual industrial T91 pipe heating surface of coal-fired boilers are investigated, and the spectral data are screened and standardized. Finally, by using the aging grade model to evaluate the aging grade of the industrial T91 pipe based on the calibrated spectral data, an accuracy of 85.17% was achieved. The results demonstrate that the portable LIBS device and the corresponding hybrid model presented here have strong discrimination and robustness for estimating the aging grade of heat-resistant steel.

    Current Issue


    Volume , No.

    Table of Contents

    Archive

    Volume

    Issue

    Most Read

    Most Cited

    Most Downloaded

    Copyright © 2025 Atomic Spectroscopy Press Ltd All rights reserved
    Supported by:Beijing E-Tiller Technology Development Co., Ltd.