Available molybdenum(Mo) in soil is an important indicator for evaluating the fertility of soil.However,its content in soil is relatively low.The accurate and rapid determination of available molybdenum in soil is of great significance for guiding the agricultural production.In this study,three kinds of extractants were used to extract available molybdenum from soil samples.Then its content was determined by inductively coupled plasma mass spectrometry(ICP-MS) using ⁹⁵Mo as the determination isotope.It was found that the matrix effect could be effectively eliminated using ¹⁰³Rh as internal standard when the available molybdenum was determined in helium(He) collision mode.The determination results of 3 extractants were compared and analyzed.It indicated that ammonium oxalate solution had certain advantage in extracting available molybdenum from soil and could better reflect the actual supply status of available molybdenum in agricultural soil.The limit of detection of this method was 0.002 mg/kg.The precision test and trueness test of soil samples were conducted.The relative standard deviation(RSD,n=6) of determination results of available molybdenum was between 1.2% and 5.4%.Two certified reference materials for analysis of soil available nutrients were determined,and the results of available molybdenum were within the reference range of certified values with relative error of 0-4.7%.Different types of soil samples were determined using two determination methods,and t-test was used for comparison and validation.It was found that there was no significant difference in measured results.The proposed method could provide reliable technical support for the determination of available molybdenum in different types of soil.

Accurate determination of available molybdenum in soil is crucial for the scientific fertilization and sustainable agricultural development.The existing standard method(NY/T 1121.9-2023),i.e.,oxalic acid-ammonium oxalate solution extraction(oscillation),suffers from time-consuming sample pretreatment(standing for 10 h) and low batch analysis efficiency.In this study,a method for the determination of available molybdenum in soil by inductively coupled plasma optical emission spectrometry(ICP-OES) after oxalic acid-ammonium oxalate solution extraction(constant-temperature vortex) was established.The single-factor and orthogonal experiments indicated that the efficient extraction could be achieved with 10 min under the optimal conditions as follows:the sample particle size was 60-100 mesh(0.250-0.149 mm),the extraction temperature was (25±3) ℃,the solid-to-liquid ratio(main controlling factor) was 1∶10,the extraction time was 10 min,and the vortex speed was 1 200 r/min.The limit of detection of this method was 0.009 mg/kg,and the limit of quantification was 0.036 mg/kg.The content of available molybdenum in certified reference material for analysis of soil available nutrients(GBW07412b,GBW07413b,GBW07414b) were determined according to the experimental method.The standard deviation(n=8) of determination results was not more than 0.017 mg/kg.The relative standard deviation(RSD, n=8) was not more than 8.4%,and the absolute value of relative error(RE) was not more than 10%.The proposed method was applied for the determination of available molybdenum in soil samples from Jiangsu Xuzhou,Hubei Jingmen and Zhejiang Jiaxing,and the RSD(n=8) of determination results was between 3.7% and 5.5%.The oscillation method in NY/T 1121.9-2023 and constant-temperature vortex method in this method were employed to treat certified reference material for analysis of soil available nutrients(GBW07412b,GBW07413b,GBW07414b,GBW07416b,GBW07458a,GBW07460a) and soil samples.Then the content of available molybdenum was determined by ICP-OES.The results indicated that the difference of average determination value between two methods was not more than 0.05 mg/kg.There was no significant difference in RSD(n=8).The measured results were all within the tolerance range.The proposed method could meet the quality control requirements of batch analysis for available molybdenum in soil.

The rare earth elements in weathering steel exhibit a strong tendency to combine with non-metallic elements such as oxygen(O) and sulfur(S),leading to the complex and diverse morphologies of rare earth inclusions in the steel,which brings severe challenges to the statistical distribution characterization of rare earth inclusions in steel.In this study,a method for the in-situ statistical distribution characterization of cerium(Ce)-containing inclusions within a large size range was established by combining the multi-field continuous observation technology of scanning electron microscope(SEM),the rapid localization and recognition algorithm for characteristic particle images,and the automated energy dispersive spectrometry(EDS) analysis.The in-situ statistical distribution characterization of rare earth inclusions in weathering steel plates with 3 different Ce contents along the rolling direction was realized.The statistical characterization area was up to 200 mm².The information regarding Ce-containing inclusions in 3 types of rare earth weathering steel was obtained,including the position,chemical composition,morphological characteristic,size range and quantity distribution.Additionally,the influence law of Ce addition amount and gaseous element content on the formation of rare earth inclusions in steel was investigated.It was found that the content of S and O in steel and their ratio had a significant impact on the type and quantity distribution of rare earth inclusions.Specifically,the particle size of Ce-O-S type inclusions was generally larger than that of Ce-O and Ce-S type inclusions,and the combination of multiple elements promoted the growth of rare earth inclusions toward larger particle size.The P-containing rare earth inclusions were affected by oxygen content,and the main distribution range of the equivalent circle diameter(ECD) shifts from (2,3] μm to (5,7] μm.

Accurate determination of the speciation distribution of Se(Ⅳ) and Se(Ⅵ) in soil available selenium is crucial for studying the migration and transformation processes of selenium in the soil-plant system. The challenge lies in completely digesting the available selenium while preserving the original valence states. In this study, the available selenium extract was obtained following NY/T 3420-2019. After digestion with a nitric-perchloric acid system (ensuring valence stability of Se(Ⅳ) and Se(Ⅵ) during the perchloric acid fuming stage), the digest was treated as follows: (1) dissolved with 50% HCl(V/V) under heating to reduce Se(Ⅵ) to Se(Ⅳ), and total available selenium was determined by hydride generation-atomic fluorescence spectrometry (HG-AFS); (2) dissolved with 10%(V/V) HCl at room temperature to maintain the valence of Se(Ⅵ), and the content of Se(Ⅳ) was determined by HG-AFS; (3) the content of Se(Ⅵ) was calculated by subtracting Se(Ⅳ) from total available selenium. A method for determining Se(Ⅳ) and Se(Ⅵ) in soil available selenium by HG-AFS was thus established. Key parameters of the method were as follows: hydrochloric acid carrier concentration of 5%(V/V), potassium borohydride solution mass concentration of 13.0 g/L; interference was negligible when the concentration of coexisting elements did not exceed 500 times that of selenium. Method validation showed good linearity for Se(Ⅳ) in the range of 2.00-12.00 μg/L, with a linear correlation coefficient (r) of 0.999 7. The limits of detection for available selenium and Se(Ⅳ) were 0.001 2 mg/kg and 0.001 6 mg/kg, respectively. The method was applied to determine total available selenium, Se(Ⅳ), and Se(Ⅵ) in soil certified reference materials GBW(E)070333, GBW(E)070334, and GBW(E)070339. The relative standard deviations (RSD,n=6) of the results ranged from 1.9% to 15%. The relative error (RE) between measured and certified values of available selenium was 0.59%-5.3%. The spike recoveries of Se(Ⅳ) and Se(Ⅵ) ranged from 91% to 108%, meeting the requirements of DZ/T 0289-2015 Specification for Regional Eco-geochemical Assessment.

At present,the hydrochloric acid-calcium acetate centrifugal exchange method is the mainstream method for the determination of cation exchange capacity in calcareous soils.However,the operation of each link in this determination method is complex,and it requires a high level of skill from the operator.It is difficult to precisely control the actual operation,and the precision of the experimental results can hardly meet the quality requirements of relevant specifications.Based on the industrial standard NY/T 1121.5-2006 Soil testing-Part 5: Determination of cation exchange capacity in calcareous soils,the experimental conditions were optimized through experiments in this paper,which specifically included the following items:the appropriate concentration of hydrochloric acid was selected to effectively destroy and decompose the carbonates and gypsum in the soil,so that the soil solution reached a hydrogen-saturated state;during the process of using 40% ethanol (volume fraction) to remove the excess hydrochloric acid,a high-speed centrifuge was selected and the number of washing was determined,which significantly reduced the risk of soil colloid loss and destruction.The potentiometric titration method was used for the determination to ensure the stability and accuracy of the data.The cation exchange capacity(CEC) in 5 reference material for available nutrients of soil was determined according to the experimental method.The relative standard deviation(RSD,n=5) of determination results was between 1.4% and 3.7%,and the absolute value of relative error(RE) was between 0.5% and 2.4%.The determination results were compared with those obtained by traditional titration method,and the results of two methods were consistent with each other,and both could meet the quality control requirements of the technical specifications for the third national soil survey.The proposed method was applied for the determination of CEC in actual calcareous soil samples,and the RSD(n=12) of measured results ranged from 3.8% to 9.3%,which could meet the quality control requirements of the technical specifications for the third national soil survey.

The quantitative analytical method for 16 major and minor components(SiO₂,Al₂O₃,Fe₂O₃,CaO,MgO,K₂O,Na₂O,Ti,P,Mn,Cr,Cu,Ba,Sr,Zn and Zr) in soil and stream sediment by wavelength dispersive X-ray fluorescence spectrometry(WDXRF) with fusion sample preparation was established in this study.The fusion sample preparation parameters were optimized:the ratio of flux to sample was 1∶10;the ignition temperature was 600 ℃;the fusion temperature was 1 050 ℃;0.5 mL of LiBr solution was used as release agent.The fused beads with good surface flatness and optical homogeneity were prepared,which effectively eliminating the influence of matrix effect and particle size effect on the analytical results.In experiments,the calibration curves were drawn using the certified reference materials soil and stream sediment as well as the calibration samples prepared.The calibration curve ranges covered the high content components such as SiO₂(12%-75%),Al₂O₃(3%-28%) and Fe₂O₃(2%-15%).The matrix effect was corrected by theoretical α coefficient method,empirical coefficient method and Compton scattering internal standard method.The experimental results showed that the limits of detection were in range of 1-20 μg/g excepted for major components.The accuracy test was conducted using the certified reference materials soil(GBW07980) and stream sediment(GBW07360).The relative standard deviations(RSD,n=6) of determination results of 16 components were less than 5%,and the absolute value of relative errors(RE) were controlled within 5%.Compared to the traditional chemical analysis methods,the proposed method exhibited significant advantages such as short analytical cycle (less than 3 h per sample),strong adaptability to matrix and environmental friendliness(avoiding strong acid digestion).It could provide technical support for efficient analysis of regional geochemical surveys and soil pollution surveys.

Municipal solid waste incineration fly ash contains harmful substances such as heavy metals and dioxins (PCDD/Fs), so it is classified as hazardous waste. The common disposal method of fly ash is sanitary landfilling after solidification/stabilization treatment. However, this method occupies a large amount of land resources and poses a risk of secondary pollution, which cannot meet the requirements of urban sustainable development. The incineration fly ash is rich in effective mineral components such as CaCO₃, SiO₂, and Al₂O₃. With the rapid development of waste incineration technologies, resource utilization has become an important development trend. In this paper, the formation process, basic composition, and typical physical and chemical properties of incineration fly ash were systematically introduced. The main sources and migration and transformation mechanisms of heavy metals in fly ash were analyzed. Then the formation pathways of PCDD/Fs in fly ash were discussed. The differences in pollutant contents in fly ash across different regions and seasons were compared. Finally, the progresses on representative resource utilization disposal technologies and heavy metal separation-extraction technologies were summarized based on the main components of fly ash.

Aluminum ash residue has been listed in the National Catalogue of Hazardous Wastes for strict management due to its environmental hazards. However, with its high aluminum content, aluminum ash residue possesses significant recycling value. This paper tracks the latest environmental regulatory requirements for aluminum ash residue. It identifies its main components and environmental hazard characteristics, particularly heavy metal leaching toxicity and Al/AlN reactivity. The environmental risk sources associated with aluminum ash residue are analyzed, and its environmental and health risks are evaluated. The progress in both harmless disposal (including wet, thermal, and combined methods) and resource utilization (primarily in the production of water purification materials, building materials, and refractory materials) of aluminum ash residue is reviewed. Finally, key research directions for developing safe and green resource utilization technologies for aluminum ash residue are proposed, providing technical support for its future effective environmental management.

The solid waste attributes of two samples declared as "lead concentrate powder" and "lead-zinc ore" were identified and analyzed. Based on characteristics such as element content, phase composition, microscopic morphology, and particle size distribution, it was concluded that the two samples were lead-containing fume and lead pyrometallurgical slag, respectively. The main elements in the "lead concentrate powder" sample were lead, sulfur, zinc, tin, chlorine and copper, and the main phases were lead sulfate, basic lead chloride and zinc stannate. The particle size was very fine, and the microscopic morphology consisted of extremely fine spherical particle aggregates. These features are inconsistent with the characteristics of common lead ores, indicating it is lead-containing fume produced during pollution control processes. The main elements in the "lead-zinc ore" sample were silicon, zinc, iron, calcium, aluminum and lead, and its main phases were hardystonite, willemite, calcium zinc silicate and gatena. Its microscopic morphology showed a honeycomb-like microporous structure, consistent with lead pyrometallurgical slag. According to GB 34330-2017, both samples were identified as solid wastes.

Since the advent of focused ion beam(FIB) technology,it has developed from a micro/nanofabrication tool in the semiconductor industry into an indispensable platform for multimodal characterization in materials science.This paper systematically summarizes the fundamental principles and equipment configuration FIB technology as well as the key applications in micro/nanofabrication.The combination characterization strategies of FIB with scanning electron microscope(SEM),energy-dispersive X-ray spectroscopy(EDS),electron backscatter diffraction(EBSD),transmission electron microscope(TEM),and atom probe tomography(APT) are emphasized.The correlative characterization is classified into two categories,i.e.,in situ integration and offline correlative analysis.The advantages of two categories in dynamic process observation and cross-scale information association are discussed,respectively.In addition,the possible irradiation damage mechanisms in FIB fabrication and the mitigation strategy are analyzed in depth.The latest developments in FIB-related standardization efforts at home and abroad are introduced.Finally,the development trend of FIB technology toward higher performance,intelligent operation and deeper integration are prospected.The key roles of FIB technology in constructing material genome map and promoting materials design and property optimization are highlighted.

This paper systematically investigated the differences among the standard curve method,the certified reference material(CRM) curve method,and the standard addition method in inductively coupled plasma atomic emission spectrometry(ICP-AES) analysis,as well as their requirements for blank solutions.By deconstructing the spectral intensity composition of the calibration,sample,and blank solutions,the following conclusions were drawn:1)For the calibration curve based on the concentration of the added standard solution versus the spectral intensity,its intercept comprised the blank value,the content of matrix elements,and the fitting error.The measurement results required compensation for the over-deducted analyte content in the matrix metal.For the calibration curve based on the sum of the standard solution concentration and the matrix element content versus the spectral intensity,its intercept reflected only the blank value and fitting error,and the measurement results were final.No dedicated blank solution preparation was necessary in both cases.2)In the CRM curve method,the intercept encompassed the blank,CRM uncertainty,and fitting error.The test results were final,blank solution preparation was unnecessary,and abnormalities could not be judged solely by the blank value.3)The standard addition method required a blank solution and had the limitation of being unable to eliminate spectral interference from coexisting elements completely.4)When the calibration and sample solutions were prepared in separate batches,deducting their respective reagent blanks before calibration effectively eliminated blank variations caused by reagent batch differences.This approach solved the problem of reusing calibration solutions and yielded accurate test results.The study also showed that a full-process blank should be used when the matrix effect is minor,whereas a matrix metal blank solution should be employed when the matrix effect is strong (with results compensation).Moreover,the content of the analyte in the blank solution must be strictly controlled below half of the quantification limit to ensure accurate determination of elements at that level.

Focused ion beam-scanning electron microscope(FIB-SEM) has become a crucial tool in shale oil and gas research due to its ability in nanoscale precision in micro-nano fabrication,high-resolution imaging capability,and extensive range of accessory functions.Particularly,it demonstrates unique advantages in characterizations of shale reservoirs microstructure,pore characteristics,and organic matter distribution.The technical advancements and comprehensive applications of FIB-SEM in shale oil and gas research in recent years were systematically reviewed in this article,which covered multiple aspects such as the three-dimensional quantitative characterization of nanopore systems,microscopic distribution analysis of organic and inorganic matters,analysis of residual oil distribution,mineral identification and analysis,and the construction of digital rock core models based on serial sectioning-imaging.Furthermore,as a vital component in shale characterization,FIB-SEM could be integrated with other advanced techniques,which enabled the comprehensive characterizations that spanned from the nanoscale to the macroscale,encompassed multiple dimensions from chemical composition to physical structure,and covered multiple temporal domains from static imaging to dynamic evolution.The evolutionary behavior of shale under subsurface conditions or extreme environments could be revealed.The multi-scale and multi-dimensional comprehensive analysis platform built based FIB-SEM as the core,combined with the automation of equipment and the application of artificial intelligence(AI) technology,could provide unprecedented integrated research solutions for addressing complex systemic challenges in shale oil and gas,which willprovide critical technical support for research on microscopic mechanisms and the construction of macro-scale cognition in the field of petroleum geology.

The development of X-ray fluorescence spectrometry (XRF) has undergone 65 years in China,and the quantity of relevant technical literatures has exceeded 14 000. In 2019, the publication of paper Bibliometric analysis on research trend of X-ray fluorescence spectrometry based on CNKI and the book The literature index of X-ray fluorescence spectrometry analysis in China (1960-2015) opened up the statistical and quantitative research on the X-ray fluorescence spectrometry(XRF) literatures in China.On the basis of above two literatures and referring to the recently published review papers,this paper summarized the basic situation of Chinese XRF literatures from 1960 to 2024 in terms of bibliometric statistics,review papers and monographs(translated works),as well as the development process of technology and new technologies and applications.The section of literature metrology and statistics briefly introduced the types of XRF literatures in China,and focused on the main achievements of statistical research,which mainly included the annual distribution of total number of literatures,the overall distribution of journal literatures and the top 10 journals with the largest number of literatures.The section of paper review compiled 226 various review papers published over a span of 65 years from 1960 to 2024.The papers were reviewed according to the categorization of comprehensive reviews,annual reviews,and thematic reviews.The thematic reviews included the instrument (devices) and core components,software and sample preparation techniques,advancements in various application fields.The evaluations of these advancements included geological sample analysis,metallurgy and non-ferrous metals,environment and materials science,agriculture,food, and biomedicine,petrochemicals and process analysis,scientific archaeology and criminal investigation,precious metal jewelry and gemstones testing,and standard methods.The section of specialized(translated) works collected 31 specialized(translated) works officially published in China since the development of X-ray fluorescence spectrometry analysis,and provided a brief introduction by category.

This study established a method for identifying the solid waste attributes of imported aluminum scrap claimed as “Recycled Casting Aluminum Alloy Raw Materials”. A combination of techniques was employed, including visual inspection, ultra-depth-of-field microscopy for microstructural morphology, inductively coupled plasma atomic emission spectroscopy (ICP-AES), X-ray fluorescence spectrometry (XRF), and X-ray diffraction (XRD) for compositional, phase, and characteristic element analysis (e.g., lithium, nickel, cobalt). Residual carbon content was measured using an infrared carbon-sulfur analyzer, and the suitability of the sample for direct use as high-quality recycled aluminum feedstock was evaluated via a high-frequency melting furnace. Results showed that the sample consisted of fine gray-white particles. Under microscopy, the aluminum scrap exhibited a wrinkled morphology with numerous black granular inclusions. After sieving through a 120-mesh sieve, XRF revealed a significant decrease in aluminum content in the fine fraction, along with synchronous increases in nickel, cobalt, manganese, and copper. ICP-AES further confirmed the abundance of copper, nickel, cobalt, manganese, and lithium in the sieved fraction. XRD and infrared carbon-sulfur analysis detected lithium nickel cobalt manganese oxide and a small amount of carbon in the sample. During high-frequency melting, the sample produced intense flashing and left substantial residue, with a metal recovery rate below 30% and failure to form liquid metal. These characteristics neither comply with the quality requirements for aluminum scrap stipulated in GB/T 38472-2023 of Recycled Casting Aluminum Alloy Raw Materials nor align with those of conventional machined aluminum scraps. The elemental composition and phase characteristics are consistent with the properties of recycled lithium battery cathode materials. Based on the analysis of the recycling process for aluminum foil current collectors from ternary lithium battery cathodes and in accordance with GB 34330-2017 of General Principles for Identification of Solid Waste Attributes, the sample is identified as solid waste derived from recycled aluminum scrap of ternary lithium battery cathode materials.

The mineralogical characteristics of the integrated process from blast furnace slag to carbide slag to chlorinated residue, along with the occurrence and transformation behavior of titanium, were systematically studied using the AMICS automatic mineral analysis system. Results indicate that titanium in blast furnace slag primarily resides in perovskite (51.76%), titanium-rich pyroxene (26.96%), and titanian diopside (21.17%). Mineral crystallization followed the sequence: metallic iron > perovskite > titanium-rich pyroxene > titanian diopside. During high-temperature carbonization, titanium in perovskite transformed into titanium carbide. Titanium carbide particles (0.5-5 μm) were encapsulated within titanian augite, forming titanium carbide coatings surrounding metallic iron. The low-temperature chlorination process demonstrated significant selectivity: successful chlorination of most titanium carbide increased the titanian augite content in the residue to 94.90%(mass fraction, the same below). Unreacted titanium carbide (3.38%) concentrated within the core zones of titanian augite grains, and zones with well-developed fractures exhibited higher chlorination completeness. These findings elucidate the phase transformation mechanism of titanium during blast furnace slag valorization, providing a theoretical basis for enhancing titanium recycling efficiency.

Silicon-based ferroalloys are widely used in the steel metallurgy and casting industries as deoxidizers,alloying agents and inoculants.For the scientific guidance of production and application,it is of great significance to accurately and rapidly detect the main and trace alloy components in silicon-based ferroalloys.Due to the advantages of high precision,high sensitivity,accuracy,rapidity and high degree of automation,X-ray fluorescence spectrometry(XRF) analysis has played a crucial role in many fields such as on-site quality control in production,research and development of new materials,exploration of physical and mineral resources,environmental protection and cultural relic identification.As an important analytical method for characterizing the chemical composition and properties of substances,XRF has gradually been deeply studied and widely applied in the composition detection of silicon-based ferroalloys since the 1990s.The author has retrieved that 4 monographs related to the analysis of silicon-based ferroalloys have been compiled by chemical detection technicians in China. 30 classic chemical analysis standard methods and 27 modern instrumental analysis standard methods for silicon-based ferroalloys were studied and formulated.A total of 44 research papers on the analysis of the chemical composition and technology of silicon-based ferroalloys by XRF method have been published in various journals,magazines and national industry conference paper collections,including 21 papers on the analysis of silicon-based ferroalloys by XRF with pressed powder pellet and 23 papers on the analysis of silicon-based ferroalloys by XRF method with fusion sample preparation.The sample preparation technology,the selection of reference materials,the calibration of working curves,the scientific nature of detection data and the application prospects of silicon-based ferroalloys analyzed by XRF were briefly reviewed in this paper. Total 105 articles were cited.

The gold ore is one of the scarce strategic ores in China.The sample processing and preparation process and the representativeness of samples are the main factors affecting the gold measurement results.In this paper,the research reports on domestic gold ore sample preparation since 2000 were retrieved and summarized.The paper publication overview,the source of gold samples,the occurrence state and particle size of gold in ore samples,the number of gold ore samples and gold grade characteristics,the coarse,middle and fine crushing of ore samples,the sample reduction and the processing research on difficult-to-break samples such as coarse gold were systematically sorted in order to provide support and reference for the processing,preparation,application and in-depth research of gold ore samples.

The research landscape, knowledge structure, and evolution trends in the field of inductively coupled plasma atomic emission spectrometry (ICP-AES) were systematically analyzed in this study based on the CNKI database, using bibliometrics and knowledge mapping methods. The analysis, conducted with the aid of visualization tools, included statistics on the yearly distribution of articls, contributions of institutions, high frequency key words, and highly cited articls. The results showed that: (1) Temporally, research on ICP-AES grew rapidly after 1991 and reached its peak in 2013 (with 571 articles published annually); (2) Different institutions exhibited distinct innovation pathways; (3) Research topics focused on heavy metal detection, industrial material analysis, and biomedical applications, while technical bottlenecks were primarily concentrated on spectral interference and uncertainty control; (4) The highly cited articles from 2001 to 2014 were concentrated in a core group of journals, namely Metallurgical Analysis, Spectroscopy and Spectral Analysis, and Rock and Mineral Analysis(collectively accounting for 45.9%), highlighting its interdisciplinary nature. The study concluded that ICP-AES technology sustains its vitality through interdisciplinary integration, and future innovation should be driven by technological convergence (e.g., integration with artificial intelligence). This study provides an empirical reference for technical planning and interdisciplinary intersection in the field of analytical chemistry.

Microbeam X-ray fluorescence spectrometry(μ-XRF) is a non-destructive technique for composition distribution characterization,and it can obtain the quantitative parameters of composition distribution at the original position of sample.Due to the high spatial resolution of μ-XRF and large size of test sample,the amount of raw data generated in test increases greatly.It is difficult for the traditional manual method to handle the processing of large conventional data and the calculation of parameters for precision testing in standard method.In this study,a DouBao artificial intelligence(AI)-assisted scheme for data automation processing and precision calculation was proposed.μ-XRF was employed for the original position quantitative statistical distribution analysis of superalloy.The quantitative statistics and precision calculation process of chromium(Cr) in superalloy were selected as an example to introduce the application of AI in raw data processing,consistency and outlier of test results,calculation of total mean and variance,establishment of precision value and average level relationship,and visual output,etc. Python codes were automatically generated using the DouBao AI tool,realizing the high-throughput processing of original position quantitative statistic results and rapid handling of precision testing data.The function relationships between repeatability limits,quasi-reproducibility limits and content were obtained.The time for raw data processing and precision calculation by μ-XRF was shortened.This study provided an innovative solution for high-throughput data processing in the field of material analysis, and it had broad application prospects.

Angola possesses favorable geological conditions with high-purity quartz deposits.However,there is no report on the analysis method for impurity elements and silicon dioxide purity in Angolan quartz ore to date.In this study,1 g of sample was calcined at 960 ℃ for 1 h,and the loss on ignition(LOI) was calculated by measuring the mass difference before and after calcination.Then 0.25 g of sample was completely digested with 5 mL of HF,0.5 mL of HNO₃,and 0.1 mL of HClO₄.After evaporation,the residue was redissolved with 5 mL of aqua regia.The contents of 16 impurity elements(potassium,calcium,sodium,magnesium,aluminum,iron,titanium,manganese,barium,zinc,nickel,copper,cobalt,chromium,lithium,and vanadium) were determined by inductively coupled plasma atomic emission spectrometry(ICP-AES).The linear correlation coefficients of calibration curves for all elements were not less than 0.999 8.The limit of detection for each element ranged from 0.02 to 2.78 μg/g.The content of impurity elements in Angolan quartz ore samples was determined according to the experimental method,and the relative standard deviations(RSD,n=6)was all less than 11%.The proposed method was applied for the determination of impurity elements in certified reference material quartz rock GBW07837,and the absolute value of relative errors(RE) of results was all below 5.8%.The LOI and impurity elements of 10 Angolan quartz ore samples were analyzed according to the experimental method.By converting the impurity contents into oxides and summing them with the LOI,the silicon dioxide purity(in mass fraction) was calculated through subtraction method.The results indicated that the silicon dioxide purity in samples all exceeded 99%.

ISO/IEC 17043:2023 Conformity assessment-General requirements for the competence of proficiency testing providers has been officially released. Due to the continuous development and evolution in the field of conformity assessment, the 2023 edition has involved in significant changes in English title and technical contents compared with the 2010 edition. In order to adapt to these changes and improve the scientificity of the standards, and also help readers further understand the connotation of international standards, in the process of the equivalent transformation of ISO/IEC 17043:2023 to China’s national recommended standards, the translators changed the translation of “performance” (which was widespread in the standard and related to result evaluation), literally from “competence evaluation” in GB/T 27043-2012 to “performance evaluation”. Meanwhile, the translation of “proficiency testing”, which had been widely accepted in China, was kept without change. The translation of “competence” was also unchanged, which was consistent with other national recommended standards for conformity assessment. This paper discriminated the connotation and differences of the above three English words, and introduced the background, reasons and guiding direction of the maintenance and change of translations, aiming to promote the correct understanding and application of the above concepts by proficiency testing providers and participants.

The unique advantage of the focused ion beam-dual beam scanning electron microscope(FIB-SEM dual-beam system) lies in its simultaneous capability for high-resolution imaging and nanoscale micro-area processing precision.In this paper,the fundamental functions of FIB-SEM dual-beam system and the conventional procedures of chip failure analysis are first briefly introduced.Then the application cases of FIB-SEM dual-beam system in defect and failure analysis of different types of chips are discussed,including three-dimensional failure analysis of silicon-based integrated circuits and hot spot cross-sectional analysis of power devices.In the case of three-dimensional failure analysis of silicon-based integrated circuits,a novel three-dimensional failure analysis method is introduced,which is more time-efficient and high-effective compared with the traditional FIB-SEM three-dimensional reconstruction method.In this method a planar transmission electron microscope(TEM) sample which covers the hot spot area is prepared in the X-Y direction,i.e.,the direction parallel to the chip surface.Subsequently,the planar-to-cross-sectional sample preparation method is adopted to convert the planar sample into a cross-sectional sample perpendicular to the chip surface.This three-dimensional analysis confirms that the abnormal point is indeed an abnormal overlap of tungsten(W).In another case of hot spot cross-sectional analysis of power devices,the silicon-based insulated gate bipolar transistors(Si-IGBT) is used as an example.The key steps and parameter selections for failure analysis of power devices using FIB-SEM are introduced in detail,including the selection of currents for ion beam cutting and protective layer deposition.Finally,the development prospect of FIB-SEM technology in this area is summarized.

Inductively coupled plasma tandem mass spectrometry (ICP-MS/MS) has great advantages in the analysis of trace and ultra-trace impurity elements in high-purity refractory metals. In this study, the high matrix introduction (HMI) ICP-MS/MS method was employed to analyze specific interfering elements in high-purity refractory metals, such as trace silver (Ag) in high-purity niobium (Nb), trace platinum (Pt) in high-purity hafnium (Hf), and trace gold (Au) in high-purity tantalum (Ta). The HMI parameters were optimized: the carrier gas flow was 0.45 L/min, and the dilution gas flow was 0.65 L/min,enabling direct quantification using calibration curves without matrix matching.The reaction mode and action mechanism of O₂/NH₃ in tandem quadrupole mass spectrometer (MS/MS) mode was investigated to eliminate the mass spectral interference of matrix on tested elements. Ag was analyzed in the O₂ on-mass mode (primary mass filter Q1=107, secondary mass filter Q2=107) with the flow rate of 0.50 mL/min. Pt and Au were analyzed in the NH₃ mass shift mode (Pt: Q1=194, Q2=228; Q1=195, Q2=229. Au: Q1=197, Q2=231) with the flow rate of 0.75 mL/min and 0.50 mL/min, respectively. The linear ranges of Ag, Pt, and Au were 0.10-50.0 ng/mL,with correlation coefficients (r) all greater than 0.999.The limits of detection were in range of 0.001-0.035 μg/g. The standard solution of Ag, Pt, and Au with known concentration was added into high-purity Nb, Hf and Ta matrixes for the standard addition recovery tests. Moreover, the precision investigations of measurement results were also conducted. The experimental results showed that the spiked recoveries of Ag, Pt, and Au were between 83.0% and 113.0%. The relative standard deviations (RSD, n=6) of determination results were between 3.0% and 7.9%. The proposed method was applied for the analysis of three high-purity refractory metals, and the results were compared with those obtained by glow discharge mass spectrometry (GDMS). It was found that the determination results of two analysis methods were basically consistent.

In view of the low content of Co in domestic reference materials copper concentrate, the content range of Co was expanded in experiments by adding spectrally pure substance Co₂O₃.The calibration curves were established using 17 certified reference materials/reference materials copper concentrate,and 5 artificially synthesized copper-cobalt mixed concentrate calibration samples.The determination of 15 components(Cu,Co,S,Pb,Zn,Mn,Ni,As,Bi,SiO₂,Al₂O₃,TFe,K₂O,CaO and MgO) in copper-cobalt mixed concentrate was achieved by X-ray fluorescence spectrometry(XRF) with fusion sample preparation.The conditions for fusion sample preparation were optimized:0.200 0 g of sample and 1.500 0 g of LiNO₃ were fully ground and mixed in agate mortar,and then encapsulated in 6.000 0 g of Li₂B₄O₇-LiBO₂ mixed flux.The mixture was pre-oxidized at 650 ℃ to effectively inhibit the volatilization of S.Then 4 drops of 500 g/L LiBr solution were added as the release agent.The fused bead was prepared by rotating and fusion at 1 050 ℃ for 10 min.The theoretical α coefficient method was used to correct the matrix effect,and interference correction was required for the elements with spectral line overlapping.The correlation coefficients of calibration curves were all higher than 0.999,and the limits of detection were between 12 μg/g and 255 μg/g.One copper-cobalt mixed concentrate sample was used for precision test,and the relative standard deviations(RSD,n=11) of determination results of components ranged from 0.32% to 8.9%.The trueness tests were conducted using reference material copper concentrate(GBW(E)070199) without participation of regression correction,artificial synthesized calibration sample(NK#) and production samples(1# and 2#).The found results by this method were basically consistent with the certified values/reference values and the results determined by national standard methods.The proposed method had certain guiding significance for the determination of copper concentrate sample with high content of Co.

The limit value of the standard deviation of 10 repeated measurements is commonly used as a criterion for factory acceptance and precision inspection of analytical instruments. However, testing standards typically provide only the laboratory repeatability limit (r), which is the critical value for the difference between two independent measurement results of the analyte. The standard deviation of repeated measurements (instrument precision, S_n) and the repeatability limit (r) cannot be directly compared. This study establishes the relationship between the repeatability limit (r) and the instrumental measurement standard deviation (S_n) using the F-test, to determine whether the instrument precision meets the precision requirements of the testing standard. The results were compared with those from the χ²-distribution method and the range method. The results indicate that when the degree of freedom γ₂=30, the F-test yields results consistent with those of the χ²-distribution method and the range method. Therefore, all three methods can be used as general approaches to evaluate whether the instrument precision complies with the requirements of a specific testing method. When γ₂ ≤ 16, the upper limit of the standard deviation obtained by the F-test is significantly higher than that calculated by the other two methods. In such cases, the F-test should be applied for data evaluation, as the other methods may incorrectly classify some qualified data as unqualified. The testing method for hydrogen content in steel was used as an example to verify whether the precision of a hydrogen analyzer meets the requirements of the testing method.

Focused ion beam(FIB) technology demonstrates significant value in semiconductor device research due to its high-precision micro/nano fabrication and in-situ analysis capabilities.This paper aimed to provide an in-depth exploration in typical applications of FIB in semiconductor device processing and elemental analysis.The FIB system was employed to realize the microelectrode fabrication for two-dimensional materials and one-dimensional nanowires,as well as to precisely process optical microstructures such as solid immersion lens(SIL) and two-dimensional photonic crystals.Furthermore,by combining FIB with time-of-flight secondary ion mass spectrometry(ToF-SIMS),a high-resolution analysis of elemental depth distribution in semiconductor multilayer film structures was achieved.The experimental results indicated that FIB enabled precise control of fabrication scales down to the 10-nanometer level,which significantly enhanced the device integration and performance.The combined FIB-ToF-SIMS technique effectively revealed the doping element and interface diffusion behavior.The study demonstrated that FIB was not only an efficient micro/nano fabrication tool,but also could synergize with characterization techniques such as ToF-SIMS to highlight its critical role as an advanced tool in the semiconductor field.It could provide essential technical support for the design,processing,and failure analysis of advanced semiconductor devices.

The accurately determination of impurity elements content in high-purity cesium is crucial for guiding the production impurity removal,improving the material performance,and ensuring the stable operation of national defense,military industry,satellite navigation and other fields.Due to the high chemical reactivity of cesium(it can be rapidly oxidized upon contact with air and it is explosive when exposed to liquid solvents),its sampling and decomposition pose severe challenges.In this study,the sampling was conducted in an argon atmosphere within an oxygen-isolated glove box.Based on the characteristic of cesium that its melting point (28.5 ℃) is slightly higher than room temperature but lower than hand temperature,the solid samples were melted into liquid using hand warmth as a heat source.A pipette was used for quantitative liquid transfer,overcoming the difficulty of sampling high-viscosity solids.The wall-hung samples were placed in open air for over 10 h.Utilizing the properties of easy oxidation for cesium,susceptibility to hydration for cesium oxides and deliquescence for cesium hydroxides,a three-stage gas-solid reaction chain of "oxidation→hydration→deliquescence" was constructed with oxygen and water vapor as reactants to achieve gradual passivation and mild decomposition.Based on this,a method for determination of 9 impurity elements in high-purity cesium,including lithium,sodium,potassium,calcium,magnesium,iron,aluminum,lead and rubidium,by inductively coupled plasma atomic emission spectrometry(ICP-AES) was established.To address the coupled ionization and physical interference effects caused by cesium matrix,a strategy was adopted that primarily used the matrix matching method(for correcting lithium,sodium,potassium,calcium,magnesium,iron,aluminum,lead) and supplemented by the standard addition method(for correcting rubidium).The calibration curves had good linear relationships,and the correlation coefficients (r) were all not less than 0.999 6.The limit of detection ranged from 0.000 001% to 0.000 042%,and the limit of quantification ranged from 0.000 01% to 0.000 42%.The content of 9 impurity elements in actual and synthetic high-purity cesium samples were determined according to the experimental method.The relative standard deviations(RSD,n=5) of the determination results were between 0.86% and 9.5%,and the recoveries ranged from 94.9% to 103% (except rubidium).The content of rubidium in sample was determined by inductively coupled plasma mass spectrometry(ICP-MS) and compared with the experimental method.It was found that the measurement results of two methods were basically consistent.

The determination of Ga, Rb, and Sr in rare earth metals and their oxides by inductively coupled plasma mass spectrometry (ICP-MS) is severely affected by double-charge interferences from matrix elements such as La, Ce, Er, Yb, and Lu, compromising the accuracy of the results. This study established a method using inductively coupled plasma tandem mass spectrometry (ICP-MS/MS). Samples were digested with nitric acid and hydrogen peroxide, and diluted with 1% (V/V) nitric acid for analysis. Rh was employed as the internal standard to correct for matrix effects, and the tandem quadrupole (MS/MS) mode was used to eliminate double-charge interferences from the rare earth matrix. The mass-to-charge ratio (m/z) of the first mass filter (Q1) was set to transmit ions at m/z of 69, 85, and 88. Ammonia (NH₃) was introduced into the collision/reaction cell. Under these conditions, the analyte ions (⁶⁹Ga⁺, ⁸⁵Rb⁺, ⁸⁸Sr⁺) do not react with NH₃, while the interfering double-charged ions (e.g., ¹³⁸La⁺⁺, ¹³⁸Ce⁺⁺, ¹⁷⁰Er⁺⁺, ¹⁷⁰Yb⁺⁺, ¹⁷⁶Yb⁺⁺, ¹⁷⁶Lu⁺⁺) undergo reaction with NH₃, forming product ions with m/z different from the analytes. The second mass filter (Q2) was then set to m/z of 69, 85, and 88, allowing only the unaffected analyte ions to pass through to the detector, thus effectively eliminating the mass spectral interference. The NH₃ flow rate was optimized, and the optimal value was found to be 1.80 mL/min. The calibration curves showed excellent linearity with correlation coefficients all greater than 0.999 9. The limits of detection (LODs) for Ga, Rb, and Sr ranged from 0.003 8 to 0.026 μg/g, and the limits of quantification (LOQs) were between 0.012 and 0.084 μg/g. This method was applied to determine Ga, Rb, and Sr in synthetic neodymium metal, synthetic samarium metal, CeO₂, Er₂O₃, and Yb₂O₃ samples. The relative standard deviations (RSDs,n=11) ranged from 3.8% to 13.5%, and the spike recoveries were in the range of 88% to 114%.

During the analysis of associated elements in coal and gangue samples by conventional methods, the ashing treatment is required. However, the operation of this process is complicated, and some elements are easily volatilized and lost. The traditional acid dissolution method cannot effectively remove organic matter, which will lead to lower determination results. In addition, there is no standard method for the determination of Li. In this study, referring to the idea of acid used for decomposing samples in GB/T 16659-2024 and DZ/T 0279.3-2016, the strong oxidizability of HNO₃, H₂SO₄ and H₂O₂ was employed to oxidize the organic matter in samples into carbon dioxide for removal. The adsorption and wrapping of carbon-containing substances on the samples were eliminated and the process of decarbonization by high-temperature burning was avoided. The addition of HF significantly enhanced the decomposition effect of silicon-containing minerals. The method for determination of Li, Be, V, Co, Ni, Cu, Ga, Pb, Mo, Sb, Th and U contents in coal and gangue by inductively coupled plasma mass spectrometry (ICP-MS) was established. The linear correlation coefficients (r) of calibration curves were between 0.999 1 and 1.000. The limits of detection in this method were 0.012-0.58 μg/g, and the limits of quantification were 0.08-2.32 μg/g. Three certified reference materials for composition analysis of trace harmful elements in coal were determined according to the experimental method. The relative standard deviations (RSD,n=7) of the measurement results for Be, Co, Ni, Cu, Pb, Mo, Sb, Th and U were between 1.9% and 8.7%, and the absolute values of relative error (RE, n=7) were between 0.28% and 7.31%. For the elements of Li,V,Ga, which have no certified values, the relative standard deviations (RSD,n=7) of the measured results were between 1.8% and 4.5%, and recovery rates were between 98% and 103%. Additionally, the results were compared with those obtained by sealed-vessel digestion-ICP-MS and they were found to be in good agreement. A statistical comparison using a t-test indicated no significant difference between the results derived from the two sample preparation methods.

As the chip structures continue to scale down,the surface defects generated during focused ion beam(FIB) sample preparation significantly affect the subsequent cross-section exposure and failure analysis results.However,the traditional manual evaluation of scanning electron microscope(SEM) images is increasingly unable to meet the efficiency and stability required by current sample preparation workflows.To address this issue,this study constructed an SEM image dataset covering 15 typical FIB-related defects and proposed a lightweight YOLOv5s-based deep learning detection method,which enabled the high-precision identification of defects under weak contrast,small target size,and complex texture backgrounds.Combined with batch detection and comma-separated value(CSV) based structured output modules,the system could automatically generate the defect categories and statistical summaries,which provided data-driven support for quality assessment and process monitoring.The experimental results demonstrated that the proposed method achieved good detection performance,robustness,and engineering applicability,which could effectively improve the automation and standardization of FIB sample quality inspection,thus offering a feasible approach for the intelligentization of microscopy analysis workflows.

During the determination of silver and copper content in silver-copper based brazing filler metal by traditional silver chloride precipitation-flame atomic absorption spectrometry(FAAS),the operation is cumbersome and time-consuming.In this study,the silver-copper based brazing filler metal sample was dissolved with nitric acid,and the content of silver and copper in solution was determined by X-ray fluorescence spectrometry(XRF).The influence of nitric acid concentration in sample solution on the determination results of silver and copper was explored in experiments.The interference of acid was eliminated by removing acid and steaming dry.The effect of solution volume on the determination results of silver and copper was also discussed,and 10 mL was selected as the optimal measurement volume.The spectral lines were examined,and AgKα and CuKα was selected as the analytical line for silver and copper,respectively.Cu 200 μm was selected as the AgKα spectral line filter,and 0.46° collimator was used for the measurement of CuKα spectral line.The correlation coefficients of calibration curves for silver and copper were both higher than 0.999 9.The proposed method was applied for the determination of silver and copper in silver-copper based brazing filler metal sample, and the relative standard deviation (RSD, n=6) of determination results was 0.16% and 0.21%, respectively. The content of silver and copper in simulation sample of silver-copper based brazing filler metal was determined according to the experimental method.The absolute value of relative error(RE) of measurement results was not more than 0.5%.The recoveries of silver and copper were 99.5%-100.3% and 99.5%-100.5%,respectively.The proposed method solved the problem of no solid referende materials,and it could effectively meet the demands of chemical composition analysis of silver-copper based brazing filler metal in welding processes.

To address the corrosion issue of platinum-gold crucible during the fusion sample preparation of ferroniobium, the effects of sample particle size, oxidant composition and dosage, and a stepwise pre-oxidation procedure were investigated. The results indicated that when the sample particle size was controlled at 0.074 mm, the fusion time could be reduced by 10 min compared to the sample particle size of 0.096 mm. A novel composite oxidant system of Li₂CO₃-LiOH-KNO₃ (mass ratio of 12∶20∶5) was employed. This system leveraged the alkaline fusion by LiOH and the assisted fusion from CO₂ release during Li₂CO₃ decomposition, while utilizing the mild oxidation characteristics of KNO₃ to replace the traditional Na₂O₂/BaO₂, significantly enhancing the reaction controllability. The interference from Br with the determination of 0.20% Al could be completely eliminated under the following experimental conditions: the fusion temperature of 1 100 ℃, 1.0 mL of LiBr solution, and a fusion time of 20 min. Based on these findings, a three-stage pre-oxidation method suitable for programmable fully automatic electric fusion furnaces was developed. In this method, the commercially available Li₂B₄O₇ crucible was used. The mass ratio of sample (0.25 g) to Li₂B₄O₇ and composite oxidant was controlled. After gradient pre-oxidation at 500-750 ℃, the sample was fused at 1 100 ℃. This approach not only completely avoided the corrosion risk of platinum-gold crucible, but also ensured the homogeneous formation of glass fusion beads. The calibration curves were established using standard reference materials, primary standard substances, and standard solutions of ferroniobium. The analysis method for simultaneous determination of eleven major and minor components (including Nb, Ta, Si, Al, P, Mn, Co, Cr, Ti, Fe and Sn) in ferroniobium by X-ray fluorescence spectrometry (XRF) was established. The linear correlation coefficients of calibration curves in this method were all not less than 0.999 5. One synthetic ferroniobium sample was determined according to the experimental method. The relative standard deviations (RSD, n=8) of determination results for Nb, Ta, Si, Al, P, Mn, Co, Cr, Ti, Fe and Sn were between 0.14% and 2.9%. One actual production sample of ferroniobium was selected for the comparison of this method and other methods as well as standard addition recovery tests. The results indicated that the determination values of Nb, Ta, Si, Al, P, Mn, Ti and Sn were consistent in two methods. The spiked recoveries of Fe, Cr and Co were between 101% and 110%.

The sample was prepared into suspension,and the effects of factors such as the dispersant and sample mass concentration in suspension on the analytical results by total reflection X-ray fluorescence spectrometry(TXRF) were investigated.The method for the determination of Ca,Ti,Cr,Mn,Fe,Co,Ni,Cu,and Zn in nickel ore samples by TXRF was established.The proposed method was applied for on-site application demonstration in Chengde,Hebei Province.The experimental results showed that the quantitative analysis accuracy of Zn would be affected when Ga or Ge was used as the internal standard element because the spectral peaks of Ga and Ge were close to those of the measured element Zn.Therefore,Se was selected as the internal standard element in experiments.The recoveries of elements were closer to 100% when ultrapure water was used as the dispersant.As the sample mass concentration in suspension increased,the recoveries of elements first showed an upward trend,then gradually stabilized at 100%,and then significantly decreased and seriously deviated from 100%.In order to obtain accurate measurement results,the sample mass concentration should be controlled in range of 10-20 mg/mL.The limits of detection were between 0.009 0 μg/g and 0.068 μg/g,and the relative standard deviations(RSD) were better than 15%.3 certified reference materials laterite nickel ore were determined according to the experimental method.The found results of TXRF analysis were consistent with the certified values and those obtained by inductively coupled plasma mass spectrometry(ICP-MS),which could meet the requirements of on-site analysis.The on-site analysis of nickel ore samples by TXRF was conducted in Chengde,Hebei Province,and the analysis results were consistent with those obtained by inductively coupled plasma atomic emission spectrometry(ICP-AES) or ICP-MS.The absolute values of relative error for most data were less than 20%,which proved the reliability of suspension sample preparation and on-site analysis of nickel ore samples. The proposed method provided technical support for the on-site exploration of nickel ore.

Gallium(Ga), as a critical strategic metal, has attracted increasing research attention due to its irreplaceable role in high-frequency semiconductors, optoelectronic devices, and new energy technologies. This paper provides a systematic review of Ga’s applications across four major domains: high-frequency semiconductor devices (e.g.,GaN HEMT power amplifiers and GaAs space solar cells), biomedical tracers (e.g.,⁶⁷Ga-labeled diagnostic agents), self-healing electrode materials (e.g.,liquid metal batteries), and magnetic functional components (e.g.,gadolinium gallium garnet magneto-optical devices). Furthermore, a comprehensive evaluation is presented on Ga detection methodologies, covering wet chemical methods, spectroscopic analysis, inductively coupled plasma mass spectrometry (ICP-MS), electrochemical methods, and emerging detection technologies. The findings aim to offer technical support for export regulatory authorities and provide a basis for establishing standardized procedures in testing institutions. Finally, this article offers a forward-looking perspective on the future directions of Ga applications and the evolution of detection technologies, with the goal of providing valuable insights for further research in this field.

Lithium ore serves as one of the primary sources of lithium metal, making the rapid and accurate determination of its lithium oxide content crucial for efficient resource development and comprehensive utilization. This study established a flame photometry method for determining lithium oxide in lithium ores. Samples were digested using a mixture of 10 mL hydrofluoric acid and 2 mL sulfuric acid (1+1), with a 0.5%-1% (V/V) sulfuric acid solution selected as the measurement medium. Results indicated that common easily ionizable elements (potassium, sodium, calcium, magnesium, rubidium, cesium, and strontium) caused no interference in the lithium determination. A excellent linear relationship was observed between the mass concentration of lithium oxide in the range of 0.50 to 30.00 μg/mL and the emission intensity, with a correlation coefficient (r) of 0.999. The method achieved a limit of detection of 0.001% for lithium oxide. The proposed method was applied to determine lithium oxide in CRMs lithium ore (GBW07152, GBW07153), CRM spodumene (GBW07734), a actual lithium ore sample, and a simulated high-lithium sample (with a lithium oxide mass fraction of 10%). The relative standard deviations (RSD, n=11) of the results ranged from 0.60% to 2.5%. Comparative analysis of one lithium ore sample and two certified reference materials (GBW07152 and GBW07153) using both this method and the national standard method (GB/T 17413.1-2010) yielded consistent results. Furthermore, the measured values for the reference materials agreed well with their certified values. This method is simple, cost-effective, and provides a reliable solution for the quantitative analysis of lithium oxide in remote mining areas and beneficiation/metallurgical laboratories.

Sulfur in tungsten tailings will cause environmental pollution and affect the product performance.Therefore,the accurate determination of sulfur content in tungsten tailings is essential to monitoring the environmental impact and support the development and utilization of tungsten tailings.In experiments,300 mg of copper sheet was used as flux agent to cover 150 mg of sample. The air was selected as the carrier gas.The sample was heated and burned at 1 250 ℃ for 4 min to convert the sulfur into sulfur dioxide.The potassium iodate standard solution was used to titrate the generated sulfurous acid with starch-potassium iodide as indicator.A method for the determination of sulfur in tungsten tailings by combustion-iodometry was established.The determination range of sulfur was 0.032%-26.58%.The content of sulfur in tungsten tailings sample was determined according to the experimental method.The relative standard deviations(RSD,n=11) of the results were between 0.13% and 2.2%,and the recoveries were between 93.4% and 101.4%.

With the surge in scrapped automobiles, the concentrations of platinum group metals (including platinum, palladium and rhodium) in the exhaust catalysts, known as "urban mines", are far higher than those in primary ore. Therefore, accurate determination of platinum, palladium and rhodium contents is essential for optimizing the recovery process, avoiding metal loss, unlocking economic value, and ensuring resource security. In this study, the sample was roasted at 600 ℃ for 4 h, then mixed with a flux (containing 0.7 g of nickel powder, 0.35 g of sulfur powder, 1.5 g of ferrous sulfide, 40 g of sodium carbonate, 5 g of silicon dioxide, 40 g of borax, and 1 g of flour). The mixture was melted at 1 050 ℃ for 60 min. After coprecipitation separation by adding 1.0 mg of tellurium, the contents of platinum, palladium and rhodium were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). This established a method for the determination of platinum, palladium and rhodium in waste automotive exhaust catalysts by nickel sulfide fire assay preconcentration combined with ICP-AES. Applying this method to waste catalyst samples, the relative standard deviations (RSD,n=11) were less than or equal to 5.5% and the spiked recoveries ranged from 99.8% to 100.4%. Analysis of the international certified reference material for automobile catalysts (SRM2556) yielded results for platinum, palladium and rhodium that were in good agreement with the certified values. The method employs a small-scale nickel sulfide fire assay technique, which ensures efficient capture of platinum, palladium and rhodium while significantly reducing nickel powder consumption. The resulting small nickel sulfide button exhibited favorable pulverization and dissolution properties. Following dissolution with aqua regia and employing tellurium coprecipitation and stannous chloride separation to effectively eliminate interference from base metals, the ICP-AES detection significantly enhanced the accuracy of precious metal determination.

Eutrophication of water bodies caused by excessive nitrogen and phosphorus is one of the water environment pollution problems worldwide. In this paper, the industrial by-product steel slag was selected as the research focus. The effects of initial pH, initial phosphorus mass concentration, steel slag dosage, and reaction time on the phosphorus removal by mechanical ball-milling modified steel slag were investigated. The phosphorus removal mechanism of steel slag was analyzed using scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). The results showed that mechanical ball-milling could significantly enhance the specific surface area of steel slag, which increased from 0.78 m²/g before modification to 4.39 m²/g. The optimal conditions for phosphorus removal were determined as follows: pH=9, dosage of 1.0 g/L, and reaction time of 24 h. Under these conditions, the adsorption capacity was 7.64 mg/g. The adsorption of phosphorus by steel slag followed the pseudo-second-order kinetic model, and the adsorption isotherms conformed to the Langmuir model. The removal of phosphorus using mechanical ball-milling modified steel slag was controlled by dual factors, i.e., physical adsorption and chemical adsorption. Monolayer chemical adsorption was dominant, which was accompanied by chemical precipitation and surface complexation.

The high mineralization degree and complex matrix components of brine result in severe matrix interference in the quantitative analysis of multiple elements. In this study, a method of standard addition correction-inductively coupled plasma emission spectrometry (ICP-AES) was developed. The gradient addition of standard solution into sample solution was used to eliminate the matrix effect. Under the recommended working parameters of the instrument, K 769.897 nm, Mg 279.078 nm, B 249.678 nm, Li 670.790 nm, Rb 780.027 nm and Cs 894.347 nm were selected as the analytical lines for potassium, magnesium, boron, lithium, rubidium and cesium, respectively. The simultaneous determination of potassium, magnesium, boron, lithium, rubidium and cesium in brine with the same matrix was achieved. The linear correlation coefficients of calibration curves for tested elements were all greater than 0.999 5. The limits of quantification in this method were between 0.036 mg/L and 1.20 mg/L. The contents of potassium, magnesium, boron, lithium, rubidium and cesium in brine samples from different regions were determined according to the experimental method. The relative standard deviations (RSD, n=11) of determination results were not more than 2.0%, and the recoveries were between 97.4% and 104.5%.

The composition design of certified reference material of cerium oxide is required for practical application based on cerium oxide product standard.In this study,the high-purity cerium oxide was used as the main matrix,then total components including 15 rare earth impurities and 23 non-rare earth impurities were added according to the properties of impurities.The methods of physical mixing,low-temperature drying and high-temperature burning were adopted.The dry-basis,pale yellow and powdery certified reference material candidates of cerium oxide for chemical composition analysis were prepared through grinding,sieving and mechanical mixing.The homogeneity and stability test results indicated the prepared certified reference material could meet the requirements.The content of 38 chemical components in certified reference material of cerium oxide for chemical composition analysis were characterized by various method with different principles in at least 9 laboratories with a high level of testing capability.The measured values were accurate and reliable,and the uncertainty evaluation was reasonable.The developed certified reference material could meet the traceability needs in actual production and scientific research.It gradually filled the gap of reference materials in the field of rare earths,and also provided a reference for the development of other types of reference materials.