To meet the higher requirements for material purity and impurity control driven by the rapid development of the rare earth market, a method for the determination of trace calcium in high-purity rare earth oxides was established using triple quadrupole inductively coupled plasma mass spectrometry (ICP-MS/MS). To address the isobaric interference encountered in the determination of calcium by ICP-MS, CH₄ was introduced as a reaction gas in MS/MS mode. This approach utilizes the charge exchange and chain reactions between CH₄ and ⁴⁰Ar⁺ to effectively suppress argon-based polyatomic ion interferences. By optimizing key parameters such as reaction gas flow rate and hexapole bias voltage, the background equivalent concentration (BEC) for ⁴⁰Ca was reduced to 3.77 μg/L under the conditions of a CH₄ flow rate of 3.0 mL/min and a hexapole bias voltage of -2 V. The method was applied to four high-purity rare earth oxide samples (purity not less than 99.99%). The relative standard deviation (RSD, n=6) ranged from 1.3% to 3.2%, and the spike recovery rates were between 94.6% and 105.8%. The results were in good agreement with those obtained from other laboratories, indicating that the proposed method is accurate, reliable, and suitable for the determination of trace calcium in high-purity rare earth oxides.

Significant progress has been made in recent years in formulating and revising standard methods for the physicochemical testing of nuclear-grade welding consumables. However, systematic divergences persist among inspection standards due to differences in national industrial bases, often leading to misinterpretation of technical requirements and ambiguity in implementation, thereby restricting international technical interoperability and equipment trade cooperation. This paper focuses on three core areas: chemical composition, mechanical properties, and metallographic inspection. It systematically compares the differences among the American (ASME), French (RCC-M), and Chinese (NB/T) codes and reviews the current application status of standard testing methods for nuclear-grade welding consumables. Furthermore, the study summarizes the technical characteristics of these three codes, identifies key issues within the current standardization system, and proposes constructive improvement measures. The findings provide technical support for establishing a more scientific and comprehensive inspection standard system for nuclear-grade welding consumables.

In the analysis of geochemical samples, traditional methods for determining silver (Ag), tin (Sn), and tungsten (W) often face challenges such as time-consuming sample treatment, complex operational procedures, and high requirements for operators’ technical proficiency and specialized knowledge. In this study, samples were digested using a high-pressure closed system with a hydrofluoric acid-nitric acid mixture, followed by the simultaneous determination of Ag, Sn, and W contents using inductively coupled plasma mass spectrometry (ICP-MS). Various digestion systems were investigated. Spectral and non-spectral interferences with the analytical isotopes of the target elements were systematically evaluated. The dilution technique and internal standard method were employed to effectively mitigate non-spectral interferences. Meanwhile, spectral interferences were successfully eliminated using the kinetic energy discrimination (KED) mode and online interference correction equations. The performance of the method was evaluated using certified reference materials (CRMs) of soil, stream sediment, and rock. The results demonstrated that the limits of detection for Ag, Sn, and W ranged from 0.016 to 0.24 μg/g. The relative errors (RE) between the measured and certified values were 0.43% to 8.33%, the logarithmic deviations (Δlg) were 0.003 to 0.035, and the relative standard deviations (RSD,n=6) were 2.0% to 7.6%. The method meets the determination requirements of the multi-objective regional geochemical survey specification (1∶250 000). It achieves simultaneous determination of multiple elements from a single digestion, significantly improving the work efficiency.

Besides being rich in major elements like copper, anode copper also contains relatively high levels of platinum group metals. Accurate determination of their content is crucial for optimizing smelting processes, assessing metal recovery rates, and controlling production workflows. In this study, a method based on nickel sulfide fire assay was established for the separation, enrichment, and determination of the six platinum group elements (PGEs: ruthenium, rhodium, palladium, osmium, iridium, and platinum) in anode copper samples. This method achieves efficient capture of PGEs through nickel sulfide fire assay and effectively eliminates matrix interference by combining the pulverization and dissolution characteristics of the nickel sulfide button with detection by inductively coupled plasma mass spectrometry (ICP-MS), thereby avoiding interference from matrix elements such as copper and nickel during ICP-MS determination. The results showed that under the optimal conditions (2 g sublimed sulfur, 15 g silicon dioxide, 5 g sodium nitrate, 10 g calcium fluoride, a covering agent of light magnesium oxide mixed with silicon carbide at a 3∶1 mass ratio, 1 050 ℃, and 20 min holding time), the nickel sulfide button exhibited a uniform texture and could be completely separated from the slag, significantly improving the enrichment efficiency of PGEs. When applied to the determination of the six PGEs in anode copper samples, this method yielded relative standard deviations (RSD, n=7) of 0.64% to 2.1%. The relative errors for the six PGEs in simulated samples ranged from -1.12% to 2.13%.

An analytical method for the determination of impurity elements in high-purity rhenium powder based on pulsed glow discharge mass spectrometry (Pulsed-GDMS) was established in this study. The experimental results indicated that the forming difficulty of rhenium powder due to high elasticity modulus could be effectively overcome using an ultra-high-pressure sample preparation system, which stepwise increased the pressure to 200 t, in combination with a thickened polytetrafluoroethylene cup as mold. The pressed powder sample obtained could meet the analytical requirements. The instrument conditions were systemically optimized and the optimal discharge parameters were obtained as follows: the pulse voltage was 950 V, the flow rate of discharge gas was 400 mL/min, the pulse duration was 90 μs, and the pre-sputtering time was 35 min. The MS interference was investigated in detail, and the appropriate isotopes and resolution mode were selected for testing elements. The limits of detection of method ranged from 0.001 to 0.98 μg/g, and the lower limits of quantification ranged from 0.003 to 3.3 μg/g. The contents of 69 impurity elements in high-purity rhenium powder were determined according to the experimental method, and the relative standard deviations (RSD, n=7) of determination results were all less than 25%. The proposed method was compared with inductively coupled plasma mass spectrometry (ICP-MS), inductively coupled plasma atomic emission spectrometry (ICP-AES) and atomic absorption spectrometry (AAS). Except for the measurement result of W, which had certain deviation with ICP-MS due to the excitation characteristics of powder sample, the determined results of other elements were basically consistent with those obtained by other methods, indicating that the proposed method had good accuracy and reliability.

The accurate determination of key target elements such as sulfur, boron, arsenic and gallium in geological samples is crucial to mineral exploration and comprehensive utilization of resources. In the conventional acid dissolution methods, boron easily reacts with acid to form volatile compounds (such as BF₃), resulting in significantly lower determination results. In this study, nitric acid-hydrogen peroxide-hydrofluoric acid-mannitol digestion system was adopted. The digestion temperature (150 ℃), mannitol solution dosage (2.0 mL, 5.0 g/L) and analytical line (S 182.034 nm, B 208.959 nm, As 189.042 nm, Ga 294.364 nm) were systemically optimized. The method for the determination of sulfur, boron, arsenic and gallium by inductively coupled plasma atomic emission spectrometry (ICP-AES) was established. The linear correlation coefficients of calibration curves were all not less than 0.999, The limit of detection (LOD) for sulfur, boron, arsenic and gallium in this method was 0.07, 0.25, 0.05, and 0.005 μg/g, respectively. The contents of sulfur, boron, arsenic and gallium in the certified reference materials (CRMs) of soil (GBW07980), stream sediment (GBW07311) and rock (GBW07103) were determined according to the experimental method, and the relative standard deviation (RSD, n=12) of determination results were all less than 10%. The measurement results were all within the range of uncertainty of certified values. The contents of sulfur, boron, arsenic and gallium in geological samples, including the soil survey sample 1#, geological mapping stream sediment sample 2# and general rock sample 3#, were determined according to the experimental method, and compared with the standard methods (DZ/T 0279.28-2016 for sulfur, DZ/T 0279.11-2016 for boron, DZ/T 0279.13-2016 for arsenic, and GB/T 14506.30-2010 for gallium). The results indicated that the determination values of this method were in good agreement with those obtained by the standard methods. The performance index of proposed method could meet the requirements of The Specification of Testing Quality Management for Geological Laboratories. The mannitol chelating agent effectively inhibited the volatilization of boron, which was suitable for the efficient analysis of multi-elements in geological samples.

Tungsten ore and molybdenum ore with multiple paragenetic and associated elements are important metal mineral resources. The accurate determination of contents of tungsten, molybdenum and associated elements is of great significance for the development of tungsten molybdenum mineral resources and the comprehensive evaluation of deposits in China. The current national standard methods generally adopt alkali fusion or open acid dissolution. However, a large amount of salt will be introduced in alkali fusion method, leading to matrix effect, which influences the determination accuracy. For the open acid dissolution method, the samples with high content of tungsten and molybdenum are hardly completely dissolved, leading to lower determination results. In this study, the sample was digested in high-pressure closed system at 180 ℃ using hydrofluoric acid and nitric acid as the digestion reagent. The redissolution with tartaric acid-aqua regia system could effectively solve the issues of hydrolysis and difficult dissolution for tungsten and molybdenum. By optimizing the digestion conditions and instrumental parameters, an analytical method for the simultaneous determination of tungsten, molybdenum, copper, lead, zinc and chromium in tungsten ore and molybdenum ore by inductively coupled plasma atomic emission spectrometry (ICP-AES) was established. The results showed that the linear relationship of each element in determination range was good, and the correlation coefficients were not less than 0.999 8. The limits of detection of this method ranged from 0.50 μg/g to 2.01 μg/g. The relative errors (RE) of determination results of certified reference materials (CRMs) were between -3.21% and 3.33%, and the relative standard deviations (RSD, n=6) ranged from 0.83% and 3.8%. The spiked recoveries were between 95.8% and 104%. The analysis results of actual samples were basically consistent with those obtained by traditional methods. The proposed method had the advantages of fast analysis speed, wide linear range, green and environmental protection, which was suitable for the rapid detection of batch samples.

The rapid and accurate determination of the vanadium content in vanadium ore is of great significance for the development and geological exploration of vanadium deposit resources. In this study, a method for the determination of vanadium (expressed as V₂O₅) in vanadium ore by inductively coupled plasma atomic emission spectrometry (ICP-AES) with microwave digestion was established. To address the characteristics of vanadium titano-magnetite (difficult to decompose) and vanadium-bearing stone coal (containing organic matter), the sample was digested using a hydrofluoric acid-nitric acid mixture in a closed-vessel microwave system. After digestion at 200 ℃ for 30 min and subsequent evaporation to near dryness at 170 ℃, the residue was leached with 5%(volume fraction) aqua regia. This procedure effectively avoided corrosion from hydrofluoric acid and interference from extraneous impurities. Based on spectral line comparison, V 292.402 nm was selected as the optimal analytical line for vanadium. The calibration curve showed good linearity for vanadium in the mass concentration range of 100-10 000 ng/mL, with a correlation coefficient (r) greater than 0.999. The limit of detection of method was 26 μg/g. The proposed method was applied to the analysis of certified reference materials (CRMs) for vanadium-titanium magnetite (GBW(E)070126-GBW(E)070130). The obtained results of V₂O₅ were in good agreement with the certified values, with relative errors (RE) ranging from -1.68% to 0.80% and relative standard deviations (RSD,n=6) between 1.7% and 3.6%, meeting the requirements of DZ/T 0130.3-2006. Method comparison experiments demonstrated that the results of this method were in better agreement with the certified values than those obtained by alkali fusion-ICP-AES. The verification results confirm that the proposed method possesses high accuracy and good repeatability, making it suitable for high-throughput and efficient detection of vanadium in vanadium ores.

The addition of zinc into steel can enhance strength and corrosion resistance. However, excessive zinc addition will compromise material properties. Therefore, accurate determination of zinc content is crucial for producing high-quality steel alloys. In this study, a method for the determination of zinc in steel by inductively coupled plasma atomic emission spectrometry (ICP-AES) was established. Elements causing significant spectral interference with zinc were identified, and their influences were analyzed under varying matrix compositions and sample masses. A mathematical correction model was developed for interference correction of the target spectral lines. The method was validated using various certified reference materials (CRMs) and samples. The results demonstrated that copper caused significant interference with Zn 202.548 nm, while nickel interfered significantly with Zn 213.856 nm. The interference effects of copper and nickel on zinc were stable across different matrices. The interference contribution varied significantly with sample mass, and the determination error correlated with it. After correction, the determination accuracy for six samples was significantly improved using Zn 202.548 nm and Zn 213.856 nm as analytical lines. The Zn 206.200 nm line experienced the minimum interference from coexisting elements and could be selected as the optimal analytical line. The determination range of this method was 0.001 0%-0.10% (mass fraction, the same below), with a linear correlation coefficient of the calibration curve not less than 0.999 8. The limit of detection was 0.000 14%, and the limit of quantification was 0.000 48%. Zinc contents in CRMs/samples were determined using the experimental method, yielding relative standard deviations (RSD, n=11) between 2.2% and 5.7%. The measured results agreed with certified/reference values. Comparison tests showed good agreement between the results of this method and those obtained by inductively coupled plasma mass spectrometry (ICP-MS).

To meet the demand for mercury content determination in mercury globules within specific industrial fields and to overcome the limitations of the existing method (inductively coupled plasma atomic emission spectrometry, ICP-AES), which requires tedious dilution and the addition of stabilizers for handling highly acidic solutions, this study aimed to establish a rapid and simple method based on energy dispersive X-ray fluorescence spectrometry (ED-XRF). Solid mercury globules were dissolved with nitric acid using ultrasonic agitation at 80 ℃ for 40 min, and the resulting solution was diluted to volume. The mercury content was directly determined by ED-XRF. The limit of detection of this method was 1.068 mg/L. Results obtained by this method were compared with those from ICP-AES for the same samples, and statistical analyses including the for outliers (Grubbs test), F test, and t test were performed. The results showed that both methods exhibited good linearity within their respective ranges (correlation coefficient r>0.999). The Grubbs test, F test, and t test results indicated no significant difference between the ED-XRF and ICP-AES results in terms of precision and trueness. For highly acidic test solutions, ED-XRF allows direct determination without dilution or stabilizer addition, thereby effectively avoiding errors associated with the dilution process and problems related to solution stability. The proposed method is suitable for the rapid and accurate determination of mercury in mercury globules.

The acid dissolution method is typically used for determining sodium in aluminum fluoride, but often fails to completely decompose the sample due to its highly stable chemical properties, leading to insufficient accuracy. To address this, lithium metaborate fusion was employed. Using anhydrous lithium metaborate as the flux, complete decomposition was achieved by fusion at 850 ℃ for 30 min. The resulting melt was then efficiently dissolved via ultrasonic leaching at 55 ℃ using a mixture of 10 mL of nitric acid (1+1) and 10 mL of water, thereby overcoming the decomposition challenge. A method based on lithium metaborate fusion followed by ultrasonic leaching and flame atomic absorption spectrometry (FAAS) was established for sodium determination. Matrix interference was eliminated by using calibration curves prepared with matched acidity, lithium, and aluminum concentrations. The calibration curve showed good linearity, with a correlation coefficient greater than 0.999. The limit of detection and limit of quantification for sodium were 0.000 63% and 0.010% (mass fraction), respectively. When applied to aluminum fluoride samples, the method yielded results with relative standard deviations (RSD, n=9) not more than 4.0% and spike recoveries between 98% and 99%.

The accurate determination of silver (Ag) content in silver-containing spent catalysts is of great significance for resource recovery. In this study, Ag in spent catalysts was leached with HNO₃-H₂O₂ system. Ag/AgCl electrode-platinum wire electrode was used as the working electrode pair, and Ag electrode-double salt bridge saturated calomel electrode was used as the indicator electrode pair in experiments. KNO₃ solution was selected as the electrolyte. The content of Ag⁺ in leachate was titrated by Cl^- generated in electrolysis. The potential jump was used to indicate the titration end point. The content of Ag was determined by coulometric titration. Consequently, the method for determination of Ag in Ag-containing spent catalysts by coulometric titration with acid-dissolution oxidation was established. The experimental parameters were systemically optimized, including the liquid-solid ratio, volume ratio of HNO₃ to H₂O₂, leaching temperature, leaching time, stirring speed, as well as the electrolyte concentration, current intensity, and anti-interference performance. The results showed that the optimal conditions were as follows: the liquid-solid ratio was 4∶1 mL/g, the volume ratio of HNO₃ to H₂O₂ was 1∶6, the leaching temperature was 50 ℃, the leaching time was 60 min, the stirring speed was 400 r/min, the electrolyte was 1.5 mol/L KNO₃ solution, the current intensity was 10-20 mA, and the coexisting metal ions had no interference. The content of Ag in Ag-containing spent catalysts was determined according to the experimental method, and the spiked recoveries were between 97.4% and 100.9%. The proposed method was applied for the determination of Ag in 4 Ag-containing spent catalyst samples, the relative standard deviations (RSD, n=5) of determination results were between 0.64% and 1.3%. The t-test revealed that there was no significant difference between the results obtained by this method and those by potentiometric titration. The proposed method had the advantages of simple operation, high efficiency and good accuracy, which could meet the recovery and detection requirements of Ag-containing spent catalysts.