Non-traditional stable isotopes are widely utilized in geoscience and other fields. However, it remains challenging to analyze many samples quickly with high accuracy and precision. In this study, new optimization strategies are proposed to improve the precision and accuracy of isotope ratio analysis using inductively coupled plasma quadrupole mass spectrometry (ICP-QMS). The instrument voltage parameters of cell entrance/exit voltage (CEV), cell rod offset (CRO), and quadrupole rod offset (QRO) were optimized to control the ion trajectory and reduce mass discrimination. The detector's signal acquisition parameters were also optimized to improve the precision of isotope ratio analysis. After optimization, the mass deviations in B, Sr, and Pb isotope measurements were significantly reduced to -0.25%, -0.13%, and -0.34%, respectively. The proposed isotope analysis method was applied to geological standard reference materials, including AGV-2, BCR-2, BHVO-2, GSR-7, GSD-21, GSD-23, and GSS-14. The measured values of B, Sr, and Pb isotopes were in agreement with the reported values. The precision values (2SD) for B, Sr, and Pb were better than 1.20‰, 0.34‰, and 0.00308, respectively. This approach enables direct analysis of various geological matrices without chemical separation and purification, making it possible to rapidly process large sample batches. It provides a more economical and simpler alternative, favoring the development of isotope-related applications in more fields.

As a valid seawater oxygen proxy, trace iodine in marine carbonates is crucial for reconstructing the redox conditions of the paleoceanography. Although highly sensitive inductively coupled plasma-mass spectrometry (ICP-MS) is often used for the determination of iodine, the accurately determining trace iodine of marine carbonates remains challenging due to its high volatility loss during the sample digestion and the matrix effect of coexisting high-calcium (Ca) in ICP-MS analysis. In this study, an ammonium bifluoride (NH4HF2) sample digestion ICP-MS method was evaluated for analyzing sub-mu g/g levels of I in marine carbonate rocks. Results show that more than 97% of the target iodine can be well retained in the digestion solution, while simultaneously achieving the removal of the coexisting calcium matrix (over 86% of the calcium remains in the residue). The limit of detection (LOD, 3 sigma) of the established method is 0.024 mu g g-1 (taken into 250-fold dilution) with the relative standard deviation (RSD, N=5) ranging from 3.2 % to 7.3 %. The proposed method was applied to determination of I in a series of carbonate rock reference materials (RMs) and the satisfactory results (recovery, 87-104%) indicate that it has great potential for the determination of trace level I in various marine carbonate rocks.

A simple and reliable external calibration strategy was developed for quantitative elemental imaging of fresh animal soft tissues using LA-ICP-MS coupled with a cryogenic ablation cell (CLA-ICP-MS). The suspension prepared with powder of certified reference material of animal tissue was frozen in the cryogenic cell and then used as the external standard. Compared to the traditional external standard preparation methods such as tabletting method, the proposed strategy has a controllable solid-liquid ratio, which not only ensures a high matrix matching with fresh animal tissue samples, but also shows a significant sensitizing effect (signal intensity increased by 1.3 times to 8.2 times). With simple and reliable process, the proposed method can ensure good dispersion and acceptable long-term stability of external standards for suspensions, which overcomes the shortcomings of gelatin standards easily deteriorated by moisture absorption. The method was validated with animal reference materials, yielding relative errors below 10% for most elements and limits of detection (LODs) ranging from 0.1 ng g-1 (Ba) to 1872 ng g-1 (K). Applied to imaging Ce distribution in mouse spleen after CeO2 NP exposure, the results was similar to the previous study, demonstrating the method's potential for investigating toxicological mechanisms of metal NPs.

Teeth provide retrospective information regarding health status, dietary habits, age, and environmental exposures. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) enables direct solid analysis with high spatial resolution, rendering it well-suited for the microanalysis of teeth. However, accurate quantification is often hampered by the lack of matrix-matched calibration standards. In this work, an external calibration strategy based on hollow short-tube hydroxyapatite ceramics (HAP-T) was established. Due to the one-dimensional tubular architecture, the sintered HAP-T ceramic exhibits high density and mechanical robustness, and its laser ablation behavior was similar to that of tooth samples. The doped trace elements were homogeneously distributed in HAP-T, with relative standard deviations (RSDs) of line scan signals in the range of 7.17–11.07

Cadmium (Cd) isotopes serve as powerful tracers for biogeochemical cycling processes. However, significant interference from organic matter exists in the Cd isotope measurements of organic-rich samples with low Cd contents. Even when the residual organic carbon content is extremely low after complete digestion, inaccuracies in the Cd isotope ratios persist. In this study, the effects of organic matter on Cd isotope measurements were investigated using NIST SRM 3108 Cd standard solutions doped with varying proportions of glucose. Results showed that Cd signal intensities and isotope ratios were influenced by glucose, even at extremely low concentrations. LC-MS chromatogram and ICP-MS analyses indicated that the effect of extremely low organic matter on Cd isotope measurements was caused by polyatomic ion interferences resulting from the incomplete ionization of the ring-structured glucose molecules rather than matrix effects. A UV/HNO3-H2O2 digestion procedure was developed and validated to eliminate these interferences. After UV digestion, accurate and high-precision Cd isotope ratios were obtained even for 10 ng mL-1 Cd solutions containing up to 5000 & micro;g mL-1 glucose. The proposed method was applied to seven certified biological reference materials. The measured delta 114Cd values for NIST SRM 1573a, GSB-14, and GSB-16 were consistent with previously reported values, while the delta 114Cd values for NIST SRM 1568b, IAEA-450, GSB-1, and GSB-6 are reported for the first time.

Cadmium (Cd) isotopes can provide vital insights into the marine biogeochemical cycling of Cd. Cd isotope fractionation during phytoplankton uptake varies with marine conditions, but the direction and magnitude remain poorly constrained. In this study, the marine diatom Thalassiosira weissflogii was cultured under a range of controlled environmental conditions to systematically investigate the direction and magnitude of Cd isotope fractionation during phytoplankton uptake. The results show that the Δ114Cddiatom-cultured solution values range from −1.08 ± 0.13‰ to −0.28 ± 0.07‰. These results demonstrate that phytoplankton preferentially take up lighter Cd isotopes, leaving isotopically heavier Cd in the cultured solution. The magnitude of Cd isotope fractionation is markedly influenced by temperature, biomass, and pH, but is independent of salinity. The variations in Cd isotope fractionation across different initial Cd concentrations and biomass levels suggest a coupling effect between Cd concentration and biomass. The bioavailable Cd concentration per cell is the primary control on this coupling effect. A distinct nonlinear trend in the Cd isotope composition of diatoms emerges with increasing diatom Cd quota across varied environmental conditions. A dynamic shift between kinetic and equilibrium effects likely governs the observed “kink” in the trend. These findings provide a valuable mechanistic framework for understanding the marine biogeochemical cycling of Cd and for refining the application of Cd isotopes as a tracer for paleoenvironmental reconstruction.

The iodine-to-calcium (I/Ca) ratio in marine carbonates can indicate changes in seawater redox. The use of inductively coupled plasma mass spectrometry (ICP-MS) to determine the I/Ca ratio in carbonates is challenging owing to low iodine content, volatility, and significant Ca matrix effects. In this study, an online extraction device was designed to evaluate the influence of extraction time on the detection of iodine signals. The intensity of I signal increased from 0 to 3 min after the addition of 2% HNO3, and a stable I signal was obtained from 3 to 8 min. After 8 min, the analytical signal decreased owing to the volatilization of iodine. Experimental results revealed a linear relationship between the intensity of I/Ca ratio and the concentration of I/Ca ratio, indicating that Ca can serve as an excellent internal standard (I/Ca ratio) to correct the attenuation of the I signal caused by Ca matrix effects. Therefore, a novel online acid extraction method coupled with ICP-MS was developed by strictly controlling extraction time (3-5 min) and using the I/Ca ratio for direct correction to obtain the final I/Ca ratio, with a detection limit of 0.02 mu mol/mol and relative standard deviation ranging from 1.5% to 10.3%. The proposed method was applied to determine the I/Ca ratio in carbonate reference materials. The measured I/Ca ratios were consistent with the reference values.

Rare earth elements (REEs) with systematically varying properties are useful indicators of marine geochemistry. However, the accurate determination of REEs in seawater is complicated because of their low elemental concentrations, highly saline matrices, and contamination of the samples during pretreatment. Herein, we report a rapid, automated, and reliable method using a novel automated separation system (ELSPE-2 Precon) that efficiently separates seawater matrix elements and elutes preconcentrated targets directly into inductively coupled plasma-mass spectrometry (ICP-MS) online detection. The detection limits (3 s) were in the range from 0.002 (Dy) to 0.097 ng L-1 (La), and the accuracy of this method was confirmed using a seawater certified reference material (NASS-6). This method was used for the long-term measurement of REEs in three new seawater reference materials (NASS-7, CASS-6, and NMIJ 7204-A) and the preferred values were provided for subsequent studies. Compared with other commercially available systems (i.e., SeaFASTT), the proposed system exhibited a higher throughput (>14 samples/h) and lower sample consumption (< 1 mL/sample).

Although the laser ablation-inductively coupled plasma-optical emission spectrometry (LA-ICP-OES) is a promising method for the elemental screening of solid food materials, the main challenge associated with this technique is the lack of commercial solid standard reference materials to serve as the external standard for quantitative calibration. In this study, a reliable internal standard-free LA-ICP-OES method for direct sampling and analysis of solid food materials was developed. The method relies on the carbon internally-standardized relative sensitivity factor (CIS-RSF) was developed, eliminating the need for calibration curves or matrix-matched external standards once the CIS-RSF has been determined. After careful evaluation of the effect of the instrumental operating parameters on the long-term stability of CIS-RSFs, this method was used to analyze a variety of microelements, including sulfur (S), phosphorus (P), zinc (Zn), iron (Fe), manganese (Mg), magnesium (Mn), copper (Cu), calcium (Ca), strontium (Sr), barium (Ba), sodium (Na), and potassium (K), with the limit of quantitation (LOQ) ranging from 0.06 (Sr) to 400 mu g g-1 (S). The accuracy and reproducibility of this proposed method were evaluated through the analysis of three food NIST reference materials and six typical food samples. The results indicated that the relative error of most target elements was less than 20% and the reproducibility (SD, n = 3) more than 10%. This developed LA-ICP-OES screening method has great potential for the high-throughput multielement determination of various solid food materials.

A simple method is presented to suppress the thermal effect for the accurate determination of multi-elements in sulfide minerals using laser ablation inductively coupled plasma mass spectrometry with a cryogenic ablation cell (CLA-ICP-MS).

Accurate determination of the thickness of multi-layered nanofilm materials is of great importance to advance the development of thin film deposition technology and ensure the quality assurance of photovoltaic materials. Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been successfully employed for depth profiling of thin film materials, such as metal coatings. However, the accuracy of interface discrimination and thin layer thickness measurement is limited by the mixing effects of elemental signals. In this work, a high-depth resolution method for measuring the thin film thickness of lead sulfide (PbS) colloidal quantum dot (CQD) photovoltaic devices by LA-ICP-MS was introduced. The influence of different laser parameters on the mixing effects of element signals during the ablation process was compared, and the results showed that the laser ablation behavior of multi-layered nanofilm materials were improved and the mixing of element signals were reduced by optimizing parameters such as laser energy density and spot diameter. Meanwhile, a self-developed aerosol rapid wash-out small volume tubular ablation cell was used to effectively improve the aerosol transport efficiency, and the wash-out time of aerosol was (1.60 +/- 0.6) s. Compared with commercial cylindrical ablation cells, the depth profile of multi-layer thin film samples was clearer. The depth profile of the interlayer interface showed a significant melting phenomenon during the ablation of the PbS CQD layer, leading to severe mixing of elemental signals at the PbS/ZnO layer interface. Under the conditions such as 2.5 J/cm2 laser energy, 32 mu m spot diameter, and 1 Hz repetition rate, the average ablation rates of Au, PbS and ZnO layers in PbS CQD photovoltaic devices were (60 +/- 2) nm/pulse, (69 +/- 5) nm/pulse, and (22 +/- 2) nm/pulse, with depth resolution of (26 +/- 2) nm, (213 +/- 11) nm, and (68 +/- 6) nm, respectively. The thickness of PbS CQD photovoltaic device films from the same batch was determined, and the test results exhibited good consistency with scanning electron microscope (SEM) measurement values, with a relative deviation of less than 6%. This method could accurately determine the thickness of nanoscale multilayer thin film samples, which was crucial for improving the performance of photovoltaic devices and controlling product quality.

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

A simple and reliable external calibration strategy of LA-ICP-MS for fresh plant soft tissues was developed. The prepared plant suspension was frozen by the designed cryogenic ablation cell and used as external standard for quantitative elemental imaging analysis of fresh plant tissues. The controllable water content of the prepared external standards provides a similar matrix with fresh soft tissues, and a homogeneous elemental distribution could be ensured due to the fine grinding particle sizes. More interestingly, the presence of water increased the signal intensity produced by the suspension by a factor of 1.6 (Pb) to 66.6 (La) compared to that of the pressed cake. The excellent dispersing property and advantage of long-term use were achieved owing to the employment of 0.1

Investigating the spatial distribution of ultra-trace mercury (ng L-1) in volcanic and geothermal areas can provide insights into geological anomalies and regional volcanism. In this study, an accurate and precise method for Hg determination in geothermal water was developed using inductively coupled plasma tandem quadrupole mass spectrometry (ICP-MS/MS) and a collision/reaction cell (CRC). The experimental conditions, including the Hg isotope type and CRC gas, were optimized to eliminate severe tungsten oxide (WO) interference that occurs in conventional ICP-MS analysis of Hg. A When O 2 was used as the CRC gas in the MS/MS mode, the limit of quantitation (LOQ) for Hg was 0.5 ng L-1. The proposed method was successfully applied to the direct determination of Hg in a groundwater- certified reference material (ERM-CA615) and five geothermal water samples, two of which had an extremely high W content. T he satisfactory results indicate the significant potential of the proposed for determining ultra-trace levels of Hg in geological samples.

BACKGROUNDMicro-geochemical information of sulfide minerals plays a crucial role in the field of geochemistry, allowing discovery of the formation mechanism and evolution process of sulfide minerals by analyzing their element composition characteristics. LA-ICP-MS is currently the most popular microanalysis technology used for sulfide analysis, having yielded successful results. Due to their unique physical and chemical properties, sulfide mineral samples show different laser ablation behavior to conventional geological samples. The most intuitive phenomenon is the melting of ablation carters caused by laser thermal effect and the deposition of a large number of material particles around the ablation carters, which is the main factor limiting the precision and accuracy of sulfide sample analysis. Walting et al[13] found that direct quantitation of multi-elements in sulfide minerals by infrared laser (1064-nm Nd:YAG laser) was impossible, which was because the strong thermal effect generated by the infrared laser will lead to severe large particle aerosol redeposition. It is reported that ablation systems with shorter wavelengths, such as ultraviolet lasers, including the 266 and 213nm laser, can be used to obtain acceptable analytical accuracy by reducing the thermal effect and aerosol particle size, but a poor precision was still observed[16-17]. Guillong et al[19] conducted a comparative study of 266, 213 and 193nm lasers and found that there were finer particle sizes of the aerosols and the weaker thermal effect when using 193nm laser ablation, and the RSDs of all elements less than 20% were obtained. In other words, collisions between photons and matter intensify in deep ultraviolet laser ablation systems (193nm) with shorter wavelength[20-21] and can help reduce the melt zone and aerosol particle size. However, there is still a slight thermal effect during 193nm UV laser ablation. Fernández et al[22] found that there is still a melting layer during 193nm laser ablation, and it leads to the formation of large particle aerosols. Different methods have been proposed to improve the thermal effect during laser ablation of sulfide. Muller et al[25] found that the precision of line scanning could be improved by 50% compared to spot ablation. Guillong’s results showed that adding a small amount of hydrogen to the analysis could increase the sensitivity of the 47 elements in the test by two to four times[26]. Moreover, research has focused on improving the thermal effect of sulfide minerals from shorter pulse width lasers and aerosol particle transport[27-31]. However, there are still some thermal effects in the process of deep ultraviolet and short wavelength laser ablation, and how to inhibit the thermal effect in the process of ablation to obtain effective analysis results is still a difficulty in the analysis of sulfide mineral elements. The LA-ICP-MS low temperature ablation cell is an ablation system developed in recent years, whose main function is to provide a low temperature ablation environment to realize the effective analysis of cells, blood and other samples. The low-temperature ablation cell may be a new approach to resolve the thermal effect during sulfide mineral ablation.OBJECTIVESIn order to establish a high precision and high accuracy multi-element analysis method for sulfide minerals.METHODSThe use of a designed cryogenic ablation cell suppressed the thermal effect and refined aerosol particle sizes, which improved analytical precision and accuracy significantly. To explore the mechanism of sulfide ablation at low temperature, the aerosols ablated at low temperature were collected using an aerosol collection setup consisting of a membrane with an aperture of 0.1μm, which was installed at the outlet of the ablation cell. According to the micro-analysis results, the laser ablation behavior under low temperature ablation environment was further discussed.RESULTSA precision and accuracy method for multi-elements analysis of sulfide minerals using CLA-ICP-MS (laser ablation inductively coupled plasma mass spectrometry with a cryogenic ablation cell) was described. Ablation craters were investigated via scanning electron microscope (SEM) images to compare the amounts of melt produced. SEM measurements showed significant differences in melting between the low temperature (−30℃) and room temperature (20℃). The diameters and size distribution of particles were measured from nanometer particle potentiometer images of the collected ablated aerosol. Particles ablated using cryogenic ablation cell were smaller in average diameter (190nm and 400nm) and shorter in distribution range (570nm). Compared to the precision of time-resolved signal during laser ablation processes between the two temperatures, the precision was significantly improved and the RSD was reduced from 20.1%-34.4% to 11.5%-15.8% with a cryogenic ablation cell. A designed cryogenic ablation cell in sulfide sample analysis was utilized to minimize the thermal effect and improve analytical precision and signal intensity. In this study, the CRM (MASS-1) sample was analyzed with spot ablation mode at low (−30℃) and room (20℃) temperatures, respectively, and the RSDs of three times parallel analysis at these two temperatures were compared. At room temperature, the RSDs of elemental signals ranged from 20.1% to 34.4%. In contrast, the RSD of elemental signals was less than 15.8% when the sample was ablated at low temperature (Fig.2a). The significant improvements may be attributed to low ablation temperature, which suppress the thermal effect. Moreover, the signal intensities of elements improved by approximately 11% to 52% with the decrease in temperature of the cryogenic ablation cell (Fig.2b). Fig.2c shows the time-resolved signals of the MASS-1 sample at room temperature, the significant fluctuations and spikes could be observed, and the RSDs of all elemental signals was more than 20.1%. Interestingly, the signals at low temperature exhibited ideal stability, and the RSDs of elemental signals were less than 15.8%, as shown in Fig.2d. In order to explore the reasons for improving the analytical performance of low temperature, the morphology of ablation under different temperature conditions of two standard sulfide samples were discussed. SEM images of four ablation craters on chalcopyrite and pyrite were taken to investigate the effect of temperature on the ablation process (Fig.3). The sulfide samples were ablated using a 193nm excimer laser with a spot size of 60nm and a fluence of 8J/cm2. The ablation craters on the chalcopyrite showed a two-layer cyclic structure, in which the inner layer was a light-colored melting zone, and the outer layer was a white aerosol vapor sediment. At low temperature, there were fewer melt layers and thinner grain sediment zone than those at room temperature (Fig.3a, Fig.3b). However, the melting zone around the ablation craters of pyrite were more irregular. More of the unwanted ablation was melted away at room temperature (Fig.3c, Fig.3d). The craters formed at room temperature (Fig.3a, Fig.3c) showed a more serious melting phenomenon than those formed at low temperature (Fig.3b, Fig.3d), as evidenced by the abundance of molten ejecta around the former, especially at high laser energy densities. In contrast, the low temperature craters showed no obvious melting phenomenon and had a flatter bottom with a reduced number of large molten spherical particles. The use of CLA-ICP-MS weakened the melting phenomenon, thereby generating smaller aerosol particles, which further improved the aerosol transport and ionization efficiency. A particle size collection experiment was conducted to explore the distribution of aerosol particles at different temperatures. SEM images were used to analyze the shapes and sizes of particles that were collected on a membrane with an aperture of 0.1μm at room temperature (20℃) and low temperature (−30℃). The same sample chamber and 1m of tubing were used to transport the particles, and the ablation pulses continuously for 2min. The SEM images showed that the particles produced at room temperature were larger and formed large agglomerates (Fig.4a), whereas the particles produced at −30℃ were smaller and there were fewer agglomerations (Fig.4c). The shape of the agglomerates and their connection by filaments suggested strong charge during particle formation, which was more prominent at room temperature. Additionally, there were more single large particles produced at room temperature (Fig.4b), while there were fewer particles at −30℃ (Fig.4d). Comparative measurements were conducted using 193nm laser to investigate the influence of temperatures on particle size distribution. Fig.4 shows a typical size distribution for LA under He atmosphere. The left part of Fig.5 shows a distribution of aerosols produced by ablation of 2min pulses at room temperature. The peak heights of mean diameter in this distribution were determined to be approximately 300nm and 700nm, respectively. Similarly, particle size distribution at −30℃ also presented a bimodal pattern, which was consistent with previous studies. The average diameters were 190nm and 400nm, both smaller than at room temperature, while the peak width was shorter. The chemical composition of fine particles produced at low temperature is closer to the sample body, improving the transport and ionization of aerosol in ICP, reducing element fractionation, and enhancing the signal strength and stability, thereby improving the analytical performance of ICP-MS.CONCLUSIONSA new high-precision and accuracy method for determination of trace elements in sulfide minerals has been developed using the CLA-ICP-MS system. This method reduces thermal effect and decreases particle size during the ablation process, improving precision by freezing sulfide samples with a designed cryogenic ablation cell. Low temperature results in better data because fewer large particles are produced; sedimentation around the ablation crater and during transport is reduced, while ionization efficiency in ICP is higher. The precision calculated for transient signals decreases obviously if the sample is kept at low temperature (−30℃) compared to room temperature (20℃), while the sensitivity improved slightly. The deviation of all elements between the test values and the standard values falls within 7% by CLA-ICP-MS. In future work, it will be necessary to investigate even lower temperatures, as low temperatures can increase aerosol viscosity and affect analysis results. It is also worth exploring whether the performance of a long pulse width laser can be improved by lowering the temperature to match that of a short pulse width laser.

Accurate monitoring of minor and trace elements in food is of great significance for maintaining human health. Although laser ablation inductively coupled plasma mass spectrometry technique (LA-ICP-MS) is well-established for the direct analysis of solid sample, the lack of an appropriate external standard for quantitative calibration remains the main challenge. Herein, we developed a novel calibration strategy based on the mixed fine particulate food reference material pellets as the external standard to accurately measure the multi-elements in various solid food samples. Three in-house prepared pellet standards exhibited good homogeneity (RSD < 9%) and the limits of quantitation (LOQs) ranged from 0.0003 (Sr) to 0.86 & mu;g g-1 (Ca). Analytical results of the food NIST reference materials and typical food samples were in good agreement with the certified or reference values, respectively. The proposed method is a promising alternative for routine elemental bulk and/or imaging analysis in food safety laboratories.

A novel method for direct high-throughput analysis of multi-elements in cerebrospinal fluid (CSF) samples by laser ablation inductively coupled plasma mass spectrometry with an aerosol local extraction cryogenic ablation cell (ALEC-LA-ICP-MS) was developed. Microliter-level CSF samples were frozen by a designed cryogenic ablation cell and directly analyzed by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) without time-consuming pretreatment. Compared with the precision obtained at room temperature (20℃), that obtained at low temperature (− 25℃) was significantly improved; the RSDs were reduced from 8.3

The whole blood samples were analyzed by LA-ICP-MS with cryogenic ablation cell, which avoid droplet splashing during the laser ablation process and improve analytical precision significantly.

Zinc (Zn) is an essential trace element in the human body, and its deficiency can seriously affect health. Agronomic Zn biofortification with ZnO nanoparticles (ZnO NPs) in consumable wheat prospectively relieves Zn deficiency. We developed an elemental quantitative imaging laser ablation-inductively coupled plasma optical emission spectrometry method to examine the distributions of Zn and other micronutrient elements in wheat grain and the endosperm. After foliar application of ZnO NPs (four rounds), Zn content in the endosperm can be significantly increased (221 ± 61%), and the Zn, Ca, Mg, and P content gradient decreased from the outside seed coat and aleurone layer to the endosperm, whereas the Fe, Mn, K, Cu, Sr, and Ba content gradient decreased from the crease region to the deeper endosperm. This may indicate how different elements enter the endosperm. Foliar application of ZnO NPs did not change the micronutrient accumulation pattern but did change their contents in wheat grain.

In this work, we prepared three CaWO 4 single crystals (CaW‐0, CaW‐1 and CaW‐3) doped with rare earth elements (REEs) at nominal mass fractions of 50, 250 and 5000 μg g ‐1 using the Czochralski method. Electron probe microanalysis (EPMA) and laser ablation‐inductively coupled plasma‐mass spectrometry (LA‐ICP‐MS) were employed to evaluate the within‐ and between‐unit homogeneity of major elements and REEs, respectively. The within‐unit variation ( s r ) of 0.40–0.84% and between‐unit s r of 0.14–1.48% for major elements were obtained. Within‐ and between‐unit s r of 0.53–5.56% were also found for REEs by LA‐ICP‐MS spot analyses. A comparison of the s r of repeat analyses was compared with the analytical uncertainty ( u ), i.e., the mean square weighted deviation (MSWD), which is close to or slightly higher than 1, indicating that no obvious chemical heterogeneity was found in these crystals. Reference values for these elements were obtained through various analytical methods across four different laboratories and applications of the reference materials to calibrating REE mass fractions in a natural scheelite were performed. No significant difference of the results was found as t values are less than 2.75 at the 99% confidence interval. The excellent linearity ( R 2 > 0.98) between the REE mass fractions and both LA‐ICP‐MS signal intensity and wafer absorbance was found, but the crater height and the absolute mass transported into ICP‐MS decreased when REE mass fractions as well as the colour of crystals increased. These results suggest that the reference materials have the potential to calibrate REE mass fractions in natural scheelite.