: In recent years, the stable isotope composition of barium has emerged as a powerful tracer for understanding crucial geo-social processes; therefore, it is necessary to develop an efficient method for Ba isotopic ratios. Herein, we describe a rapid method for determining the isotopic ratios of Ba using a multi-collector inductively coupled plasma mass spectrometer in the low-resolution mode (Neptune Plus). In this method, the exact amount of the resin and the low eluted volume of the acid used in column purification significantly reduce the time required for Ba separation. Instrumental mass bias calibrations were performed for both standard-sample bracketing (SSB) and double-spike methods. The results show that the double-spike method provided Ba isotopic ratios with higher precision than the SSB technique. The effects of acid molarity and concentration mismatch, as well as the potential matrix effect, were investigated in the wet plasma mode. We evaluated the Ba isotopic compositions of ten geological reference materials, namely, BCR-2, BHVO-2, AGV-2, GSP-2, RGM-2, G-2, GSR-3, GSR-5, GSR-8, and GSR-11. Results indicated that these compositions were highly accurate with respect to the international Ba isotope standard, NIST SRM 3104a. Furthermore, the Ba isotopic compositions of most geological reference materials examined in this study agreed well with previously published data within the quoted analytical uncertainties. The long-term reproducibility analyses of all standards indicated that the obtained isotopic ratios were highly reproducible for δ 138/134 Ba, with precisions of ≤ ±0.05‰ (2SD). Compared to previous reports, we optimized the process of chemical purification, separated Ba samples faster, and improved the efficiency of the analyses employed in this study.
{"title":"Rapid Two-Column Separation Method For Determining Barium Isotopic Compositions Using MC-ICP-MS","authors":"Kaiyun Chen","doi":"10.46770/as.2022.105","DOIUrl":"https://doi.org/10.46770/as.2022.105","url":null,"abstract":": In recent years, the stable isotope composition of barium has emerged as a powerful tracer for understanding crucial geo-social processes; therefore, it is necessary to develop an efficient method for Ba isotopic ratios. Herein, we describe a rapid method for determining the isotopic ratios of Ba using a multi-collector inductively coupled plasma mass spectrometer in the low-resolution mode (Neptune Plus). In this method, the exact amount of the resin and the low eluted volume of the acid used in column purification significantly reduce the time required for Ba separation. Instrumental mass bias calibrations were performed for both standard-sample bracketing (SSB) and double-spike methods. The results show that the double-spike method provided Ba isotopic ratios with higher precision than the SSB technique. The effects of acid molarity and concentration mismatch, as well as the potential matrix effect, were investigated in the wet plasma mode. We evaluated the Ba isotopic compositions of ten geological reference materials, namely, BCR-2, BHVO-2, AGV-2, GSP-2, RGM-2, G-2, GSR-3, GSR-5, GSR-8, and GSR-11. Results indicated that these compositions were highly accurate with respect to the international Ba isotope standard, NIST SRM 3104a. Furthermore, the Ba isotopic compositions of most geological reference materials examined in this study agreed well with previously published data within the quoted analytical uncertainties. The long-term reproducibility analyses of all standards indicated that the obtained isotopic ratios were highly reproducible for δ 138/134 Ba, with precisions of ≤ ±0.05‰ (2SD). Compared to previous reports, we optimized the process of chemical purification, separated Ba samples faster, and improved the efficiency of the analyses employed in this study.","PeriodicalId":8642,"journal":{"name":"Atomic Spectroscopy","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44953319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: In this study, a deep eutectic solvent (DES)-based rapid synergistic cloud point extraction (RS-CPE) was coupled with inductively coupled plasma optical emission spectrometry (ICP-OES). This unprecedented method was used for the simultaneous determination of Cd and Ni in the medicinal plant Salvia yunnanensis C. H. Wright ( S. yunnanensis ). Compared with traditional CPE, RS-CPE was accomplished rapidly at room temperature. In this study, DES was used as an environmentally friendly cloud point and synergic reagent to decrease the cloud point temperature (CPT) of Triton X-114 (TX-114) and assist the subsequent rapid extraction process, thereby replacing toxic organic reagents. The experimental parameters affecting extraction efficiency were investigated and optimized. Using this combined extraction method and analytical technique, the analytical performance of ICP-OES was notably improved. Under the optimal conditions, the limits of detection (LOD) of Cd and Ni were 0.01 and 0.05 μg L -1 , and the limits of quantification (LOQ) were 0.04 and 0.16 μg L -1 , respectively. The enhancement factors (EFs) of Cd and Ni were 33 and 30; the spiked recoveries were 96.1–105% and 90.3–106%, respectively. The established method was applied to analyze S. yunnanensis samples with satisfactory results and provided a simple, rapid, sensitive, and green method for the determination of potentially toxic elements in medicinal herbs. reagent. results showed that there was no statistical difference between the results obtained for the real samples, as determined by the established method, compared with those obtained using ICP-MS. These results indicate that the proposed method is accurate and reliable.
本研究将基于深共晶溶剂(DES)的快速协同云点萃取(RS-CPE)与电感耦合等离子体发射光谱(ICP-OES)相结合。本方法首次应用于云南丹参中镉和镍的同时测定。与传统CPE相比，RS-CPE在室温下快速完成。本研究采用DES作为环保型云点和协同试剂，降低Triton X-114 (TX-114)的云点温度(CPT)，辅助后续的快速提取过程，从而取代有毒的有机试剂。对影响提取效率的实验参数进行了研究和优化。采用该萃取方法与分析技术相结合，ICP-OES的分析性能明显提高。在最佳条件下，Cd和Ni的检出限分别为0.01和0.05 μg L -1，定量限分别为0.04和0.16 μg L -1。Cd和Ni的增强因子(EFs)分别为33和30;加标回收率分别为96.1 ~ 105%和90.3 ~ 106%。将所建立的方法应用于云南石竹样品的分析，结果令人满意，为中药材中潜在有毒元素的检测提供了一种简便、快速、灵敏、绿色的方法。试剂结果表明，用所建立的方法测定的真实样品的结果与用ICP-MS测定的结果没有统计学差异。结果表明，该方法准确可靠。
{"title":"Simultaneous Determination Of Cd And Ni In Salvia Yunnanensis By Deep Eutectic Solvent-Based Rapidly Synergistic Cloud Point Extraction And ICP-OES Analysis","authors":"Wen Wen","doi":"10.46770/as.2022.100","DOIUrl":"https://doi.org/10.46770/as.2022.100","url":null,"abstract":": In this study, a deep eutectic solvent (DES)-based rapid synergistic cloud point extraction (RS-CPE) was coupled with inductively coupled plasma optical emission spectrometry (ICP-OES). This unprecedented method was used for the simultaneous determination of Cd and Ni in the medicinal plant Salvia yunnanensis C. H. Wright ( S. yunnanensis ). Compared with traditional CPE, RS-CPE was accomplished rapidly at room temperature. In this study, DES was used as an environmentally friendly cloud point and synergic reagent to decrease the cloud point temperature (CPT) of Triton X-114 (TX-114) and assist the subsequent rapid extraction process, thereby replacing toxic organic reagents. The experimental parameters affecting extraction efficiency were investigated and optimized. Using this combined extraction method and analytical technique, the analytical performance of ICP-OES was notably improved. Under the optimal conditions, the limits of detection (LOD) of Cd and Ni were 0.01 and 0.05 μg L -1 , and the limits of quantification (LOQ) were 0.04 and 0.16 μg L -1 , respectively. The enhancement factors (EFs) of Cd and Ni were 33 and 30; the spiked recoveries were 96.1–105% and 90.3–106%, respectively. The established method was applied to analyze S. yunnanensis samples with satisfactory results and provided a simple, rapid, sensitive, and green method for the determination of potentially toxic elements in medicinal herbs. reagent. results showed that there was no statistical difference between the results obtained for the real samples, as determined by the established method, compared with those obtained using ICP-MS. These results indicate that the proposed method is accurate and reliable.","PeriodicalId":8642,"journal":{"name":"Atomic Spectroscopy","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2022-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45307517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: Zircon, a common U-rich accessory mineral occurring in terrestrial and extraterrestrial rocks, serves as a crucial tool for unraveling the temporal and geochemical clues on geologic events that have taken place on Earth and other planetary bodies. Zircon water content analysis has been advanced in the past three years via a novel sample preparation method using Sn-Bi alloy as a mounting material. Here, we present an improved Pb-free Sn-Bi alloy material for mounting samples and investigate whether the alloy mounts are suitable for in situ U-Pb dating. The secondary ion mass spectrometry (SIMS) U-Pb dating results show that the count rates of 204 Pb for zircon standards in the alloy mount are less than 0.01 cps/nA, and the calculated U-Pb and Pb-Pb ages of zircon standards are consistent with the recommended values within analytical uncertainties. Our results indicate that the alloy material used in this study is a good mounting material for U-Pb dating. Therefore, we recommend that this Pb-free Sn-Bi alloy material can be applied to mount geological samples for water abundance and U-Pb systematic analyses.
{"title":"Improved Pb-Free Sn-Bi Alloy Mounting Technique For Ion Probe U-Pb Analyses Of Zircon","authors":"Sen Hu","doi":"10.46770/as.2022.065","DOIUrl":"https://doi.org/10.46770/as.2022.065","url":null,"abstract":": Zircon, a common U-rich accessory mineral occurring in terrestrial and extraterrestrial rocks, serves as a crucial tool for unraveling the temporal and geochemical clues on geologic events that have taken place on Earth and other planetary bodies. Zircon water content analysis has been advanced in the past three years via a novel sample preparation method using Sn-Bi alloy as a mounting material. Here, we present an improved Pb-free Sn-Bi alloy material for mounting samples and investigate whether the alloy mounts are suitable for in situ U-Pb dating. The secondary ion mass spectrometry (SIMS) U-Pb dating results show that the count rates of 204 Pb for zircon standards in the alloy mount are less than 0.01 cps/nA, and the calculated U-Pb and Pb-Pb ages of zircon standards are consistent with the recommended values within analytical uncertainties. Our results indicate that the alloy material used in this study is a good mounting material for U-Pb dating. Therefore, we recommend that this Pb-free Sn-Bi alloy material can be applied to mount geological samples for water abundance and U-Pb systematic analyses.","PeriodicalId":8642,"journal":{"name":"Atomic Spectroscopy","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2022-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42402427","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: Precise determination of the chemical composition of lunar samples is crucial for obtaining cosmogenic noble gas production rates and reliable cosmic ray exposure (CRE) ages. In this study, we established a new non-destructive method for determining the chemical composition of small mineralogically heterogeneous lunar basaltic clasts (<1 mg) using high-resolution X-ray microcomputed tomography (μCT). The volume of the individual mineral grains in each clast was obtained via μCT and combined with the chemical composition and density of the minerals to estimate the bulk chemical composition of each sample. The calculated chemical compositions were ultimately used to determine cosmogenic nuclide production rates. We used the lunar mare simulant sample (LMS-1) to evaluate the uncertainty of our method on the calculation of production rates of cosmogenic Ne ( 20 Ne, 21 Ne, and 22 Ne) and Ar ( 36 Ar and 38 Ar) (4% and 5% were adopted as suggested values, respectively). By applying this method to five Chang’E-5 basaltic clasts, we demonstrated that the chemical compositions of lunar regolith clastic samples (basalts) were different and the maximum variations of P 21 (the production rate of cosmogenic 21 Ne) and P 38 (the production rate of cosmogenic 38 Ar) among the five basaltic clasts were in the range of 18–20%. Therefore, the average chemical composition cannot be used to represent a single grain. In our study, mineral heterogeneity influenced the theoretical production rate of cosmogenic noble gases. Furthermore, the maximum cosmogenic 21 Ne production rate deviation from the average value reached 18.4% (~2 g/cm 2 ). Our method significantly minimized the uncertainties in the production rate calculations caused by the mineral heterogeneity of the sub-milligram samples and when applied routinely would result in more reliable CRE ages.
{"title":"Mineral Heterogeneity Of Lunar Sub-Milligram Basaltic Clasts And Its Effect On The Production Rates Of Cosmogenic Nuclides","authors":"Huaiyu He","doi":"10.46770/as.2022.013","DOIUrl":"https://doi.org/10.46770/as.2022.013","url":null,"abstract":": Precise determination of the chemical composition of lunar samples is crucial for obtaining cosmogenic noble gas production rates and reliable cosmic ray exposure (CRE) ages. In this study, we established a new non-destructive method for determining the chemical composition of small mineralogically heterogeneous lunar basaltic clasts (<1 mg) using high-resolution X-ray microcomputed tomography (μCT). The volume of the individual mineral grains in each clast was obtained via μCT and combined with the chemical composition and density of the minerals to estimate the bulk chemical composition of each sample. The calculated chemical compositions were ultimately used to determine cosmogenic nuclide production rates. We used the lunar mare simulant sample (LMS-1) to evaluate the uncertainty of our method on the calculation of production rates of cosmogenic Ne ( 20 Ne, 21 Ne, and 22 Ne) and Ar ( 36 Ar and 38 Ar) (4% and 5% were adopted as suggested values, respectively). By applying this method to five Chang’E-5 basaltic clasts, we demonstrated that the chemical compositions of lunar regolith clastic samples (basalts) were different and the maximum variations of P 21 (the production rate of cosmogenic 21 Ne) and P 38 (the production rate of cosmogenic 38 Ar) among the five basaltic clasts were in the range of 18–20%. Therefore, the average chemical composition cannot be used to represent a single grain. In our study, mineral heterogeneity influenced the theoretical production rate of cosmogenic noble gases. Furthermore, the maximum cosmogenic 21 Ne production rate deviation from the average value reached 18.4% (~2 g/cm 2 ). Our method significantly minimized the uncertainties in the production rate calculations caused by the mineral heterogeneity of the sub-milligram samples and when applied routinely would result in more reliable CRE ages.","PeriodicalId":8642,"journal":{"name":"Atomic Spectroscopy","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2022-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48976866","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: NanoSIMS features a capability of high spatial resolution, which allows for Pb/Pb and U/Pb dating at the submicron scale, using a recently established radio-frequency (RF) oxygen ion source. However, the secondary ion yield of Pb + is relatively low when using 16 O - as the primary beam species compared to that obtained using large-geometry secondary ion mass spectrometry (LG-SIMS), which limits the precision of Pb/Pb and U/Pb dating. In this study, using 16 O 2- as the primary species with an RF oxygen source on a CAMEA NanoSIMS 50L ion probe, we acquired Pb sensitivity in zircon of approximately 12 cps/nA/ppm. Analyses of the zircon reference materials M257 and OG1 resulted in Pb isotopic compositions consistent with their reference values and Pb/Pb age with an uncertainty of ~3 % for the target region of interest (ROI) smaller than an area of 2 μm × 2 μm. Pb/U age with an uncertainty < 2.2% was acquired via Pb/U correction based on the Pb/U vs. UO 2 /U power relationship or the Pb/UO vs. UO 2 /UO one. The adoption of 16 O 2- as the primary species for the RF ion source is as a possible approach for accurate U/Pb age determination. It scale, with low precious extraterrestrial
{"title":"Pb/Pb And U/Pb Dating By NanoSIMS With The Radio-Frequency Ion Source Using 16O2- As The Primary Species","authors":"Ya-nan Yang","doi":"10.46770/as.2022.019","DOIUrl":"https://doi.org/10.46770/as.2022.019","url":null,"abstract":": NanoSIMS features a capability of high spatial resolution, which allows for Pb/Pb and U/Pb dating at the submicron scale, using a recently established radio-frequency (RF) oxygen ion source. However, the secondary ion yield of Pb + is relatively low when using 16 O - as the primary beam species compared to that obtained using large-geometry secondary ion mass spectrometry (LG-SIMS), which limits the precision of Pb/Pb and U/Pb dating. In this study, using 16 O 2- as the primary species with an RF oxygen source on a CAMEA NanoSIMS 50L ion probe, we acquired Pb sensitivity in zircon of approximately 12 cps/nA/ppm. Analyses of the zircon reference materials M257 and OG1 resulted in Pb isotopic compositions consistent with their reference values and Pb/Pb age with an uncertainty of ~3 % for the target region of interest (ROI) smaller than an area of 2 μm × 2 μm. Pb/U age with an uncertainty < 2.2% was acquired via Pb/U correction based on the Pb/U vs. UO 2 /U power relationship or the Pb/UO vs. UO 2 /UO one. The adoption of 16 O 2- as the primary species for the RF ion source is as a possible approach for accurate U/Pb age determination. It scale, with low precious extraterrestrial","PeriodicalId":8642,"journal":{"name":"Atomic Spectroscopy","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2022-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42862178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: Polymeric tungstates exhibit different toxicities and mobilities when compared to those of monomeric tungstates. However, there is limited information on the occurrence of polytungstates in natural waters due to the lack of a reliable analytical approach for the determination of aqueous polytungstates. In this study, we conducted a simultaneous analysis of monomeric and polymeric tungsten species in natural water using reverse-phase ion pair chromatography coupled with inductively coupled plasma mass spectrometry (RP-IPC-ICP-MS). Polytungstates and five monotungstates, including tungstate as well as mono, di, tri, and tetrathiotungstate, were chromatographically separated within 35 min of using ethanol (12 - 48% gradient) as the mobile phase. The detection limit of polytungstates was 1.50 µg/L. Although common for the analsis of metals, experimental studies based on electrospray ionization - high resolution mass spectrometry (ESI-HRMS) have indicated that samples containing polytungstates should not be acidified, as it could result in the transformation of monotungstates to artifact polytungstates. Overall, our study offers an effective method for the analysis of various tungsten species, especially polytungstates, at environmentally relevant concentrations.
{"title":"Simultaneous Determination Of Tungstates, Thiotungstates, And Polytungstates In Natural Waters By Reverse Phase Ion Pair Chromatography Coupled With ICP-MS","authors":"Q. Guo","doi":"10.46770/as.2022.032","DOIUrl":"https://doi.org/10.46770/as.2022.032","url":null,"abstract":": Polymeric tungstates exhibit different toxicities and mobilities when compared to those of monomeric tungstates. However, there is limited information on the occurrence of polytungstates in natural waters due to the lack of a reliable analytical approach for the determination of aqueous polytungstates. In this study, we conducted a simultaneous analysis of monomeric and polymeric tungsten species in natural water using reverse-phase ion pair chromatography coupled with inductively coupled plasma mass spectrometry (RP-IPC-ICP-MS). Polytungstates and five monotungstates, including tungstate as well as mono, di, tri, and tetrathiotungstate, were chromatographically separated within 35 min of using ethanol (12 - 48% gradient) as the mobile phase. The detection limit of polytungstates was 1.50 µg/L. Although common for the analsis of metals, experimental studies based on electrospray ionization - high resolution mass spectrometry (ESI-HRMS) have indicated that samples containing polytungstates should not be acidified, as it could result in the transformation of monotungstates to artifact polytungstates. Overall, our study offers an effective method for the analysis of various tungsten species, especially polytungstates, at environmentally relevant concentrations.","PeriodicalId":8642,"journal":{"name":"Atomic Spectroscopy","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2022-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49488537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: Fe, Ca, and Mg isotopes have been applied to Apollo and Luna samples in order to explore the origin and evolution of the Moon. In most previous studies, only one specific element was separated and measured for its isotope compositions, thereby consuming different splits of samples. Considering the rarity and preciousness of lunar samples, herein we present a three-step purification scheme to separate Fe, Ca, and Mg from a single aliquot of sample solutions with the amounts of these elements down to 20, 15, and 10 μg, respectively. Fe was first collected using 0.4 mL of AG1-X8 resin in a HCl medium. Matrices from the first column containing Ca and Mg were then passed through columns filled with 0.4 mL of DGA resin, with Mg being eluted by 11.5 mL of 4N HNO 3 , and Ca being quantitatively recovered by 10 mL of 8N HNO 3 + 0.2N HF. Mg was then purified using AG50W-X8 in a 1N HNO 3 medium. Fe and Mg isotope analyses were conducted by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), and Ca isotope data were obtained by Triton Plus thermal ionization mass spectrometry (TIMS) following procedures previously established in the same laboratory. Quantitative recovery of Fe, Ca, and Mg for the entire procedure was demonstrated by ten composite samples analogous to the representative lunar samples from the Apollo missions. The shifts in δ 56 Fe, δ 44/42 Ca, and δ 26 Mg of the composite samples were -0.003 ± 0.013‰ (2SD, N = 30), -0.007 ± 0.028‰ (2SD, N = 7), and 0.006 ± 0.015‰ (2SD, N = 29), respectively, ensuring high precision and accuracy of the procedure for combined Fe, Ca, and Mg isotope analyses. The robustness of the procedure was further assessed by replicate analyses of three well-characterized international reference materials (BCR-2, BHVO-2, and W-2a), and the results were consistent with previously published values. The procedure established herein allowed us to obtain combined Fe, Ca, and Mg isotopic datasets from single splits of precious extra-terrestrial samples, thereby providing new insights into the origin and evolution of their parent bodies ( e.g. , the Moon).
{"title":"Combined Separation Of Iron, Calcium, And Magnesium From Composite Lunar Samples For High-Precision Isotope Analyses","authors":"Yongsheng He","doi":"10.46770/as.2022.020","DOIUrl":"https://doi.org/10.46770/as.2022.020","url":null,"abstract":": Fe, Ca, and Mg isotopes have been applied to Apollo and Luna samples in order to explore the origin and evolution of the Moon. In most previous studies, only one specific element was separated and measured for its isotope compositions, thereby consuming different splits of samples. Considering the rarity and preciousness of lunar samples, herein we present a three-step purification scheme to separate Fe, Ca, and Mg from a single aliquot of sample solutions with the amounts of these elements down to 20, 15, and 10 μg, respectively. Fe was first collected using 0.4 mL of AG1-X8 resin in a HCl medium. Matrices from the first column containing Ca and Mg were then passed through columns filled with 0.4 mL of DGA resin, with Mg being eluted by 11.5 mL of 4N HNO 3 , and Ca being quantitatively recovered by 10 mL of 8N HNO 3 + 0.2N HF. Mg was then purified using AG50W-X8 in a 1N HNO 3 medium. Fe and Mg isotope analyses were conducted by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), and Ca isotope data were obtained by Triton Plus thermal ionization mass spectrometry (TIMS) following procedures previously established in the same laboratory. Quantitative recovery of Fe, Ca, and Mg for the entire procedure was demonstrated by ten composite samples analogous to the representative lunar samples from the Apollo missions. The shifts in δ 56 Fe, δ 44/42 Ca, and δ 26 Mg of the composite samples were -0.003 ± 0.013‰ (2SD, N = 30), -0.007 ± 0.028‰ (2SD, N = 7), and 0.006 ± 0.015‰ (2SD, N = 29), respectively, ensuring high precision and accuracy of the procedure for combined Fe, Ca, and Mg isotope analyses. The robustness of the procedure was further assessed by replicate analyses of three well-characterized international reference materials (BCR-2, BHVO-2, and W-2a), and the results were consistent with previously published values. The procedure established herein allowed us to obtain combined Fe, Ca, and Mg isotopic datasets from single splits of precious extra-terrestrial samples, thereby providing new insights into the origin and evolution of their parent bodies ( e.g. , the Moon).","PeriodicalId":8642,"journal":{"name":"Atomic Spectroscopy","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2022-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47058908","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Herein we report procedures based on multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) for high-precision Fe isotopic analysis using a 57Fe-58Fe double spike technique. Iron purification was achieved using AG1-X8 in HCl media following previously or newly established procedures. In the new procedure, smaller columns with 4 mm diameter were used, containing 0.4 mL AG1-X8, thus greatly reducing the operation time and the amount of acid and resin consumed compared to the previously established method using 1 mL resin. Potential trace Ni interference on 58Fe was suppressed by increasing the total Fe ion intensity to ≥ 120 V. Measurements of GSB Fe solutions doped with mono-elements demonstrated that a mass bias correction by the 57Fe-58Fe double spike was robust if Ca/Fe ≤ 1.0, Al/Fe ≤ 1.0, Cu/Fe ≤ 1.0, Co/Fe ≤ 0.1, Ni/Fe ≤ 10-4, and Cr/Fe ≤ 10-4. Monitoring of pure Fe standard solutions, viz. IRMM-014 and NIST3126a, and geological reference materials, viz. JP-1, BHVO-2, W-2a, GSP-2, and COQ-1, over nine months yielded δ56Fe (relative to IRMM-014) values of 0.003 ± 0.013‰ (2 SD, N = 20), 0.368 ± 0.011‰ (2 SD, N = 30), 0.019 ± 0.018‰ (2 SD, N = 15), 0.109 ± 0.017‰ (2 SD, N = 30), 0.049 ± 0.018‰ (2 SD, N = 17), 0.155 ± 0.018‰ (2 SD, N = 14), and -0.066 ± 0.022‰ (2 SD, N = 20), respectively, consistent with the recommended values within quoted errors. Based on repeated analyses of the standards, the long-term precision of our double spike method is better than 0.02‰ for δ56Fe on average, proving its ability to distinguish small isotope fractionation among high-temperature samples.
{"title":"High-Precision Fe Isotope Analysis On MC-ICPMS Using A 57Fe-58Fe Double Spike Technique","authors":"Yongsheng He","doi":"10.46770/as.2022.062","DOIUrl":"https://doi.org/10.46770/as.2022.062","url":null,"abstract":"Herein we report procedures based on multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) for high-precision Fe isotopic analysis using a 57Fe-58Fe double spike technique. Iron purification was achieved using AG1-X8 in HCl media following previously or newly established procedures. In the new procedure, smaller columns with 4 mm diameter were used, containing 0.4 mL AG1-X8, thus greatly reducing the operation time and the amount of acid and resin consumed compared to the previously established method using 1 mL resin. Potential trace Ni interference on 58Fe was suppressed by increasing the total Fe ion intensity to ≥ 120 V. Measurements of GSB Fe solutions doped with mono-elements demonstrated that a mass bias correction by the 57Fe-58Fe double spike was robust if Ca/Fe ≤ 1.0, Al/Fe ≤ 1.0, Cu/Fe ≤ 1.0, Co/Fe ≤ 0.1, Ni/Fe ≤ 10-4, and Cr/Fe ≤ 10-4. Monitoring of pure Fe standard solutions, viz. IRMM-014 and NIST3126a, and geological reference materials, viz. JP-1, BHVO-2, W-2a, GSP-2, and COQ-1, over nine months yielded δ56Fe (relative to IRMM-014) values of 0.003 ± 0.013‰ (2 SD, N = 20), 0.368 ± 0.011‰ (2 SD, N = 30), 0.019 ± 0.018‰ (2 SD, N = 15), 0.109 ± 0.017‰ (2 SD, N = 30), 0.049 ± 0.018‰ (2 SD, N = 17), 0.155 ± 0.018‰ (2 SD, N = 14), and -0.066 ± 0.022‰ (2 SD, N = 20), respectively, consistent with the recommended values within quoted errors. Based on repeated analyses of the standards, the long-term precision of our double spike method is better than 0.02‰ for δ56Fe on average, proving its ability to distinguish small isotope fractionation among high-temperature samples.","PeriodicalId":8642,"journal":{"name":"Atomic Spectroscopy","volume":"1 1","pages":""},"PeriodicalIF":3.4,"publicationDate":"2022-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41568157","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Here we report the Si isotope compositions of four potential reference materials, including one fused quartz glass (Glass-Qtz), one natural quartz (Qinghu-Qtz), and two natural zircons (Qinghu-Zir and Penglai-Zir), suitable for in-situ Si isotopic microanalysis. Repeated SIMS (Secondary Ion Mass Spectrometry) analyses demonstrate that these materials are more homogeneous in Si isotopes (with the spot-to-spot uncertainty of 0.090-0.102‰), compared with the widely used NIST RM 8546 (previously NBS-28) quartz standard (with the spot-to-spot uncertainty poorer than 0.16‰). Based on the solution-MC-ICP-MS determination, the recommended 𝛿30Si values are −0.10 ± 0.04 ‰ (2SD), −0.03 ± 0.05 ‰ (2SD), −0.45 ± 0.06 ‰ (2SD), and −0.34 ± 0.06 ‰ (2SD), for Glass-Qtz, Qinghu-Qtz, Qinghu-Zir, and Penglai-Zir, respectively. Our results reveal no detectable matrix effect on SIMS Si isotopic microanalysis between the fused quartz glass (Glass-Qtz) and natural quartz (Qinghu-Qtz) standards. Therefore, we propose that this synthetic quartz glass may be used as an alternative, more homogenous standard for SIMS Si isotopic microanalysis of natural quartz samples.
{"title":"New Quartz And Zircon Si Isotopic Reference Materials For Precise And Accurate SIMS Isotopic Microanalysis","authors":"Yu Liu, Xian‐Hua Li","doi":"10.46770/as.2021.1110","DOIUrl":"https://doi.org/10.46770/as.2021.1110","url":null,"abstract":"Here we report the Si isotope compositions of four potential reference materials, including one fused quartz glass (Glass-Qtz), one natural quartz (Qinghu-Qtz), and two natural zircons (Qinghu-Zir and Penglai-Zir), suitable for in-situ Si isotopic microanalysis. Repeated SIMS (Secondary Ion Mass Spectrometry) analyses demonstrate that these materials are more homogeneous in Si isotopes (with the spot-to-spot uncertainty of 0.090-0.102‰), compared with the widely used NIST RM 8546 (previously NBS-28) quartz standard (with the spot-to-spot uncertainty poorer than 0.16‰). Based on the solution-MC-ICP-MS determination, the recommended 𝛿30Si values are −0.10 ± 0.04 ‰ (2SD), −0.03 ± 0.05 ‰ (2SD), −0.45 ± 0.06 ‰ (2SD), and −0.34 ± 0.06 ‰ (2SD), for Glass-Qtz, Qinghu-Qtz, Qinghu-Zir, and Penglai-Zir, respectively. Our results reveal no detectable matrix effect on SIMS Si isotopic microanalysis between the fused quartz glass (Glass-Qtz) and natural quartz (Qinghu-Qtz) standards. Therefore, we propose that this synthetic quartz glass may be used as an alternative, more homogenous standard for SIMS Si isotopic microanalysis of natural quartz samples.","PeriodicalId":8642,"journal":{"name":"Atomic Spectroscopy","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2022-04-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48972538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: The major element composition analysis of lunar mare basalt bulk rock is crucial for understanding the thermochemical evolution of the lunar interior. However, lunar regolith and soils returned by the Apollo and Chang’E-5 missions have small particle sizes (mostly < 3 mm), making quantitative analyses of the bulk rock composition difficult. Herein, we developed a non-destructive technique to determine the bulk composition (comprising SiO 2 , TiO 2 , Al 2 O 3 , FeO, MnO, MgO, CaO, Na 2 O, and K 2 O) of rare lunar samples with a small size using scanning electron microscopy and energy dispersive X-ray spectroscopy (EDS) mapping techniques. In this study, a set of certified reference materials were used to calibrate the spectrometer; the precision and accuracy of the EDS analyses were verified using silicate glass and mineral reference materials. Measurements performed on a lunar meteorite sample with a known composition, NWA 4734, confirmed the reliability of the mapping method. The EDS data for the standard glasses and minerals were consistent with the reference values, within the error limits. A small fragment of NWA 4734 was measured using EDS mapping, and the bulk composition obtained was comparable to that measured using inductively coupled plasma mass spectrometry and inductively coupled plasma atomic emission spectrometry. Our method is standardized and minimizes the acquisition time compared to other quantitative mapping methods. The non-destructive and quantitative analysis method used in this study can support research on the bulk compositions of Chang’E-5 lunar samples and can be applied to research on both terrestrial and extraterrestrial samples at the micron- to centimeter-scale.
{"title":"Quantitative Analysis Of Bulk Composition Of Small-Size Lunar Samples Using Energy Dispersive X-Ray Spectroscopy","authors":"Yi Chen","doi":"10.46770/as.2022.003","DOIUrl":"https://doi.org/10.46770/as.2022.003","url":null,"abstract":": The major element composition analysis of lunar mare basalt bulk rock is crucial for understanding the thermochemical evolution of the lunar interior. However, lunar regolith and soils returned by the Apollo and Chang’E-5 missions have small particle sizes (mostly < 3 mm), making quantitative analyses of the bulk rock composition difficult. Herein, we developed a non-destructive technique to determine the bulk composition (comprising SiO 2 , TiO 2 , Al 2 O 3 , FeO, MnO, MgO, CaO, Na 2 O, and K 2 O) of rare lunar samples with a small size using scanning electron microscopy and energy dispersive X-ray spectroscopy (EDS) mapping techniques. In this study, a set of certified reference materials were used to calibrate the spectrometer; the precision and accuracy of the EDS analyses were verified using silicate glass and mineral reference materials. Measurements performed on a lunar meteorite sample with a known composition, NWA 4734, confirmed the reliability of the mapping method. The EDS data for the standard glasses and minerals were consistent with the reference values, within the error limits. A small fragment of NWA 4734 was measured using EDS mapping, and the bulk composition obtained was comparable to that measured using inductively coupled plasma mass spectrometry and inductively coupled plasma atomic emission spectrometry. Our method is standardized and minimizes the acquisition time compared to other quantitative mapping methods. The non-destructive and quantitative analysis method used in this study can support research on the bulk compositions of Chang’E-5 lunar samples and can be applied to research on both terrestrial and extraterrestrial samples at the micron- to centimeter-scale.","PeriodicalId":8642,"journal":{"name":"Atomic Spectroscopy","volume":" ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2022-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42731103","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：