This work evaluates the use of femtosecond laser ablation multiple collector inductively coupled plasma mass spectrometry(fs-LA-MC-ICP-MS) for Zr isotopic analysis in zircons. The mass fractionation caused by instrume...This work evaluates the use of femtosecond laser ablation multiple collector inductively coupled plasma mass spectrometry(fs-LA-MC-ICP-MS) for Zr isotopic analysis in zircons. The mass fractionation caused by instrumental mass discrimination was corrected by a combination of internal correction using Sr as an internal standard(coming from a NIST SRM 987 standard solution) and external correction using a matrix-matched standard. Several important instrument parameters were investigated, such as the effect of the addition of N;and "wet" plasma condition, the mass fractionation behaviors between Zr isotopes and Sr isotopes, the position effect in laser ablation cell and the effect of laser ablation parameters(laser spot size and energy density). The Zr isotope compositions of seven zircons(GJ-1, 91500, Ple?ovice, Rak-17, Paki, Aus and Mala) were determined by the developed fs-LAMC-ICP-MS and thermal ionization mass spectrometry(TIMS). Our fs-LA-MC-ICP-MS results for Zr isotope compositions agreed with TIMS analyses within analytical uncertainties, indicating the presented method is a suitable tool to resolve isotopic zoning in natural zircons. The results also suggest that GJ-1, 91500, Ple?ovice, Paki, Aus and Mala had the homogenous Zr isotope composition and could be considered as the potential candidates for the Zr isotope analysis in zircons, except Rak-17 which presented the large Zr isotope variation.展开更多
LA-MC-ICP-MS offers the ability to directly measure small variations in isotope composition at the micrometer scale in geological samples.However,when analyzing isotope ratios in complex minerals,mass spectrometric in...LA-MC-ICP-MS offers the ability to directly measure small variations in isotope composition at the micrometer scale in geological samples.However,when analyzing isotope ratios in complex minerals,mass spectrometric interferences from themselves and isotopic mass fractionation arising from the analytical process need to be carefully corrected.The lack of professional software to visualize and process raw data presents a significant challenge for all of LA-MC-ICP-MS labs.Moreover,the rapid development of instruments and the innovations in micro-analytical techniques necessitate specialized software to complete the complex correction and improve efficiency,such as for in situ isochron dating or new linear regression correction techniques.In this study,Plume,a free data processing software,was developed specifically for isotopic data processing in LA-MC-ICP-MS.The software provides a comprehensive set of functions,including baseline correction,signal selection and integration,mass spectrometric interference correction,isotopic fractionation correction,uncertainty propagation,delta value calculation,and real-time data processing.It also supports a complete correction workflow for the latest isochron dating using LA-(MC)-ICP-MS/MS,including isotopic and elemental ratios correction,the isochron drawing,and age calculation for multiple models.Additionally,a dedicated linear regression calculation unit has been developed in Plume to specialize in data processing of low signal-to-noise ratio or high spatial resolution analysis.These new features expand the application range of LA-MC-ICP-MS and improve work efficiency through batch processing.展开更多
We proposed a new laser analytical mode,which used the high-frequency laser ablation to deliberately obtain the peak-shape signal profile,combined with the linear regression calibration(LRC)method to calculate element...We proposed a new laser analytical mode,which used the high-frequency laser ablation to deliberately obtain the peak-shape signal profile,combined with the linear regression calibration(LRC)method to calculate elemental or isotopic ratios.In order to assess the performance of the new laser analytical mode for the application in the field of earth science,we systematically investigated the elemental quantitative analysis with high spatial resolution(10μm),rapid U-Pb dating in zircons and accurate Sr-Hf isotope analysis in geological samples.The new high-frequency laser analysis technology(20 Hz,100 pulses)reduced the limit of detection(LOD)of 25 elements to 0.005-0.16μg g^(-1) with crater diameters of 10μm,which are significantly lower(decrease to 2-20%)than previous researches.The quantitative analysis of five silicate glass reference materials showed that the precision and accuracy of the 25 trace elements(with the concentration ranging from 0.17 to 683μg g^(-1))were better than 16% and 15%,respectively.The new methods raised the analytical throughput of zircon U-Pb dating,Sr isotope ratios and Hf isotope ratios to 250 analyses per hour,144 analyses per hour and 120 analyses per hour in theory,while the analytical accuracy and precision were not affected.The detailed investigations showed that the proposed new laser analytical mode has good application effects in the field of earth sciences.展开更多
基金supported by the National Natural Science Foundation of China(Nos.41973013,41730211)the Natural Science Foundation of Hubei Province(No.2020CFA045)the Most Special Fund from the State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(Nos.MSFGPMR04 and MSFGPMR08)。
文摘This work evaluates the use of femtosecond laser ablation multiple collector inductively coupled plasma mass spectrometry(fs-LA-MC-ICP-MS) for Zr isotopic analysis in zircons. The mass fractionation caused by instrumental mass discrimination was corrected by a combination of internal correction using Sr as an internal standard(coming from a NIST SRM 987 standard solution) and external correction using a matrix-matched standard. Several important instrument parameters were investigated, such as the effect of the addition of N;and "wet" plasma condition, the mass fractionation behaviors between Zr isotopes and Sr isotopes, the position effect in laser ablation cell and the effect of laser ablation parameters(laser spot size and energy density). The Zr isotope compositions of seven zircons(GJ-1, 91500, Ple?ovice, Rak-17, Paki, Aus and Mala) were determined by the developed fs-LAMC-ICP-MS and thermal ionization mass spectrometry(TIMS). Our fs-LA-MC-ICP-MS results for Zr isotope compositions agreed with TIMS analyses within analytical uncertainties, indicating the presented method is a suitable tool to resolve isotopic zoning in natural zircons. The results also suggest that GJ-1, 91500, Ple?ovice, Paki, Aus and Mala had the homogenous Zr isotope composition and could be considered as the potential candidates for the Zr isotope analysis in zircons, except Rak-17 which presented the large Zr isotope variation.
基金supported by the National Key Research and Development Program of China(Grant No.2024YFF0808200)the National Natural Science Foundation of China(Grant Nos.42330104,42473035)+1 种基金Hubei Provincial Natural Science Foundation of China(Grant No.2025AFA005)the Most Special Fund from the State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(Grant Nos.MSFGPMR04 and MSFGPMR08)。
文摘LA-MC-ICP-MS offers the ability to directly measure small variations in isotope composition at the micrometer scale in geological samples.However,when analyzing isotope ratios in complex minerals,mass spectrometric interferences from themselves and isotopic mass fractionation arising from the analytical process need to be carefully corrected.The lack of professional software to visualize and process raw data presents a significant challenge for all of LA-MC-ICP-MS labs.Moreover,the rapid development of instruments and the innovations in micro-analytical techniques necessitate specialized software to complete the complex correction and improve efficiency,such as for in situ isochron dating or new linear regression correction techniques.In this study,Plume,a free data processing software,was developed specifically for isotopic data processing in LA-MC-ICP-MS.The software provides a comprehensive set of functions,including baseline correction,signal selection and integration,mass spectrometric interference correction,isotopic fractionation correction,uncertainty propagation,delta value calculation,and real-time data processing.It also supports a complete correction workflow for the latest isochron dating using LA-(MC)-ICP-MS/MS,including isotopic and elemental ratios correction,the isochron drawing,and age calculation for multiple models.Additionally,a dedicated linear regression calculation unit has been developed in Plume to specialize in data processing of low signal-to-noise ratio or high spatial resolution analysis.These new features expand the application range of LA-MC-ICP-MS and improve work efficiency through batch processing.
基金supported by the National Natural Science Foundation of China(Grant Nos.41973013,41730211)the Natural Science Foundation of Hubei Province(Grant No.2020CFA045)the Most Special Fund from the State Key Laboratory of Geological Processes and Mineral Resources,China University of Geosciences(Grant Nos.MSFGPMR04,MSFGPMR08)。
文摘We proposed a new laser analytical mode,which used the high-frequency laser ablation to deliberately obtain the peak-shape signal profile,combined with the linear regression calibration(LRC)method to calculate elemental or isotopic ratios.In order to assess the performance of the new laser analytical mode for the application in the field of earth science,we systematically investigated the elemental quantitative analysis with high spatial resolution(10μm),rapid U-Pb dating in zircons and accurate Sr-Hf isotope analysis in geological samples.The new high-frequency laser analysis technology(20 Hz,100 pulses)reduced the limit of detection(LOD)of 25 elements to 0.005-0.16μg g^(-1) with crater diameters of 10μm,which are significantly lower(decrease to 2-20%)than previous researches.The quantitative analysis of five silicate glass reference materials showed that the precision and accuracy of the 25 trace elements(with the concentration ranging from 0.17 to 683μg g^(-1))were better than 16% and 15%,respectively.The new methods raised the analytical throughput of zircon U-Pb dating,Sr isotope ratios and Hf isotope ratios to 250 analyses per hour,144 analyses per hour and 120 analyses per hour in theory,while the analytical accuracy and precision were not affected.The detailed investigations showed that the proposed new laser analytical mode has good application effects in the field of earth sciences.
