Sulfur isotopes of S-bearing materials are powerful tools to trace various geological processes and sulfur sources in earth sciences,especially in ore deposits where sulfide-sulfate pair coprecipitates widely.However,...Sulfur isotopes of S-bearing materials are powerful tools to trace various geological processes and sulfur sources in earth sciences,especially in ore deposits where sulfide-sulfate pair coprecipitates widely.However,in-situ S isotope determination of barite is challenging without natural matrix-matched reference material.In this study,we present two natural barite reference materials(1-YS and 294-YS)for in-situ sulfur isotopic analysis.Independent LA-MC-ICP-MS laboratories were utilized to test theδ34S micron-scale homogeneity of 1-YS and 294-YS barites that have 2s repeatabilities of better than±0.45‰and±0.41‰,respectively.Meanwhile,the in-situ analysis results are consistent with the results of the bulk analysis by GS-IRMS within uncertainty.The grand meanδ~(34)S values of 1-YS(13.37‰±0.42‰,2s)and 294-YS(14.38‰±0.44‰,2s)are the final recommended values obtained from four independent laboratories.All the results confirm the suitability of 1-YS and 294-YS barite used as calibration materials with respect to in-situ S isotopic analysis.Moreover,the new developed barite reference materials were used as matrix-matched standard to calibrate the barite samples from the Huayangchuan carbonatite-hosted U-polymetallic deposit(Qinling orogenic belt,western China)to obtainδ34S values.Utilizing the temperaturedependentδ34S fractionation of barite-pyrite pair,we calculate the formation temperature of barite(i.e.,506 to 537°C)and theδ34S value of mineralizing fluid(i.e.,-7.11‰to-7.59‰)in the Huayangchuan deposit.The results indicate an involvement of sedimentary sulfur,presumably acting as a potential uranium source(e.g.,upper crustal materials)for the giant Huayangchuan deposit.展开更多
Carbonaceous aerosol,including organic carbon(OC)and elemental carbon(EC),has significant influence on human health,air quality and climate change.Accurate measurement of carbonaceous aerosol is essential to reduce th...Carbonaceous aerosol,including organic carbon(OC)and elemental carbon(EC),has significant influence on human health,air quality and climate change.Accurate measurement of carbonaceous aerosol is essential to reduce the uncertainty of radiative forcing estimation and source apportionment.The accurate separation of OC and EC is controversial due to the charring of OC.Therefore,the development of reference materials(RM)for the validation of OC/EC separation is an important basis for further study.Previous RMs were mainly based on ambient air sampling,which could not provide traceability of OC and EC concentration.To develop traceable RMs with known OC/EC contents,our study applied an improved aerosol generation and mixing technique,providing uniform deposition of particles on quartz filters.To generate OC aerosol with similar pyrolytic property of ambient aerosol,both water soluble organic carbon(WSOC)and water insoluble organic carbon(WIOC)were used,and amorphous carbon was selected for EC surrogate.The RMs were analyzed using different protocols.The homogeneity within the filter was validated,reaching below 2%.The long-term stability of RMs has been validated with RSD ranged from 1.7%–3.2%.Good correlationwas observed between nominal concentration of RMswithmeasured concentration by two protocols,while the difference of EC concentration was within 20%.The results indicated that the newly developed RMs were acceptable for the calibration of OC and EC,which could improve the accuracy of carbonaceous aerosol measurement.Moreover,the laboratory-generated EC-RMs could be suitable for the calibration of equivalent BC concentration by Aethalometers.展开更多
To solve the problem of the lack of reference material(RM)for determination of allergenic ingredients in food,a RM of cashew nut powder was developed in the study.Cashew nut powder was prepared from cashew nut kernel ...To solve the problem of the lack of reference material(RM)for determination of allergenic ingredients in food,a RM of cashew nut powder was developed in the study.Cashew nut powder was prepared from cashew nut kernel by selecting,cleaning,crushing,n-hexane degreasing and sieving treatment.The reliability and traceability of RM was verified using real-time quantitative polymerase chain reaction(qPCR)and phylogenetic tree analysis.The cashew nut powder RM showed good homogeneity,and good stability under long-term storage at 4℃and short-term simulated transportation from-20 to 45℃.The RM was determined jointly by 8 collaborative laboratories,and the characteristic CT value was 24.732,and the extended uncertainty was 1.052%(k=2).The RM was applied to verify the amplification efficiency and the limit of detection for qPCR assay,and showed good applicability.The RM could be used for method validation and quality control,for the determination of allergenic ingredients in food mixed with trace amounts of cashew nut.展开更多
Lead(Pb)isotopes have been extensively employed in tracing sources of Pb and its transport pathways through the environment.However,Pb isotopic ratios in related geochemical reference materials are scarce.Here,we repo...Lead(Pb)isotopes have been extensively employed in tracing sources of Pb and its transport pathways through the environment.However,Pb isotopic ratios in related geochemical reference materials are scarce.Here,we report high-precision Pb isotopic ratios measured by Nu Plasma II MC-ICP-MS using calibrated ^(205)Tl/^(203)Tl=2.38865(NIST SRM 997)for mass discrimination correction.The long-term external precision(2SD)for NISTSRM 981 of Pb,BCR-2,and BHVO-2 are 0.31‰(n=105),0.42‰(n=11),and 0.25‰(n=5)for ^(208)Pb/ ^(206)Pb and 0.16‰,0.53‰,and 0.07‰for ^(206)Pb/ ^(207)Pb,both respectively,and their Pb isotopic ratios are in excellent agreement with the recommended values.Using this method,we report for the first time Pb isotopic compositions in shale SGR-1b(USGS);coal CLB-1(USGS);stream sediments GSD-17,-21,and-23(IGGE);soils GSS-12,-13,-14,-15,and-16(IGGE);plants GSV-1,-2,and-3(IGGE);and human hair GSH-1(IGGE).展开更多
Salvianolic acid A(Sal A),a water-soluble ingredient in Danshen,has various biological activities.Sal A and its impurities have similar physical and chemical properties,as well as strong reducibility;therefore,they ar...Salvianolic acid A(Sal A),a water-soluble ingredient in Danshen,has various biological activities.Sal A and its impurities have similar physical and chemical properties,as well as strong reducibility;therefore,they are difficult to prepare and purify.In this study,high-purity Sal A was obtained by purification of sephadex chromatography and preparative chromatography.Furthermore,HPLC-DAD tandem ECD and HPLC-DAD tandem MS methods were used for non-volatile organic impurity analysis,ICP-MS method was used for non-volatile inorganic impurities and mass balance method and quantitative nuclear magnetic resonance were employed to certify the product.The structures of Sal A and its relative impurities were validated by nuclear magnetic resonance spectroscopy and mass spectrometry,and their contents were quantified as well.Following the principles of ISO Guides 34:2009 and 35:2005,a Sal A reference material was certified,covering homogeneity studies,stability studies,characterization,and uncertainty estimations.展开更多
Ti separation was achieved by ion-exchange chromatography using Bio-Rad AG 1-X8 anion-exchange and DGA resins.For high-Fe/Ti and high-Mg/Ti igneous samples,a three-column procedure was required,whereas a two-column pr...Ti separation was achieved by ion-exchange chromatography using Bio-Rad AG 1-X8 anion-exchange and DGA resins.For high-Fe/Ti and high-Mg/Ti igneous samples,a three-column procedure was required,whereas a two-column procedure was used for low-Fe/Ti and low-Mg/Ti igneous samples.The Ti isotopes were analysed by MC-ICP-MS,and instrumental mass bias was corrected using a ^(47)Ti-^(49)Ti double-spike technique.The ^(47)Ti-^(49)Ti double-spike and SRM 3162a were calibrated using SRM 979-Cr,certificated value ^(53)Cr/^(52)Crt rue=0.11339.Isobaric interference was evaluated by analysing Alfa-Ti doped with Na,Mg,Ca,and Mo,and results indicate that high concentrations of Na and Mg have no significant effect on Ti isotope analyses;however,Ca and Mo interferences lead to erroneousδ^(49/47)Ti values when Ca/Ti and Mo/Ti ratios exceed 0.01 and 0.1,respectively.Titanium isotopic compositions were determined for 12 igneous reference materials,BCR-2,BHVO-2,GBW07105,AGV-1,AGV-2,W-2,GBW07123,GBW07126,GBW07127,GBW07101,JP-1,and DTS-2b.Samples yieldδ^(49/47)Ti(‰)of−0.035±0.022,−0.038±0.031,0.031±0.022,0.059±0.038,0.044±0.037,0.000±0.015,0.154±0.044,−0.044±0.018,0.010±0.022,0.064±0.043,0.169±0.034,and−0.047±0.025(relative to OL-Ti,±2SD),respectively;of which isotopic compositions of DTS-2b,JP-1,GBW07101,GBW07105,GBW07123,GBW07126,and GBW07127 are reported for the first time.Standard Alfa-Ti was analysed repeatedly over a ten-month period,indicating a reproducibility of±0.047(2SD)forδ^(49/47)Ti,similar to the precisions obtained for geochemical reference materials.展开更多
In order to develop new reference materials for microanalytical nuclear techniques, scanning proton microprobe (SPM) technique was used to determine homogeneity level within 100×200 μm 2 micro area on the small ...In order to develop new reference materials for microanalytical nuclear techniques, scanning proton microprobe (SPM) technique was used to determine homogeneity level within 100×200 μm 2 micro area on the small pieces of IAEA urban dust reference materials. The experimental methods were described in detail. The results show that IAEA 396A/M Vienna urban dust is homogeneous enough for small sample analysis of standard reference material (SRM).展开更多
This paper describes the quantitative determination of rare-earth elements cerium, dysprosium and non-rare-earth element copper, lead and the homogeneity examination of these four elements in yttrium oxide reference m...This paper describes the quantitative determination of rare-earth elements cerium, dysprosium and non-rare-earth element copper, lead and the homogeneity examination of these four elements in yttrium oxide reference material by isotope dilution spark source mass spectrometry (ID-SSMS). The sensitivity of the meth- od is l0^(-5)～10^(-7%). The precision is better than 6%. The accuracy is better than 5%. The interferences of the spectra and the optimum amount of the spike added to the sample are discussed. The choice of the conducting material for the sample electrodes is studied.展开更多
Potala PalaceConstruction of the Potala Palace began in the mid-7th century for the Tubo King Songtsan Gambo to greet his Han wife, Princess Wencheng. It comprised 999 rooms then, plus one built atop the Red Hill, whi...Potala PalaceConstruction of the Potala Palace began in the mid-7th century for the Tubo King Songtsan Gambo to greet his Han wife, Princess Wencheng. It comprised 999 rooms then, plus one built atop the Red Hill, which, said to have 1,000 rooms, was later destroyed by thunderbolts and wars. What we see today is a structure built during the 17th century.In the mid-17th century, the White House was added to the Potala Palace, which spread along the Red Hill in Lhasa.The palace is a structure of clay, wood and stone. The palace was the residence of the Dalai Lama of various generations. Beginning with the period of the 5th Dalai Lama, major religious and political ceremonies were held there.The palace covers a total area of 360,000 square meters, with major building rising 117 meters high in 13 floors, and extends some 360 meters from east to west.From 1989 to 1994, the State earmarked some 55 million Yuan and large quantities of gold and silver to repair the palace.In December 1994, the palace found its展开更多
Caffeine intake by pregnant women, adults and children can be harmful to the health of all particularly fetuses if the intake exceeds the permissible limits. Therefore, it is of fundamental importance to measure its c...Caffeine intake by pregnant women, adults and children can be harmful to the health of all particularly fetuses if the intake exceeds the permissible limits. Therefore, it is of fundamental importance to measure its concentration accurately using certified reference materials (CRMs). In the literature, no scientific details are published about the certification of caffeine standard solutions, and therefore, the present article covers this gap. A batch of caffeine solution was prepared in concentration of 1000 mg/kg and bottled. Homogeneity and stability of the candidate reference material were assessed by HPLC-UV and the results showed that the material is homogenous and stable enough. Characterization of the caffeine reference material was performed by HPLC-UV, LC-MS/MS and UV-VIS-NIR spectrophotometer in three different days and the characterization uncertainty was estimated in accordance with the requirements of ISO GUM. The certified value (999.86 ± 8.57 mg/kg) was derived as a weighted mean from the gravimetry and the three characterization methods and the certified uncertainty was calculated according to ISO Guide 35. The produced CRM is of strong interest to the food and drug analytical laboratories for the validity and credibility of their caffeine measurement results.展开更多
Natural gas (NG) is one of the most important sources of energy for industrial and domestic consumption in the present era because it is cheap and free from sulfur impurities. Therefore, accurate and precise measureme...Natural gas (NG) is one of the most important sources of energy for industrial and domestic consumption in the present era because it is cheap and free from sulfur impurities. Therefore, accurate and precise measurement of its composition is of fundamental importance for trade reasons. To improve the quality of NG gas measurements, certified reference materials (CRMs) should be used for calibration of measuring equipment in order to ensure the traceability of the measurement results to the SI units. For the traceability purpose, a multicomponent natural gas mixture was prepared gravimetrically as a reference material according to ISO 6142 from pure helium, hydrogen, n-pentane, i-pentane, n-butane, i-butane, propane, ethane, hexane, methane and nitrogen. The preparation was done in two dilution steps in 5 L aluminum cylinders. The calculated mole fractions and associated uncertainties of natural gas components were verified by a dual GC-FID/TCD system in accordance with ISO 6143 calibrated by a series of primary gas mixtures (CRMs) produced by an NMI. The results obtained by gravimetry and by GC measurements have been checked for compatibility as required by ISO 6142 and were found in very good agreement. Details of the preparation and calculation of the mole fractions and uncertainties of all gas components are explained in this article.展开更多
Maize unsound kernel content is one of the limited items in maize trade, and generally determined by sensory detection. A certified reference material(CRM) for visual inspection of maize unsound kernels was developed ...Maize unsound kernel content is one of the limited items in maize trade, and generally determined by sensory detection. A certified reference material(CRM) for visual inspection of maize unsound kernels was developed according to a national standard of China, GB 1353-2018, and five items, such as insect-damaged kernels, spotted kernels, broken kernels, sprouted kernels and moldy kernels, were included. Unsound maize kernels were collected from fields or prepared in a laboratory, then screened, and ten kernels demonstrating varying levels of unsoundness or damage for each item were embedded in epoxy resin. The CRM showed excellent homogeneity and stability, which was stable for 14 days at the temperature from-20℃ to 45℃ and for at least 18 months at room temperature out of direct sunlight and strong light. Co-laboratory confirmation showed the CRM conformed to the morphological characteristics described in GB 1353-2018. The research filled the gap of unsound maize kernel CRM in maize detection.展开更多
Caffeine intake by pregnant women, adults and children can be harmful to the health of all particularly fetuses if the intake exceeds the permissible limits. Therefore, it is of fundamental importance to measure its c...Caffeine intake by pregnant women, adults and children can be harmful to the health of all particularly fetuses if the intake exceeds the permissible limits. Therefore, it is of fundamental importance to measure its concentration accurately using certified reference materials (CRMs). In the literature, no scientific details are published about the certification of caffeine standard solutions, and therefore, the present article covers this gap. A batch of caffeine solution was prepared in concentration of 1000 mg/kg and bottled. Homogeneity and stability of the candidate reference material were assessed by HPLC-UV and the results showed that the material is homogenous and stable enough. Characterization of the caffeine reference material was performed by HPLC-UV, LC-MS/MS and UV-VIS-NIR spectrophotometer in three different days and the characterization uncertainty was estimated in accordance with the requirements of ISO GUM. The certified value (999.86 ± 8.57 mg/kg) was derived as a weighted mean from the gravimetry and the three characterization methods and the certified uncertainty was calculated according to ISO Guide 35. The produced CRM is of strong interest to the food and drug analytical laboratories for the validity and credibility of their caffeine measurement results.展开更多
High-accuracy gas reference material is an important prerequisite to guaranteeing the accuracy of stoichiometry.At present,however,the existing procedures of preparing gas reference material are complicated and time-c...High-accuracy gas reference material is an important prerequisite to guaranteeing the accuracy of stoichiometry.At present,however,the existing procedures of preparing gas reference material are complicated and time-consuming with high degree of uncertainty,so it is difficult to realize the high-accuracy measurement of gas compositions.In this paper,a loop method of preparing the gas reference material was developed.Then,its uncertainty degree on trace materials and preparation process was assessed and compared with the preparation process of the traditional dilution method.Finally,its weighing value was verified by means of a gas chromatography.And the following research results were obtained.First,the weighing cylinder of traditional preparation methods need a balance of wide range and low precision,so the uncertainty degree in the weighing process is introduced many times by multi-stage dilution.Second,when the loop method is adopted to prepare mixed gas reference material,the preparation can be completed in one step,so the uncertainty degree introduced in the preparation process is decreased by one order of magnitude.Third,by virtue of the loop method,the previously-used preparation procedures are simplified,the consumption of raw material is reduced and the preparation efficiency of mixed gas reference material is increased.Fourth,the loop method has been successfully applied to the preparation of gas reference material of natural gas and sulfide mixtures,and it is promising in more extensive application to realize efficient preparation and accurate valuing of gas reference material.And fifth,a gas chromatography is used to verify the nominal value of mixed gas reference material prepared by the loop method.And it is indicated that the loop method is of strong feasibility and accuracy.展开更多
It is widely accepted that quantitative reference materials (RM), are indispensable tools for verification of the precision and accuracy of analytical measurements. The RM can be used by food microbiology laboratories...It is widely accepted that quantitative reference materials (RM), are indispensable tools for verification of the precision and accuracy of analytical measurements. The RM can be used by food microbiology laboratories, as part of their quality assurance programmes, to achieve their quality control. In Brazil, Anvisa RDC No. 12/01 specifies the enumeration of coliforms as one of the parameters for evaluating cheese quality. The aim of this study was to produce a quantitative RM for proficiency testing (PT) for use in the testing of enumeration of coliforms in cheese matrixes. A sample of an ultra-filtered cheese with a coliforms count of <3.0 MPN/g and a total n? of viable aerobes of 1.2 × 103 CFU/g was used as the matrix to produce the RM. The ultra-filtered cheese matrix was distributed in flasks, contaminated with a specific concentration of an Escherichia coli strain and submitted to freeze-drying. Sucrose was used as the cryo-protector. The RM produced was considered sufficiently homogeneous and stable at ≤ ?70?C during the entire study period (348 days). The material was also considered sufficiently stable at 4?C for six days, but instable at 30?C and 35?C for the same period. At ?20?C the RM was sufficiently stable for 161 days. It was concluded that the material showed all the necessary requirements for a quality RM to be used as PT items and could be transported to the laboratories taking part in a PT at up to 4?C for up to 6 days, since the results indicated maintenance of the cell concentrations during this period. This is the first study to describe a methodology for producing RM containing coliforms in a cheese matrix.展开更多
To evaluate the suitability of Penglai zircon as a reference material for zircon fission track thermochronology,we analyzed natural zircon megacrysts from Penglai,northern Hainan Island,southern China,using the fissio...To evaluate the suitability of Penglai zircon as a reference material for zircon fission track thermochronology,we analyzed natural zircon megacrysts from Penglai,northern Hainan Island,southern China,using the fission track dating by LA-ICP-MS method.Through rigorous validation against the internationally recognized Fish Canyon Tuff zircon(FCT)standards,we demonstrate that our laboratory's measurement processes for fission track dating by the LA-ICP-MS method are reliable and practical.Three fission track ages of 4.02±0.23 Ma(1σ),4.11±0.26 Ma(1σ),and 4.16±0.27 Ma(1σ)were obtained from 52 fragments of three Penglai zircon megacrysts.The obtained fission track ages are homogeneous and highly reproducible,aligning with the(U-Th)/He ages.The chemical and textural analyses described by the CL and BSE imaging and EPMA results indicate that the three Penglai zircon megacrysts are nearly homogeneous.Penglai zircon megacrysts exhibit near homogeneity,weak broad zoning,unlimited quantity,rapid cooling,consistent fission track ages,and identical(U-Th)/He ages.These results confirm that Penglai zircon is suitable for use as a reference material for fission track thermochronology,provided that some caution is taken to verify fission track ages before selecting a Penglai zircon megacryst as a reference material.展开更多
High-throughput technologies for multiomics or molecular phenomics profiling have been extensively adopted in biomedical research and clinical applications,offering a more comprehensive understanding of biological pro...High-throughput technologies for multiomics or molecular phenomics profiling have been extensively adopted in biomedical research and clinical applications,offering a more comprehensive understanding of biological processes and diseases.Omics reference materials play a pivotal role in ensuring the accuracy,reliability,and comparability of laboratory measurements and analyses.However,the current application of omics reference materials has revealed several issues,including inappropriate selection and underutilization,leading to inconsistencies across laboratories.This review aims to address these concerns by emphasizing the importance of well-characterized reference materials at each level of omics,encompassing(epi-)genomics,transcriptomics,proteomics,and metabolomics.By summarizing their characteristics,advantages,and limitations along with appropriate performance metrics pertinent to study purposes,we provide an overview of how omics reference materials can enhance data quality and data integration,thus fostering robust scientific investigations with omics technologies.展开更多
To meet the rapid development of zircon U-Pb geochronology and Hf-O isotope geochemistry,it is imperative to develop well-characterized zircon reference materials for microbeam analysis.Here,zircon KV01 separated from...To meet the rapid development of zircon U-Pb geochronology and Hf-O isotope geochemistry,it is imperative to develop well-characterized zircon reference materials for microbeam analysis.Here,zircon KV01 separated from the Kaap Valley pluton,South Africa is introduced as a potential Archean reference material for microbeam U-Pb age and Hf-O isotope determination.SIMS and LA-ICP-MS U-Pb isotopic measurements gave grand mean 207Pb/206Pb ages of 3233±16 Ma(2 s,n=90)and 3230±26 Ma(2 s,n=52),which are consistent with reported CA-ID-TIMS results.Slight heterogeneity of oxygen isotopes is revealed by SIMS analyses that yielded a relatively largeδ18O range of 4.61–6.51‰.Among them,the zircon grains with clear oscillatory zones give a grand meanδ18O value of 6.17±0.33‰(2 s),which is suggested to record the primary O isotopic compositions.The homogeneity in the Hf isotopic compositions of KV01 zircon was checked by the laser ablation and solution MC-ICP-MS methods.They yielded consistent results with a recommended 176Hf/177Hf ratio of 0.280810±0.000013(2 s).The results reported here demonstrate that KV01 zircon could be a reliable reference material for microbeam 207Pb/206Pb age and Hf isotope determinations of ancient zircons,and be suitable as a quality monitor for SIMS oxygen isotopic analysis.展开更多
基金supported by the National Natural Science Foundation of China(Nos.42003014,42363004,42073051,42303023)Jiangxi Provincial Natural Science Foundation(No.20232BAB213070)the Natural Science Foundation of Shandong Province(No.ZR2022QD050)。
文摘Sulfur isotopes of S-bearing materials are powerful tools to trace various geological processes and sulfur sources in earth sciences,especially in ore deposits where sulfide-sulfate pair coprecipitates widely.However,in-situ S isotope determination of barite is challenging without natural matrix-matched reference material.In this study,we present two natural barite reference materials(1-YS and 294-YS)for in-situ sulfur isotopic analysis.Independent LA-MC-ICP-MS laboratories were utilized to test theδ34S micron-scale homogeneity of 1-YS and 294-YS barites that have 2s repeatabilities of better than±0.45‰and±0.41‰,respectively.Meanwhile,the in-situ analysis results are consistent with the results of the bulk analysis by GS-IRMS within uncertainty.The grand meanδ~(34)S values of 1-YS(13.37‰±0.42‰,2s)and 294-YS(14.38‰±0.44‰,2s)are the final recommended values obtained from four independent laboratories.All the results confirm the suitability of 1-YS and 294-YS barite used as calibration materials with respect to in-situ S isotopic analysis.Moreover,the new developed barite reference materials were used as matrix-matched standard to calibrate the barite samples from the Huayangchuan carbonatite-hosted U-polymetallic deposit(Qinling orogenic belt,western China)to obtainδ34S values.Utilizing the temperaturedependentδ34S fractionation of barite-pyrite pair,we calculate the formation temperature of barite(i.e.,506 to 537°C)and theδ34S value of mineralizing fluid(i.e.,-7.11‰to-7.59‰)in the Huayangchuan deposit.The results indicate an involvement of sedimentary sulfur,presumably acting as a potential uranium source(e.g.,upper crustal materials)for the giant Huayangchuan deposit.
基金supported by the National Natural Science Foundation of China(No.22206180)the funds for establishing basic quality and technology capabilities(No.ANL2203)the special fund for basic scientific research business of central public research institutes(No.AKYZD2207-4)。
文摘Carbonaceous aerosol,including organic carbon(OC)and elemental carbon(EC),has significant influence on human health,air quality and climate change.Accurate measurement of carbonaceous aerosol is essential to reduce the uncertainty of radiative forcing estimation and source apportionment.The accurate separation of OC and EC is controversial due to the charring of OC.Therefore,the development of reference materials(RM)for the validation of OC/EC separation is an important basis for further study.Previous RMs were mainly based on ambient air sampling,which could not provide traceability of OC and EC concentration.To develop traceable RMs with known OC/EC contents,our study applied an improved aerosol generation and mixing technique,providing uniform deposition of particles on quartz filters.To generate OC aerosol with similar pyrolytic property of ambient aerosol,both water soluble organic carbon(WSOC)and water insoluble organic carbon(WIOC)were used,and amorphous carbon was selected for EC surrogate.The RMs were analyzed using different protocols.The homogeneity within the filter was validated,reaching below 2%.The long-term stability of RMs has been validated with RSD ranged from 1.7%–3.2%.Good correlationwas observed between nominal concentration of RMswithmeasured concentration by two protocols,while the difference of EC concentration was within 20%.The results indicated that the newly developed RMs were acceptable for the calibration of OC and EC,which could improve the accuracy of carbonaceous aerosol measurement.Moreover,the laboratory-generated EC-RMs could be suitable for the calibration of equivalent BC concentration by Aethalometers.
基金supported by the National Key Research and Development Pro-gram of China(2021YFF0601902)the National Reference Material Development Project(S2022234).
文摘To solve the problem of the lack of reference material(RM)for determination of allergenic ingredients in food,a RM of cashew nut powder was developed in the study.Cashew nut powder was prepared from cashew nut kernel by selecting,cleaning,crushing,n-hexane degreasing and sieving treatment.The reliability and traceability of RM was verified using real-time quantitative polymerase chain reaction(qPCR)and phylogenetic tree analysis.The cashew nut powder RM showed good homogeneity,and good stability under long-term storage at 4℃and short-term simulated transportation from-20 to 45℃.The RM was determined jointly by 8 collaborative laboratories,and the characteristic CT value was 24.732,and the extended uncertainty was 1.052%(k=2).The RM was applied to verify the amplification efficiency and the limit of detection for qPCR assay,and showed good applicability.The RM could be used for method validation and quality control,for the determination of allergenic ingredients in food mixed with trace amounts of cashew nut.
基金supported by National Key Basic Research Program of China(2014CB238903)the National Natural Science Foundation of China(Nos.41473028,41673017,U1612441)the Opening Fund of State Key Laboratory of Environmental Geochemistry(SKLEG2015201)
文摘Lead(Pb)isotopes have been extensively employed in tracing sources of Pb and its transport pathways through the environment.However,Pb isotopic ratios in related geochemical reference materials are scarce.Here,we report high-precision Pb isotopic ratios measured by Nu Plasma II MC-ICP-MS using calibrated ^(205)Tl/^(203)Tl=2.38865(NIST SRM 997)for mass discrimination correction.The long-term external precision(2SD)for NISTSRM 981 of Pb,BCR-2,and BHVO-2 are 0.31‰(n=105),0.42‰(n=11),and 0.25‰(n=5)for ^(208)Pb/ ^(206)Pb and 0.16‰,0.53‰,and 0.07‰for ^(206)Pb/ ^(207)Pb,both respectively,and their Pb isotopic ratios are in excellent agreement with the recommended values.Using this method,we report for the first time Pb isotopic compositions in shale SGR-1b(USGS);coal CLB-1(USGS);stream sediments GSD-17,-21,and-23(IGGE);soils GSS-12,-13,-14,-15,and-16(IGGE);plants GSV-1,-2,and-3(IGGE);and human hair GSH-1(IGGE).
基金The authors acknowledge National Key R&D Program of China(Grant No.2016YFC1000900)The Drug Innovation Major Project(Grant No.2018ZX09711001-001-015)should be substituted by Drug Innovation Major Project(Grant No.2018ZX09711001-003-022)CAMS Innovation Fund for Medical Sciences(Grant No.2016-I2M-3-007)for financing this work.
文摘Salvianolic acid A(Sal A),a water-soluble ingredient in Danshen,has various biological activities.Sal A and its impurities have similar physical and chemical properties,as well as strong reducibility;therefore,they are difficult to prepare and purify.In this study,high-purity Sal A was obtained by purification of sephadex chromatography and preparative chromatography.Furthermore,HPLC-DAD tandem ECD and HPLC-DAD tandem MS methods were used for non-volatile organic impurity analysis,ICP-MS method was used for non-volatile inorganic impurities and mass balance method and quantitative nuclear magnetic resonance were employed to certify the product.The structures of Sal A and its relative impurities were validated by nuclear magnetic resonance spectroscopy and mass spectrometry,and their contents were quantified as well.Following the principles of ISO Guides 34:2009 and 35:2005,a Sal A reference material was certified,covering homogeneity studies,stability studies,characterization,and uncertainty estimations.
基金financially supported by the National Natural Science Foundation of China(Project Nos.41473005,41973020,41873027)。
文摘Ti separation was achieved by ion-exchange chromatography using Bio-Rad AG 1-X8 anion-exchange and DGA resins.For high-Fe/Ti and high-Mg/Ti igneous samples,a three-column procedure was required,whereas a two-column procedure was used for low-Fe/Ti and low-Mg/Ti igneous samples.The Ti isotopes were analysed by MC-ICP-MS,and instrumental mass bias was corrected using a ^(47)Ti-^(49)Ti double-spike technique.The ^(47)Ti-^(49)Ti double-spike and SRM 3162a were calibrated using SRM 979-Cr,certificated value ^(53)Cr/^(52)Crt rue=0.11339.Isobaric interference was evaluated by analysing Alfa-Ti doped with Na,Mg,Ca,and Mo,and results indicate that high concentrations of Na and Mg have no significant effect on Ti isotope analyses;however,Ca and Mo interferences lead to erroneousδ^(49/47)Ti values when Ca/Ti and Mo/Ti ratios exceed 0.01 and 0.1,respectively.Titanium isotopic compositions were determined for 12 igneous reference materials,BCR-2,BHVO-2,GBW07105,AGV-1,AGV-2,W-2,GBW07123,GBW07126,GBW07127,GBW07101,JP-1,and DTS-2b.Samples yieldδ^(49/47)Ti(‰)of−0.035±0.022,−0.038±0.031,0.031±0.022,0.059±0.038,0.044±0.037,0.000±0.015,0.154±0.044,−0.044±0.018,0.010±0.022,0.064±0.043,0.169±0.034,and−0.047±0.025(relative to OL-Ti,±2SD),respectively;of which isotopic compositions of DTS-2b,JP-1,GBW07101,GBW07105,GBW07123,GBW07126,and GBW07127 are reported for the first time.Standard Alfa-Ti was analysed repeatedly over a ten-month period,indicating a reproducibility of±0.047(2SD)forδ^(49/47)Ti,similar to the precisions obtained for geochemical reference materials.
文摘In order to develop new reference materials for microanalytical nuclear techniques, scanning proton microprobe (SPM) technique was used to determine homogeneity level within 100×200 μm 2 micro area on the small pieces of IAEA urban dust reference materials. The experimental methods were described in detail. The results show that IAEA 396A/M Vienna urban dust is homogeneous enough for small sample analysis of standard reference material (SRM).
文摘This paper describes the quantitative determination of rare-earth elements cerium, dysprosium and non-rare-earth element copper, lead and the homogeneity examination of these four elements in yttrium oxide reference material by isotope dilution spark source mass spectrometry (ID-SSMS). The sensitivity of the meth- od is l0^(-5)～10^(-7%). The precision is better than 6%. The accuracy is better than 5%. The interferences of the spectra and the optimum amount of the spike added to the sample are discussed. The choice of the conducting material for the sample electrodes is studied.
文摘Potala PalaceConstruction of the Potala Palace began in the mid-7th century for the Tubo King Songtsan Gambo to greet his Han wife, Princess Wencheng. It comprised 999 rooms then, plus one built atop the Red Hill, which, said to have 1,000 rooms, was later destroyed by thunderbolts and wars. What we see today is a structure built during the 17th century.In the mid-17th century, the White House was added to the Potala Palace, which spread along the Red Hill in Lhasa.The palace is a structure of clay, wood and stone. The palace was the residence of the Dalai Lama of various generations. Beginning with the period of the 5th Dalai Lama, major religious and political ceremonies were held there.The palace covers a total area of 360,000 square meters, with major building rising 117 meters high in 13 floors, and extends some 360 meters from east to west.From 1989 to 1994, the State earmarked some 55 million Yuan and large quantities of gold and silver to repair the palace.In December 1994, the palace found its
文摘Caffeine intake by pregnant women, adults and children can be harmful to the health of all particularly fetuses if the intake exceeds the permissible limits. Therefore, it is of fundamental importance to measure its concentration accurately using certified reference materials (CRMs). In the literature, no scientific details are published about the certification of caffeine standard solutions, and therefore, the present article covers this gap. A batch of caffeine solution was prepared in concentration of 1000 mg/kg and bottled. Homogeneity and stability of the candidate reference material were assessed by HPLC-UV and the results showed that the material is homogenous and stable enough. Characterization of the caffeine reference material was performed by HPLC-UV, LC-MS/MS and UV-VIS-NIR spectrophotometer in three different days and the characterization uncertainty was estimated in accordance with the requirements of ISO GUM. The certified value (999.86 ± 8.57 mg/kg) was derived as a weighted mean from the gravimetry and the three characterization methods and the certified uncertainty was calculated according to ISO Guide 35. The produced CRM is of strong interest to the food and drug analytical laboratories for the validity and credibility of their caffeine measurement results.
文摘Natural gas (NG) is one of the most important sources of energy for industrial and domestic consumption in the present era because it is cheap and free from sulfur impurities. Therefore, accurate and precise measurement of its composition is of fundamental importance for trade reasons. To improve the quality of NG gas measurements, certified reference materials (CRMs) should be used for calibration of measuring equipment in order to ensure the traceability of the measurement results to the SI units. For the traceability purpose, a multicomponent natural gas mixture was prepared gravimetrically as a reference material according to ISO 6142 from pure helium, hydrogen, n-pentane, i-pentane, n-butane, i-butane, propane, ethane, hexane, methane and nitrogen. The preparation was done in two dilution steps in 5 L aluminum cylinders. The calculated mole fractions and associated uncertainties of natural gas components were verified by a dual GC-FID/TCD system in accordance with ISO 6143 calibrated by a series of primary gas mixtures (CRMs) produced by an NMI. The results obtained by gravimetry and by GC measurements have been checked for compatibility as required by ISO 6142 and were found in very good agreement. Details of the preparation and calculation of the mole fractions and uncertainties of all gas components are explained in this article.
基金financially supported by the National Key Research & Development Program of China (2016YFF0201803)
文摘Maize unsound kernel content is one of the limited items in maize trade, and generally determined by sensory detection. A certified reference material(CRM) for visual inspection of maize unsound kernels was developed according to a national standard of China, GB 1353-2018, and five items, such as insect-damaged kernels, spotted kernels, broken kernels, sprouted kernels and moldy kernels, were included. Unsound maize kernels were collected from fields or prepared in a laboratory, then screened, and ten kernels demonstrating varying levels of unsoundness or damage for each item were embedded in epoxy resin. The CRM showed excellent homogeneity and stability, which was stable for 14 days at the temperature from-20℃ to 45℃ and for at least 18 months at room temperature out of direct sunlight and strong light. Co-laboratory confirmation showed the CRM conformed to the morphological characteristics described in GB 1353-2018. The research filled the gap of unsound maize kernel CRM in maize detection.
文摘Caffeine intake by pregnant women, adults and children can be harmful to the health of all particularly fetuses if the intake exceeds the permissible limits. Therefore, it is of fundamental importance to measure its concentration accurately using certified reference materials (CRMs). In the literature, no scientific details are published about the certification of caffeine standard solutions, and therefore, the present article covers this gap. A batch of caffeine solution was prepared in concentration of 1000 mg/kg and bottled. Homogeneity and stability of the candidate reference material were assessed by HPLC-UV and the results showed that the material is homogenous and stable enough. Characterization of the caffeine reference material was performed by HPLC-UV, LC-MS/MS and UV-VIS-NIR spectrophotometer in three different days and the characterization uncertainty was estimated in accordance with the requirements of ISO GUM. The certified value (999.86 ± 8.57 mg/kg) was derived as a weighted mean from the gravimetry and the three characterization methods and the certified uncertainty was calculated according to ISO Guide 35. The produced CRM is of strong interest to the food and drug analytical laboratories for the validity and credibility of their caffeine measurement results.
基金supported by the Program Funded by the National Key Research and Development Plan“Study on measurement standards and reference materials urgently needed in the production safety and protection field”(No.:2016YFF0201101)the Program of the National Science and Technology Support Plan“Study on key technology of traceability of the values of micro and trace harmful components in ambient gas”(No.:2013BAK12B04).
文摘High-accuracy gas reference material is an important prerequisite to guaranteeing the accuracy of stoichiometry.At present,however,the existing procedures of preparing gas reference material are complicated and time-consuming with high degree of uncertainty,so it is difficult to realize the high-accuracy measurement of gas compositions.In this paper,a loop method of preparing the gas reference material was developed.Then,its uncertainty degree on trace materials and preparation process was assessed and compared with the preparation process of the traditional dilution method.Finally,its weighing value was verified by means of a gas chromatography.And the following research results were obtained.First,the weighing cylinder of traditional preparation methods need a balance of wide range and low precision,so the uncertainty degree in the weighing process is introduced many times by multi-stage dilution.Second,when the loop method is adopted to prepare mixed gas reference material,the preparation can be completed in one step,so the uncertainty degree introduced in the preparation process is decreased by one order of magnitude.Third,by virtue of the loop method,the previously-used preparation procedures are simplified,the consumption of raw material is reduced and the preparation efficiency of mixed gas reference material is increased.Fourth,the loop method has been successfully applied to the preparation of gas reference material of natural gas and sulfide mixtures,and it is promising in more extensive application to realize efficient preparation and accurate valuing of gas reference material.And fifth,a gas chromatography is used to verify the nominal value of mixed gas reference material prepared by the loop method.And it is indicated that the loop method is of strong feasibility and accuracy.
基金Conselho Nacional de Desenvolvimento Cientifico e Tecnologico(CNPq),Inovatec/Fiocruz and INCQS/Fiocruz for financial support
文摘It is widely accepted that quantitative reference materials (RM), are indispensable tools for verification of the precision and accuracy of analytical measurements. The RM can be used by food microbiology laboratories, as part of their quality assurance programmes, to achieve their quality control. In Brazil, Anvisa RDC No. 12/01 specifies the enumeration of coliforms as one of the parameters for evaluating cheese quality. The aim of this study was to produce a quantitative RM for proficiency testing (PT) for use in the testing of enumeration of coliforms in cheese matrixes. A sample of an ultra-filtered cheese with a coliforms count of <3.0 MPN/g and a total n? of viable aerobes of 1.2 × 103 CFU/g was used as the matrix to produce the RM. The ultra-filtered cheese matrix was distributed in flasks, contaminated with a specific concentration of an Escherichia coli strain and submitted to freeze-drying. Sucrose was used as the cryo-protector. The RM produced was considered sufficiently homogeneous and stable at ≤ ?70?C during the entire study period (348 days). The material was also considered sufficiently stable at 4?C for six days, but instable at 30?C and 35?C for the same period. At ?20?C the RM was sufficiently stable for 161 days. It was concluded that the material showed all the necessary requirements for a quality RM to be used as PT items and could be transported to the laboratories taking part in a PT at up to 4?C for up to 6 days, since the results indicated maintenance of the cell concentrations during this period. This is the first study to describe a methodology for producing RM containing coliforms in a cheese matrix.
基金supported by the National Science and Technology Major Project(Grant No.2024ZD1001102)the National Natural Science Foundation of China(Grant Nos.42241161,42072242)the Fundamental Research Fund of Institute of Geomechanics,Chinese Academy of Geological Sciences(DZLXJK202303)。
文摘To evaluate the suitability of Penglai zircon as a reference material for zircon fission track thermochronology,we analyzed natural zircon megacrysts from Penglai,northern Hainan Island,southern China,using the fission track dating by LA-ICP-MS method.Through rigorous validation against the internationally recognized Fish Canyon Tuff zircon(FCT)standards,we demonstrate that our laboratory's measurement processes for fission track dating by the LA-ICP-MS method are reliable and practical.Three fission track ages of 4.02±0.23 Ma(1σ),4.11±0.26 Ma(1σ),and 4.16±0.27 Ma(1σ)were obtained from 52 fragments of three Penglai zircon megacrysts.The obtained fission track ages are homogeneous and highly reproducible,aligning with the(U-Th)/He ages.The chemical and textural analyses described by the CL and BSE imaging and EPMA results indicate that the three Penglai zircon megacrysts are nearly homogeneous.Penglai zircon megacrysts exhibit near homogeneity,weak broad zoning,unlimited quantity,rapid cooling,consistent fission track ages,and identical(U-Th)/He ages.These results confirm that Penglai zircon is suitable for use as a reference material for fission track thermochronology,provided that some caution is taken to verify fission track ages before selecting a Penglai zircon megacryst as a reference material.
基金supported in part by Shanghai Sailing Program(22YF1403500)the National Natural Science Foundation of China(32300536,31720103909 and 32170657)+2 种基金the National Key R&D Project of China(2018YFE0201603 and 2018YFE0201600)State Key Laboratory of Genetic Engineering(SKLGE-2117)the 111 Project(B13016).
文摘High-throughput technologies for multiomics or molecular phenomics profiling have been extensively adopted in biomedical research and clinical applications,offering a more comprehensive understanding of biological processes and diseases.Omics reference materials play a pivotal role in ensuring the accuracy,reliability,and comparability of laboratory measurements and analyses.However,the current application of omics reference materials has revealed several issues,including inappropriate selection and underutilization,leading to inconsistencies across laboratories.This review aims to address these concerns by emphasizing the importance of well-characterized reference materials at each level of omics,encompassing(epi-)genomics,transcriptomics,proteomics,and metabolomics.By summarizing their characteristics,advantages,and limitations along with appropriate performance metrics pertinent to study purposes,we provide an overview of how omics reference materials can enhance data quality and data integration,thus fostering robust scientific investigations with omics technologies.
基金supported by the National Key R&D Program of China(Grant No.2016YFC0600109)the B-type Strategic Priority Program of the Chinese Academy of Sciences(Grant No.XDB41000000)+2 种基金the National Natural Science Foundation of China(Grant Nos.41973035&41688103)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2020068)the State Key Laboratory of Lithospheric Evolution(Grant No.SKL-Z201901-YT)。
文摘To meet the rapid development of zircon U-Pb geochronology and Hf-O isotope geochemistry,it is imperative to develop well-characterized zircon reference materials for microbeam analysis.Here,zircon KV01 separated from the Kaap Valley pluton,South Africa is introduced as a potential Archean reference material for microbeam U-Pb age and Hf-O isotope determination.SIMS and LA-ICP-MS U-Pb isotopic measurements gave grand mean 207Pb/206Pb ages of 3233±16 Ma(2 s,n=90)and 3230±26 Ma(2 s,n=52),which are consistent with reported CA-ID-TIMS results.Slight heterogeneity of oxygen isotopes is revealed by SIMS analyses that yielded a relatively largeδ18O range of 4.61–6.51‰.Among them,the zircon grains with clear oscillatory zones give a grand meanδ18O value of 6.17±0.33‰(2 s),which is suggested to record the primary O isotopic compositions.The homogeneity in the Hf isotopic compositions of KV01 zircon was checked by the laser ablation and solution MC-ICP-MS methods.They yielded consistent results with a recommended 176Hf/177Hf ratio of 0.280810±0.000013(2 s).The results reported here demonstrate that KV01 zircon could be a reliable reference material for microbeam 207Pb/206Pb age and Hf isotope determinations of ancient zircons,and be suitable as a quality monitor for SIMS oxygen isotopic analysis.
