稀土镁铸铁光谱分析用标准物质的研制

对稀土镁铸铁光谱分析用标准物质的制备、分析定值及应用进行了系统研究。研制了我国第一套稀土镁铸铁光谱分析用标准物质,确定了14个项目的标准定值,该系列标准物质有良好的均匀性,其化学成分呈梯度分布,线性关系良好。     

光谱分析用中合金钢标准物质的研制

介绍了光谱分析用25Cr3Mo3NiNbZrA中合金钢标准物质的研制过程。采用合理的冶炼锻轧工艺,选取不同部位的样品进行均匀性检验,确定了16个元素的认定值及扩展不确定度,并进行了线性、一致性考察以及与国内外同类标准物质的比对。     

特种铸造铝合金光谱分析用标准物质的研制

介绍特种铸造铝合金光谱分析用标准物质的研制过程。采用熔炼和浇铸以及精炼、除渣等工艺,制备了系列铸造铝合金标准物质;在不同部位取样,用F检验法进行均匀性检验,结果表明,均匀性良好;经过60个月长期稳定性考察,稳定性良好;经8家实验室采用电感耦合等离子体原子发射光谱法、原子吸收光谱法、GB/T 20975.5–2008等方法进行定值分析,确定了每套标准物质中Si,Fe,Cu,Mg,Zn,Pb,Bi等7种元素的标准值,含量范围分别为7.45%～13.39%,0.301%～1.42%,0.382%～1.39%,0.076%～0.911%,0.090%～0.659%,0.282%～1.28%,0.099%～0.947%。进行成线性及与国内外同类标准物质一致性考察,相关系数均大于0.99。该系列标准物质适用于类似铸造铝合金元素的成分分析。     

透光率计滤光片标准物质的研制

以中性灰玻璃及特种石英玻璃为材料,采用切割、研磨、抛光等工艺,制备了校准透光率计用系列滤光片标准物质,标准物质的均匀性不确定度为0.08%,校准周期内的稳定性不确定度为0.19%,扩展不确定度为0.5%(k=2)。该标准物质可广泛用于校准透光率计,具有携带方便、性能稳定等优点。     

甲烷中微量噻吩气体标准物质研制

研制了甲烷中噻吩气体标准物质。以高纯噻吩、高纯甲烷为原材料，包装容器为4 L内壁经抛光处理的铝合金瓶，通过微量转移与常规相结合的方法完成了甲烷中微量噻吩气体标准物质制备。利用气相色谱法对标准物质进行了均匀性检验及稳定性考察。F检验和回归曲线法实验结果表明，该气体标准物质在压力为0.5～10 MPa范围内，均匀性良好，在常温条件下保存12个月稳定。采用称量法对该气体标准物质进行了定值，并对定值、均匀性和稳定性引入的不确定度进行了评定，该系列甲烷中微量噻吩气体标准物质标称摩尔分数为1.00～10.0μmol/mol，定值结果的相对扩展不确定度为2%(k=2)。     

血液中乙醇含量检测用标准物质的研制

制备8种不同浓度的血液中乙醇含量检测用水中乙醇标准物质。采用重量–容量法配制水中乙醇溶液标准物质,以配制值作为定值结果。采用气相色谱法对标准样品进行了均匀性和稳定性检验,并对定值结果进行验证。对定值结果的不确定度进行了评估。结果表明,水中乙醇标准物质的均匀性和稳定性良好,可稳定12个月。该系列标准物质已获批为国家二级标准物质,编号为GBW(E) 083145～GBW(E) 083152。     

耐辐照玻璃成分分析标准物质的研制

采用高温熔融方法制备了玻璃成分分析标准物质.对标准物质的制备技术、均匀性检验、稳定性考察及定值不确定度进行了分析.研制的耐辐照成分分析标准物质具有良好的均匀性和稳定性,各组分不确定度均小于5％.     

甲基对硫磷溶液标准物质的研制

采用重量–容量法研制了1.00 ng/μL甲基对硫磷农药标准物质,对研制的甲醇中甲基对硫磷溶液标准物质量值进行了均匀性和稳定性检验,对定值结果的不确定度进行了评定。结果表明,该标准物质均匀性良好,在一年内量值没有显著性变化,具有良好的稳定性,定值结果的相对扩展不确定度为3%(k=2)。该标准物质可用于农药残留测量结果的准确性评价。     

焦炭特性及成分分析用标准物质的研制

介绍焦炭特性及成分分析用标准物质的研制过程。对标准物质进行了均匀性检验和稳定性考察,8家权威实验室用准确可靠的方法参与协作定值,确定了22个项目的标准值和扩展不确定度。粒度分析和成分分析结果表明该标准物质均匀性良好,在5年内性质稳定。     

20nm银粉末粒度标准物质的研制

研制了用于X射线小角散射仪校准的20 nm粉末粒度标准物质,并对标准物质的制备技术、均匀性检验、稳定性考察及定值不确定度进行了分析。研制的银粉末粒度标准物质具有良好的均匀性和稳定性,标准值为17.2 nm,相对扩展不确定度为6%。     

Matrix certified reference materials for environmental monitoring from the National Metrology Institute of Japan (NMIJ)

Matrix certified reference materials (CRMs) are playing an increasingly important role in environmental monitoring in Japan. The National Metrology Institute of Japan (NMIJ)/National Institute of Advanced Industrial Science and Technology (AIST) has been developing matrix CRMs for environmental monitoring since 2001, and has issued nine kinds of CRMs as NMIJ CRMs. The development of the CRMs was conducted in NMIJ in cooperation with candidate material producers. The isotope dilution mass spectrometry (IDMS) was principally adopted to give reliable certified values. Meanwhile, two or more analytical methods, whose levels of accuracy were well evaluated, were applied to avoid any possible analytical bias. Two typical certification processes, the certification of river water CRMs for trace element analysis and that of marine sediment CRMs for PCB and organochlorine pesticide analysis, are outlined as examples. Presented at -- “BERM-10” -- April 2006, Charleston, SC, USA.     

Preparation and certification of the new reference materials; plastics (disk form, JSAC 0621-0625) for determination of mercury using x-ray fluorescent analysis.

The Japan Society for Analytical Chemistry has developed some new plastic certified reference materials (CRMs) for the analysis of mercury in polyester disks using XRF analysis. These CRMs (named as JSAC 0621-0625) were prepared by casting polyesters including a toluene solution of organometallic compounds as a standard. Concentrations of the five levels of mercury ranged from 0 to 250 mg/kg. Homogeneity tests of prepared disks had shown excellent results. Interlaboratory comparison study for the certification was performed by 15 laboratory participants. The z-scores in robust statistical method was applied for the evaluation of outliers. The certified values were assigned after discarding outliers. The uncertainties of certified values were determined as the confidence levels of 95%.     

Quantitative NMR spectroscopy for accurate purity determination of amino acids,and uncertainty evaluation for different signals

Purity evaluation of amino acids using nuclear magnetic resonance spectroscopy is reported. Three amino acids (aspartic acid, valine, and arginine) and certified reference materials (CRMs), such as acidic, neutral, and basic amino acids, as well as a low pure sample of valine were used as the analytes. DCl solution, D₂O, and NaOD solution were used as the preparation solvents. The quantitative values were obtained from all observed signals and compared with the certified values of the CRMs. When an amino acid was dissolved in water, a strong HOD signal due to proton exchange was observed. When the signal adjoining the HOD signal was considered in the evaluation, the accurate quantitative value could not be obtained. Therefore, under optimized conditions, the analyte signals separated from the HOD signal were chosen for purity determination of amino acids. As a result, the quantitative values were in agreement with the certified values of CRMs. An expanded uncertainty was estimated to be approximately 0.002 kg kg^?1. We also discuss the effect of impurities on purity determination based on all signals and conclude that agreement of quantitative values determined from different signals in a molecule is a good indication of the accuracy of the results.     

标准物质定值方法优选方案

将田口方法中代表设计研究或生产工艺研究中功能稳定性的信噪比概念用于标准物质定值方法的研究．为标准物质定值方法的优化提供数据处理模式和选择思路。以锌合金标准物质为例,采用原子吸收光谱法和紫外一可见分光光度法对锌合金标准物质中的铜元素定值,分别计算这两种方法定值数据的信噪比值,通过比较信噪比值的大小来判断两种分析方法的可靠性和分析体系的稳定性。     

Using inductively coupled plasma-mass spectrometry for calibration transfer between environmental CRMs

Multielement analyses of environmental reference materials have been performed using existing certified reference materials (CRMs) as calibration standards for inductively coupled plasma-mass spectrometry. The analyses have been performed using a high-performance methodology that results in comparison measurement uncertainties that are significantly less than the uncertainties of the certified values of the calibration CRM. Consequently, the determined values have uncertainties that are very nearly equivalent to the uncertainties of the calibration CRM. Several uses of this calibration transfer are proposed, including, re-certification measurements of replacement CRMs, establishing traceability of one CRM to another, and demonstrating the equivalence of two CRMs. RM 8704, a river sediment, was analyzed using SRM 2704, Buffalo River Sediment, as the calibration standard. SRM 1632c, Trace Elements in Bituminous Coal, which is a replacement for SRM 1632b, was analyzed using SRM 1632b as the standard. SRM 1635, Trace Elements in Subbituminous Coal, was also analyzed using SRM 1632b as the standard.     

Multielement determination of trace metals in seawater by ICP-MS with aid of down-sized chelating resin-packed minicolumn for preconcentration

The multielement determination of trace metals in seawater was carried out by inductively coupled plasma mass spectrometry (ICP-MS) with aid of a down-sized chelating resin-packed minicolumn for preconcentration. The down-sized chelating resin-packed minicolumn was constructed with two syringe filters (DISMIC 13HP and Millex-LH) and an iminodiacetate chelating resin (Chelex 100, 200-400 mesh), with which trace metals in 50 mL of original seawater sample were concentrated into 0.50 mL of 2 M nitric acid, and then 100-fold preconcentration of trace metals was achieved. Then, 0.50 mL analysis solution was subjected to the multielement determination by ICP-MS equipped with a MicroMist nebulizer for micro-sampling introduction. The preconcentration and elution parameters such as the sample-loading flow rate, the amount of 1 M ammonium acetate for elimination of matrix elements, and the amount of 2 M nitric acid for eluting trace metals were optimized to obtain good recoveries and analytical detection limits for trace metals. The analytical results for V, Mn, Co, Ni, Cu, Zn, Mo, Cd, Pb, and U in three kinds of seawater certified reference materials (CRMs; CASS-3, NASS-4, and NASS-5) agreed well with their certified values. The observed values of rare earth elements (REEs) in the above seawater CRMs were also consistent with the reference values. Therefore, the compiled reference values for the concentrations of REEs in CASS-3, NASS-4, and NASS-5 were proposed based on the observed values and reference data for REEs in these CRMs.     

碳增强效应与内标选择-电感耦合等离子体质谱法测定高温合金中痕量碲

采用电感耦合等离子体质谱法直接测定镍基高温合金中痕量碲,不需要对基体进行萃取等复杂的分离手段,通过对碳增敏剂与内标选择等因素进行优化,同时降低了多原子离子的干扰。依照质量数和ICP指数的角度选择铑为内标,校正了测定过程中信号的漂移,乙醇作为增敏剂,确定了在线的内标和增敏剂的加入模式。方法提高了痕量碲的检测灵敏度,测定下限达到0.00004% (0.4 ppm)。为了验证该方法的有效性,对高温合金的标准物质(GBW01619-01620)进行了分析,测定值与认定值吻合良好,其中结果精密度试验RSD(n=3)<10%。     

Using inductively coupled plasma–mass spectrometry for calibration transfer between environmental CRMs

Multielement analyses of environmental reference materials have been performed using existing certified reference materials (CRMs) as calibration standards for inductively coupled plasma–mass spectrometry. The analyses have been performed using a high-performance methodology that results in comparison measurement uncertainties that are significantly less than the uncertainties of the certified values of the calibration CRM. Consequently, the determined values have uncertainties that are very nearly equivalent to the uncertainties of the calibration CRM. Several uses of this calibration transfer are proposed, including, re-certification measurements of replacement CRMs, establishing traceability of one CRM to another, and demonstrating the equivalence of two CRMs. RM 8704, a river sediment, was analyzed using SRM 2704, Buffalo River Sediment, as the calibration standard. SRM 1632c, Trace Elements in Bituminous Coal, which is a replacement for SRM 1632b, was analyzed using SRM 1632b as the standard. SRM 1635, Trace Elements in Subbituminous Coal, was also analyzed using SRM 1632b as the standard.     

Input of missing trace elements in some IAEA/NBS biological certified reference materials using INAA

IAEA and NBS biological certified reference materials have been analyzed by instrumental neutron activation analysis and concentration of 17 elements was determined. The elements determined were either completely missing or their certified values were not given in the original compilations. For quality assurance of our work, a comparison of data on missing trace elements in some of the CRMs has been presented. It seems that second round of analysis for the certification of these elements would be useful.