Instrumental Neutron Activation Analysis for Certification of Ion-Implanted Arsenic in Silicon

Standard reference material (SRM) 2134 Arsenic Implant in Silicon was produced at the National Institute of Standards and Technology (NIST) as a calibrant for secondary ion mass spectrometry. Instrumental neutron activation analysis was used as a primary method for certification of the arsenic implanted dose. A complete evaluation of all sources of uncertainty yielded an expanded relative uncertainty for the mean value of this SRM to be 0.38% at approximately the 95% level of confidence. No evidence indicating significant heterogeneity among samples was observed.     

电感耦合等离子体质谱法测定镍基高温合金中磷含量的不确定度评定

采用电感耦合等离子体质谱(ICP-MS)法测定镍基高温合金中磷杂质含量,对该测定方法的不确定度进行评定。建立了不确定度评定的数学模型,对不确定度的来源进行了全面分析,通过计算得到扩展不确定度。采用ICP-MS法测定YSBC 41503-2012标准物质中的磷含量,测定值为0.0035%,测定结果与证书参考值一致。按照建立的不确定度评定方法得扩展不确定度为0.0002%(k=2)。该方法适用于ICP-MS法测定高温合金中磷含量的不确定度评定。     

氮中丙烯腈气体标准物质的研制

以高纯丙烯腈和高纯氮气为原料,采用称量法配制氮中丙烯腈气体标准物质。对配制的气体标准物质分别进行机械混匀试验、压力均匀性和时间稳定性试验。经F检验,2.00μmol/mol及5.00μmol/mol两种浓度的样品在0.5~10 MPa范围内标准值无显著变化,具有较好的压力均匀性;在–20℃和40℃条件下保存7 d,其量值无显著变化,可满足运输环节量值稳定;在常温下贮存9个月量值无显著变化,表明其稳定性良好,满足国家二级标准物质对有效期的要求。对定值结果的不确定度进行评定。配制的氮中丙烯腈气体标准物质标准值为(2~5)×10~(–6)mol/mol,相对扩展不确定度为9%(k=2)。该标准物质达到国家二级标准物质的相关技术要求,可用于对丙烯腈气体报警器的校准。     

Assessment uncertainty associated to the analysis of organic compounds linked to particulate matter of atmospheric aerosols

Current work has evaluated uncertainty associated to quantification of several organic compounds present in particulate matter of atmospheric aerosols, setting out the stages of analytical procedure that contribute most to the global uncertainty. Several sources of uncertainty have been identified, which were clustered into five main contributions: sampling, extraction, clean-up, derivatization and analysis. A discussion of the main contributions to the overall uncertainty is reported, allowing authors to locate the largest ones and plan future improvements. Combined uncertainties ranged between 10-18% (alkanes), 12-16% (PAHs), 10-18% (alcohols) and 9-21% (acids). The analytical procedure was validated by analysing a standard reference material (SRM1649a, urban dust). Also, the proposed method was applied to the analysis of four samples of particulate matter.     

乙酰甲胺磷丙酮溶液标准物质的制备及定值

采用乙酰甲胺磷纯度标准物质为原料,以丙酮为溶剂,制备了浓度为1．00mg／mL的乙酰甲胺磷丙酮溶液标准物质,用液相色谱法和气相色谱法进行了确认,A类标准不确定度为0．009％,B类标准不确定度包括标准物质制备、原料纯度、不均匀性和不稳定性引入的不确定度,其量值分别为0．43％,0．10％,0．87％和0．24％,合成不确定度为0．03mg／mL（k=-2）,乙酰甲胺磷丙酮溶液标准物质的浓度为（1．00±0．03）mg／mL。     

注射重量法制备乙醇气体标准物质的不确定度

分析了注射重量法制备乙醇气体标准物质不确定度的来源,包括乙醇称量过程引入的不确定度、氮气称量过程引入的不确定度、乙醇纯度引入的不确定度、氮气纯度引入的不确定度。合成不确定度及扩展不确定度分别为0.08%、0.16%(k=2)     

原子吸收光谱法测定载金碳中金含量的不确定度评定

介绍了原子吸收光谱法(AAS)测定载金碳中金含量的不确定度评定方法。建立了不确定度评定的数学模型,对不确定度来源进行分析,并对不确定度分量进行量化。测量不确定度的主要来源为测量重复性引入的标准不确定度、样品称量引入的标准不确定度、样品溶液中金含量测定值的标准不确定度、样品溶解后定容体积的不确定度,其中测量重复性引入的标准不确定度和样品溶液中金含量测定值引入的标准不确定度为不确定度主要来源。当载金碳中金含量为0.56 g/kg时,其扩展不确定度为0.02 g/kg(k=2)。     

Evaluation of measurement uncertainty in EA–IRMS: for determination of δ 13C value and C-4 plant sugar content in adulterated honey

In this study, the method for determining the stable carbon isotope ratio value was validated. Measurement uncertainty of stable carbon isotope ratio value of whole honey and its extracted protein derived from repeatability, reference gas, reference standards and calibration curve was calculated by applying the “bottom-up” approach according to Eurachem/CITAC guide. The expanded uncertainties for all results ranged from 0.14 to 0.19 ‰, with most of them between 0.15 and 0.16 ‰ (the coverage factor k = 2, the level of confidence p is approximately 95 %). The percentage contribution of each source to the relative combined uncertainty was calculated. The data indicated that calibration curves have more contribution to the relative combined uncertainty than repeatability and reference standards. On the other hand, the measurement uncertainty of C-4 sugar content in honey was estimated. Based on these results, 58 honey samples, such as acacia, chaste, Northeast China black bee, flowers and jujube honey, have been gathered to determine the C-4 plant sugar content adulteration in honey by elemental analyzer with an isotope ratio mass spectrometer. It can be found that all honey samples were not adulterated by C-4 plant sugar.     

差示扫描量热法对芝麻酚纯度标准物质的定值

建立了采用差示扫描量热法对芝麻酚纯度标准物质的定值及不确定度评价的数学模型、有效检测技术和分析方法.采用差示扫描量热法测量芝麻酚样品纯度的实验条件为升温速率3.0 K/min,称样量3.4～4.7 mg,炉内气体为静态空气.对通过均匀性检验和长期稳定性考察的芝麻酚纯度标准物质进行定值和不确定度评价,同时采用高效液相色谱...     

From experimental design to uncertainty estimation for the European Pharmacopoeia HPLC analysis of human insulin

In this paper the process from experimental design (e.g. ruggedness test) to uncertainty estimation is described. The uncertainty estimate was calculated for the peak area of insulin plus A21 desamido insulin resulting from an HPLC analysis of a sample of an injectable human insulin preparation, Actrapid HM 100 IU ml(-1) (Novo Nordisk A/S). The analytical method used was the European Pharmacopoeia assay. (4) An expanded uncertainty (1) of 1.8% (of the area from the HPLC analysis) at an approximately 95% confidence level was found and confirmed by a validation study. This uncertainty refers to the peak area of the analyte from a single injection of the sample. The input parameters to the uncertainty estimate were found from a factorial experimental design (e.g. ruggedness test) consisting of 9 factors applied to the HPLC analysis. The input parameters were chosen to cover the probable contributors to the variability of the measured area of the HPLC analysis, including the sample preparation, but excluding uncertainty deriving from the reference material(s).     

Determination of cocaine and heroin vapor pressures using commercial and illicit samples

The establishment of drug vapor pressure reference values provides valuable information in the development of vapor sensing devices for drug detection. The purpose of this work was to determine equilibrium headspace vapor pressures for commercial and illicit drug samples for use in such applications. Samples of cocaine, both free base and hydrochloride forms, and heroin hydrochloride were evaluated. The procedure used to measure the vapor pressures was a modification of a previously published method. Vapor pressure values at 20 degrees C previously reported for cocaine free base range from 0.37 x 10(-7) to 1.20 x 10(-7) Torr. The vapor pressure value determined in this study was 2.96 x 10(-7) Torr. It is likely that the discrepancies are due to differences in experimental conditions, varying sources of samples, and uncertainty in the methodologies. When the values were compared for commercial (99% purity) and illicit (unknown purity) sources of cocaine free base, there were no statistical differences in the projected room temperature (20 degrees C) vapor pressure values. However, the commercial and illicit samples of cocaine hydrochloride did show statistical differences. Although no comparison was made with the vapor pressure values for a pure, commercial sample, the vapor pressures of heroin hydrochloride (81% purity) at various temperatures were determined using the method developed for cocaine and are reported in this paper.     

MIC-SSMS analyses of eight new geological standard glasses

To obtain suitable geological reference materials for microanalytical purposes, a set of eight natural glasses was prepared by direct fusion of rock chips. Multi-ion counting spark source mass spectrometry (MIC-SSMS) has been applied for trace element analysis of these reference materials. The overall analytical uncertainty of the MIC-SSMS results was determined by considering 14 possible sources of errors. It generally ranges between < 2–7% depending on the element and its concentration. Nearly all MIC-SSMS data agree with the reference values within 0–10%, indicating that the estimate of the overall analytical uncertainty is reasonable. Received: 21 December 1998 / Revised: 2 March 1999 / Accepted: 3 March 1999     

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。     

河豚毒素标准样品的研制

采用质谱、核磁、红外及紫外对河豚毒素样品进行结构确证,采用柱后衍生高效液相荧光法对该纯度标准样品进行定值并进行了均匀性、稳定性检验。标准样品经国内6个具有分析资质的实验室进行协同定值,定值结果为99.45%,其扩展不确定度(95%置信区间)为0.51%。该标准样品达到国家标准样品的技术要求,可用于有关河豚毒素的方法校正和质量控制。     

MIC-SSMS analyses of eight new geological standard glasses

To obtain suitable geological reference materials for microanalytical purposes, a set of eight natural glasses was prepared by direct fusion of rock chips. Multi-ion counting spark source mass spectrometry (MIC-SSMS) has been applied for trace element analysis of these reference materials. The overall analytical uncertainty of the MIC-SSMS results was determined by considering 14 possible sources of errors. It generally ranges between < 2–7% depending on the element and its concentration. Nearly all MIC-SSMS data agree with the reference values within 0–10%, indicating that the estimate of the overall analytical uncertainty is reasonable. Received: 21 December 1998 / Revised: 2 March 1999 / Accepted: 3 March 1999     

引入不确定度的基础化学实验数据处理方法探讨

根据当前不确定度的应用现状,讨论了基础化学实验中计算不确定度的必要性和可行性。建议在学习基本误差理论的基础上找出误差的主要来源,在真值已知时直接计算误差,在真值未知时确定主要不确定度分量。计算不确定度时只考虑1~2个主要不确定度分量、忽略次要不确定度分量。上述实验数据处理方法可以满足基础化学实验的要求。     

氟喹诺酮混合溶液标准物质研制

建立甲醇中8种氟喹诺酮药物混合溶液标准物质的制备方法。采用重量-容量法配制混合溶液标准物质,以配制值作为标准物质的特性量值,考察不同氟喹诺酮药物之间互为杂质情况,采用高效液相色谱法对标准物质进行均匀性和稳定性检验,并对制备过程产生的不确定度进行评定。研制的甲醇中8种氟喹诺酮药物混合溶液标准物质具有良好的均匀性和稳定性,其质量浓度均为100 mg/L,相对扩展不确定度为2%~3%(k=2),已被批准为国家二级标准物质,编号为GBW(E)083598。该混合溶液标准物质可为农产品质量安全监测与风险评估中氟喹诺酮类药物残留测定提供溯源保障。     

Uncertainty in analytical results from solid materials with electrothermal atomic absorption spectrometry: a comparison of methods

The combined uncertainty in the analytical results of solid materials for two methods (ET-AAS, analysis after prior sample digestion and direct solid sampling) are derived by applying the Guide to the Expression of Uncertainty in Measurement from the International Standards Organization. For the analysis of solid materials, generally, three uncertainty components must be considered: (i) those in the calibration, (ii) those in the unknown sample measurement and (iii) those in the analytical quality control (AQC) process. The expanded uncertainty limits for the content of cadmium and lead from analytical data of biological samples are calculated with the derived statistical estimates. For both methods the expanded uncertainty intervals are generally of similar width, if all sources of uncertainty are included. The relative uncertainty limits for the determination of cadmium range from 6% to 10%, and for the determination of lead they range from 8% to 16%. However, the different uncertainty components contribute to different degrees. Though with the calibration based on reference solutions (digestion method) the respective contribution may be negligible (precision < 3%), the uncertainty from a calibration based directly on a certified reference material (CRM) (solid sampling) may contribute significantly (precision about 10%). In contrast to that, the required AQC measurement (if the calibration is based on reference solutions) contributes an additional uncertainty component, though for the CRM calibration the AQC is “built-in”. For both methods, the uncertainty in the certified content of the CRM, which is used for AQC, must be considered. The estimation of the uncertainty components is shown to be a suitable tool for the experimental design in order to obtain a small uncertainty in the analytical result.     

镉溶液标准物质的研制

介绍镉溶液标准物质的研制过程。以高纯镉为原料,1%硝酸溶液为基体,利用重量–容量和一步稀释法制备镉溶液标准物质。分别采用F检验和回归曲线法对研制的标准物质进行均匀性和稳定性考察。采用电感耦合等离子体发射光谱法与国家一级标准物质比对定值,并对镉溶液浓度量值进行不确定度评定。利用原子吸收分光光度法和电感耦合等离子体发射光谱法对研制的标准物质与国家二级标准物质进行比对。结果表明,研制的镉溶液标准物质的定值结果为100μg/m L,相对扩展不确定度U_(rel)=1.0%(k=2)。该标准物质量值准确且具有溯源性。     

化学法测定锌铁合金钢板镀层中铁含量测量结果的不确定度评定

对用化学法测定锌铁合金钢板镀层铁含量测量结果的不确定度进行评定,分析了该方法测定过程的不确定度来源主要是分析锌铁合金钢板镀层中铁质量的不确定度和分析锌铁合金钢板镀层质量的不确定度,建立数学模型并计算了各不确定度分量,经合成得标准不确定度为0.21%,扩展不确定度为0.42%(k=2).