氢化物原子荧光法测定人发中砷含量的不确定度评定

目的评定氢化物原子荧光法测定人发中砷含量的不确定度。方法以人发标准样品为分析对象,依据化学分析中不确定度的评估指南等指导性文件,分析测定过程中砷含量测定值（C）、样品处理后的总体积（V）、样品称量值（m）以及重复测量（rep）等多个不确定度分量,计算检测结果的合成标准不确定度和扩展不确定度。结果本文方法测定人发中砷含量的不确定度评定结果为：人发样品中砷的含量为（0.57±0.06）mg/kg,置信概率（p）=95%,自由度（υeff）=4。结论本文方法测量不确定度的主要来源是重复性和校准曲线,测定结果在标准物质给出的含量范围之内。     

HS-GC内标曲线法测定血中乙醇含量的不确定度评估

目的建立自动顶空-气相色谱(HS-GC)内标曲线法测定血中乙醇含量的不确定评估方法。方法从分析测定程序着手,依据不确定度评定的指导性文件,分析不确定度来源,量化不确定度分量,计算检测结果的合成标准不确定度和扩展不确定度。结果各相对不确定度来自于检材重复性检测为3.4%,乙醇标准溶液为0.71%,检材为0.61%,叔丁醇内标溶液为0.41%,标准曲线为1.1%,气相色谱仪为1.3%,血液中乙醇的相对扩展不确定度为3.9%。结论血液中乙醇含量的不确定度主要来源于检材重复性检测、气相色谱仪、乙醇标准曲线。     

毒物定量分析测量不确定度评定

第四讲 测量不确定度的评定、合成方法及运算公式 测量不确定度评定中,JJF1059—1999《测量不确定度评定与表示》给出评定的要求及方法,主要分A类评定和B类评定。这里就毒物定量分析特点作简要介绍,以方便实施。     

GC/MS测定尿液中氯胺酮含量不确定度评定

目的评定气相色谱—质谱法（GC/MS）测定尿液中氯胺酮含量的不确定度。方法依据不确定度评定的指导性文件,从测定程序分析了不确定度的来源,量化不确定度分量,计算检测结果的合成标准不确定度和扩展不确定度。结果尿液检材中测定结果平均值为0.257μg/mL的扩展不确定度为0.016μg/mL。结论尿液中氯胺酮含量的不确定度主要来源于标准品纯度和标准曲线。     

汽车风挡玻璃的鉴别方法研究

目的研究油浸法和X射线荧光光谱法对汽车风挡玻璃的鉴别能力。方法应用油浸法对30个风挡玻璃样品进行折射率测试，并将所得数据进行t检验分析。对不能区分的样品再用X射线荧光光谱进行元素成分分析。结果30个样品共组成的435对中，折射率t检验在置信度959／5时区分427对，其余8对通过元素成分实现区分。结论折射率测试和元素分析相结合，可对常见汽车风挡玻璃进行有效区分。     

自动顶空GC/MS测定血液中乙醇含量不确定度评定

目的评定自动顶空—气相色谱—质谱法(GC/MS)测定血液中乙醇含量的不确定度。方法从分析测量过程着手,依据不确定度评定的指导性文件,分析了不确定度来源,量化不确定度分量,计算检测结果的合成标准不确定度和扩展不确定度。结果血液样本两次测定结果平均值为0.738mg/mL的扩展不确定度为0.084mg/mL。结论血液中乙醇含量的不确定度主要来源于样品检测、乙醇标准溶液和标准曲线。     

油浸法鉴别汽车后视镜玻璃的研究

目的研究油浸法对汽车后视镜玻璃的鉴别能力。方法应用油浸法对20种汽车后视镜玻璃进行折射率值测定并用t检验法对数据进行处理。结果在置信度为95％时，20个后视镜玻璃样品的区分率为97．9％。结论油浸法对汽车后视镜玻璃有很好的区分能力，而且使用样品量少，可以达到微克级，是一种鉴别后视镜玻璃的有效方法。     

顶空气相色谱法测定血液中乙醇不确定度的评估

目的 评估血液中乙醇测定结果的不确定度。方法 用顶空气相色谱法测定血液样本中乙醇质量浓度,从测定程序分析测量不确定度的来源,计算测定结果的不确定度。结果 血液样本中乙醇质量浓度两次测定平均值为1.00mg/mL,扩展不确定度为0.02 mg/mL。结论 血液中乙醇测定结果的不确定度主要来源于平行测定的误差。     

顶空气相色谱内标法测定人血中乙醇含量的不确定度评定

目的建立顶空气相色谱内标法测定人血中乙醇含量的不确定度评定的方法。方法结合顸空法乙醇含量测定的全部过程,假设传播系数为1,则对产生不确定度的各分量因子进行分析计算与合成。结果不确定度因素的来源主要包含样品检测时产生的误差值、检测仪器的精密度、使用标准物质的标示值的不确定度和使用的量器、容量器皿等的不确定度。结论本评定方法得出检测的最大误差来自于两个平行样品检测时所产生的误差值。     

气相色谱法测定海洛因含量的测量不确定度评定

目的探讨气相色谱法测定海洛因含量的测量不确定度评定。方法从测定程序分析不确定度来源,并计算各不确定度分量及合成不确定度,得出总不确定度。结果重复性测定不确定度分量最大,气相色谱仪误差次之,而玻璃容量器具天平及对照品所引起的不确定度分量对总不确定度的影响可忽略不计。结论气相色谱法测定海洛因含量的测量不确定度主要来源于重复性测定的误差及气相色谱仪的误差。     

气相色谱法测定人血中乙醇的不确定度评估

本文建立了气相色谱法测定人血中乙醇含量的不确定度评定方法,考虑不确定度的来源主要包括仪器的精密度、标准物质标称值的不确定度、样品及标准物质体积的不确定度等。假定传播系数为1,对各分量进行计算与合成。经实验验证,理论推导的结果与实验结果基本吻合。     

The influence of alcohol content variation in UK packaged beers on the uncertainty of calculations using the Widmark equation

It is common for forensic practitioners to calculate an individual's likely blood alcohol concentration following the consumption of alcoholic beverage(s) for legal purposes, such as in driving under the influence (DUI) cases. It is important in these cases to be able to give the uncertainty of measurement on any calculated result, for this reason uncertainty data for the variables used for any calculation are required. In order to determine the uncertainty associated with the alcohol concentration of beer in the UK the alcohol concentration (%v/v) of 218 packaged beers (112 with an alcohol concentration of ≤5.5%v/v and 106 with an alcohol concentration of >5.5%v/v) were tested using an industry standard near infra-red (NIR) analyser. The range of labelled beer alcohol by volume (ABV's) tested was 3.4%v/v – 14%v/v. The beers were obtained from a range of outlets throughout the UK over a period of 12?months. The root mean square error (RMSE) was found to be ±0.43%v/v (beers with declared %ABV of ≤5.5%v/v) and ±0.53%v/v (beers with declared %ABV of >5.5%v/v) the RMSE for all beers was ±0.48%v/v. The standard deviation from the declared %ABV is larger than those previously utilised for uncertainty calculations and illustrates the importance of appropriate experimental data for use in the determination of uncertainty in forensic calculations.     

Expressing Uncertainty in Dental Age Estimation: A Comparison between Two Methods of Calculating the “Average” Standard Deviation

The expression of uncertainty is defined by the standard deviation and is usually expressed in multiples of the standard deviation (±1sd, ±2sd, and ±3sd). The objective was to use weighting of the sd calculation by the number or count of subjects for each tooth development stage. A comparison shows the difference between the range of uncertainty using the unweighted sd and the weighted sd. The range of uncertainty related to Dental Age Estimation is statistically significantly greater (p < 0.001) for the weighted sd compared to the unweighted sd. It is concluded that the number of subjects for each Tooth Development Stage in the Reference Data set should be included in the calculation for a single Dental Age Estimation using the Simple Average Method when presenting the uncertainty associated with the point estimate of the “mean” for Dental Age Estimation of a single subject of unknown age.     

Measurement of Uncertainty for Aqueous Ethanol Wet‐Bath Simulator Solutions Used with Evidential Breath Testing Instruments

Aqueous ethanol wet‐bath simulator solutions are used to perform calibration adjustments, calibration checks, proficiency testing, and inspection of breath alcohol instruments. The Toxicology Bureau of the New Mexico Department of Health has conducted a study to estimate a measurement of uncertainty for the preparation and testing of these wet‐bath simulator solutions. The measurand is identified as the mass concentration of ethanol (g/100 mL) determined through dual capillary column headspace gas chromatography with flame ionization detector analysis. Three groups were used in the estimation of the aqueous ethanol wet‐bath simulator solutions uncertainty: GC calibration adjustment, GC analytical, and certified reference material. The standard uncertainties for these uncertainty sources were combined using the method of root‐sum‐squares to give u_c = 0.8598%. The combined standard uncertainty was expanded to U = 1.7% to reflect a confidence level of 95% using a coverage factor of 2. This estimation applies to all aqueous ethanol wet‐bath simulator solution concentrations produced by this laboratory.     

二乙酰吗啡盐酸盐标准物质的研制（2）-定值和不确定度评定

目的对研制的二乙酰吗啡盐酸盐标准物质进行定值,并评定定值结果的不确定度。方法采用定量核磁共振法和质量平衡法进行定值;采用液质联用法用于有机物杂质的定性分析,采用电感耦合等离子质谱法、离子色谱法、顶空-气质联用法和卡尔费休滴定法测定无机阳离子、阴离子、挥发性有机溶剂残留和水分等杂质的含量。结果定量核磁共振法的纯度为95．6％,不确定度为0．13％;质量平衡法的纯度为95．3％,不确定度为0．93%。结论二乙酰吗啡盐酸盐标准物质的纯度值为95．6％,扩展不确定度为1．2％（k=2）。