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测定食品标准物质中铅含量的不确定度评定 总被引:1,自引:0,他引:1
目的对氢化物原子荧光法测定食品标准物质中铅含量进行不确定度的评定,了解不确定度来源及其大小并采取相应措施加以纠正,提高实验室铅检测能力和质量控制能力。方法用原子荧光仪测定食品标准物质中铅含量,根据测定方法建立数学模型,分析测量不确定度来源,计算各不确定度分量和扩展不确定度。结果当k=2(95%置信概率)时,食品标准物质中铅含量为0.36 mg/kg,不确定度为±0.035 mg/kg。结论测量不确定度的主要来源为标准曲线拟合引入的不确定度以及重复测定时产生的不确定度。实验室分析误差可控制在容许值内。 相似文献
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张光建 《公共卫生与预防医学》2013,24(1):101-102
JJF1135-2005《化学分析测量不确定度评定》中对测量不确定度定义为表征合理的赋予被测量之值的分散性,与测量结果相联系的参数[1],不确定度的评定已成为理化检验人员的基本技能.氟化物的测定常采用标准曲线法和标准加入法定量,采用标准曲线法评定不确定度已有文献报道[2-7],庞敏晖等所写文章《连续标准加入法测定焚烧飞灰中氟化物的不确定度分析》[8]实际上还是采用标准曲线法进行评定,采用标准加入法的不确定度的分析尚未见报道.文章根据JJF1135-2005《化学分析测量不确定度评定》的要求,对离子选择电极标准加入法测定生活饮用水中氟化物进行不确定度的评定. 相似文献
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[目的]分析与评定自配硝酸银标准滴定溶液的不确定度。[方法]按GB/T 5009-2003《硝酸银标准滴定溶液配制标定》自配硝酸银标准滴定液,并分析评定。[结果]对氯化钠标准物质、称量误差、使用玻璃量器、重复性测定、终点观察误差、温度引起的误差等不确定度分量的分析与评定,求得本次自配硝酸银标准滴定溶液的相对合成标准不确定度为0.79%。[结论]评定本次自配硝酸银标准滴定溶液的合成标准不确定度,为提高实验室和化学分析人员的技术水平、评价分析方法提供了重要依据。 相似文献
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《中国卫生工程学》2017,(2)
目的建立水中六价铬标准物质评价的不确定度评定。方法采用《生活饮用水标准检验方法金属指标》〔GB/T 5750.6-2006(10.1)〕中,二苯碳酰二肼分光光度法,对给定浓度的六价铬标准物质进行测量,评定其不确定度。结果方法线性范围为0~0.16 mg/L,相关系数(r)为0.999 9,最低检测质量浓度为0.004 mg/L。该样品测定结果为0.100 2 mg/L,取包含因子k=2(置信水平约为95%),扩展不确定度U=0.001 7 mg/L。结论本次测量不确定度主要来源为标准溶液稀释、标准曲线拟合、样品稀释和样品重复测量这4项引入的不确定度分量。 相似文献
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一切测量结果都不可避免地具有不确定度,它是由测量过程中的随机效应和已识别的系统效应的影响,以及数据处理中的修约产生的。笔者以GB/T5009.1—2003附录B“标准滴定溶液”中配制并标定浓度为0.1mol/L盐酸标准滴定溶液为例,根据JJF1059—1999《测定不确定度评定与表示》分析产生测量不确定度的原因,将测量模型化, 相似文献
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依据标准GB3053-93<血压计和血压表>,使用血压计标准器对台式血压计(简称血压计)的示值误差进行测定,系统分析测定过程中的不确定度来源,并对测定结果的不确定度进行评定. 相似文献
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本文随机选取了日常工作中按GB/T5009.1—2003配制和标定0.1mol/L盐酸标准滴定溶液的一组数据,对此进行不确定度评定,旨在分析其不确定度的大小及来源,为评定检测结果质量提供可靠依据。 相似文献
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Replacement of the international standard for tetanus antitoxin and the use of the standard in the flocculation test 总被引:2,自引:0,他引:2
Since 1935 the International Unit for Tetanus Antitoxin has been defined as the activity contained in a certain weight of the first International Standard for Tetanus Antitoxin. As stocks of this standard had become depleted, 11 laboratories in 8 countries were requested to participate in a collaborative assay of a preparation proposed as a replacement. 相似文献
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David S Egilman Sarah Bagley Molly Biklen Alison Stern Golub Susanna Rankin Bohme 《Int J Health Serv》2003,33(4):769-812
Brush Wellman, the world's leading producer and supplier of beryllium products, has systematically hidden cases of beryllium disease that occurred below the threshold limit value (TLV) and lied about the efficacy of the TLV in published papers, lectures, reports to government agencies, and instructional materials prepared for customers and workers. Hypocritically, Brush Wellman instituted a zero exposure standard for corporate executives while workers and customers were told the 2 microgram standard was "safe." Brush intentionally used its workers as "canaries for the plant," and referred to them as such. Internal documents and corporate depositions indicate that these actions were intentional and that the motive was money. Despite knowledge of the inadequacy of the TLV, Brush has successfully used it as a defense against lawsuits brought by injured workers and as a sales device to provide reassurance to customers. Brush's policy has reaped an untold number of victims and resulted in mass distribution of beryllium in consumer products. Such corporate malfeasance is perpetuated by the current market system, which is controlled by an organized oligopoly that creates an incentive for the neglect of worker health and safety in favor of externalizing costs to victimized workers, their families, and society at large. 相似文献
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