共查询到19条相似文献,搜索用时 234 毫秒
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采用电感耦合等离子体原子发射法测定银中的硒、碲含量,对测定结果的不确定度进行评定.通过对测量过程中测量重复性、标准曲线变动性、试液体积、试料质量、标准溶液浓度和移取体积等影响因素进行分析,结果表明,测量重复性和标准曲线变动性对总不确定度影响较大.因此,在测定中应适当增加样品和标准溶液重复测定次数,不断优化仪器参数,准确... 相似文献
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《现代测量与实验室管理》2015,(4)
建立了高效液相色谱法(HPLC)测定戊醛中的催化剂含量不确定度评定的数学模型。通过对整个测定过程中各种不确定度因素的研究,分析和评定了不确定度的来源,确定了不确定度分量和合成不确定度。结果表明,当戊醛中的催化剂含量为848mg/kg时,其扩展不确定度为6mg/kg(取包含因子k=2,置信概率约为95%),其中标准物质的纯度、标准样品和样品测量重复性对测量不确定度的影响较大,实验室应对其采取措施,减低不确定度。 相似文献
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粘土砖体积密度测定的不确定度评定 总被引:1,自引:0,他引:1
齐书祥 《理化检验(物理分册)》2005,41(2):83-84,88
按致密定形耐火材料制样及体积密度检验方法标准,取具有代表性的一块粘土砖样品,对影响其体积密度测定的不确定度因素进行了分析,且对影响其体积密度测定不确定度的各个分量进行计算和合成,给出了该粘土砖不确定度的报告;通过评定其体积密度的不确定度,了解到影响该粘土砖的不确定度的主要因素为重复性试验(包括制样及检测)。 相似文献
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塑料复合膜、袋溶剂残留量不确定度评估 总被引:3,自引:2,他引:1
目的为提高包装用塑料复合膜、袋中溶剂残留的检测水平,建立溶剂残留测定结果的不确定度评定方法模型。方法以GB/T 10004—2008《包装用塑料复合膜、袋干法复合、挤出复合》中溶剂残留的检测方法为基础,参考相关标准和文献系统分析该法测量结果的不确定度来源,并对不确定度各个分量进行评估和合成。结果样品中溶剂残留总量的测定结果可表示为(22.40+1.421)mg/m2,k=2,P=95%。样品中苯系物残留量的测定结果可表示为(1.748+0.090 06)mg/m2,k=2,P=95%。最小二乘法得到的拟合校准工作曲线是溶剂残留结果测量不确定度的主要来源。结论溶剂残留测量结果的不确定度可作为表征测量结果准确度的指标之一。 相似文献
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通过酚试剂分光光度法测定了能力验证考核样品中甲醛的含量并对测量结果进行了不确定度评定。根据《化学分析中不确定度的评估指南》提供的不确定度分析思路,系统分析了影响测量不确定度的各个因素,对测量结果的不确定度进行分析、评定和表述。本次测量结果的扩展不确定度为0.015mg/m~3,主要由标准溶液的配制、标准曲线的拟合以及样品采集过程产生的不确定度所引起。因此,实验室应规范做好标准溶液的配制、工作曲线的绘制及样品采集几个关键环节,以保证测量结果准确、可靠,提高检测工作质量。 相似文献
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本文采用全自动凯式定氮仪测定酱油中全氮含量,对测定过程中的不确定度进行分析和量化,给出各分量对测定结果不确定度的相对贡献,求出测定结果的标准不确定度和扩展不确定度并对结果进行表述。结果表明:由样品重复性试验和移取试样体积引入的不确定度最大,其次是盐酸标准溶液浓度的不确定度。 相似文献
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柴油中脂肪酸甲酯含量的测定广泛采用红外光谱法,针对此方法的检测能力和准确性进行了研究。试验测定红外光谱法检测柴油中脂肪酸甲酯的检出限和定量限分别为0.0066g/L和0.0220g/L,加标回收率为99.2%~101.3%,结果表明试验方法具备良好的准确性,能够准确灵敏地检测柴油中脂肪酸甲酯。测定的合成相对标准不确定度为0.0123(置信概率取95%,包含因子k=2),脂肪酸甲酯含量为(3.960±0.097)g/L。分析结果表明标准溶液配制和待测样品配制为引入不确定度的主要因素。 相似文献
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A simple and efficient headspace solvent microextraction (HSME) was developed for the simultaneous determination of the trace concentrations of some n-alkanes in water samples. Therefore, a microdrop of an organic solvent was extruded from the needle tip of a gas chromatographic syringe to the headspace above the surface of the solution in a sealed vial. Then the volatile organic compounds are extracted and concentrated in the microdrop. Next, the microdrop was retracted into the microsyringe and injected directly into the gas chromatograph. Experimental parameters which control the performance of HSME such as the type of microextraction solvent, organic drop and sample volume, sample stirring rate, sample solution and microsyringe needle temperatures, salt addition and exposure time profiles were investigated and optimized. Finally, the enrichment factor, dynamic linear range (DLR), limit of detection (LOD) and precision of the method were evaluated. Using optimum extraction conditions, good linearity with correlation coefficients in the range of 0.995相似文献
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采用GB/T 17657-2013《人造板及饰面人造板理化性能试验方法》中的干燥器法,对卫浴家具中人造板甲醛释放量的检测过程进行试验研究,并依据JJF 1059.1-2012《测量不确定度评定与表示》分析影响甲醛释放量测定的各种不确定因素,量化和评定各不确定度分量。结果表明:甲醛释放量为(1.06±0.05)mg·L-1,扩展不确定度的包含因子k=2,其置信概率P=95%。经分析,由标准物质认定值和样品的重复测定引入的不确定度最大,其次为标准曲线拟合的变动性所引入的不确定度。 相似文献
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J. W. Magee 《International Journal of Refrigeration》1992,15(6):372-380
The molar heat capacity at constant volume was measured by applying an adiabatic method. Heat capacities at 310 state conditions were measured. Measurements were made on liquid in equilibrium with its vapour, and on compressed liquid samples of 1,1,1,2-tetrafluoroethane (R134a), at temperatures from 172 to 343 K with pressures as high as 35 MPa. In the course of these measurements, a determination of the triple point temperature (169.85 ± 0.01 K) was made. For the high purity (0.9999 +) sample, results were obtained for two-phase (Cv(2)), saturated liquid (Cσ) and single-phase (Cv) molar heat capacities as a function of measured temperature,pressure and density. The maximum probable uncertainty of the heat capacity values is estimated not exceed ±0.5%. 相似文献
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为提高鸡蛋食品安全检测结果准确性,建立了一种液相色谱串联质谱法(liquid chromatography-tandem mass spectrometry, LC-MS/MS)测定鸡蛋中的利巴韦林及其代谢物总残留量的不确定度数学模型。依据SN/T 4519-2016《出口动物源食品中利巴韦林残留量的测定》中的方法,对整个检测过程进行了不确定度评定。不确定度分量主要来源有测量的重复性、回收率、样品的称量、样品前处理稀释和定容、标准溶液配制、标准曲线拟合及仪器测定引入。经评定鸡蛋中利巴韦林及其代谢物总残留量结果为X=(9.94±0.88)μg/kg, k=2; 其中标准曲线拟合过程中引入的不确定度分量影响最大。 相似文献
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Fourier transform infrared (FT-IR) spectroscopy has been successfully employed to follow the formation of phthalic anhydride and 1,8-naphthalic anhydride on heating their corresponding acids. The effects of three heterocumulenes, cyanamide, dicyandiamide, and sodium cyanate, on the temperature of formation of the anhydrides were also investigated using this method. It was found that the carbodiimides cyanamide and dicyandiamide dramatically lowered the temperature at which thermal dehydration of the acid led to anhydride formation. It was noted that cyanamide had a stronger catalytic effect than dicyandiamide, presumably due to the electron-withdrawing effect of the amidine group. Sodium cyanate was also found to promote the thermal dehydration of the acids to form the corresponding anhydrides. Under more severe conditions, phthalic acid anhydride formed is seen to react further, leading to the formation of phthalimide. The discrepancy between the products obtained with cyanamide and sodium cyanate leads to the conclusion that, unlike earlier claims, imide formation is not due to the reaction of the anhydride with the urea formed but with sodium cyanate itself. However, only the phthalic anhydride five-membered ring system is sufficiently reactive towards the CNO- nucleophile to form the imide; the six-membered 1,8-naphthalic anhydride system does not react in this way. 相似文献