气相色谱-质谱仪测定蔬菜中敌敌畏残留量的不确定度评定

简要介绍了用气相色谱-质谱法测定蔬菜中敌敌畏残留量的方法,建立了数学模型;通过对测定过程中不确定度分量来源的分析,计算了各不确定度分量,最后计算出合成标准不确定度和扩展不确定度,对测量结果进行了表述,达到了对其测量不确定度合理评定的目的.     

气相色谱法测定面粉中毒死蜱农药残留量的测量不确定度评定

本文建立了气相色谱法测定面粉中毒死蜱残留量的数学模型;通过对测定过程中不确定度分量来源的分析,计算了各不确定度分量,最后计算出合成标准不确定度和扩展不确定度,并对测量结果进行了表述,达到了对其测量不确定度合理评定的目的,反映了实验室的技术和设备水平.     

气相色谱法测定蔬菜中有机磷农药残留量不确定度评定研究

通过对气相色谱法测定蔬菜中有机磷农药残留量的测定过程的分析,应用数学模型,计算出测定过程中的不确定分量,最后计算出相对合成标准不确定度和扩展不确定度,找出了影响测量结果不确定度的主要来源为重复测量、定容样品溶液体积、测定仪器和标准液制备,反映了实验室蔬菜中有机磷农药残留量的检测水平和能力。     

离子选择电极法测定水体中氟化物的不确定度分析

建立了离子选择电极法测定水体中氟化物的合成标准不确定度的数学模式,它由质量的标准测量不确定度、体积的标准测量不确定度和酸度计的标准测量不确定度组成。应用一个实例对这三部分标准不确定度的分量作了详尽的分析和计算,得出测量扩展不确定度的结果。     

大豆油酸价测量不确定度的评定

分析了测定大豆油酸价测量不确定度的来源，评定了大豆油酸价测定过程中测量重复性、天平、滴定管、标准溶液浓度等因素对大豆油酸价测量不确定度的影响，计算得大豆油酸价测定结果扩展不确定度为O．032mg。在大豆油酸价测定过程中，滴定管的准确度是影响大豆油酸价测量不确定度的主要因素。     

气相色谱法测定黄瓜中马拉硫磷农药残留量的不确定度评定

对气相色谱法测定黄瓜中马拉硫磷残留量过程进行研究,分析其不确定度来源并建立测量模型,评估各不确定度分量,计算出合成标准不确定度和扩展不确定度。结果表明,影响结果测量不确定度的主要来源为标准溶液配制和样品重复测定。     

火焰原子吸收法测定饲料中锌的不确定度分析

根据《测量不确定度评定与表示》(JJF1059.1—2012)技术规范的要求,对火焰原子吸收法测定饲料中锌含量的结果进行不确定度分析。结果表明,影响样品溶液浓度测定结果不确定度的主要来源包括标准溶液的不确定度、工作曲线方程的不确定度、重复测定样品的不确定度,计算出各种不确定度分量并将其合成,以此计算出饲料中锌的测量不确定度。     

HPLC-ICP-MS测定牛黄解毒片中砷形态分析的不确定度

建立了液相-电感耦合等离子体质谱联用技术(HPLC-ICP-MS)测定牛黄解毒片中砷元素形态的不确定度评价方法。根据JJF1059.1-2012《测量不确定度评定与表示》技术规范的要求,对液相-电感耦合等离子体质谱联用技术测定牛黄解毒片中砷元素形态含量的结果进行不确定度分析。结果表明,影响样品溶液浓度测定结果不确定度的主要包括标准溶液的不确定度、工作曲线方程的不确定度、重复测定样品的不确定度,计算出各种不确定度分量并将其合成,以此计算出牛黄解毒片中砷元素形态测量的不确定度。     

DPD分光光度法测定水中游离氯的不确定度评定

[目的]建立分光光度法测定水中游离氯的不确定度评定方法。[方法]根据HJ 586—2010规定的检测方法,对DPD分光光度法测定水中游离氯进行了不确定度评定。对测量不确定度分量的来源,包括标准物质、标准溶液配制和稀释过程、测量重复性、标准曲线线性拟合等进行分析。最后计算了合成不确定度和扩展不确定度。[结果]曲线线性拟合引入的不确定度对合成不确定度贡献最大,其次为测量重复性和标准系列溶液配制引入的不确定度,标准贮备液引入的不确定度分量贡献最小,可忽略不计。[结论]该研究可为准确测定水中游离氯含量提供理论支持。     

石墨炉原子吸收法测定海洋沉积物中镉含量不确定度评定

通过石墨炉原子吸收法对海洋沉积物中镉含量进行了测定,对影响测量结果的不确定度分量进行了量化的计算,结果表明影响镉含量测定不确定度的主要因素为测量重复性和校准曲线拟合,但样品称量、消解液定容、标准储备液稀释定容时所引起的不确定度也不能忽略。     

Carbon monoxide balance in nature

Consideration of the steady-state equations for stable carbon monoxide and for radioactive carbon monoxide in the troposphere leads to the conclusion that carbon monoxide is produced at a rate of 5x10(15) grams per year, a value some 25 times greater than the rate of carbon monoxide production from combustion. The concomitant residence time for carbon monoxide is 0.1 year, in agreement with a previous estimate of Weinstock. Hydroxyl radicals are shown to account for both the production of this large amount of carbon monoxide by methane oxidation and for its removal by carbon monoxide oxidation. The average concentration of hydroxyl radicals in the troposphere required to achieve this effect is 2.3x10(6) molecules per cubic centimeter, with a daytime concentration of twice that. Levy and McConnell, McElroy, and Wofsy have deduced concentrations of hydroxyl radicals in the troposphere of the same magnitude from purely photochemical considerations, in support of this model.     

Soil as a sink for atmospheric carbon monoxide

The rate of carbon monoxide oxidation by soil increased with increasing carbon monoxide concentration in the gas phase, in line with Michaelis-Menten kinetics. Rates of carbon monoxide oxidation were determined for 20 soils at 0 degrees , 10 degrees , 20 degrees , and 30 degrees C. The observed oxidation rates were used to calculate a global soil uptake rate of atmospheric carbon monoxide of 4.1 x 10(14) grams per year, which is slightly less than the amount of carbon monoxide believed to be produced annually as a result of fossil fuel combustion.     

Carbon monoxide: residence time in the atmosphere

A lower limit of 0.1 year for the residence time of carbon monIoxide in the atmosphere is derived from radiocarbon measurements. The action of certain microorganisms and atmospheric photochemical reactions are possible mechanisms for the removal of carbon monoxide. This value can be compared with 2.7 years, a value deduced from estimated rates of carbon monoxide production and global measurements of atmospheric concentrations of carbon monoxide.     

Airborne lead and carbon monoxide at 45th Street, New York City

Daily business-day traffic determines the diurnal lead concentration as well as diurnal carbon monoxide concentration. Daily averages of 7.5 micrograms per cubic meter for lead and 13 parts per million of carbon monoxide were found for the 10-week period of the study. Correlations were demonstrated for lead and traffic and lead and carbon monoxide.     

Carboxyhemoglobin elevation after exposure to dichloromethane

Inhalation of dichloromethane vapor in concentrations of 500 to 1000 parts per million for 1 to 2 hours promptly initiated the formation of significant quantities of carbon monoxide in human subjects. The evidence suggests that carbon monoxide may be a metabolite of dichloromethane and, that exposure to concentrations of dichloromethane below the industrial threshold limit values may result in the formation of carbon monoxide in amounts that exceed the allowable limits.     

Carbon monoxide in rainwater

Concentrations of carbon monoxide in rainwater collected at widely diverse locations show up to a 200-fold supersaturation relative to the partial pressure of the gas in the atmosphere. These results indicate the existence of an additional natural source of carbon monoxide not heretofore considered. Production of carbon monoxide in clouds is tentatively attributed to the photochemical oxidation of organic matter or the slight dissociation of carbon dioxide induced by electrical discharges, or both. Methane concentrations measured in the same rainwater show that the partitioning of this gas, unlike that of carbon monoxide, is very close to a state of equilibrium.     

Cytochrome a3 structure in carbon monoxide-bound cytochrome oxidase

The iron-carbon monoxide stretching mode and the iron-carbon-oxygen bending mode in carbon monoxide-bound cytochrome oxidase have been assigned at 520 and 578 cm-1, respectively. The frequencies, widths, and intensities of these modes show that the Fe-C-O grouping in carbon monoxide-cytochrome a3 is linear but tilted from the normal to the heme plane; that the iron-histidine bond in both five- and six-coordinate cytochrome a3 is strained; and that the carbon monoxide and the proximal histidine each have characteristic, well-defined orientations in all molecules. These data can account for the binding affinities of carbon monoxide and dioxygen under physiological conditions.     

Volcanic gases in the april 1979 soufriere eruption

Six gas samples from the 17 April 1979 Soufriere eruption plume were analyzed for carbonyl sulfide, carbon disulfide, carbon monoxide, carbon dioxide, methane, nitrous oxide, fluorocarbon-11, fluorocarbon-12, methyl chloroform, and carbon tetrachloride. Only carbon monoxide, carbon dioxide, carbonyl sulfide, and carbon disulfide were found to have increased mixing ratios as compared with those in clean tropospheric air, but the increases were not sufficient to contribute greatly to the global budgets of these four components.     

叶片加料回潮工序对卷烟叶组化学成分的影响

运用现代分析技术分析叶片加料回潮工序对卷烟叶组及其制品的化学成分的变化规律。结果表明：叶片加料回潮工序对卷烟叶组的总氮、烟气一氧化碳释放量影响较大,其中总氮含量升高11%,而一氧化碳释放量则降低11%,焦油释放量、烟碱和一氧化碳均与总植物碱的相关性较强,其中焦油释放量与总植物碱呈负相关,烟碱和一氧化碳则与其呈正相关。     

Microwave measurement of mesospheric carbon monoxide

Ground-based observation of atmospheric absorption of solar radiation at a wavelength of 2.6 millimeters has provided the first measurement of mesospheric carbon monoxide. The measurement agrees with photochemical predictions of a carbon monoxide source in the lower thermosphere due to dissociation of carbon dioxide by solar radiation, and has implications for the magnitude of vertical transport in the mesosphere.