共查询到20条相似文献,搜索用时 437 毫秒
1.
建立了用于油指纹鉴别的内标法检测原油中多环芳烃的分析方法.讨论了前处理中层析分离能力,结果表明柱层析分离效果良好,全部多环芳烃组分均进入第二部分洗脱液中;确定了基于谱图特征,结合离子碎片信息和计算保留指数的组分定性方法,并对101种多环芳烃化合物进行了定性,计算了保留指数;分析了6个平行样,得到22个多环芳烃组分浓度的相对标准偏差为2.64%~8.54%,回收率为74%~107%,方法检出限为2.05 μg/g.基于本方法分析的多环芳烃浓度信息,对4个不同原油进行了指纹比对,鉴别结果较好. 相似文献
2.
分析比较了ISO 6603-2和ASTM D3763中关于塑料多轴冲击试验方法的异同,着重讨论了这些标准在测试技术上的不同要求,探讨了试验机性能对试验结果的影响,并提出了对试验机测控系统软硬件设计的技术要求。 相似文献
3.
反相高效液相色谱流动相组分最优化中初始条件的迅速选择 总被引:7,自引:5,他引:2
〕本文从梯度和等浓度两方面讨论了反相色谱流动相组分最优化过程中初始条件的迅速选择。讨论了不同梯度参数对确定初始流动相组分的影响;对不适于梯度洗脱的情况,提出了用逐步逼近的等浓度洗脱过程确定初始流动相组分的方法。以多环芳烃和去痛片组分为例验证了方法的可靠性。 相似文献
4.
1 引 言多环芳烃是一类重要的致癌物质 ,环境样品中痕量的多环芳烃分析具有重要意义。其中高效液相色谱 程序波长荧光检测器检测是测定多环芳烃最常用的方法。紫外二极管矩阵检测器具有检验峰纯度、比较未知光谱与谱库光谱辅助定性的功能 ,其检测结果可靠性比程序波长荧光检测器高。但是紫外检测器灵敏度比荧光检测器低近两个数量级 ,对于清洁水样 ,多环芳烃含量很难达到紫外检测器的定量范围。为了解决清洁水样中多环芳烃的紫外二极管矩阵检测器检测 ,我们研究了色谱柱在线富集的方法 ,大大提高了多环芳烃的富集倍数 ,清洁水样中多… 相似文献
5.
6.
采用二次量子化方法和酉变换讨论了O3分子在激光场中的多光子激发.推导出了O3分子的振动Hamiltonian 算子、从基态到各激发态的跃迁几率公式,以及O3分子从激光场中吸收的光子数公式,并分析了计算结果.这包括对O3分子伸缩振动能谱的计算及与实验结果的比较,跃迁几率随外场频率的变化、随时间的变化,以及O3分子在辐射场中的能量吸收情况(取光场强度为5×10-2 W/cm2).建立讨论所有具有C2v对称分子从基态到第四激发态以下各态多光子激发问题的模型. 相似文献
7.
多尺度科学的研究进展 总被引:9,自引:0,他引:9
近些年来,化学家们开始关注多尺度现象,而在更广泛的意义上是关注一门新学科-- 多尺度科学--研究具有广泛时空尺度耦合现象的科学.本文分析了包括化学在内 的各个学科中的多尺度现象,讨论了多尺度研究的几个主要内容和方法并展望了它的未来. 我们认为,多尺度科学应作为一门独立的科学来对待,多尺度现象将是21世纪科学家们面临的最大挑战. 相似文献
8.
9.
10.
仪器定量分析中几个问题的探讨 总被引:1,自引:0,他引:1
邓勃 《中国无机分析化学》2011,1(2):1-5
详细介绍了分析方法的评价指标,包括检出限、测定限、灵敏度、精密度、准确度、动态范围和线性范围、抗干扰能力等,单因素优化方法与加标回收实验评定测定结果准确度的可靠性,并就分析工作中遇到的一些实际问题进行了讨论. 相似文献
11.
12.
A harmonized European framework for method validation to support research on emerging pollutants 总被引:1,自引:0,他引:1
Any investigation of environmental processes related to chemical substances or their effects depends on reliable, comparable analytical data. This also holds true for the impact of climate change on occurrence, distribution and effects of emerging pollutants, with respect to which there is particular concern regarding the reliability of analytical data, due to lack of harmonization in method validation and requirements for quality assurance and quality control (QA/QC).We present a recent European approach to developing a harmonized framework for method validation, QA/QC and provision of environmental data on emerging pollutants. The validation approach has been tested and improved by three case studies. We outline the main concept of the validation approach as well as the results of the case studies. This European validation framework turned out to be a feasible tool to check the fitness for purpose of analytical methods and to improve the reliability of environmental analytical data, particularly for emerging pollutants. 相似文献
13.
14.
This paper presents a numerical method based on Fluctuationlessness Theorem for the solution of Ordinary Differential Equations
over appropriately defined Hilbert Spaces. We focus on the linear differential equations in this work. The approximated solution
is written in the form of an nth degree polynomial of the independent variable. The unknown coefficients are obtained by setting up a system of linear equations
which satisfy the initial or boundary conditions and the differential equation at the grid points, which are constructed as
the independent variable’s matrix representation restricted to an n dimensional subspace of the Hilbert Space. An error comparison of the numerical solution and the MacLaurin series with the
analytical solution is performed. The results show that the numerical solution obtained here converges to the analytical solution
without using too many mesh points. 相似文献
15.
16.
17.
Rozet E Govaerts B Lebrun P Michail K Ziemons E Wintersteiger R Rudaz S Boulanger B Hubert P 《Analytica chimica acta》2011,705(1-2):193-206
Methods validation is mandatory in order to assess the fitness of purpose of the developed analytical method. Of core importance at the end of the validation is the evaluation of the reliability of the individual results that will be generated during the routine application of the method. Regulatory guidelines provide a general framework to assess the validity of a method, but none address the issue of results reliability. In this study, a Bayesian approach is proposed to address this concern. Results reliability is defined here as "the probability (π) of an analytical method to provide analytical results (X) within predefined acceptance limits (±λ) around their reference or conventional true concentration values (μ(T)) over a defined concentration range and under given environmental and operating conditions." By providing the minimum reliability probability (π(min)) needed for the subsequent routine application of the method, as well as specifications or acceptance limits (±λ), the proposed Bayesian approach provides the effective probability of obtaining reliable future analytical results over the whole concentration range investigated. This is summarised in a single graph: the reliability profile. This Bayesian reliability profile is also compared to two frequentist approaches, the first one derived from the work of Dewé et al. [W. Dewé, B. Govaerts, B. Boulanger, E. Rozet, P. Chiap, Ph. Hubert, Chemometr. Intell. Lab. Syst. 85 (2007) 262-268] and the second proposed by Govaerts et al. [B. Govaerts, W. Dewé, M. Maumy, B. Boulanger, Qual. Reliab. Eng. Int. 24 (2008) 667-680]. Furthermore, to illustrate the applicability of the Bayesian reliability profile, this approach is also applied here to a bioanalytical method dedicated to the determination of ketoglutaric acid (KG) and hydroxymethylfurfural (HMF) in human plasma by SPE-HPLC-UV. 相似文献
18.
Method validation is important in analytical chemistry to obtain the reliability of an analytical method. Guidelines provided by the regulatory bodies can be used as a general framework to assess the validity of a method. Since these guidelines do not focus on the reliability of analytical results exclusively, this study was aimed to combine a few recently evolved strategies that may render analytical method validation more reliable and trustworthy. In this research, the analytical error function was determined by appropriate polynomial regression statistics that determine the range of analyte concentration that may lead to more accurate measurements by producing the least possible total error in the assay and can be regarded as a reliable weighting method. The reliability of the analytical results over a particular concentration range has been proposed by a Bayesian probability study. In order to ensure the applicability of this approach, it was applied for the validation of an HPLC–UV assay method dedicated to the quantification of cefepime and tazobactam in human plasma. A comparison between the newer approach and the usual method validation revealed that the application of analytical error function and Bayesian analysis at the end of the validation process can produce significant improvements in the analytical results. 相似文献
19.
解决数值计算、科学绘图等科学和工程问题的一般步骤是:先利用Fortran、C或Pascal等计算机语言进行编程,再经过调试,最后得到结果。这种方法要求计算者对所运用的计算机语言具有一定的编程能力。本文以分析化学中的pH计算、型体曲线绘制和滴定曲线绘制为例,讨论了MATLAB在分析化学中的应用。并由此想到能否参照其它的工具箱编制用于分析化学的MATLAB的M函数库。结果表明,这种方法简单实用,效率高,数值稳定性好。 相似文献
20.
Analysis of trace elements in medicinal plants with energy dispersive X-ray fluorescence 总被引:1,自引:0,他引:1
N. Ekinci R. Ekinci R. Polat G. Budak 《Journal of Radioanalytical and Nuclear Chemistry》2004,260(1):127-131
Mankind still depend on traditional herbal medicine for the treatment of various diseases and ailments. This paper discusses
the elemental composition and concentration of medicinal plants investigated by energy dispersive X-ray fluorescence. The
elements present in medicinal plants are P, Cl, K, Ca, S, Al, Ti, V, Rb, Sr, Zr, Nb, Mo, In, Sn, I and Ce. The physical basis
of the used analytical method, the experimental set up and the procedure of sample preparation are presented.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献