仪器分析导论双语

1、WELCOME TO INSTRUMENTAL ANALYSIS,INSTRUMENTAL ANALYSIS e-COURSE NOTE,Principles of Instrumental Analysis 5th, Douglas A. Skoog, F. James Holler, Timothy A. Nieman, Harcourt College Publishers,Teaching Purpose,仪器分析是物理、化学、材料、电子、医学、 环境、工程等许多专业必修了解的基础内容之一。 通过本课程的学习 要求学生掌握: Principle of instrumental anal

2、ytical methods in common use and simple setup； 要求学生初步具有 An ability to develop appropriate analytical procedure according to the analytical purpose based on the advantage and application fields of different instrumental analyses studied.,Chapter 1 PREFACE,Description of Validation Parameters Accuracy

3、 Closeness of agreement between the value obtained by the method and the true value.,Precision Expresses the closeness of agreement between a series of measurements obtained from multiple sampling. Precision is often expressed as the standard deviation or Relative standard deviation of replicate mea

4、surements (later on RSD). Note that a method can be precise, but not accurate (so all your measurements may be close together, but the result is wrong).,Specificity The ability to measure the analyte in the presence of components which we expect to be present in the sample matrix. So if you are dete

5、rmining the concentration of Iron and Chromium in water by UV/Vis spectroscopy, if there are small amounts of Fluoride and Chloride in the sample, will that affect your measurement?,Detection Limit The lowest amount of analyte in a sample that can be detected, but not necessarily quantitated. Usuall

6、y the lowest limit is evaluated as the Signal-to-Noise ratio that is equivalent to 3 times the standard deviation of the noise ( S/N = 3s).,Quantitation Limit The lowest amount of analyte in a sample that can be quantitated with suitable precision and accuracy. Usually the Quantitation limit is eval

7、uated as the Signal-to-Noise ratio that is equivalent to 10 times the standard deviation of the noise ( S/N = 10s).,Continued,Linearity The range of concentrations of analyte for which the procedure provides test results that are in direct correlation to the amount of analyte in the sample.,Range Th

8、e same as linearity, except the test results must also be accurate and precise (over the concentrations tested). Robustness (Ruggedness) Measure of an methods capacity to remain unaffected by small but deliberate variations in method parameters.,Continued,Analysis, Assay, Determination, Measurement,

9、 Identification These phrases are usually used to describe one process to determine the concentration of the analytes in a sample,Protocol, operation, method, procedure, measure, technique These phrases means a method to evaluate the concentration of the analytes in a sample,分析化学化学分析、仪器分析,Analytical

10、 chemistry A subject to study chemical composition, structure and state of substances including chemical analysis and instrumental analysis. Chemical analysis A method to determine chemical composition and content of the analytes in a sample based on chemical reaction and stoichiometric relation of

11、reactants usually requiring chemical reagents, balance and glassware. Instrumental analysis is an analytical method based on determination of physical and physical chemical properties which needs some complicated apparatus. 仪器分析的产生为分析化学带来革命性的变化，仪器分析是分析化学的发展方向。,Characteristics of Instrumental Analyse

12、s（与化学分析比较）,Higher sensitivity, detection limit down to lower level 如样品用量由化学分析的mL、mg级降低到仪器分析的g、L级，甚至更低。适合于微量（micro-)、痕量(trace)和超痕量(ultratrace)成分的测定。 Higher selectivity 很多的仪器分析方法可以通过选择或调整测定的条件，使共存的组分测定时，相互间不产生干扰。 Simpler operation, faster assay & easy of automation Poorer relative error 化学分析一般可用于常量和高含

13、量成分分析，准确度较高，误差小于千分之几。多数仪器分析相对误差较大，一般为5%，不适用于常量和高含量成分分析。 More expensive apparatus,常量分析、半微量和微量分析,Mass spectra (Mass/charge ratio),Classification of instrumental analyses,Stripping Voltammetry溶出伏安法,Development Tendency,Higher accuracy, sensitivity, selectivity, faster and simpler (更准确、更灵敏、专一、快速、简便),Liv

14、e organism assay,Non-destructive assay,Application of computer and stoichiometry, intelligentization of data analysis(信息采集，数据处理的智能化）,Multi-apparatus coupling techniques,On-line analysis,一、分析化学的发展 分析化学是一门信息科学，它的基本 目的是研究如何获取有关物质系统化学成 分与化学结构方面定性、定量的相关信息 ，它对化学科学发展的贡献极大，甚至被 有些人称为 “现代化学之父”。分析化 学的发展历史上已出现过

15、三次巨大变革： 1、19世纪末20世纪初叶：由“技 艺”上升到科学理论，标志工具 是：天平的使用。,2、20世纪四十年代 20世纪八十年代： 由“分析技术科学”上升到“化学信息科 学”。标志工具是：大量电子分析仪器、 仪表的使用。 3、20世纪八十年代 21世纪初：由“化 学信息科学”上升到“系统信息科 学” 。标志工具是：微型计算机控制 的现代智能型分析仪器的大量使用。 现代分析化学是一门崭新而年轻的学科，它属于与数学、电子学、物理学、计算机科学、现代信息技术科学交叉发展的新学科。,二、仪器分析的内容与分类 化学分析 Chemical Analysis 分析化学 仪器分析 Instrumen

16、tal Analysis 仪器分析（instrumental analysis）： 用精密分析仪器测量物质的某些物理或物理化学性质以确定其化学组成、含量及化学结构的一类分析方法，又称为物理和物理化学分析法。,物理分析法 (physical analysis)： 根据被测物质的某种物理性质与组分的关系，不经化学反应直接进行定性或定量分析的方法。如：光谱分析等。 物理化学分析法 (physical-chemical analysis)： 根据被测物质在化学变化中的某种物理性质与组分之间的关系，进行定性或定量分析的方法。如电位分析法等。,方法分类 主要分析方法 被测物理性质 光谱分析 发射光谱分析、

17、火焰光度分析 辐射的发射 分子发光分析法、放射分析法 紫外-可见分光光度法 辐射的吸收 原子吸收分光光度法 红外光谱法、核磁共振波谱法 比浊法、拉曼光谱法 辐射的散射 折射法、干涉法 辐射的折射 X-射线衍射法、电子衍射法 辐射的衍射 圆二色谱法 辐射偏振方向的旋转 电化学分析 电位法 电极电位 电导法 电导 极谱法、溶出伏安法 电流-电压 色谱分析 气相色谱法、液相色谱法 薄层色谱法 两相间的分配 热分析 热导法、差热分析法 热性质 质量分析 质谱法 质荷比,仪器分析方法分类,根据用以测量的物质性质，仪器分析方法主要分为以下几类:,三、仪器分析的特点和应用原则 仪器分析的主要优点如下： 1、

18、 灵敏度极高； 2 、选择性好，适于复杂组分试样的 分析； 3 、分析迅速，适于批量试样的分析； 4、 适于微量、超痕量组分的测定； 5、 能进行无损分析； 5 、组合能力和适应性强，能在线分析； 6 、数据的采集和处理易于自动化和智 能化。,常量分析、半微量和微量分析,Higher sensitivity, detection limit down to lower level 如样品用量由化学分析的mL、mg级降低到仪器分析的g、L级，甚至更低。适合于微量（micro-)、痕量(trace)和超痕量(ultratrace)成分的测定。, Higher selectivity 很多的仪器分析

19、方法可以通过选择或调整测定的条件，使共存的组分测定时，相互间不产生干扰。, Poorer relative error 化学分析一般可用于常量和高含量成分分析，准确度较高，误差小于千分之几。多数仪器分析相对误差略大（约1 5%）多数不适用于常量和高含量成分分析。,四、标示仪器分析方法的几个参数 准确度( Accuracy) : Closeness of agreement between the value obtained by the method and the true value. It is often expressed as absolute error or relative

20、 error 绝对误差和相对误差 精密度( Precision) : The closeness of agreement between a series of measurements obtained from multiple sampling. Precision is often expressed as the standard deviation or Relative standard deviation ( RSD). 标准偏差和相对标准偏差,特效性 （Specificity）： The ability to measure the analyte in the presence of components which we expect to be present in the sample matrix. 效度值 检测限（Detection Limit）： The lowest amount of analyte in a sample that can be detected, but not necessarily quantitated. Usually the lowest limit is evaluated as the Signal-to-Noise ratio （S/N ）that i