儀器分析導(dǎo)論雙語(yǔ)

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,儀器分析是物理、化學(xué)、材料、電子、醫(yī)學(xué)、 環(huán)境、工程等許多專(zhuān)業(yè)必修了解的基礎(chǔ)內(nèi)容之一。 通過(guò)本課程的學(xué)習(xí) 要求學(xué)生掌握: Principle of instrumental anal

2、ytical methods in common use and simple setup； 要求學(xué)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,分析化學(xué)化學(xué)分析、儀器分析,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. 儀器分析的產(chǎn)生為分析化學(xué)帶來(lái)革命性的變化，儀器分析是分析化學(xué)的發(fā)展方向。,Characteristics of Instrumental Analyse

12、s（與化學(xué)分析比較）,Higher sensitivity, detection limit down to lower level 如樣品用量由化學(xué)分析的mL、mg級(jí)降低到儀器分析的g、L級(jí)，甚至更低。適合于微量（micro-)、痕量(trace)和超痕量(ultratrace)成分的測(cè)定。 Higher selectivity 很多的儀器分析方法可以通過(guò)選擇或調(diào)整測(cè)定的條件，使共存的組分測(cè)定時(shí)，相互間不產(chǎn)生干擾。 Simpler operation, faster assay & easy of automation Poorer relative error 化學(xué)分析一般可用于常量和高含

13、量成分分析，準(zhǔn)確度較高，誤差小于千分之幾。多數(shù)儀器分析相對(duì)誤差較大，一般為5%，不適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 (更準(zhǔn)確、更靈敏、專(zhuān)一、快速、簡(jiǎn)便),Liv

14、e organism assay,Non-destructive assay,Application of computer and stoichiometry, intelligentization of data analysis(信息采集，數(shù)據(jù)處理的智能化）,Multi-apparatus coupling techniques,On-line analysis,一、分析化學(xué)的發(fā)展 分析化學(xué)是一門(mén)信息科學(xué)，它的基本 目的是研究如何獲取有關(guān)物質(zhì)系統(tǒng)化學(xué)成 分與化學(xué)結(jié)構(gòu)方面定性、定量的相關(guān)信息 ，它對(duì)化學(xué)科學(xué)發(fā)展的貢獻(xiàn)極大，甚至被 有些人稱(chēng)為 “現(xiàn)代化學(xué)之父”。分析化 學(xué)的發(fā)展歷史上已出現(xiàn)過(guò)

15、三次巨大變革： 1、19世紀(jì)末20世紀(jì)初葉：由“技 藝”上升到科學(xué)理論，標(biāo)志工具 是：天平的使用。,2、20世紀(jì)四十年代 20世紀(jì)八十年代： 由“分析技術(shù)科學(xué)”上升到“化學(xué)信息科 學(xué)”。標(biāo)志工具是：大量電子分析儀器、 儀表的使用。 3、20世紀(jì)八十年代 21世紀(jì)初：由“化 學(xué)信息科學(xué)”上升到“系統(tǒng)信息科 學(xué)” 。標(biāo)志工具是：微型計(jì)算機(jī)控制 的現(xiàn)代智能型分析儀器的大量使用。 現(xiàn)代分析化學(xué)是一門(mén)嶄新而年輕的學(xué)科，它屬于與數(shù)學(xué)、電子學(xué)、物理學(xué)、計(jì)算機(jī)科學(xué)、現(xiàn)代信息技術(shù)科學(xué)交叉發(fā)展的新學(xué)科。,二、儀器分析的內(nèi)容與分類(lèi) 化學(xué)分析 Chemical Analysis 分析化學(xué) 儀器分析 Instrumen

16、tal Analysis 儀器分析（instrumental analysis）： 用精密分析儀器測(cè)量物質(zhì)的某些物理或物理化學(xué)性質(zhì)以確定其化學(xué)組成、含量及化學(xué)結(jié)構(gòu)的一類(lèi)分析方法，又稱(chēng)為物理和物理化學(xué)分析法。,物理分析法 (physical analysis)： 根據(jù)被測(cè)物質(zhì)的某種物理性質(zhì)與組分的關(guān)系，不經(jīng)化學(xué)反應(yīng)直接進(jìn)行定性或定量分析的方法。如：光譜分析等。 物理化學(xué)分析法 (physical-chemical analysis)： 根據(jù)被測(cè)物質(zhì)在化學(xué)變化中的某種物理性質(zhì)與組分之間的關(guān)系，進(jìn)行定性或定量分析的方法。如電位分析法等。,方法分類(lèi) 主要分析方法 被測(cè)物理性質(zhì) 光譜分析 發(fā)射光譜分析、

17、火焰光度分析 輻射的發(fā)射 分子發(fā)光分析法、放射分析法 紫外-可見(jiàn)分光光度法 輻射的吸收 原子吸收分光光度法 紅外光譜法、核磁共振波譜法 比濁法、拉曼光譜法 輻射的散射 折射法、干涉法 輻射的折射 X-射線(xiàn)衍射法、電子衍射法 輻射的衍射 圓二色譜法 輻射偏振方向的旋轉(zhuǎn) 電化學(xué)分析 電位法 電極電位 電導(dǎo)法 電導(dǎo) 極譜法、溶出伏安法 電流-電壓 色譜分析 氣相色譜法、液相色譜法 薄層色譜法 兩相間的分配 熱分析 熱導(dǎo)法、差熱分析法 熱性質(zhì) 質(zhì)量分析 質(zhì)譜法 質(zhì)荷比,儀器分析方法分類(lèi),根據(jù)用以測(cè)量的物質(zhì)性質(zhì)，儀器分析方法主要分為以下幾類(lèi):,三、儀器分析的特點(diǎn)和應(yīng)用原則 儀器分析的主要優(yōu)點(diǎn)如下： 1、

18、 靈敏度極高； 2 、選擇性好，適于復(fù)雜組分試樣的 分析； 3 、分析迅速，適于批量試樣的分析； 4、 適于微量、超痕量組分的測(cè)定； 5、 能進(jìn)行無(wú)損分析； 5 、組合能力和適應(yīng)性強(qiáng)，能在線(xiàn)分析； 6 、數(shù)據(jù)的采集和處理易于自動(dòng)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 如樣品用量由化學(xué)分析的mL、mg級(jí)降低到儀器分析的g、L級(jí)，甚至更低。適合于微量（micro-)、痕量(trace)和超痕量(ultratrace)成分的測(cè)定。, Higher selectivity 很多的儀器分析

19、方法可以通過(guò)選擇或調(diào)整測(cè)定的條件，使共存的組分測(cè)定時(shí)，相互間不產(chǎn)生干擾。, Poorer relative error 化學(xué)分析一般可用于常量和高含量成分分析，準(zhǔn)確度較高，誤差小于千分之幾。多數(shù)儀器分析相對(duì)誤差略大（約1 5%）多數(shù)不適用于常量和高含量成分分析。,四、標(biāo)示儀器分析方法的幾個(gè)參數(shù) 準(zhǔn)確度( 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 絕對(duì)誤差和相對(duì)誤差 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). 標(biāo)準(zhǔn)偏差和相對(duì)標(biāo)準(zhǔn)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 檢測(cè)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