Separation, Electroanalytical and Spectrochemical Techniques Separation, Electroanalytical and Spectrochemical Techniques Prepared by Vincent MAKOKHA African Virtual university Université Virtuelle Africaine Universidade Virtual Africana African Virtual University NOTICE This document is published under the conditions of the Creative Commons http://en.wikipedia.org/wiki/Creative_Commons Attribution http://creativecommons.org/licenses/by/2.5/ License (abbreviated “cc-by”), Version 2.5. I have received kind permission to reproduce diagrams and text from • Dr. Scott Van Bramer for Mass Spectrometry • Dr. William Reusch of Michigan State University for Molecular Spectroscopy African Virtual University Table of ConTenTs I. Separation, Electroanalytical, and Spectrochemical Techniques _______ 3 II. Prerequisite Courses or Knowledge ____________________________ 3 III. Time ____________________________________________________ 3 IV. Materials _________________________________________________ 3 V. Module Rationale __________________________________________ 4 VI. Content __________________________________________________ 4 6.1 Resume ____________________________________________ 4 6.2 Outline _____________________________________________ 5 6.3 Graphic Organizer _____________________________________ 7 VII. General Objective __________________________________________ 8 VIII. Specific Learning Objective(s) _________________________________ 8 IX. Teaching and Learning Activities ______________________________ 12 X. Key Concepts ____________________________________________ 18 XI. Learning Tips ____________________________________________ 23 XII. Compulsory Reading _______________________________________ 24 XIII. Useful links ______________________________________________ 26 XIV. Multimedia Resources _____________________________________ 34 XV. Learning Activities _________________________________________ 36 XVI. Synthesis of the Module ___________________________________ 106 XVII. Summative Evaluation _____________________________________ 108 XIII. Main Author of the Module _________________________________ 110 XIX. References ______________________________________________ 111 XX. File Structure ____________________________________________ 111 African Virtual University I. Separation, electroanalytical, and spectrochemical Techniques by Vincent Makokha II. Prerequisite Knowledge • Atomic structure and the concept of energy levels • RedOx introduction • Balancing RedOx equations • Standard reduction potentials • Nernst equation • Concepts of Sampling • Errors and statistics • Theories of bonding • Electrochemistry III. Time • Separation and Chromatographic Techniques 25 hours • Electrochemical Techniques 15 hours • Spectroscopy and Atomic Spectroscopic Techniques 20 hours • Molecular Spectroscopy 1(UV and IR) 30 hours • Molecular Spectroscopy 2 (NMR) 15 hours • Mass Spectrometry 15 hours IV. Materials You will require the following tools and resources for completing this module • Computer, CD-ROMs, and e-library • To access this module, exams, and other relevant materials on a computer • Internet Connection to access the module and other suggested reference ma- terials. • For interactive discussions/chat sessions • Recommended textbooks and reference materials to assist learning and further understanding of the topics in the module • Macromedia flash player African Virtual University V. Module Rationale Separation, Electro analytical and Spectroscopic Techniques are the basis of instru- mental analysis widely applied in industry, chemistry, biochemistry, environment and school science. These techniques are based on principles of chemistry taught at school level. Therefore in this module we shall study the principles on which these techniques are based and acquire the basic skills necessary to use the techniques. Studying this area deepens the understanding of the underlying chemistry principles making the learner better able to teach them at school level. VI. Content 6.1 Resume This module consists of three interrelated subject areas; Separation Techniques and Chromatographic Techniques, Electro analytical Techniques and Spectroscopic Methods. The module will be taught in six learning units reflecting common concepts and approaches. Separation Techniques and Chromatographic Techniques unit will review elemen- tary separation techniques that are usually taught in the school system, followed by a discussion of Chromatography Techniques; these are covered by introducing the general chromatographic theory, followed by its application in different techniques of plane and column chromatographic techniques. Electro Analytical Techniques will introduce principles on which potentiometry is based, elaborate the common applications of potentiometry, this will be followed by voltammetry, starting with polarographic techniques ending with cyclic and anodic stripping voltammetry. The unit on Spectroscopy and Atomic Spectroscopic techniques will review concepts of energy matter interaction, energy levels in atoms and molecules, and the unit will end with a discussion of atomic spectroscopic techniques. Molecular Spectroscopy 1 will start with a discussion of the theory of UV-Visible spectroscopy, how it arises and how it is used in qualitative and quantitative analysis, instrumentation of the modern UV-visible spectrophotometer. The unit will end with a discussion of infrared spectroscopy starting with how the spectra arises, the different peaks exhibited by specific functional groups and how to apply IR in identification of functional groups and compounds. Molecular Spectroscopy 2 will introduce nuclear magnetic resonance phenomenon, followed by a discussion of proton NMR, the relationship of chemical shift with the African Virtual University molecular chemical environment and how proton NMR is used in identification of functional groups. The unit ends with a discussion of the carbon NMR and how it compliments proton NMR in analysis of compounds. The last learning unit will be Mass Spectrometry starting with how mass spectra arises, how it is used in identification of organic compounds ending with the Instru- mentation for mass spectrometry. 6.2 Outline Uniti I Separation And Chromatographic Techniques- 25 Hours • Separation Techniques o Solvent Extraction o Distillation • Chromatography o Theory of Chromatography o The Development Process • Types of Chromatographic Techniques o Plane Chromatography o Plane Chromatography o Liquid Chromatography o Gas Chromatography Unit II Electroanalytical Techniques- 15 Hours • Potentiometry. o Ion Selective Electrodes o pH Glass Electrodes o Potentiometric Titrations • Voltammetry o Polarography o Pulse Polarography o Cyclic Voltammetry o Anodic Stripping Voltammetry African Virtual University Unit III Spectroscopy And Atomic Spectroscopic Techniques- 20 Hours • Spectroscopy: o Electromagnetic Radiation o The Atom and Atomic Spectroscopy o Beers law • Atomic Spectroscopic Techniques Unit IV Molecular Spectrocopy 1: Uv-visible And Ir- 30 Hours • Ultraviolet- Visible Spectroscopy o Electronic transitions o Identification of functional groups Using UV o Instrumentation for UV Visible Spectrometry • Infrared Spectroscopy o Molecular Vibration and IR Spectroscopy o Relative energies of IR Absorptions o Identifying Functional Groups by Infrared Spectroscopy Unit V Molecular Spectroscopy 2: Nuclear Magnetic Resonance 15 Hours • Nuclear Magnetic Resonance Spectroscopy o Proton NMR o Chemical Shift o Correlation of HNMR With Structure • Carbon NMR Spectroscopy Unit VI Mass Spectrometry- 15 Hours • Mass Spectrometry o Fragmentation Patterns o Finger Print Spectrum African Virtual University 6.3 Graphic Organiser African Virtual University VII. General objective The general objectives of this module are three: to explain the concepts underlying modern analytical techniques, give learners the basic skills to apply the concepts to simulated real world problems and deepen the students understanding of chemistry principles governing these techniques. VIII. Specific learning objectives Unit Learning objective(s) 1. Separation and At the end of the unit learners will be able to: Chromatographic • Recall Separation methods that are taught in Techniques School • Explain the principles underlying solvent extrac- tion • Solve hypothetical numerical solvent Extraction problems • Name and draw apparatus used for solvent ex- traction • Name common column and plane Chromatogra- phic Techniques. • Explain the theory underlying each column and plane Chromatographic Techniques • Recall equipment for plane and column chroma- tography African Virtual University Unit Learning objective(s) 2. Electro analyti- At the End of this unit the student will be able to: cal Techniques • Recall the theory on which potentiometry is based • Explain the application of potentiometry to pH measurement, ion selective electrode and auto- matic titration stations • Recall the theory of Voltammetry • Interpret Voltammetric data • quantitatively and qualitatively • Explain the concept of on which • polarographic analysis is based • Interpret polarographic data to identify and quan- tify chemical Species 3. Introduction to At the end of the unit learners be able to: Spectroscopic and • Name the parts of the electromagnetic spectrum Atomic Spectro- • Recall effects of radiation on atoms and molecu- scopic Techniques les • Recall Plank’s law and apply it to spectroscopic problems • Electronic energy levels in atoms and molecu- les • Recall Beers law and apply