Table Of Content

11 Analytical Chemistry 0111 0111 0111 0111 0 11 ii Section K – Lipid metabolism The INSTANT NOTES series Series editor B.D. Hames School of Biochemistry and Molecular Biology, University of Leeds, Leeds, UK Animal Biology Biochemistry 2nd edition Chemistry for Biologists Developmental Biology Ecology 2nd edition Genetics Immunology Microbiology Molecular Biology 2nd edition Neuroscience Plant Biology Psychology Forthcoming titles Bioinformatics The INSTANT NOTES Chemistry series Consulting editor: Howard Stanbury Analytical Chemistry Inorganic Chemistry Medicinal Chemistry Organic Chemistry Physical Chemistry 11 Analytical Chemistry 0111 D. Kealey School of Biological and Chemical Sciences Birkbeck College, University of London, UK 0111 and Department of Chemistry University of Surrey, Guildford, UK and 0111 P. J. Haines Oakland Analytical Services, Farnham, UK 0111 0 11 © BIOS Scientific Publishers Limited, 2002 First published 2002 (ISBN 1 85996 189 4) This edition published in the Taylor & Francis e-Library, 2005. “To purchase your own copy of this or any of Taylor & Francis or Routledge’s collection of thousands of eBooks please go to www.eBookstore.tandf.co.uk.” All rights reserved. No part of this book may be reproduced or transmitted, in any form or by any means, without permission. A CIP catalogue record for this book is available from the British Library. ISBN 0-203-64544-8 Master e-book ISBN ISBN 0-203-68109-6 (Adobe eReader Format) ISBN 1 85996 189 4 (Print Edition) BIOS Scientific Publishers Ltd 9 Newtec Place, Magdalen Road, Oxford OX4 1RE, UK Tel. +44 (0)1865 726286. Fax +44 (0)1865 246823 World Wide Web home page: http://www.bios.co.uk/ Distributed exclusively in the United States, its dependent territories, Canada, Mexico, Central and South America, and the Caribbean by Springer-Verlag New York Inc, 175 Fifth Avenue, New York, USA, by arrangement with BIOS Scientific Publishers, Ltd, 9 Newtec Place, Magdalen Road, Oxford OX4 1RE, UK C ONTENTS 11 Abbreviations vii Preface ix Section A – The nature and scope of analytical chemistry 1 0111 A1 Analytical chemistry, its functions and applications 1 A2 Analytical problems and procedures 3 A3 Analytical techniques and methods 5 A4 Sampling and sample handling 10 A5 Calibration and standards 15 A6 Quality in analytical laboratories 18 Section B − Assessment of data 21 B1 Errors in analytical measurements 21 B2 Assessment of accuracy and precision 26 0111 B3 Significance testing 34 B4 Calibration and linear regression 41 B5 Quality control and chemometrics 49 Section C − Analytical reactions in solution 55 C1 Solution equilibria 55 C2 Electrochemical reactions 61 C3 Potentiometry 66 C4 pH and its control 74 0111 C5 Titrimetry I: acid–base titrations 80 C6 Complexation, solubility and redox equilibria 85 C7 Titrimetry II: complexation, precipitation and redox titrations 90 C8 Gravimetry 95 C9 Voltammetry and amperometry 98 C10 Conductimetry 104 Section D − Separation techniques 109 D1 Solvent and solid-phase extraction 109 0111 D2 Principles of chromatography 119 D3 Thin-layer chromatography 131 D4 Gas chromatography: principles and instrumentation 137 D5 Gas chromatography: procedures and applications 149 D6 High-performance liquid chromatography: principles and instrumentation 155 D7 High-performance liquid chromatography: modes, procedures and applications 166 D8 Electrophoresis and electrochromatography: principles and instrumentation 174 0 D9 Electrophoresis and electrochromatography: modes, 11 procedures and applications 182 vi Contents Section E − Spectrometric techniques 189 E1 Electromagnetic radiation and energy levels 189 E2 Atomic and molecular spectrometry 195 E3 Spectrometric instrumentation 201 E4 Flame atomic emission spectrometry 206 E5 Inductively coupled plasma spectrometry 209 E6 X-ray emission spectrometry 214 E7 Atomic absorption and atomic fluorescence spectrometry 218 E8 Ultraviolet and visible molecular spectrometry: principles and instrumentation 223 E9 Ultraviolet and visible molecular spectrometry: applications 228 E10 Infrared and Raman spectrometry: principles and instrumentation 233 E11 Infrared and Raman spectrometry: applications 242 E12 Nuclear magnetic resonance spectrometry: principles and instrumentation 248 E13 Nuclear magnetic resonance spectrometry: interpretation of proton and carbon-13 spectra 261 E14 Mass spectrometry 270 Section F − Combined techniques 283 F1 Advantages of combined techniques 283 F2 Sample identification using multiple spectrometric techniques data 285 F3 Gas chromatography–mass spectrometry 294 F4 Gas chromatography–infrared spectrometry 298 F5 Liquid chromatography–mass spectrometry 302 Section G − Thermal methods 305 G1 Thermogravimetry 305 G2 Differential thermal analysis and differential scanning calorimetry 311 G3 Thermomechanical analysis 316 G4 Evolved gas analysis 320 Section H – Sensors, automation and computing 323 H1 Chemical sensors and biosensors 323 H2 Automated procedures 328 H3 Computer control and data collection 331 H4 Data enhancement and databases 333 Further reading 337 Index 339 A BBREVIATIONS 11 AAS atomic absorption spectrometry ICP-MS ICP-mass spectrometry ADC analog-to-digital converter IEC ion-exchange chromatography AFS atomic fluorescence spectrometry ISE ion-selective electrode ANOVA analysis of variance LVDT linear variable differential ATR attenuated total reflectance transformer 0111 BPC bonded-phase chromatography MEKC micellar electrokinetic CC chiral chromatography chromatography CGE capillary gel electrophoresis MIR multiple internal reflectance CI confidence interval MS mass spectrometry CIEF capillary isoelectric focusing NIR near infrared CL confidence limits NMR nuclear-magnetic resonance CPU central processing unit NPD nitrogen-phosphorus detector CRM certified reference material PAH polycyclic aromatic hydrocarbons CZE capillary zone electrophoresis PC paper chromatography DAC digital-to-analog converter PCA principal component analysis 0111 DAD diode array detector PCR principal component regression DMA dynamic mechanical analysis PDMS polydimethylsiloxane DME dropping mercury electrode PLS partial least squares DSC differential scanning calorimetry QA quality assurance DTA differential thermal analysis QC quality control DTG derivative thermogravimetry RAM random access memory DVM digital voltmeter RF radiofrequency ECD electron-capture detector RI refractive index EDAX energy dispersive analysis ROM read only memory of X-rays RMM relative molecular mass 0111 EDTA ethylenediaminetetraacetic acid SCE saturated calomel electrode EGA evolved gas analysis SDS sodium dodecyl sulfate FA factor analysis SDS-PAGE SDS-polyacrylamide gel FAES flame atomic emission electrophoresis spectometry SE solvent extraction FFT fast Fourier transform SEC size-exclusion chromatography FID flame ionization detector SHE standard hydrogen electrode or free induction decay SIM selected ion monitoring GC gas chromatography SPE solid phase extraction GLC gas liquid chromatography SPME solid phase microextraction 0111 GSC gas solid chromatography SRM standard reference material HATR horizontal attenuated total TCD thermal conductivity detector reflectance TG thermogravimetry HPLC high-performance liquid TIC total ion current chromatography TISAB total ionic strength adjustment IC ion chromatography buffer ICP inductively coupled plasma TLC thin-layer chromatography ICP-AES ICP-atomic emission spectrometry TMA thermomechanical analysis ICP-OES ICP-optical emission spectrometry 0 11 P REFACE Analytical chemists and others in many disciplines frequently ask questions such as: What is this substance?; How concentrated is this solution?; What is the structure of this molecule? The answers to these and many other similar questions are provided by the techniques and methods of analytical chemistry. They are common to a wide range of activities, and the demand for analytical data of a chemical nature is steadily growing. Geologists, biologists, environmental and materials scientists, physicists, pharmacists, clinicians and engineers may all find it necessary to use or rely on some of the techniques of analysis described in this book. If we look back some forty or fifty years, chemical analysis concentrated on perhaps three main areas: qualitative testing, quantitative determinations, particularly by ‘classical’ techniques such as titrimetry and gravimetry, and structural analysis by procedures requiring laborious and time-consuming calcu- lations. The analytical chemist of today has an armoury of instrumental techniques, automated systems and computers which enable analytical measurements to be made more easily, more quickly and more accurately. However, pitfalls still exist for the unwary! Unless the analytical chemist has a thorough understand- ing of the principles, practice and limitations of each technique he/she employs, results may be inaccu- rate, ambiguous, misleading or invalid. From many years of stressing the importance of following appropriate analytical procedures to a large number of students of widely differing abilities, backgrounds and degrees of enthusiasm, the authors have compiled an up-to-date, unified approach to the study of analytical chemistry and its applications. Surveys of the day-to-day operations of many industrial and other analytical laboratories in the UK, Europe and the USA have shown which techniques are the most widely used, and which are of such limited application that extensive coverage at this level would be inappropriate. The text therefore includes analytical techniques commonly used by most analytical laboratories at this time. It is intended both to complement those on inorganic, organic and physical chemistry in the Instant Notesseries, and to offer to students in chemistry and other disciplines some guid- ance on the use of analytical techniques where they are relevant to their work. We have not given extended accounts of complex or more specialized analytical techniques, which might be studied beyond first- and second-year courses. Nevertheless, the material should be useful as an overview of the subject for those studying at a more advanced level or working in analytical laboratories, and for revision purposes. The layout of the book has been determined by the series format and by the requirements of the overall analytical process. Regardless of the discipline from which the need for chemical analysis arises, common questions must be asked: ● How should a representative sample be obtained? ● What is to be determined and with what quantitative precision? ● What other components are present and will they interfere with the analytical measurements? ● How much material is available for analysis, and how many samples are to be analyzed? ● What instrumentation is to be used? ● How reliable is the data generated? These and related questions are considered in Sections A and B. Most of the subsequent sections provide notes on the principles, instrumentation and applications of both individual and groups of techniques. Where suitable supplementary texts exist, reference is made to them, and some suggestions on consulting the primary literature are made. We have assumed a background roughly equivalent to UK A-level chemistry or a US general chemistry course. Some simplification of mathematical treatments has been made; for example, in the sections on statistics, and on the theoretical basis of the various techniques. However, the texts listed under Further Reading give more comprehensive accounts and further examples of applications.