Analytical Atomic Spectrometry with Flames and Plasmas. Jose A. C. Broekaert Copyright > 2002 Wiley-VCH Verlag GmbH & Co. KGaA ISBNs: 3-527-30146-1 (Hardback); 3-527-60062-0 (Electronic) Jose A. C. Broekaert Analytical Atomic Spectrometry with Flames and Plasmas Analytical Atomic Spectrometry with Flames and Plasmas. Jose A. C. Broekaert Copyright > 2002 Wiley-VCH Verlag GmbH & Co. KGaA ISBNs: 3-527-30146-1 (Hardback); 3-527-60062-0 (Electronic) Analytical Atomic Spectrometry with Flames and Plasmas Valeur, B. Molecular Fluorescence. Principles and Applications 2001. ISBN 3-527-29919-X Gunzler, H. and Williams, A. Handbook of Analytical Techniques 2001. ISBN 3-527-30165-8 Hubschmann, H.-J. Handbook of GC/MS 2001. ISBN 3-527-30170-4 Welz, B. and Sperling, M. Atomic Absorption Spectrometry Third, Completely Revised Edition 1998. ISBN 3-527-28571-7 Analytical Atomic Spectrometry with Flames and Plasmas. Jose A. C. Broekaert Copyright > 2002 Wiley-VCH Verlag GmbH & Co. KGaA ISBNs: 3-527-30146-1 (Hardback); 3-527-60062-0 (Electronic) Jose A. C. Broekaert Analytical Atomic Spectrometry with Flames and Plasmas Weinheim ± New York ± Chichester ± Brisbane ± Singapore ± Toronto Analytical Atomic Spectrometry with Flames and Plasmas. Jose A. C. Broekaert Copyright > 2002 Wiley-VCH Verlag GmbH & Co. KGaA ISBNs: 3-527-30146-1 (Hardback); 3-527-60062-0 (Electronic) Prof. Dr. Jose A. C. Broekaert Typesetting Asco Typesetters, Hong Kong UniversitaÈt Leipzig Printing betz-druck gmbH, D-64291 Institut fuÈr Analytische Chemie Darmstadt LinneÂstraûe 3 Bookbinding Wilhelm Osswald & Co., 67433 04103 Leipzig Neustadt Germany ISBN 3-527-30146-1 9 This book was carefully produced. Nevertheless, author and publisher do not warrant the information contained therein to be free of errors. Readers are advised to keep in mind that statements, data, illustrations, procedural details or other items may inadvertently be inaccurate. Library of Congress Card No.: applied for A catalogue record for this book is available from the British Library. Die Deutsche Bibliothek ± CIP Cataloguing-in-Publication-Data A catalogue record for this publication is available from Die Deutsche Bibliothek ( WILEY-VCH Verlag GmbH, D-69469 Weinheim (Federal Republic of Germany). 2002 All rights reserved (including those of translation in other languages). No part of this book may be reproduced in any form ± by photoprinting, micro®lm, or any other means ± nor transmitted or translated into machine language without written permission from the publishers. Registered names, trademarks, etc. used in this book, even when not speci®cally marked as such, are not to be considered unprotected by law. Printed in the Federal Republic of Germany. Printed on acid-free paper. Analytical Atomic Spectrometry with Flames and Plasmas. Jose A. C. Broekaert Copyright > 2002 Wiley-VCH Verlag GmbH & Co. KGaA ISBNs: 3-527-30146-1 (Hardback); 3-527-60062-0 (Electronic) To my wife Paula and our daughters Ilse, Sigrid and Carmen Analytical Atomic Spectrometry with Flames and Plasmas. Jose A. C. Broekaert Copyright > 2002 Wiley-VCH Verlag GmbH & Co. KGaA ISBNs: 3-527-30146-1 (Hardback); 3-527-60062-0 (Electronic) vii Contents Preface xi Introduction 1 1 Basic Principles 4 1.1 Atomic structure 4 1.2 Plasmas 8 1.3 Emission and absorption of radiation 9 1.4 Ionization 18 1.5 Dissociation 23 1.6 Sources for atomic spectrometry 27 1.7 Analytical atomic spectrometry 31 2 Spectrometric Instrumentation 34 2.1 Figures of merit of an analytical method 34 2.2 Optical spectrometers 51 2.2.1 Optical systems 52 2.2.2 Radiation detectors 61 2.2.3 Non-dispersive spectrometers 70 2.3 Mass spectrometers 72 2.3.1 Types of mass spectrometers 73 2.3.2 Ion detection 80 2.3.3 Ion extraction 82 2.3.4 Ion optics and transmission 84 2.4 Data acquisition and treatment 84 3 Sample Introduction Devices 88 3.1 Sample introduction by pneumatic nebulization 90 3.2 Ultrasonic nebulization 103 3.3 Hydride and other volatile species generation 105 3.4 Electrothermal vaporization 109 3.4.1 The volatilization process 109 3.4.2 Types of electrothermal devices 111 viii Contents 3.4.3 Temperature programming 114 3.4.4 Analytical performance 115 3.5 Direct solids sampling 117 3.5.1 Thermal methods 117 3.5.2 Slurry atomization 120 3.5.3 Arc and spark ablation 124 3.5.4 Laser ablation 131 3.6 Cathodic sputtering 135 4 Atomic Absorption Spectrometry 148 4.1 Principles 148 4.2 Atomic absorption spectrometers 150 4.2.1 Spectrometers 150 4.2.2 Primary radiation sources 152 4.3 Flame atomic absorption 158 4.3.1 Flames and burners 159 4.3.2 Nebulizers 161 4.3.3 Figures of merit 162 4.4 Electrothermal atomic absorption 164 4.4.1 Atomizers 165 4.4.2 Thermochemistry 168 4.4.3 Figures of merit 169 4.5 Special techniques 172 4.5.1 Hydride and cold-vapor techniques 172 4.5.2 Direct solids sampling 174 4.5.3 Indirect determinations 175 4.5.4 Flow injection analysis 175 4.5.5 Diode laser atomic absorption spectrometry 176 4.6 Background correction techniques 177 4.6.1 Correction for background absorption with the deuterium lamp technique 177 4.6.2 Background correction with the aid of the Zeeman eect 179 4.6.3 Smith±Hieftje technique 182 4.6.4 Coherent forward scattering 183 4.7 Fields of application 184 4.8 Outlook 191 5 Atomic Emission Spectrometry 192 5.1 Principles 192 5.2 Atomic emission spectrometers 202 5.3 Flame emission 210 5.4 Arcs and sparks 210 5.4.1 Arc emission spectrometry 210 5.4.1.1 Arc characteristics 210 Contents ix 5.4.1.2 Dc arc spectrometry 211 5.4.1.3 Ac arc spectrometry 213 5.4.2 Spark emission spectrometry 213 5.4.2.1 Sparks 213 5.4.2.2 Analytical features 215 5.5 Plasma source AES 216 5.5.1 Dc plasma-jet AES 217 5.5.1.1 Types of plasma jets 217 5.5.1.2 Three-electrode plasma jet 218 5.5.2 Inductively coupled plasma AES 219 5.5.2.1 The inductively coupled plasma 219 5.5.2.2 Instrumentation 221 5.5.2.3 Analytical performance 223 5.5.2.4 Applications 232 5.5.3 Low-power high-frequency plasmas 233 5.5.4 Microwave plasmas 234 5.6 Glow discharge AES 241 5.6.1 Hollow cathodes for AES 242 5.6.2 Furnace emission spectrometry 243 5.6.3 Dc glow discharges with a ¯at cathode 244 5.6.4 Rf glow discharges 248 5.6.5 New developments 249 5.7 Laser sources 251 6 Plasma Mass Spectrometry 254 6.1 ICP mass spectrometry 255 6.1.1 Instrumentation 255 6.1.2 Analytical features 257 6.1.3 Applications 268 6.1.4 Outlook 272 6.2 Glow discharge mass spectrometry 275 6.2.1 Instrumentation 277 6.2.2 Analytical performance 281 6.2.3 Analytical applications 282 7 Atomic Fluorescence Spectrometry 290 7.1 Principles 290 7.2 Instrumentation 293 7.3 Analytical performance 295 8 Laser Enhanced Ionization Spectrometry 297 8.1 Principles 297 8.2 Figues of merit 300 8.3 Analytical applications 301 x Contents 9 Sample Preparation for Atomic Spectrometry 302 9.1 Sample preparation in direct compact sample analysis 302 9.2 Grinding, sieving and compaction of powders 302 9.3 Sample dissolution 304 9.3.1 Wet chemical methods 304 9.3.2 Fusion procedures 304 9.3.3 Microwave-assisted methods 305 9.3.4 Combustion techniques 305 9.4 Flow injection analysis 305 9.5 Leaching sample preparation methods 306 10 Comparison with Other Methods 307 10.1 Power of detection 307 10.2 Analytical accuracy 309 10.3 Economic aspects 310 Literature 312 Index 348 Analytical Atomic Spectrometry with Flames and Plasmas. Jose A. C. Broekaert Copyright > 2002 Wiley-VCH Verlag GmbH & Co. KGaA ISBNs: 3-527-30146-1 (Hardback); 3-527-60062-0 (Electronic) xi Preface Spectrochemical analysis is a powerful instrumental principle for the determina- tion of the chemical elements and their species in a variety of sample types of dif- ferent size, at widely dierent concentration levels and with very diering cost performance ratios and time consumption. In addition, not only monoelement but also multielement determinations are possible with widely diering precision and accuracy using the various dierent methods. The basic principles of spectro- chemical analysis are related to the atomic and molecular structure and also to gas discharge physics as well as to instrumentation and measurement sciences. There- fore, research into spectrochemical analysis requires knowledge of the aforemen- tioned disciplines to enable innovative developments of new methodologies to be achieved in terms of the improvement of power of detection, accuracy and cost performance ratios, these being the driving forces in analytical innovation. The development of analytical procedures also requires the analytical chemist to have a knowledge of the theory and the principles of the above mentioned disciplines. It is the aim of this monograph to bring together the theory and principles of todays spectrochemical methods that make use of ¯ames and plasma sources. This should enable researchers to enter the ®eld of spectrochemical research, where innovation is through the use and development of new sources and the application of new types of spectrometers, and also to face challenges from emerging ®elds of appli- cation, which is as straightforward today as it was even in the time of Bunsen and Kirchho. This work should appeal both to chemists and physicists, the coopera- tion of whom is instrumental for progress to be made in this ®eld of analytical chemistry as well as to users from dierent areas of science, including the life sciences, material sciences, environmental sciences, geochemistry, chemical pro- cess technology, etc.