A practical guide to ICP emission spectrometry, updated with information on the latest developments and applications

The revised and updated third edition ofICP Emission Spectrometrycontains all the essential information needed for successful ICP OES analyses. In addition, the third edition reflects the most recent developments and applications in the field. Filled with illustrative examples and written in a user-friendly style, the book contains material on the instrumentation instructions on how to develop effective methods.

Throughout the text, the authora noted expert on the topicincorporates typical questions and problems and provides checklists and detailed instructions for implementation. The third edition includes 10 new chapters that cover recent progress in both the application and methodology of the technology. New information on plasma, the optics, and the detector of the spectrometer is also highlighted. This revised third edition:

Contains fresh chapters on the newest developmentsPresents several new chapters on plasma as well as the optics and the detector of the spectrometerOffers a helpful troubleshooting guide as well as examples of practical applicationsIncludes myriad illustrative examples

Written for lab technicians, students, environmental chemists, water chemists, soil chemists, soil scientists, geochemists, and materials scientists,ICP Emission Spectrometry, Third Editioncontinues to offer the basics for successful ICP OES analyses and has been updated with the latest developments and applications.

Joachim Nölte studied and completed his PhD degree in environmental analysis at the University of Hamburg, Germany. His work has focussed on ICP OES since 1981 and he has worked at Perkin Elmer on method development. He has extensive experience in teaching the method through courses and presentations. In 2000 he founded a consulting agency called AnalytikSupport.

Foreword ix

Preface xi

1 An Overview1

1.1 Features of ICP-OES 1

1.2 Inductively Coupled Plasma Optical Emission Spectrometry the Name Describes the Technique 2

1.3 Distribution of ICP-OES 4

1.4 Related Techniques for Elemental Analysis 4

1.5 Terms 8

2 Plasma9

2.1 The Spectrometric Plasma 9

2.1.1 The Operating Gas 10

2.1.1.1 Argon 10

2.1.1.2 Addition of Air or Oxygen 11

2.1.2 Plasma Torch 12

2.1.3 Ignition of the Plasma 15

2.1.4 Orientation of the Plasma with Respect to the Torch 15

2.2 Excitation to Emit Electromagnetic Radiation (Light) 16

2.2.1 Emission Lines 16

2.2.2 Energy and Temperature 19

2.2.3 Spectroscopic Properties of the ICP 22

2.2.4 Plasma Viewing 28

2.2.4.1 Radial Viewing 29

2.2.4.2 Axial Viewing 30

2.2.4.3 Radial and Axial Viewing in One Instrument (Dual View) 31

2.3 Excitation Unit 35

2.3.1 Radio Frequency Generator 35

2.3.2 Induction Coil 38

2.4 Sample Introduction System 38

2.4.1 Nebulizer 40

2.4.1.1 Pneumatic Nebulizers 41

2.4.1.2 High-Pressure Nebulizer 45

2.4.1.3 Ultrasonic Nebulizer 46

2.4.2 Nebulizer Chamber 48

2.4.2.1 Tasks of the Nebulizer Chamber 48

2.4.2.2 Temperature of the Nebulizer Chamber 49

2.4.2.3 Materials and Surface Properties 52

2.4.2.4 Common Types of Nebulizer Chambers 54

2.4.2.5 Waste from the Nebulizer Chamber 55

2.4.3 Pump 56

2.4.4 Other Forms of Sample Introduction 59

2.4.4.1 Special Techniques for Liquid Samples 60

2.4.4.2 Gaseous Samples 60

2.4.4.3 Solid Sampling 63

3 Optics and Detector of the Spectrometer67

3.1 Basic Principles of Optics 67

3.1.1 Resolution 67

3.1.2 Relevant Optical Terms 72

3.1.3 Optical Mounts 76

3.1.3.1 PaschenRunge Mount 76

3.1.3.2 CzernyTurnerMount 76

3.1.3.3 Echelle Mount 78

3.1.3.4 Littrow Mount 80

3.1.4 Light Transfer from the Plasma to the Optics 80

3.1.4.1 Separation of Plasma Compartment and Optics 80

3.1.4.2 Transparency of the Optics in the Vacuum-UV Range 82

3.2 Detectors 85

3.2.1 Photomultiplier Tube (PMT) 86

3.2.2 Solid-State Detectors 87

3.3 Types of Emission Spectrometer Mounts 95

3.3.1 Classical Spectrometers 96

3.3.1.1 Monochromators 96

3.3.1.2 Polychromators 96

3.3.2 Array Spectrometers 97

3.3.2.1 Scanning Array Spectrometers 97

3.3.2.2 Simultaneous Array Spectrometers 97

4 Method Development99

4.1 Wavelength Selection 101

4.1.1 Working Range 101

4.1.1.1 Background Equivalent Concentration (BEC) 102

4.1.2 Freedom from Spectral Interference 103

4.1.2.1 Generation of Spectra for the Estimation of the Background 107

4.1.2.2 Generation of Spectra for Detecting Interfering Lines from the Matrix 111

4.1.2.3 Evaluating Spectra 114

4.2 Processing and Correction Techniques 117

4.2.1 Signal Processing 117

4.2.1.1 Calculation of the Peak Height 117

4.2.1.2 Calculation of the Peak Area or of the Partial Peak Area 119

4.2.1.3 Calibration of the Peak Position 122

4.2.2 Background Correction 123

4.2.2.1 Calculation of the Background Correction 126

4.2.2.2 Number the Background Correction Points 128

4.2.3 Impact of Peak Processing and Background Correction on Detection Limits 132

4.2.4 Correction of Spectral Interference 137

4.2.4.1 Inter-element Correction 137

4.2.4.2 Correction Using Multivariate Regression 138

4.2.4.3 Multivariate Regression and Inter-element Correction 147

4.3 Non-spectral Interference 147

4.3.1 Correction of Non-spectral Interference 148

4.3.1.1 Matrix Matching 148

4.3.1.2 Internal Standard 149

4.3.1.3 Calibration with Analyte Addition (Standard Addition) 151

4.3.1.4 Further Measures to Compensate for Non-spectral Interference 153

4.4 Optimization 153

4.4.1 Optimization Goals 154

4.4.2 Optimization Parameters 155

4.4.3 Optimization Algorithms 155

4.5 Validation 157

4.5.1 Accuracy and Specificity 157

4.5.2 Reproducibility 159

4.5.3 Limit of Detection 160

4.5.4 Working Range 164

4.5.5 Robustness 166

5 Routine Analysis169

5.1 Preparation 169

5.1.1 Sample Preparation 169

5.1.2 Warm-up Time 170

5.1.3 Delay and Rinse Times 171

5.2 Calibration 173

5.2.1 Calibration Solutions 173

5.2.1.1 Number of Calibration Solutions 173

5.2.1.2 Concentrations in Calibration Solutions 174

5.2.1.3 Multielement Calibration Solutions 176

5.2.1.4 Multi-bottle Calibration 176

5.2.1.5 Stability of Calibration Solutions 177

5.2.2 Calibration Functions 177

5.2.2.1 External Calibration 178

5.2.2.2 Calibration by Analyte Addition (Standard Addition) 179

5.2.2.3 Bracketing Calibration 179

5.2.3 Examination of the Calibration Data 181

5.3 Quality Assurance 182

5.4 Software and Data Processing 184

6 Troubleshooting and Maintenance187

7 Applications197

7.1 General Notes 197

7.1.1 Material of Containers 197

7.1.2 Stability of Solutions 197

7.1.3 Matrix Effects 198

7.1.4 Contaminations 198

7.2 Comments on Selected Elements 198

7.3 Selected Applications 200

7.3.1 Environment 201

7.3.1.1 Drinking, Ground, and SurfaceWater 202

7.3.1.2 Wastewater, Leachates 202

7.3.1.3 Sludges 204

7.3.1.4 Soil Samples, Sediments 204

7.3.1.5 Airborne Particles, Fly Ashes 205

7.3.2 Samples of Biological Origin 206

7.3.2.1 Plant and Animal Samples 206

7.3.2.2 Clinical and Forensic Materials 207

7.3.2.3 Food and Animal Feeds 208

7.3.3 Geological Materials 208

7.3.4 Metallurgy 210

7.3.4.1 Steel and Iron Matrices 210

7.3.4.2 Nonferrous Metals 212

7.3.4.3 Noble Metals 212

7.3.4.4 Special Alloys 212

7.3.5 Material Sciences 213

7.3.5.1 Semiconductors 213

7.3.5.2 Ceramics 215

7.3.6 Industrial Applications 215

7.3.6.1 Industrial Chemicals and Fertilizers 215

7.3.6.2 Galvanizing/Electroplating Baths 216

7.3.6.3 Brines and Salts 216

7.3.6.4 Cement, Gypsum, Calcium Matrix 216

7.3.6.5 Glass 217

7.3.6.6 Other Industrial Applications 218

7.3.7 Organic Solvents 218

7.3.7.1 Wear Metals and Contamination in Oil 221

7.3.7.2 Additives 223

7.3.7.3 Tar 223

7.3.7.4 Edible Oils 223

8 Procurement of Equipment and Preparation of the Laboratory225

8.1 Which Atomic Spectrometric Technique is the Most Suitable? 225

8.2 Which ICP Emission Spectrometer is the Most Suitable? 227

8.3 Preparation of the Laboratory 230

References 233

Index 269