Provides comprehensive coverage on using X-ray fluorescence for laboratory applications
This book focuses on the practical aspects of X-ray fluorescence (XRF) spectroscopy and discusses the requirements for a successful sample analysis, such as sample preparation, measurement techniques and calibration, as well as the quality of the analysis results.
X-Ray Fluorescence Spectroscopy for Laboratory Applications begins with a short overview of the physical fundamentals of the generation of X-rays and their interaction with the sample material, followed by a presentation of the different methods of sample preparation in dependence on the quality of the source material and the objective of the measurement. After a short description of the different available equipment types and their respective performance, the book provides in-depth information on the choice of the optimal measurement conditions and the processing of the measurement results. It covers instrument types for XRF; acquisition and evaluation of X-Ray spectra; analytical errors; analysis of homogeneous materials, powders, and liquids; special applications of XRF; process control and automation.
- An important resource for the analytical chemist, providing concrete guidelines and support for everyday analyses
- Focuses on daily laboratory work with commercially available devices
- Offers a unique compilation of knowledge and best practices from equipment manufacturers and users
- Covers the entire work process: sample preparation, the actual measurement, data processing, assessment of uncertainty, and accuracy of the obtained results
X-Ray Fluorescence Spectroscopy for Laboratory Applications appeals to analytical chemists, analytical laboratories, materials scientists, environmental chemists, chemical engineers, biotechnologists, and pharma engineers.
Table of Contents
Preface xvii
List of Abbreviations and Symbols xix
About the Authors xxiii
1 Introduction 1
2 Principles of X-ray Spectrometry 7
2.1 Analytical Performance 7
2.2 X-ray Radiation and Their Interaction 11
2.2.1 Parts of an X-ray Spectrum 11
2.2.2 Intensity of the Characteristic Radiation 13
2.2.3 Nomenclature of X-ray Lines 15
2.2.4 Interaction of X-rays with Matter 15
2.2.4.1 Absorption 16
2.2.4.2 Scattering 17
2.2.5 Detection of X-ray Spectra 20
2.3 The Development of X-ray Spectrometry 21
2.4 Carrying Out an Analysis 26
2.4.1 Analysis Method 26
2.4.2 Sequence of an Analysis 27
2.4.2.1 Quality of the Sample Material 27
2.4.2.2 Sample Preparation 27
2.4.2.3 Analysis Task 28
2.4.2.4 Measurement and Evaluation of the Measurement Data 28
2.4.2.5 Creation of an Analysis Report 29
3 Sample Preparation 31
3.1 Objectives of Sample Preparation 31
3.2 Preparation Techniques 32
3.2.1 Preparation Techniques for Solid Samples 32
3.2.2 Information Depth and Analyzed Volume 32
3.2.3 Infinite Thickness 36
3.2.4 Contaminations 37
3.2.5 Homogeneity 38
3.3 Preparation of Compact and Homogeneous Materials 39
3.3.1 Metals 39
3.3.2 Glasses 40
3.4 Small Parts Materials 41
3.4.1 Grinding of Small Parts Material 42
3.4.2 Preparation by Pouring Loose Powder into a Sample Cup 43
3.4.3 Preparation of the Measurement Sample by Pressing into a Pellet 44
3.4.4 Preparation of the Sample by Fusion Beads 48
3.4.4.1 Improving the Quality of the Analysis 48
3.4.4.2 Steps for the Production of Fusion Beads 49
3.4.4.3 Loss of Ignition 53
3.4.4.4 Quality Criteria for Fusion Beads 53
3.4.4.5 Preparation of Special Materials 54
3.5 Liquid Samples 55
3.5.1 Direct Measurement of Liquids 55
3.5.2 Special Processing Procedures for Liquid Samples 58
3.6 Biological Materials 58
3.7 Small Particles, Dust, and Aerosols 59
4 XRF Instrument Types 61
4.1 General Design of an X-ray Spectrometer 61
4.2 Comparison of Wavelength- and Energy-Dispersive X-Ray Spectrometers 63
4.2.1 Data Acquisition 63
4.2.2 Resolution 64
4.2.2.1 Comparison of Wavelength- and Energy-Dispersive Spectrometry 64
4.2.2.2 Resolution of WDS Instruments 66
4.2.2.3 Resolution of EDS Instruments 68
4.2.3 Detection Efficiency 70
4.2.4 Count Rate Capability 71
4.2.4.1 Optimum Throughput in ED Spectrometers 71
4.2.4.2 Saturation Effects in WDSs 72
4.2.4.3 Optimal Sensitivity of ED Spectrometers 73
4.2.4.4 Effect of the Pulse Throughput on the Measuring Time 74
4.2.5 Radiation Flux 75
4.2.6 Spectra Artifacts 76
4.2.6.1 Escape Peaks 76
4.2.6.2 Pile-Up Peak 77
4.2.6.3 Diffraction Peaks 77
4.2.6.4 Shelf and Tail 79
4.2.7 Mechanical Design and Operating Costs 79
4.2.8 Setting Parameters 80
4.3 Type of Instruments 80
4.3.1 ED Instruments 81
4.3.1.1 Handheld Instruments 82
4.3.1.2 Portable Instruments 83
4.3.1.3 Tabletop Instruments 84
4.3.2 Wavelength-Dispersive Instruments 85
4.3.2.1 Sequential Spectrometers 85
4.3.2.2 Multichannel Spectrometers 87
4.3.3 Special Type X-Ray Spectrometers 87
4.3.3.1 Total Reflection Instruments 88
4.3.3.2 Excitation by Monoenergetic Radiation 90
4.3.3.3 Excitation with Polarized Radiation 91
4.3.3.4 Instruments for Position-Sensitive Analysis 93
4.3.3.5 Macro X-Ray Fluorescence Spectrometer 94
4.3.3.6 Micro X-Ray Fluorescence with Confocal Geometry 95
4.3.3.7 High-Resolution X-Ray Spectrometers 96
4.3.3.8 Angle Resolved Spectroscopy - Grazing Incidence and Grazing Exit 96
4.4 Commercially Available Instrument Types 98
5 Measurement and Evaluation of X-ray Spectra 99
5.1 Information Content of the Spectra 99
5.2 Procedural Steps to Execute a Measurement 101
5.3 Selecting the Measurement Conditions 102
5.3.1 Optimization Criteria for the Measurement 102
5.3.2 Tube Parameters 103
5.3.2.1 Target Material 103
5.3.2.2 Excitation Conditions 104
5.3.2.3 Influencing the Energy Distribution of the Primary Spectrum 105
5.3.3 Measurement Medium 107
5.3.4 Measurement Time 108
5.3.4.1 Measurement Time and Statistical Error 108
5.3.4.2 Measurement Strategies 108
5.3.4.3 Real and Live Time 109
5.3.5 X-ray Lines 110
5.4 Determination of Peak Intensity 112
5.4.1 Intensity Data 112
5.4.2 Treatment of Peak Overlaps 112
5.4.3 Spectral Background 114
5.5 Quantification Models 117
5.5.1 General Remarks 117
5.5.2 Conventional Calibration Models 118
5.5.3 Fundamental Parameter Models 121
5.5.4 Monte Carlo Quantifications 124
5.5.5 Highly Precise Quantification by Reconstitution 124
5.5.6 Evaluation of an Analytical Method 126
5.5.6.1 Degree of Determination 126
5.5.6.2 Working Range, Limits of Detection (LOD) and of Quantification 127
5.5.6.3 Figure of Merit 129
5.5.7 Comparison of the Various Quantification Models 129
5.5.8 Available Reference Materials 131
5.5.9 Obtainable Accuracies 132
5.6 Characterization of Layered Materials 133
5.6.1 General Form of the Calibration Curve 133
5.6.2 Basic Conditions for Layer Analysis 135
5.6.3 Quantification Models for the Analysis of Layers 138
5.7 Chemometric Methods for Material Characterization 140
5.7.1 Spectra Matching and Material Identification 141
5.7.2 Phase Analysis 141
5.7.3 Regression Methods 143
5.8 Creation of an Application 143
5.8.1 Analysis of Unknown Sample Qualities 143
5.8.2 Repeated Analyses on Known Samples 144
6 Analytical Errors 149
6.1 General Considerations 149
6.1.1 Precision of a Measurement 151
6.1.2 Long-Term Stability of the Measurements 153
6.1.3 Precision and Process Capability 154
6.1.4 Trueness of the Result 156
6.2 Types of Errors 156
6.2.1 Randomly Distributed Errors 157
6.2.2 Systematic Errors 158
6.3 Accounting for Systematic Errors 159
6.3.1 The Concept of Measurement Uncertainties 159
6.3.2 Error Propagation 160
6.3.3 Determination of Measurement Uncertainties 161
6.3.3.1 Bottom-Up Method 161
6.3.3.2 Top-Down Method 162
6.4 Recording of Error Information 164
7 Other Element Analytical Methods 167
7.1 Overview 167
7.2 Atomic Absorption Spectrometry (AAS) 168
7.3 Optical Emission Spectrometry 169
7.3.1 Excitation with a Spark Discharge (OES) 169
7.3.2 Excitation in an Inductively Coupled Plasma (ICP-OES) 170
7.3.3 Laser-Induced Breakdown Spectroscopy (LIBS) 171
7.4 Mass Spectrometry (MS) 172
7.5 X-Ray Spectrometry by Particle Excitation (SEM-EDS, PIXE) 173
7.6 Comparison of Methods 175
8 Radiation Protection 177
8.1 Basic Principles 177
8.2 Effects of Ionizing Radiation on Human Tissue 178
8.3 Natural Radiation Exposure 179
8.4 Radiation Protection Regulations 181
8.4.1 Legal Regulations 181
9 Analysis of Homogeneous Solid Samples 183
9.1 Iron Alloys 183
9.1.1 Analytical Problem and Sample Preparation 183
9.1.2 Analysis of Pig and Cast Iron 184
9.1.3 Analysis of Low-Alloy Steel 185
9.1.4 Analysis of High-Alloy Steel 187
9.2 Ni-Fe-Co Alloys 188
9.3 Copper Alloys 189
9.3.1 Analytical Task 189
9.3.2 Analysis of Compact Samples 189
9.3.3 Analysis of Dissolved Samples 189
9.4 Aluminum Alloys 191
9.5 Special Metals 192
9.5.1 Refractories 192
9.5.1.1 Analytical Problem 192
9.5.1.2 Sample Preparation of Hard Metals 192
9.5.1.3 Analysis of Hard Metals 193
9.5.2 Titanium Alloys 194
9.5.3 Solder Alloys 194
9.6 Precious Metals 195
9.6.1 Analysis of Precious Metal Jewelry 195
9.6.1.1 Analytical Task 195
9.6.1.2 Sample Shape and Preparation 196
9.6.1.3 Analytical Equipment 197
9.6.1.4 Accuracy of the Analysis 198
9.6.2 Analysis of Pure Elements 198
9.7 Glass Material 199
9.7.1 Analytical Task 199
9.7.2 Sample Preparation 200
9.7.3 Measurement Equipment 202
9.7.4 Achievable Accuracies 202
9.8 Polymers 203
9.8.1 Analytical Task 203
9.8.2 Sample Preparation 204
9.8.3 Instruments 205
9.8.4 Quantification Procedures 205
9.8.4.1 Standard-Based Methods 205
9.8.4.2 Chemometric Methods 206
9.9 Abrasion Analysis 209
10 Analysis of Powder Samples 213
10.1 Geological Samples 213
10.1.1 Analytical Task 213
10.1.2 Sample Preparation 214
10.1.3 Measurement Technique 215
10.1.4 Detection Limits and Trueness 215
10.2 Ores 216
10.2.1 Analytical Task 216
10.2.2 Iron Ores 216
10.2.3 Mn, Co, Ni, Cu, Zn, and Pb Ores 217
10.2.4 Bauxite and Alumina 218
10.2.5 Ores of Precious Metals and Rare Earths 219
10.3 Soils and Sewage Sludges 221
10.3.1 Analytical Task 221
10.3.2 Sample Preparation 221
10.3.3 Measurement Technology and Analytical Performance 222
10.4 Quartz Sand 223
10.5 Cement 223
10.5.1 Analytical Task 223
10.5.2 Sample Preparation 224
10.5.3 Measurement Technology 225
10.5.4 Analytical Performance 226
10.5.5 Determination of Free Lime in Clinker 227
10.6 Coal and Coke 227
10.6.1 Analytical Task 227
10.6.2 Sample Preparation 228
10.6.3 Measurement Technology and Analytical Performance 229
10.7 Ferroalloys 230
10.7.1 Analytical Task 230
10.7.2 Sample Preparation 230
10.7.3 Analysis Technology 232
10.7.4 Analytical Performance 234
10.8 Slags 235
10.8.1 Analytical Task 235
10.8.2 Sample Preparation 235
10.8.3 Measurement Technology and Analytical Accuracy 236
10.9 Ceramics and Refractory Materials 237
10.9.1 Analytical Task 237
10.9.2 Sample Preparation 237
10.9.3 Measurement Technology and Analytical Performance 238
10.10 Dusts 239
10.10.1 Analytical Problem and Dust Collection 239
10.10.2 Measurement 242
10.11 Food 242
10.11.1 Analytical Task 242
10.11.2 Monitoring of Animal Feed 243
10.11.3 Control of Infant Food 244
10.12 Pharmaceuticals 245
10.12.1 Analytical Task 245
10.12.2 Sample Preparation and Analysis Method 245
10.13 Secondary Fuels 246
10.13.1 Analytical Task 246
10.13.2 Sample Preparation 247
10.13.2.1 Solid Secondary Raw Materials 247
10.13.2.2 Liquid Secondary Raw Materials 249
10.13.3 Instrumentation and Measurement Conditions 250
10.13.4 Measurement Uncertainties in the Analysis of Solid Secondary Raw Materials 251
10.13.5 Measurement Uncertainties for the Analysis of Liquid Secondary Raw Materials 252
11 Analysis of Liquids 253
11.1 Multielement Analysis of Liquids 254
11.1.1 Analytical Task 254
11.1.2 Sample Preparation 254
11.1.3 Measurement Technology 254
11.1.4 Quantification 255
11.2 Fuels and Oils 255
11.2.1 Analysis of Toxic Elements in Fuels 256
11.2.1.1 Measurement Technology 256
11.2.1.2 Analytical Performance 258
11.2.2 Analysis of Additives in Lubricating Oils 258
11.2.3 Identification of Abrasive Particles in Used Lubricants 260
11.3 Trace Analysis in Liquids 261
11.3.1 Analytical Task 261
11.3.2 Preparation by Drying 261
11.3.3 Quantification 262
11.4 Special Preparation Techniques for Liquid Samples 263
11.4.1 Determination of Light Elements in Liquids 263
11.4.2 Enrichment Through Absorption and Complex Formation 264
12 Trace Analysis Using Total Reflection X-Ray Fluorescence 267
12.1 Special Features of TXRF 267
12.2 Sample Preparation for TXRF 269
12.3 Evaluation of the Spectra 271
12.3.1 Spectrum Preparation and Quantification 271
12.3.2 Conditions for Neglecting the Matrix Interaction 272
12.3.3 Limits of Detection 273
12.4 Typical Applications of the TXRF 274
12.4.1 Analysis of Aqueous Solutions 274
12.4.1.1 Analytical Problem and Preparation Possibilities 274
12.4.1.2 Example: Analysis of a Fresh Water Standard Sample 275
12.4.1.3 Example: Detection of Mercury in Water 277
12.4.2 Analysis of the Smallest Sample Quantities 278
12.4.2.1 Example: Pigment Analysis 278
12.4.2.2 Example: Aerosol Analysis 279
12.4.2.3 Example: Analysis of Nanoparticles 279
12.4.3 Trace Element Analysis on Human Organs 280
12.4.3.1 Example: Analysis of Blood and Blood Serum 280
12.4.3.2 Example: Analysis of Trace Elements in Body Tissue 282
12.4.4 Trace Analysis of Inorganic and Organic Chemical Products 283
12.4.5 Analysis of Semiconductor Electronics 284
12.4.5.1 Ultra-Trace Analysis on SiWafers with VPD 284
12.4.5.2 Depth Profile Analysis by Etching 285
13 Nonhomogeneous Samples 287
13.1 Measurement Modes 287
13.2 Instrument Requirements 288
13.3 Data Evaluation 290
14 Coating Analysis 291
14.1 Analytical Task 291
14.2 Sample Handling 292
14.3 Measurement Technology 293
14.4 The Analysis Examples of Coated Samples 294
14.4.1 Single-Layer Systems: Emission Mode 294
14.4.2 Single-Layer Systems: Absorption Mode 297
14.4.3 Single-Layer Systems: Relative Mode 298
14.4.3.1 Analytical Problem 298
14.4.3.2 Variation of the Specified Working Distance 298
14.4.3.3 Sample Size and Spot Size Mismatch 299
14.4.3.4 Non-detectable Elements in the Layer: NiP Layers 300
14.4.4 Characterization of Ultrathin Layers 302
14.4.5 Multilayer Systems 304
14.4.5.1 Layer Systems 304
14.4.5.2 Measurement Technology 305
14.4.5.3 Example: Analysis of CIGS Solar Cells 305
14.4.5.4 Example: Analysis of Solder Structures 306
14.4.6 Samples with Unknown Coating Systems 307
14.4.6.1 Preparation of Cross Sections 308
14.4.6.2 Excitation at Grazing Incidence with Varying Angles 309
14.4.6.3 Measurement in Confocal Geometry 311
15 Spot Analyses 313
15.1 Particle Analyses 313
15.1.1 Analytical Task 313
15.1.2 Sample Preparation 314
15.1.3 Analysis Technology 315
15.1.4 Application Example:Wear Particles in Used Oil 315
15.1.5 Application Example: Identification of Glass Particles by Chemometrics 316
15.2 Identification of Inclusions 318
15.3 Material Identification with Handheld Instruments 318
15.3.1 Analytical Tasks 318
15.3.2 Analysis Technology 319
15.3.3 Sample Preparation and Test Conditions 320
15.3.4 Analytical Accuracy 320
15.3.5 Application Examples 321
15.3.5.1 Example: Lead in Paint 321
15.3.5.2 Example: Scrap Sorting 321
15.3.5.3 Example: Material Inspection and Sorting 322
15.3.5.4 Example: Precious Metal Analysis 322
15.3.5.5 Example: Prospecting and Screening in Geology 323
15.3.5.6 Example: Investigation of Works of Art 323
15.4 Determination of Toxic Elements in Consumer Products: RoHS Monitoring 324
15.4.1 Analytical Task 324
15.4.2 Analysis Technology 325
15.4.3 Analysis Accuracy 327
15.5 Toxic Elements in Toys: Toys Standard 328
15.5.1 Analytical Task 328
15.5.2 Sample Preparation 328
15.5.3 Analysis Technology 330
16 Analysis of Element Distributions 331
16.1 General Remarks 331
16.2 Measurement Conditions 332
16.3 Geology 333
16.3.1 Samples Types 333
16.3.2 Sample Preparation and Positioning 333
16.3.3 Measurements on Compact Rock Samples 334
16.3.3.1 Sum Spectrum and Element Distributions 334
16.3.3.2 Object Spectra 335
16.3.3.3 Treatment of Line Overlaps 336
16.3.3.4 Maximum Pixel Spectrum 339
16.3.4 Thin Sections of Geological Samples 340
16.4 Electronics 342
16.5 Archeometric Investigations 344
16.5.1 Analytical Tasks 344
16.5.2 Selection of an Appropriate Spectrometer 346
16.5.3 Investigations of Coins 347
16.5.4 Investigations of Painting Pigments 349
16.6 Homogeneity Tests 350
16.6.1 Analytical Task 350
16.6.2 Homogeneity Studies Using Distribution Analysis 351
16.6.3 Homogeneity Studies Using Multi-point Measurements 352
17 Special Applications of the XRF 355
17.1 High-Throughput Screening and Combinatorial Analysis 355
17.1.1 High-Throughput Screening 355
17.1.2 Combinatorial Analysis for Drug Development 357
17.2 Chemometric Spectral Evaluation 358
17.3 High-Resolution Spectroscopy for Speciation Analysis 361
17.3.1 Analytical Task 361
17.3.2 Instrument Technology 361
17.3.3 Application Examples 362
17.3.3.1 Analysis of Different Sulfur Compounds 362
17.3.3.2 Speciation of Aluminum Inclusions in Steel 363
17.3.3.3 Determination of SiO2 in SiC 365
18 Process Control and Automation 367
18.1 General Objectives 367
18.2 Off-Line and At-Line Analysis 369
18.2.1 Sample Supply and Analysis 369
18.2.2 Automated Sample Preparation 371
18.3 In-Line and On-Line Analysis 376
19 Quality Management and Validation 379
19.1 Motivation 379
19.2 Validation 380
19.2.1 Parameters 384
19.2.2 Uncertainty 385
Appendix A Tables 387
Appendix B Important Information 419
B.1 Coordinates of Main Manufacturers of Instruments and Preparation Tools 419
B.2 Main Suppliers of Standard Materials 422
B.2.1 Geological Materials and Metals 422
B.2.2 Stratified Materials 423
B.2.3 Polymer Standards 424
B.2.4 High Purity Materials 424
B.2.5 Precious Metal Alloys 425
B.3 Important Websites 425
B.3.1 Information About X-Ray Analytics and Fundamental Parameters 425
B.3.2 Information About Reference Materials 426
B.3.3 Scientific Journals 427
B.4 Laws and Acts, Which Are Important for X-Ray Fluorescence 427
B.4.1 Radiation Protection 427
B.4.2 Regulations for Environmental Control 428
B.4.3 Regulations for Performing Analysis 428
B.4.4 Use of X-ray Fluorescence for the Chemical Analysis 428
B.4.4.1 General Regulations 428
B.4.4.2 Analysis of Minerals 429
B.4.4.3 Analysis of Oils, Liquid Fuels, Grease 430
B.4.4.4 Analysis of Solid Fuels 432
B.4.4.5 Coating Analysis 433
B.4.4.6 Metallurgy 433
B.4.4.7 Analysis of Electronic Components 434
References 435
Index 453
