X-Ray Fluorescence Spectroscopy for Laboratory Applications

Michael Haschke, PhD, has been working in the product management of various companies for more than 35 years where he was responsible for the development and introduction to market of new x-ray fluorescence techniques, mainly in the field of energy-dissipative spectroscopy.   Jörg Flock, PhD, is Head of the Central Laboratory of ThyssenKrupp Stahl AG and well-versed with different analytical techniques, in particular with x-ray fluorescence spectroscopy. He has extensive practical experience in using this technique for the analysis of samples with different qualities and the interpretation of the acquired results.   Michael Haller has been using X-rays as an analytical tool for over thirty years, first in X-ray crystallography, then later in the development and application of polycapillary X-ray optics. Further he has developed new applications for coating thickness instruments. In 2018 he became co-owner of CrossRoads Scientific, a company specializing in the development of analytical X-ray software.

• Preface xviiList of Abbreviations and Symbols xixAbout the Authors xxiii1 Introduction 12 Principles of X-ray Spectrometry 72.1 Analytical Performance 72.2 X-ray Radiation and Their Interaction 112.2.1 Parts of an X-ray Spectrum 112.2.2 Intensity of the Characteristic Radiation 132.2.3 Nomenclature of X-ray Lines 152.2.4 Interaction of X-rays with Matter 152.2.4.1 Absorption 162.2.4.2 Scattering 172.2.5 Detection of X-ray Spectra 202.3 The Development of X-ray Spectrometry 212.4 Carrying Out an Analysis 262.4.1 Analysis Method 262.4.2 Sequence of an Analysis 272.4.2.1 Quality of the Sample Material 272.4.2.2 Sample Preparation 272.4.2.3 Analysis Task 282.4.2.4 Measurement and Evaluation of the Measurement Data 282.4.2.5 Creation of an Analysis Report 293 Sample Preparation 313.1 Objectives of Sample Preparation 313.2 Preparation Techniques 323.2.1 Preparation Techniques for Solid Samples 323.2.2 Information Depth and Analyzed Volume 323.2.3 Infinite Thickness 363.2.4 Contaminations 373.2.5 Homogeneity 383.3 Preparation of Compact and Homogeneous Materials 393.3.1 Metals 393.3.2 Glasses 403.4 Small Parts Materials 413.4.1 Grinding of Small Parts Material 423.4.2 Preparation by Pouring Loose Powder into a Sample Cup 433.4.3 Preparation of the Measurement Sample by Pressing into a Pellet 443.4.4 Preparation of the Sample by Fusion Beads 483.4.4.1 Improving the Quality of the Analysis 483.4.4.2 Steps for the Production of Fusion Beads 493.4.4.3 Loss of Ignition 533.4.4.4 Quality Criteria for Fusion Beads 533.4.4.5 Preparation of Special Materials 543.5 Liquid Samples 553.5.1 Direct Measurement of Liquids 553.5.2 Special Processing Procedures for Liquid Samples 583.6 Biological Materials 583.7 Small Particles, Dust, and Aerosols 594 XRF Instrument Types 614.1 General Design of an X-ray Spectrometer 614.2 Comparison of Wavelength- and Energy-Dispersive X-Ray Spectrometers 634.2.1 Data Acquisition 634.2.2 Resolution 644.2.2.1 Comparison of Wavelength- and Energy-Dispersive Spectrometry 644.2.2.2 Resolution of WDS Instruments 664.2.2.3 Resolution of EDS Instruments 684.2.3 Detection Efficiency 704.2.4 Count Rate Capability 714.2.4.1 Optimum Throughput in ED Spectrometers 714.2.4.2 Saturation Effects in WDSs 724.2.4.3 Optimal Sensitivity of ED Spectrometers 734.2.4.4 Effect of the Pulse Throughput on the Measuring Time 744.2.5 Radiation Flux 754.2.6 Spectra Artifacts 764.2.6.1 Escape Peaks 764.2.6.2 Pile-Up Peak 774.2.6.3 Diffraction Peaks 774.2.6.4 Shelf and Tail 794.2.7 Mechanical Design and Operating Costs 794.2.8 Setting Parameters 804.3 Type of Instruments 804.3.1 ED Instruments 814.3.1.1 Handheld Instruments 824.3.1.2 Portable Instruments 834.3.1.3 Tabletop Instruments 844.3.2 Wavelength-Dispersive Instruments 854.3.2.1 Sequential Spectrometers 854.3.2.2 Multichannel Spectrometers 874.3.3 Special Type X-Ray Spectrometers 874.3.3.1 Total Reflection Instruments 884.3.3.2 Excitation by Monoenergetic Radiation 904.3.3.3 Excitation with Polarized Radiation 914.3.3.4 Instruments for Position-Sensitive Analysis 934.3.3.5 Macro X-Ray Fluorescence Spectrometer 944.3.3.6 Micro X-Ray Fluorescence with Confocal Geometry 954.3.3.7 High-Resolution X-Ray Spectrometers 964.3.3.8 Angle Resolved Spectroscopy – Grazing Incidence and Grazing Exit 964.4 Commercially Available Instrument Types 985 Measurement and Evaluation of X-ray Spectra 995.1 Information Content of the Spectra 995.2 Procedural Steps to Execute a Measurement 1015.3 Selecting the Measurement Conditions 1025.3.1 Optimization Criteria for the Measurement 1025.3.2 Tube Parameters 1035.3.2.1 Target Material 1035.3.2.2 Excitation Conditions 1045.3.2.3 Influencing the Energy Distribution of the Primary Spectrum 1055.3.3 Measurement Medium 1075.3.4 Measurement Time 1085.3.4.1 Measurement Time and Statistical Error 1085.3.4.2 Measurement Strategies 1085.3.4.3 Real and Live Time 1095.3.5 X-ray Lines 1105.4 Determination of Peak Intensity 1125.4.1 Intensity Data 1125.4.2 Treatment of Peak Overlaps 1125.4.3 Spectral Background 1145.5 Quantification Models 1175.5.1 General Remarks 1175.5.2 Conventional Calibration Models 1185.5.3 Fundamental Parameter Models 1215.5.4 Monte Carlo Quantifications 1245.5.5 Highly Precise Quantification by Reconstitution 1245.5.6 Evaluation of an Analytical Method 1265.5.6.1 Degree of Determination 1265.5.6.2 Working Range, Limits of Detection (LOD) and of Quantification 1275.5.6.3 Figure of Merit 1295.5.7 Comparison of the Various Quantification Models 1295.5.8 Available Reference Materials 1315.5.9 Obtainable Accuracies 1325.6 Characterization of Layered Materials 1335.6.1 General Form of the Calibration Curve 1335.6.2 Basic Conditions for Layer Analysis 1355.6.3 Quantification Models for the Analysis of Layers 1385.7 Chemometric Methods for Material Characterization 1405.7.1 Spectra Matching and Material Identification 1415.7.2 Phase Analysis 1415.7.3 Regression Methods 1435.8 Creation of an Application 1435.8.1 Analysis of Unknown Sample Qualities 1435.8.2 Repeated Analyses on Known Samples 1446 Analytical Errors 1496.1 General Considerations 1496.1.1 Precision of a Measurement 1516.1.2 Long-Term Stability of the Measurements 1536.1.3 Precision and Process Capability 1546.1.4 Trueness of the Result 1566.2 Types of Errors 1566.2.1 Randomly Distributed Errors 1576.2.2 Systematic Errors 1586.3 Accounting for Systematic Errors 1596.3.1 The Concept of Measurement Uncertainties 1596.3.2 Error Propagation 1606.3.3 Determination of Measurement Uncertainties 1616.3.3.1 Bottom-Up Method 1616.3.3.2 Top-Down Method 1626.4 Recording of Error Information 1647 Other Element Analytical Methods 1677.1 Overview 1677.2 Atomic Absorption Spectrometry (AAS) 1687.3 Optical Emission Spectrometry 1697.3.1 Excitation with a Spark Discharge (OES) 1697.3.2 Excitation in an Inductively Coupled Plasma (ICP-OES) 1707.3.3 Laser-Induced Breakdown Spectroscopy (LIBS) 1717.4 Mass Spectrometry (MS) 1727.5 X-Ray Spectrometry by Particle Excitation (SEM-EDS, PIXE) 1737.6 Comparison of Methods 1758 Radiation Protection 1778.1 Basic Principles 1778.2 Effects of Ionizing Radiation on Human Tissue 1788.3 Natural Radiation Exposure 1798.4 Radiation Protection Regulations 1818.4.1 Legal Regulations 1819 Analysis of Homogeneous Solid Samples 1839.1 Iron Alloys 1839.1.1 Analytical Problem and Sample Preparation 1839.1.2 Analysis of Pig and Cast Iron 1849.1.3 Analysis of Low-Alloy Steel 1859.1.4 Analysis of High-Alloy Steel 1879.2 Ni–Fe–Co Alloys 1889.3 Copper Alloys 1899.3.1 Analytical Task 1899.3.2 Analysis of Compact Samples 1899.3.3 Analysis of Dissolved Samples 1899.4 Aluminum Alloys 1919.5 Special Metals 1929.5.1 Refractories 1929.5.1.1 Analytical Problem 1929.5.1.2 Sample Preparation of Hard Metals 1929.5.1.3 Analysis of Hard Metals 1939.5.2 Titanium Alloys 1949.5.3 Solder Alloys 1949.6 Precious Metals 1959.6.1 Analysis of Precious Metal Jewelry 1959.6.1.1 Analytical Task 1959.6.1.2 Sample Shape and Preparation 1969.6.1.3 Analytical Equipment 1979.6.1.4 Accuracy of the Analysis 1989.6.2 Analysis of Pure Elements 1989.7 Glass Material 1999.7.1 Analytical Task 1999.7.2 Sample Preparation 2009.7.3 Measurement Equipment 2029.7.4 Achievable Accuracies 2029.8 Polymers 2039.8.1 Analytical Task 2039.8.2 Sample Preparation 2049.8.3 Instruments 2059.8.4 Quantification Procedures 2059.8.4.1 Standard-Based Methods 2059.8.4.2 Chemometric Methods 2069.9 Abrasion Analysis 20910 Analysis of Powder Samples 21310.1 Geological Samples 21310.1.1 Analytical Task 21310.1.2 Sample Preparation 21410.1.3 Measurement Technique 21510.1.4 Detection Limits and Trueness 21510.2 Ores 21610.2.1 Analytical Task 21610.2.2 Iron Ores 21610.2.3 Mn, Co, Ni, Cu, Zn, and Pb Ores 21710.2.4 Bauxite and Alumina 21810.2.5 Ores of Precious Metals and Rare Earths 21910.3 Soils and Sewage Sludges 22110.3.1 Analytical Task 22110.3.2 Sample Preparation 22110.3.3 Measurement Technology and Analytical Performance 22210.4 Quartz Sand 22310.5 Cement 22310.5.1 Analytical Task 22310.5.2 Sample Preparation 22410.5.3 Measurement Technology 22510.5.4 Analytical Performance 22610.5.5 Determination of Free Lime in Clinker 22710.6 Coal and Coke 22710.6.1 Analytical Task 22710.6.2 Sample Preparation 22810.6.3 Measurement Technology and Analytical Performance 22910.7 Ferroalloys 23010.7.1 Analytical Task 23010.7.2 Sample Preparation 23010.7.3 Analysis Technology 23210.7.4 Analytical Performance 23410.8 Slags 23510.8.1 Analytical Task 23510.8.2 Sample Preparation 23510.8.3 Measurement Technology and Analytical Accuracy 23610.9 Ceramics and Refractory Materials 23710.9.1 Analytical Task 23710.9.2 Sample Preparation 23710.9.3 Measurement Technology and Analytical Performance 23810.10 Dusts 23910.10.1 Analytical Problem and Dust Collection 23910.10.2 Measurement 24210.11 Food 24210.11.1 Analytical Task 24210.11.2 Monitoring of Animal Feed 24310.11.3 Control of Infant Food 24410.12 Pharmaceuticals 24510.12.1 Analytical Task 24510.12.2 Sample Preparation and Analysis Method 24510.13 Secondary Fuels 24610.13.1 Analytical Task 24610.13.2 Sample Preparation 24710.13.2.1 Solid Secondary Raw Materials 24710.13.2.2 Liquid Secondary Raw Materials 24910.13.3 Instrumentation and Measurement Conditions 25010.13.4 Measurement Uncertainties in the Analysis of Solid Secondary Raw Materials 25110.13.5 Measurement Uncertainties for the Analysis of Liquid Secondary Raw Materials 25211 Analysis of Liquids 25311.1 Multielement Analysis of Liquids 25411.1.1 Analytical Task 25411.1.2 Sample Preparation 25411.1.3 Measurement Technology 25411.1.4 Quantification 25511.2 Fuels and Oils 25511.2.1 Analysis of Toxic Elements in Fuels 25611.2.1.1 Measurement Technology 25611.2.1.2 Analytical Performance 25811.2.2 Analysis of Additives in Lubricating Oils 25811.2.3 Identification of Abrasive Particles in Used Lubricants 26011.3 Trace Analysis in Liquids 26111.3.1 Analytical Task 26111.3.2 Preparation by Drying 26111.3.3 Quantification 26211.4 Special Preparation Techniques for Liquid Samples 26311.4.1 Determination of Light Elements in Liquids 26311.4.2 Enrichment Through Absorption and Complex Formation 26412 Trace Analysis Using Total Reflection X-Ray Fluorescence 26712.1 Special Features of TXRF 26712.2 Sample Preparation for TXRF 26912.3 Evaluation of the Spectra 27112.3.1 Spectrum Preparation and Quantification 27112.3.2 Conditions for Neglecting the Matrix Interaction 27212.3.3 Limits of Detection 27312.4 Typical Applications of the TXRF 27412.4.1 Analysis of Aqueous Solutions 27412.4.1.1 Analytical Problem and Preparation Possibilities 27412.4.1.2 Example: Analysis of a Fresh Water Standard Sample 27512.4.1.3 Example: Detection of Mercury in Water 27712.4.2 Analysis of the Smallest Sample Quantities 27812.4.2.1 Example: Pigment Analysis 27812.4.2.2 Example: Aerosol Analysis 27912.4.2.3 Example: Analysis of Nanoparticles 27912.4.3 Trace Element Analysis on Human Organs 28012.4.3.1 Example: Analysis of Blood and Blood Serum 28012.4.3.2 Example: Analysis of Trace Elements in Body Tissue 28212.4.4 Trace Analysis of Inorganic and Organic Chemical Products 28312.4.5 Analysis of Semiconductor Electronics 28412.4.5.1 Ultra-Trace Analysis on SiWafers with VPD 28412.4.5.2 Depth Profile Analysis by Etching 28513 Nonhomogeneous Samples 28713.1 Measurement Modes 28713.2 Instrument Requirements 28813.3 Data Evaluation 29014 Coating Analysis 29114.1 Analytical Task 29114.2 Sample Handling 29214.3 Measurement Technology 29314.4 The Analysis Examples of Coated Samples 29414.4.1 Single-Layer Systems: Emission Mode 29414.4.2 Single-Layer Systems: Absorption Mode 29714.4.3 Single-Layer Systems: Relative Mode 29814.4.3.1 Analytical Problem 29814.4.3.2 Variation of the Specified Working Distance 29814.4.3.3 Sample Size and Spot Size Mismatch 29914.4.3.4 Non-detectable Elements in the Layer: NiP Layers 30014.4.4 Characterization of Ultrathin Layers 30214.4.5 Multilayer Systems 30414.4.5.1 Layer Systems 30414.4.5.2 Measurement Technology 30514.4.5.3 Example: Analysis of CIGS Solar Cells 30514.4.5.4 Example: Analysis of Solder Structures 30614.4.6 Samples with Unknown Coating Systems 30714.4.6.1 Preparation of Cross Sections 30814.4.6.2 Excitation at Grazing Incidence with Varying Angles 30914.4.6.3 Measurement in Confocal Geometry 31115 Spot Analyses 31315.1 Particle Analyses 31315.1.1 Analytical Task 31315.1.2 Sample Preparation 31415.1.3 Analysis Technology 31515.1.4 Application Example:Wear Particles in Used Oil 31515.1.5 Application Example: Identification of Glass Particles by Chemometrics 31615.2 Identification of Inclusions 31815.3 Material Identification with Handheld Instruments 31815.3.1 Analytical Tasks 31815.3.2 Analysis Technology 31915.3.3 Sample Preparation and Test Conditions 32015.3.4 Analytical Accuracy 32015.3.5 Application Examples 32115.3.5.1 Example: Lead in Paint 32115.3.5.2 Example: Scrap Sorting 32115.3.5.3 Example: Material Inspection and Sorting 32215.3.5.4 Example: Precious Metal Analysis 32215.3.5.5 Example: Prospecting and Screening in Geology 32315.3.5.6 Example: Investigation of Works of Art 32315.4 Determination of Toxic Elements in Consumer Products: RoHS Monitoring 32415.4.1 Analytical Task 32415.4.2 Analysis Technology 32515.4.3 Analysis Accuracy 32715.5 Toxic Elements in Toys: Toys Standard 32815.5.1 Analytical Task 32815.5.2 Sample Preparation 32815.5.3 Analysis Technology 33016 Analysis of Element Distributions 33116.1 General Remarks 33116.2 Measurement Conditions 33216.3 Geology 33316.3.1 Samples Types 33316.3.2 Sample Preparation and Positioning 33316.3.3 Measurements on Compact Rock Samples 33416.3.3.1 Sum Spectrum and Element Distributions 33416.3.3.2 Object Spectra 33516.3.3.3 Treatment of Line Overlaps 33616.3.3.4 Maximum Pixel Spectrum 33916.3.4 Thin Sections of Geological Samples 34016.4 Electronics 34216.5 Archeometric Investigations 34416.5.1 Analytical Tasks 34416.5.2 Selection of an Appropriate Spectrometer 34616.5.3 Investigations of Coins 34716.5.4 Investigations of Painting Pigments 34916.6 Homogeneity Tests 35016.6.1 Analytical Task 35016.6.2 Homogeneity Studies Using Distribution Analysis 35116.6.3 Homogeneity Studies Using Multi-point Measurements 35217 Special Applications of the XRF 35517.1 High-Throughput Screening and Combinatorial Analysis 35517.1.1 High-Throughput Screening 35517.1.2 Combinatorial Analysis for Drug Development 35717.2 Chemometric Spectral Evaluation 35817.3 High-Resolution Spectroscopy for Speciation Analysis 36117.3.1 Analytical Task 36117.3.2 Instrument Technology 36117.3.3 Application Examples 36217.3.3.1 Analysis of Different Sulfur Compounds 36217.3.3.2 Speciation of Aluminum Inclusions in Steel 36317.3.3.3 Determination of SiO2 in SiC 36518 Process Control and Automation 36718.1 General Objectives 36718.2 Off-Line and At-Line Analysis 36918.2.1 Sample Supply and Analysis 36918.2.2 Automated Sample Preparation 37118.3 In-Line and On-Line Analysis 37619 Quality Management and Validation 37919.1 Motivation 37919.2 Validation 38019.2.1 Parameters 38419.2.2 Uncertainty 385Appendix A Tables 387Appendix B Important Information 419B.1 Coordinates of Main Manufacturers of Instruments and Preparation Tools 419B.2 Main Suppliers of Standard Materials 422B.2.1 Geological Materials and Metals 422B.2.2 Stratified Materials 423B.2.3 Polymer Standards 424B.2.4 High Purity Materials 424B.2.5 Precious Metal Alloys 425B.3 Important Websites 425B.3.1 Information About X-Ray Analytics and Fundamental Parameters 425B.3.2 Information About Reference Materials 426B.3.3 Scientific Journals 427B.4 Laws and Acts, Which Are Important for X-Ray Fluorescence 427B.4.1 Radiation Protection 427B.4.2 Regulations for Environmental Control 428B.4.3 Regulations for Performing Analysis 428B.4.4 Use of X-ray Fluorescence for the Chemical Analysis 428B.4.4.1 General Regulations 428B.4.4.2 Analysis of Minerals 429B.4.4.3 Analysis of Oils, Liquid Fuels, Grease 430B.4.4.4 Analysis of Solid Fuels 432B.4.4.5 Coating Analysis 433B.4.4.6 Metallurgy 433B.4.4.7 Analysis of Electronic Components 434References 435Index 453

X-ray fluorescence spectroscopy for laboratory applications is a strongly recommended, high-quality monograph in the field of X-ray spectroscopy. [?] [I]t is a unique resource for practitioners and scientists.Kerstin Leopold in Analytical and Bioanalytical Chemistry (29.07.2021)