ICP Emission Spectrometry

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 ixPreface xi1 An Overview 11.1 Features of ICP-OES 11.2 Inductively Coupled Plasma Optical Emission Spectrometry – the Name Describes the Technique 21.3 Distribution of ICP-OES 41.4 Related Techniques for Elemental Analysis 41.5 Terms 82 Plasma 92.1 The Spectrometric Plasma 92.1.1 The Operating Gas 102.1.1.1 Argon 102.1.1.2 Addition of Air or Oxygen 112.1.2 Plasma Torch 122.1.3 Ignition of the Plasma 152.1.4 Orientation of the Plasma with Respect to the Torch 152.2 Excitation to Emit Electromagnetic Radiation (Light) 162.2.1 Emission Lines 162.2.2 Energy and Temperature 192.2.3 Spectroscopic Properties of the ICP 222.2.4 Plasma Viewing 282.2.4.1 Radial Viewing 292.2.4.2 Axial Viewing 302.2.4.3 Radial and Axial Viewing in One Instrument (“Dual View”) 312.3 Excitation Unit 352.3.1 Radio Frequency Generator 352.3.2 Induction Coil 382.4 Sample Introduction System 38 2.4.1 Nebulizer 402.4.1.1 Pneumatic Nebulizers 412.4.1.2 High-Pressure Nebulizer 452.4.1.3 Ultrasonic Nebulizer 462.4.2 Nebulizer Chamber 482.4.2.1 Tasks of the Nebulizer Chamber 482.4.2.2 Temperature of the Nebulizer Chamber 492.4.2.3 Materials and Surface Properties 522.4.2.4 Common Types of Nebulizer Chambers 542.4.2.5 Waste from the Nebulizer Chamber 552.4.3 Pump 562.4.4 Other Forms of Sample Introduction 592.4.4.1 Special Techniques for Liquid Samples 602.4.4.2 Gaseous Samples 602.4.4.3 Solid Sampling 633 Optics and Detector of the Spectrometer 673.1 Basic Principles of Optics 673.1.1 Resolution 673.1.2 Relevant Optical Terms 723.1.3 Optical Mounts 763.1.3.1 Paschen–Runge Mount 763.1.3.2 Czerny–TurnerMount 763.1.3.3 Echelle Mount 783.1.3.4 Littrow Mount 803.1.4 Light Transfer from the Plasma to the Optics 803.1.4.1 Separation of Plasma Compartment and Optics 803.1.4.2 Transparency of the Optics in the Vacuum-UV Range 823.2 Detectors 853.2.1 Photomultiplier Tube (PMT) 863.2.2 Solid-State Detectors 873.3 Types of Emission Spectrometer Mounts 953.3.1 Classical Spectrometers 963.3.1.1 Monochromators 963.3.1.2 Polychromators 963.3.2 Array Spectrometers 973.3.2.1 Scanning Array Spectrometers 973.3.2.2 Simultaneous Array Spectrometers 974 Method Development 994.1 Wavelength Selection 1014.1.1 Working Range 1014.1.1.1 Background Equivalent Concentration (BEC) 1024.1.2 Freedom from Spectral Interference 1034.1.2.1 Generation of Spectra for the Estimation of the Background 1074.1.2.2 Generation of Spectra for Detecting Interfering Lines from the Matrix 1114.1.2.3 Evaluating Spectra 1144.2 Processing and Correction Techniques 1174.2.1 Signal Processing 1174.2.1.1 Calculation of the Peak Height 1174.2.1.2 Calculation of the Peak Area or of the Partial Peak Area 1194.2.1.3 Calibration of the Peak Position 1224.2.2 Background Correction 1234.2.2.1 Calculation of the Background Correction 1264.2.2.2 Number the Background Correction Points 1284.2.3 Impact of Peak Processing and Background Correction on Detection Limits 1324.2.4 Correction of Spectral Interference 1374.2.4.1 Inter-element Correction 1374.2.4.2 Correction Using Multivariate Regression 1384.2.4.3 Multivariate Regression and Inter-element Correction 1474.3 Non-spectral Interference 1474.3.1 Correction of Non-spectral Interference 1484.3.1.1 Matrix Matching 1484.3.1.2 Internal Standard 1494.3.1.3 Calibration with Analyte Addition (Standard Addition) 1514.3.1.4 Further Measures to Compensate for Non-spectral Interference 1534.4 Optimization 1534.4.1 Optimization Goals 1544.4.2 Optimization Parameters 1554.4.3 Optimization Algorithms 1554.5 Validation 1574.5.1 Accuracy and Specificity 1574.5.2 Reproducibility 1594.5.3 Limit of Detection 1604.5.4 Working Range 1644.5.5 Robustness 1665 Routine Analysis 1695.1 Preparation 1695.1.1 Sample Preparation 1695.1.2 Warm-up Time 1705.1.3 Delay and Rinse Times 1715.2 Calibration 1735.2.1 Calibration Solutions 1735.2.1.1 Number of Calibration Solutions 1735.2.1.2 Concentrations in Calibration Solutions 1745.2.1.3 Multielement Calibration Solutions 1765.2.1.4 Multi-bottle Calibration 1765.2.1.5 Stability of Calibration Solutions 1775.2.2 Calibration Functions 1775.2.2.1 External Calibration 1785.2.2.2 Calibration by Analyte Addition (Standard Addition) 1795.2.2.3 Bracketing Calibration 1795.2.3 Examination of the Calibration Data 1815.3 Quality Assurance 1825.4 Software and Data Processing 1846 Troubleshooting and Maintenance 1877 Applications 1977.1 General Notes 1977.1.1 Material of Containers 1977.1.2 Stability of Solutions 1977.1.3 Matrix Effects 1987.1.4 Contaminations 1987.2 Comments on Selected Elements 1987.3 Selected Applications 2007.3.1 Environment 2017.3.1.1 Drinking, Ground, and SurfaceWater 2027.3.1.2 Wastewater, Leachates 2027.3.1.3 Sludges 2047.3.1.4 Soil Samples, Sediments 2047.3.1.5 Airborne Particles, Fly Ashes 2057.3.2 Samples of Biological Origin 2067.3.2.1 Plant and Animal Samples 2067.3.2.2 Clinical and Forensic Materials 2077.3.2.3 Food and Animal Feeds 2087.3.3 Geological Materials 2087.3.4 Metallurgy 2107.3.4.1 Steel and Iron Matrices 2107.3.4.2 Nonferrous Metals 2127.3.4.3 Noble Metals 2127.3.4.4 Special Alloys 2127.3.5 Material Sciences 2137.3.5.1 Semiconductors 2137.3.5.2 Ceramics 2157.3.6 Industrial Applications 2157.3.6.1 Industrial Chemicals and Fertilizers 2157.3.6.2 Galvanizing/Electroplating Baths 2167.3.6.3 Brines and Salts 2167.3.6.4 Cement, Gypsum, Calcium Matrix 2167.3.6.5 Glass 2177.3.6.6 Other Industrial Applications 2187.3.7 Organic Solvents 2187.3.7.1 Wear Metals and Contamination in Oil 2217.3.7.2 Additives 2237.3.7.3 Tar 2237.3.7.4 Edible Oils 2238 Procurement of Equipment and Preparation of the Laboratory 2258.1 Which Atomic Spectrometric Technique is the Most Suitable? 2258.2 Which ICP Emission Spectrometer is the Most Suitable? 2278.3 Preparation of the Laboratory 230References 233Index 269