Applied thin-layer chromatography : best practice and avoidance of mistakes
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Bibliographic Information
Applied thin-layer chromatography : best practice and avoidance of mistakes
Wiley-VCH,, c2007
2nd rev. and enl. ed
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Dünnschicht-Chromatographie
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Note
Previous ed.: 2000
Includes bibliographical references and index
Description and Table of Contents
Description
Thin-layer chromatography (TLC) is a powerful, fast and inexpensive analytical method. It has proven its usefulness in pharmaceutical, food and environmental analysis. This new edition of the practical TLC guide features a completely revised chapter on documentation, now including the use of digital cameras. Selected new sorbents and instruments are also introduced.
Why has the prior edition been successful? All steps of the analytical procedure are clearly explained, starting with the choice of a suitable TLC technique and ending with data evaluation and documentation. Special emphasis is put on the proper choice of materials for TLC. Properties and functions of various materials and the TLC equipment are described, covering e.g. precoated layers, solvents and developing chambers, including information on suppliers. Many practical hints for trouble shooting are given. All this is illustrated with numerous coloured figures.
How to use TLC in compliance with GLP/GMP regulations is described in detail, including the required documentation. Therefore the reader can very easily compile his own standard operating procedures.
Table of Contents
1 Introduction 1
1.1 What Does TLCMean? 1
1.2 When Is TLC Used? 2
1.3 Where Is TLC Used? 3
1.4 How Is the Result of a TLC Represented? 4
1.5 What Kinds of Reference Substances Are Used in TLC? 8
1.6 The Literature on TLC 9
2 Precoated Layers 15
2.1 Precoated Layers--Why? 15
2.2 What Are Precoated Layers Produced? 16
2.3 What Types of Precoated Layers Are There? 21
2.4 What Are the Uses of Precoated Layers? 27
2.5 Criteria for the Selection of Stationary Phases in TLC 27
2.6 Effect of the Stationary Phase When Mobile Phases Are Identical 30
2.7 Advice on the Ordering and Storage of Precoated Layers 31
2.8 Problems in the Naming and Arrangement of Precoated Layers 33
3 Before the TLC Development Process 35
3.1 Handling of Precoated Layers 35
3.2 Prewashing 41
3.3 Activation 43
3.4 Conditioning 44
3.5 Impregnation 46
3.6 Application of Samples 50
3.7 Positioning of the Samples 65
3.8 Drying Before the Development 67
4 Solvent Systems, Developing Chambers and Development 69
4.1 Solvent Systems 69
4.2 TLC Developing Chambers 87
4.3 Development of Thin-Layer Chromatograms 99
4.4 Drying After Development 111
5 Evaluation Without Derivatization 113
5.1 Direct Visual Evaluation 113
5.2 Direct Optical Evaluation Using Instruments 116
5.3 Diode-Array Detection 120
5.4 Coupled Methods for Substance Identification 122
5.5 Documentation Without or Before Derivatization 123
6 Derivatization 125
6.1 Thermochemical Reaction 126
6.2 Irradiation with High-Energy Light 127
6.3 Reaction with Reagents 129
6.4 Special Cases of Derivatization 143
6.5 Further Treatment of Derivatized Chromatograms 148
7 Evaluation After Derivatization 153
7.1 Visual Evaluation 153
7.2 Evaluation Using a TLC Scanner 154
7.3 Evaluation Using a Video System 174
7.4 Evaluation by Flat-Bed Scanner 178
7.5 Evaluation Using a Digital Camera 178
8 Documentation 181
8.1 Description of a Thin-Layer Chromatogram 181
8.2 Documentation by Drawing, Tracing and Photocopying 182
8.3 Photographic Documentation 183
8.4 Video Documentation 188
8.5 DocumentationWith Digital Cameras 198
8.6 TLC Scanner Documentation 199
8.7 Flat-Bed Scanner Documentation 199
8.8 BioluminescenceMeasurements 200
9 GMP/GLP-Conforming Operations in TLC 203
9.1 Validation of TLC Methods 207
9.2 Use of Qualified/Calibrated Equipment 211
9.3 GMP/GLP-Conforming Raw Data Sheets 214
9.4 Examples of GMP/GLP-Conforming Testing Procedures (TPs) 223
10 Effects of Stress 241
10.1 Controlled Stress on a Substance 241
10.2 TLC-Sensitive Substances 242
11 Special Methods in TLC 247
11.1 AMD -- AutomatedMultiple Development 247
11.2 OPLC -- Overpressured Layer Chromatography 248
11.3 HPPLC -- High Pressure Planar Liquid Chromatography 249
11.4 TLC-FID/FTID -- Combination of TLC and Flame-Ionization Detector or Flame-Thermionic Ionization Detector 249
11.5 TLC-NDIR 250
11.6 RPC -- Rotation Planar Chromatography 252
12 Appendix 253
12.1 CHROMart 253
12.2 References 255
12.3 Abbreviations 263
12.4 Acknowledgements 267
12.5 Market Overview 268
Photograph Section 271
Subject Index 309
List of Tables
Table 1: Types of sorbents and supports for precoated layers 18
Table 2: Meanings of code letters and numbers in product designations 19
Table 3a: Important commercially available precoated layers and examples of typical applications 22--23
Table 3b: New precoated layers 23
Table 4: Peppermint oil (Oleum menthae piperitae) 24
Table 5: Production of constant humidity in closed vessels 44
Table 6: Greater Celandine (Chelidonium majus L.) 49
Table 7: Semiautomatic application using the Linomat IV 59
Table 8: Eluotropic Series 71
Table 9: Carbamazepine 75
Table 10: Birch leaves (Betulae folium) 76
Table 11: Primula root (Primulae radix) 77
Table 12: Liquorice root (Liquiritiae radix) 78
Table 13: Solvent requirements for different TLC separation chambers 81
Table 14: Dry extract of nettle root (Urticae radix) 83
Table 15: Spironolactone and furosemide 85
Table 16: Theophylline, theobromine, caffeine 86
Table 17: Influence of the chamber atmosphere as shown with different samples of greater celandine 93
Table 18: Sugar 102--103
Table 19: Coneflower (Echinacea) 136--137
Table 20: Comparison of parallel measurement with transverse 166
Table 21: Comparison of semiquantitative visual and quantitative video evaluation of Figure 69 176
Table 22: Assay of Caffeine [%] in various samples of coffee and tea 177
Table 23: Photographic documentation using single lens reflex cameras 184
Table 24: Fundamental guidelines according to the ICH 207
Table 25: Qualities of solvents 224
Table 26: Benchmarking between HPLC and HPTLC for assay of theophylline tablets 225
by "Nielsen BookData"
