Thin-Layer Chromatography

This volume is the second of a series of practice-orientated TLC/HPTLC books published by VCH. As in the first volume, a series of reagents and detection methods have been reviewed with the intention of helping the practical analysit increase the detection specificity. This volume is divided into two parts which eencompass about the same amount of material as Volume 1a. Thus part 1 begins with specific detection methods including the known photochemical, thermochemical and electrochemical activation methods. Here microchemical reactions are described that are caried out without the use of reagents. Detection involves the use of light, heat and electric current. Then follows a selection of group-specific reagents, in response to requests from practical workers after the publication of Volume 1a. This part should be seen in reference to the monograph that follow or have already been published. The section on "Reaction Series" has also been included at the request of practitioners. There are many publications describing the application of a series of different reagents to the same chromatogram.
Reagents intended for the preparatory reaction of certain substances so that the final reagent applied can yield specific detection results are dealt with in this volume. Independnent reagents, each capable of detection, combined on the same chromatogram to increase selectivity, for example by specifically altering certain colours (= potentiated multi-detection) will be treated in Volume 1c. Such combinaitons are frequently used in the fileds of clinical and forensic chemistry and in the analysis of natural product extras. Part 1, which contains tested examples together with more than 220 literature references, is followed by Part 2; this consists of 65 reagent monographs in alphabetical order. Once again, each includes an example that has been tested in the laboratory and is supplemented by numerous literature references. In the past it is just these references that have helped provide the practical worker with an entry to the earlier literature. Great importance has been attached to the inclusion of original chroatograms in the examples tested along with absorption photometric or fluorometric scans.
These show at a glance that modern thin-layer chromatography is a microanalyticial separation method that should be taken seriously and that its development certainly conforms to the state of the analytical art. Particular attention has been devoted to the compilation of the cumulative index. Every reference work is only as good as its indexing system. For this reason, a presentation has been chosed which allones one to recognize immediately in which volume the key work appears. The same also applies to named reagents which can be traced back to the original publication in almost all cases in order to be able to correct any errors that have crept in. This type of presentation will be used in future volumes. This volume includes a new feature in the collection of reagents into groups that are discussed comparatively. Such groups include the chloramine T, the diaminobenzaldehyde or the vanillan reagents. The iodine reagents are also dealth with as a group. A similar comparison of the Dragendorff or the ninhydrin reagents will follow in Volume 1c.