PRELIMINARY-RESULTS OF A COLLABORATIVE STUDY OF OVERPRESSURED DERIVATIZATION

Of the steps involved in planar chromatography, derivatization appears to be most subject to the human factor - the other stages of the tech nique - sample application, development, and photodensitometric detect ion - are increasingly being performed by instrumental methods. During the last three years, a new process of derivatization, over-pressured derivatization, has been developed in our research laboratory. This t echnique entails pressing a pad of polymeric foam containing the react ive solution on to the chromatographic plate in order to obtain homoge neous and complete distribution of the reagent over the whole plate. T his paper presents the first results of a collaborative study performe d by a group of European industrial and university laboratories in ord er to evaluate and then perfect this technique. The present stage of o ur study is a comparison of the application of spraying, dipping, and overpressured derivatization to the analysis of amino acids, sugars, a nd other compounds.