The feasibility of using kinetic detection and simultaneous kinetic methods for the determination of species separated on thin-layer chromatographic plates has been explored. The proposed method was tested by monitoring the reaction of ninhydrin with leucine, isoleucine, and phenylalanine. The results obtained using three instruments (two scanning instruments and an imaging instrument) were compared. Although none of the instruments provided ideal results, the premise of the kinetic approach for the in situ quantification of analytes was shown to be valid. The possibility of using kinetic methods to resolve responses from overlapped species was also investigated, and shows promise for improving the overall resolution of thin-layer chromatographic methods. A discussion of the instrumental requirements for successful utilization of the kinetic detection method is also given.
Kinetic
-based determinations have become increasingly popular in recent years owing to the widespread availability of microcomputers for data acquisition and processing. Most enzyme determinations are accomplished by using some type of kinetic method, and a variety of nonenzymatic, catalytically-based kinetic determinations have been described [ 11. A distinguishing feature of all of these methods is that they have been done nearly exclusively in homogeneous solution. Guilbault and Zimmerman [2,3] have described a procedure for the determination of several enzymes on a solid medium; however, this kinetic method is still largely governed by solution-phase considerations. Hence, in this paper, a novel application of kinetic methods is proposed and evaluated in which rate methods are used as a means of detecting and quantifying analytes following separation by thin-layer chromatography (TLC ). The feasibility of kinetic resolution of coeluting species is also addressed. The determination of amino acids is required for a number of reasons in both clinical laboratories and biochemical research laboratories. Here, the development of an in situ, quantitative kinetic detection method for the determination of amino acids following separation on TLC plates is described. The