A Simple and Inexpensive Preparative TLC Applicator The purification of chemical mixtures often relies on preparative thin-layer chromatography. However, commercial applicators are expensive, and a survey of the literature on the suhject (J. CHEM. EDUC.and J . Chromotogr.) shows that the homemade ones can he elaborate to build and require some glssshlowing. Furthermore, thei~.utilization can he tedious.
The applicator which is used extensively in our laboratories and described here offers the advantages of low cost, rapid construction from commercial parts, and easy cleaning. Moreover, i t allows for the application of narrow streaks without holes or grooves, even when homemade plates are used. This applicator, held in the hand, is moved along the plate, the edge of the bench being used as aguide. The hole made in the plastic cup must he small enough t o hold the capillary firmly in place. A commercial disposable pipette (20 @I)that is easily bent with the flame of a match can he used as a capillary. P. Lavallee National Research Council OTtawa, Ontario. Canada K I A OR6
J. Muzart Labormire de Photochimie E.R.A. no. 688 Facuite des Sciences 51062 Reims, France
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Journal of Chemical Education
