Brother Joseph M. wakh
College of Santa Fe Sonto Fe, New Mexico
A Simple Apparatus for Scoring TLC Plates
The scoring of thin-layer chromatography plates breaks the surface of the adsorbent and prevents lateral movement of the sample during development. Thus, samples spotted as close as 5 mm to each ot,her can be readily developed without running into each other; however, more practical distances would be 1-2 cm. Recently, in THIS JOURNAL,^ a method for scoring narrow width plates was present,ed. An apparatus for scoring the larger (20 X 20 em) plates, as well as the narrower ones, is described here. As indicated in the illustrution, the plastic sheet2 (26 X 21.5 X 0.6 cm) is supported on plastic or glass rods (7-8 mm od) and has a series of ,125-in. (or 3-mm) holes drilled 1 cm apart and 2 cm from one edge of the plastic sheet. The apparat,us is placed over the TLC plate in such a way that the plate is flush with the supporting rod. The minimal contact of the supporthg rod with both the table surface and the edge of the glass plate permits much easier sliding than if a rectangular support were used. The scoring is done by S o . 4 finishing nails with the heads cut off 3 cm from the pointed ends. The headless nails are inserted in thr holes, their weight being sufficient to breuk the surface 'MILLER,F. W., J. CHEM.EDOC., 43, 29 (1066). Obtained from Industt.ial Art,%and S~lpplyCO., 3002 Hennepin Ave., Minneapolis 8, Minn.
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Journal o f Chemicol Education
of the TLC plate. The relative motion of apparatus to the TLC plate then produces evenly scored lines on the plate. At the end of the operation the plastic sheet is raised and the nails fall through.
Diogrom of apparatus for scoring TLC plates
