An Inexpensive -preparative TLC Applicator The application of long even sample streaks is required for optimum resolution in preparative thin layer ehromatography. Commercial instruments for this purpose are expensive ( ~ $ 4 0 0 )and hand-spotting with a syringe is a tedious operation which often yields uneven streaks. We have found that a suitable applicator giving continuous streaks up to 10 cm long can he made from a strip of ordinary staples. A streak of epoxy cement (We used Duro E-pox-E cement and filler) is applied to the inside surface of the staple strip so that one arm and approximately half of the adjoining inner face are covered over the entire length of the strip. After the cement has hardened, the uncemented half of the staple strip is moistened with acetone. This lwsens the adhesive binder which is carefully peeled from the outside surface of the uncemented portion of the strip. The uncemented half of the strip is now a series of fine capillaries and, depending on the length of staple strip selected, can be used to apply streaks of any length up to 10em. The applicator edge runs along the outside of the rounded corner of the staples. The applicator may be loaded by dipping the applicator edge briefly in the sample solution. (A Fisher Scoopula with the ends bent up makes a suitable trough for containing the solution.) The applicator edge is then lightly touched to the tle surface to produce the desired streak. The applicator works equally well for preparative paper chromatography or electrophoresis.
Howard C. Price Marshall University Huntington, West Virginia 25701
Volume 51. Number4, April 1974
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