A Convenient Method for Preparing Chromatography Columns
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We have found t h a t the usual design of flash chromatography pressure regulators, shown in the accompanying diagram, allows them t o he used as very convenient aids for the rapid filling of columns for Silica Gel chromatography. In particular, Still e t al.' recommend loading the column with dry Silica Gel, followed by flushing withsolvent, for best results in flash chromatography. All too frequently, the fine Silica Gel is carried about by air currents. This drifting dust is a health hazard if inhaled and a t best is a messy nuisance. This difficulty may be easily overcome, and columns Loaded more quickly, by the use of a flash chromatography adapter as described below. The column is clamped upright and a plug of glass wool (A) followed by a layer of sand (B)are placed in the column as usual. The outlet of the column (C) is then attached via a length of rubber tubing t o a source of vacuum, thus allowing a current of air to be drawn through the column. The flash chromatography adapter is placed on top. A piece of amber latex tuhing is attached t o the adapter's air The free end of the tuhing is dipped into the jar of Silica Gel. Covering the air outlet (El with inlet (D). a fineer .. causes the Silica Gel to be sweot into the column bv the stream of air. When a sufficient quantity of Silica Gel has been luaded. ;he free end of the t;bing is remwed from the jsr and the residual silica in the tubing is allowed t ~ he r carried inla the column. 'The source oivaruum is shut off, the tubing is removed from C and I) and the preparation of the column is completed in the usual
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A funher measure tocontnd siliradust that we have found effective ism hnrea hole. large enough toaccommodate the latex tuhing twithseveral millimeterr tuspare), in the plasticcap of the Silica Gel jar. The tubing rs fed through this hole when filling n ~ l u m n without s the cap having been removed. When not in use, thr hole is closrd with a cork.
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Stlii. W, C.; Kahn, M.; Mltra, A. J. Org. Chem. 1978, 43, 2923-2925. Stephen W. Wrlght and Ann S. Wrlght Medlcal Products Department, E. I. DuPont de Nemours, Inc.. Experimental Station Wllmington. DE 19880
Volume 67
Number 6
June 1990
517
