A Compact Easily Cleaned and Packed Column for Gas-liquid Partition Chromatography Instruments J. R. Carew, Chemical Physics Research Laboratory, The Dow Chemical Co., Midland, Mich. HE COLUMNS made of small diameter Ttubing as used in many gas-liquid partition chromatography instruments have certain disadvantages. The packing of long, small diameter columns is often a slow, tedious process, and the act of bending or otherwise manipulating the packed column may introduce changes in the column structure, which are difficult or impossible to reproduce exactly. Also conventional columns are not very robust and are difficult to heat uniformly. The packing and bending, or shaping
of a 3/~-inch diameter column of 10foot length requires 3 hours. The grooved plate column required 1 hour for packing and assembly. Also, it can be rapidly dismantled, cleaned, and packed with no special equipment or technique. No trouble has been experienced with leaks or loosened packing. It is useful where column length must be restricted because of lack of room, to organizations that use a number of different packings and must keep their cost down, and to those that find i t costly to discard the tubing when the
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MACHlNG COVEROF 3/8X
TAPPED
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packing becomes contaminated. Also if the packing cannot be duplicated, it can be reclaimed and re-used. The grooved plate column consists of two 3/p X 7 X 4 "18 inch brass plates and a l/16 X 7 X 4 5,'~6 inch Teflon gasket, fastened with 29 S o . 8 cap screws. One plate, the cover, is machined flat. The other plate (Figure 1 ) has a continuous groove, inch wide X inch deep, machined in it, working from one side to the other and leaving a l/aZ-inch wall between grooves. The total groove length is approxi-
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y i BRASS
W I T H BODY HOLES T O MATCH MAIN BLOCK
CHROMATOGRAPHY C O L U M N
SPECT. L A O . D O W CHEM. C O . SCALE
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Figure 1.
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ANALYTICAL CHEMISTRY
Drawing of grooved plate
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