Sister Helene Ven Horrt, Helen Ven Horst, and Karen O'Connor Morycrest College Davenport, iowo
A Technique for Packing Columns for Gas Chromatography
The problem of packing columns for use in gas chromatography can become a tedious and timeconsuming one when the operation is performed manually. In order to eliminate this difficulty, a simple device has been designed which is easily constructed from readily-procured pieces of apparatus and which provides for packing either a sinele column or two columns simultaneously. In Figure 1the following parts are identified. Part A is the motor and shaft of a record player mounted vertically on angle irons which are fastened to the seat of a laboratory stool. Part B is a thin metal disc, 6 in. in diameter, mounted on the shaft of the motor. A similar disc is mounted opposite this one and is connected by a 2-in. shaft, 11/, in. off center. This shaft has on it a wooden spool from a spool of sewing thread. The metal rod of the shaft is small enough so that the spool easily rolls when the disc is rotated. Mounted on the outside edge of the second disc and Figure 1. Apparatus designed 180°from the position of the for fillino rinale column; A. C, spool is a 21/rin. length of motor; B, bar solder. indicated as nart D, jacket. C in the picture. Part D is a 45-in. piece of '/,-in. copper tubing, which has a 21/2-in. side arm of the same tubing welded a t 90' and in a position 32 in. from the lower end. This tube has a rubber covering at the base for the Purpose of absorbing some of the sound. Two small ring clamps guide the jacket, one mounted on the lowest rung of the stool about 6 in. above the floor, and the second on the top of the stool, 24 in. above the floor. Inside this tube is placed the 4-ft.-long, '/ain. tube which has previously been plugged a t the lower end with a wad of glass wool. A small plastic funnel is fastened to the upper end with a piece of rubber tubing. When the motor is started, the disc rotates, lifting up the jacket and column and raising them about 3 in.
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above the floor. The rate of lifting is 78 times per minute. The spool carrying the jacket rolls under the side arm until it reaches the end, causing the jacket and its contents to drop to the floor. The heavy load which is being lifted is counterbalanced by the piece of bar solder mounted opposite the spool. The only manual work necessarv is neriodicallv to add the substance which is being &ed fill the cb~umn. The apparatus is modified slightly in such cases where it is desirable to fill two columns simultaneously. I n Figure 2 the leverage system is made of 1/2-in. strap iron and mounted to a second jacket, similar to the one described above. As the spool makes its path downward, it depresses lever E, raising the jacket. As the
Figure 2.
E, lever
Apporatur designed for Rlling two columns ~imulfoneoudy
spool rolls off this lever, the jacket will drop to the floor giving the same type of motion as was accomplished in the other jacket. A comparison was made between the columns which were filled manually and those which were filled by means of this technique. I n both cases the flow rate of helium through the columns was the same for the same external pressure of the gas. The efficiency of the columns was also identical. Since this problem of packing columns can be a noticeis done by more than able variable when the one individual, this piece of apparatushas been of advantage both in achieving in packing and in saving time. Acknowledgment is due to John H. Ven Horst for his assistance in constructing the apparatus.
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Erratum
The price of MCA's "Matter, Energy ttnd Change" as quoted on page 445 of the September issue is in error. It should read ' 7 2 cents per copy, no discount on quantity order." Write Halt, Rinehart and Winston, Inc., 383 Madison Ave., New York 17, N. Y .
Volume 37, Number 7 1, November 1960
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