Electrolyte Solution Heating Element for Steam Microbath A L E X A N D E R P. M A R I O N , Queens College, Flushing, N. Y.
has an automatic cutoff feature and requires no external transformer or resistance control.
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The apparatus is a vessel of about 200-ml. capacity covered by a metal water bath adapter through which the electrodes pass. The electrodes are two pieces of No. 12 copper wire bared for a length of 4 cm. and insulated from the adapter by Lucite bushings. The wires fit snugly into holes drilled through the Lucite. One of the bushings is cut t o permit the electrode to be partially raised out of the solution, thereby altenng the effective size of the electrode. Two parallel grooves, each the thickness of the metal plate and 1 cm. apart, are cut in a 2.5-cm. length of 0.94cm. (0.375-inch) diameter Lucite rod. The section below the uppermost groove is then filed to have two parallel flat faces, the material down to the depth of the groove being removed. The opening in the metal plate is made by drillin a hole and filing until the lower end of this bushing will pass &rough. Then by
Semimicro Ion-Exchange Column American Home
N O R M A N APPLEZWEIG Products Corporation, Products Development Laboratory, 454 West B l s t St., N e w York, N. Y.
capacity - of exchangers and recovery data it was found expedient
column and providing an oyerflow tube.
to use small quantities of exchange materials. The ion-exchange columns recommended by investigators in the waterconditioning field (1-4) were found to be oversized (200- to 1000-ml. exchanger beds) and cumbersome to operate. A need was felt for a column which would hold from 5 to 20 ml. of exchanger and could easily be assembled, backwashed, or connected in series with another column. Such an apparatus was constructed by using a 9-mm. standard Kimble condenser tube measuring 42.5 cm. long when the beveled end had been cut off. A plug of glass wool was inserted a t the bottom and a three-way stopcock was attached by means of a rubber stopper. A complete assembly of two columns is shown in Figure 1. The solution to be run enters C1 by means of a funnel and constant-head device. After flowing through the exchange bed in the first column it passes to the second by means of a tube leading from B1to C2. Samples from the first column may be taken a t any time through A' by turning the stopcock.
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Even a t moderately rapid backwash rates the exchangers remained suspended in the wide part of the tube a t CY? and showed no tendency to be spilled over. N o trouble was caused by entrapped air, as is usual in larger columns. Flow rates could be adjusted with fair accuracy over a wide range. Where necessary, the tube may be calibrated to study bed volume changes. This apparatus has been found useful in studies on the ion-exchange adsorption and recovery of alkaloids, amino acids, and other organic compounds. LITERATURE CITED
Figure I 82
(1) Am. Water Works Assoc., "Tentative Methods for Examination of Zeolites", 1940. ( 2 ) Bur. Mines, Bull. R.I.3559 (1941). (3) Myers, R. J., Eastes, J. W., and Mvers. F. J.. IND.ENQ.CHEM.,33, - -" 697 ( i b i ) . (4) Permutit Co., "Operating Directions for Permutit Zeo-Karb H Laboratory Tests", New York, 1942.
