V O L U M E 2 8 , NO. 6, J U N E 1 9 5 6
1063
LITERATURE CITED
(1) Bowman, R. L., Caulfield, P. A,, Udenfriend, S., Science 122, 32 (1955). ( 2 ) Burdett, R. A., Jones, L. C., J . O p t . SOC.Amer. 37, 554 (1947). (3) Germann, F. E. E., Brown. F. T., Wissell, R., Waugh, T. D., Science 120, 540 (1954). (4) Gornall, A. G., Kalant, H., ANAL.CHEN.27, 474 (1955). (5) Huke, F. B., Heidel, R. H., Fassel, V. A., J . O p t . SOC.Amer. 4 3 , 400 (1953). (6) Lauer, J. L., Rosenbaum, E. J., Ibid.,41,450 (1951). (7) McAnally, J. S., A x . 4 ~CHEM. . 26, 1526 (1954).
Buffer flow rate is controlled by a constant buffer level and a system of wicks. The following modifications of this apparatus allow controlled temperature, regulated current by control of pH and conductivity of buffer in electrode vessels, and easy manipulation of sample tubes.
Modiflcation of Continuous Electrophoresis Apparatus Ernil R. Adamik, National Institute of Arthritis and Metabolic Diseases, National Institutes of Health, Bethesda, Md.
apparatus described by Saroff [Nature 896 (1955)] T for continuous electrophoresis employs a sheet of filter paper wrapped around a cylindrical jar containing the buffer solution. 175,
HE
Figure 3.
Top view of plate (0)
The temperature of the apparatus is maintained constant by circulating water a t constant temperature through coil A (Figure 1). Cooling the apparatus necessitates the removal of condensate from the bottom of the buffer cylinder, K. This removal is accomplished by the filter paper, L, and wicks, M , as illustrated (Figure 1). Conductivity and p H changes of the buffer in the electrode vessels are controlled by mixing of the buffer in the vessels by means of the two air-lift pumps, B, in a common reservoir, C (Figure 2). The air-lift pump system is arranged to prevent the flow of electricity through the exchange system. The air-lift pump traps a small volume of buffer, pushes it up through tubing, which is relatively perpendicular, and discharges the buffer into the electrode vessels. Overflow tubes then feed the buffer back to reservoir, C . (In long runs, the reservoir may be cooled for control of bacterial growth.) A Lucite plate, D,with funnel-shaped holes, E (Figures 1 and 3), is held a t proper height above a false base, F , by means of a short cylinder, G, of Lucite permitting easy access to wick threads H for changing collecting bottles I and taking test samples during a run. Threads H used to carry sample from paper 0 to collecting bottles I pass through the funnel-shaped holes, E, and are knotted above and below the plate to prevent accidental detachment from the paper. Figure 1. Continuous electrophoresis apparatus
Apparatus for Automatically Increasing Solvent Polarity in Partition Chromatography Earl J. Roberts and Austin Mason, Southern Regional Research Laboratory, New Orleans, La.
chromatography on columns of adsorbents has found E wide application in the separation of small quantities of materials. The development of automatic fraction-collecting LUTION
Figure 2.
Circulating system for buffer in electrode vessels
devices has done much to eliminate the tedium of manual operation. However, certain types of partition chromatography, such as those described by Claborn and Patterson (I), Marvel and Rands (4), and Higuchi, Hill, and Corcoran (S),in which a series of solvents of increasing polarity is employed, still require constant attention, because the solvent must be changed manually. Donaldson, Tulane, and Marshall ( 2 ) have described an apparatus for automatically increasing the solvent polarity by allowing a mixture of a polar and a nonpolar solvent contained in a reservoir to flow into a mixing chamber containing only the nonpolar solvent. The effluent from the mixing chamber increases logarithmically in polarity and approaches the composition of the solvent in the reservoir as a limit. This method is
