RADIOACTIVE
INSTRUMENTATION GAS O U T L E T
TIJHt CONSTANT PRESSURE RESERVOIR
COLLECTION
TUBES
Figure 3. Flow arrangement feeding the electrophoresis curtain and electrode channels in the CPE
. . . and dozens of other radioisotopes f r o m s t o c k WITH THE RANGE OF SPECIFIC ACTIVITY you r e q u i r e — H i g h Specific Activity, Intermediate Specific Activity, L o w Specific A c t i v i t y — a l l listed in your free copy of the NSEC Radioactive Materials catalog . . . w r i t e for it.
NSEC
Nuclear Science Division of International Chemical & Nuclear Corp. P. O. Box 10901-Pittsburgh, Pa. 15236 Phone 412-462-4000 Circle No. 184 on Readers' Service Card
104 A
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ANALYTICAL CHEMISTRY
toward the anode at the right. The sample introduction tube is positioned in the left half of the cell to more fully utilize the curtain width. Figure 3 illustrates the flow arrangement feeding the electrophoresis curtain and electrode channels. Electrolyte buffer solution flows from a supply container to a variable speed peristaltic pump which forces the electrolyte through a microporous filter, removing any particulate matter from the solution. From the filter the electrolyte passes to a constant level reservoir. Excess solution returns, via an overflow drain, to the supply container. The duct to the cell passes through a metering valve and flow meter and admits curtain electrolyte at the top of the cell. An air release vent at the top of the cell allows air to escape when the cell is being filled. Within the cell, the electrolyte descends as a highly stable curtain and empties at the bottom into 48 tubes. The electrode rinse solution usually has the same composition as the curtain solution but is separated from the curtain solution by a membrane in each electrode chamber. The electrode rinse solution is continuously recirculated from an electrode rinse supply container by a pump. Rinse solution enters a constant pressure reservoir. From this reservoir, it is passed through the electrode chamber and back to the electrode rinse supply container. Characteristics which in many respects are unique, include a sample handling capacity of 200 microliters per minute and a response time of about three minutes. The latter is equivalent to the vertical transit time of particles through the cell. The system readily separates homogeneous components differing by as little as 5 to 10% in mobility. The voltage gradient is stable to 1%. Band deflections
are stable to within 1 to 2% short term and 3 % long term. The voltage gradient is adjustable between 10 to 120 volts per centimeter. The cell is easily taken apart and reassembled for use in a few minutes. Meters and monitors indicate voltage gradient, total applied voltage, current and flow rate. Some applications of this instrument include the fractionation of biological mixtures such as nuclei, mitochondria, microsomes, whole tissue cells, blood cells, bacteria, and viruses. Relative electrophoretic mobilities of importance in immunology, and colloid investigations, such as the study of detergents and water clarification, and the study of surface phenomena and structure are possible. Other applications are the separation and collection of mineral components in natural clays ; fractionation of mixed colloidal carbon samples and the separation of polymer microbeads having different adsorbed substances. Wo suspect that the latter application might offer extensive and exciting possibilities. The study of particle surface phenomena and structure includes adsorption and desorption, ionization, ion exchange, and surface chemical reactions. Fields of endeavor in which the technique can also be applied are water clarification, soil stability, and the manufacture of ceramics, refractories, paints, inks, adhesives, and pharmaceuticals. In our opinion, the development of this instrument will lead to many useful and unexpected applications. As always, we contend that well known and well understood phenomena have been and will continue to be instrumented to the limit and almost without regard to cost. Beyond this, new vistas and unsuspected treasures lie. He who does not believe this should re-read the tales and adventures of the three Princes of Serendip. Circle No. 143 on Readers' Service Card
