Diffusion cell with recirculating receptor chamber

An automated system of diffusion cells, comprising:

• a plurality of diffusion cells, each diffusion cell comprising
• a receptor chamber having an upper end and a lower end opposite the upper end;
• a membrane in contact with the receptor chamber;
• a conduit having a first port near, and in fluid communication with, the lower end of the receptor chamber and a second port above the first port, the second port being near, and in fluid communication with, the upper end of the receptor chamber;
• a bubble trap in fluid communication with the upper end of the receptor chamber and having a third port positioned higher than the second port of the conduit;
• an auger disposed in the receptor chamber;
• and
• a stir bar disposed in the receptor chamber and adapted to drive the auger,
• wherein the auger driven by the stir bar causes a flow of fluid to recirculate through the conduit and the receptor chamber, whereby at least a portion of the flow of fluid is transmitted from the receptor chamber through the conduit and back into the receptor chamber, and
• wherein recirculation of the at least a portion of the flow of fluid through the conduit and the receptor chamber removes at least some bubbles from near the membrane in the receptor chamber and transports at least some of said bubbles from the receptor chamber to the bubble trap.

An apparatus for removing bubbles from a diffusion cell, comprising:

• a conduit having a first port near, and in fluid communication with a lower end of a receptor chamber and a second port above the first port, the second port being near, and in fluid communication with, an upper end of the receptor chamber;
• and
• a bubble trap in fluid communication with the upper end of the receptor chamber and having a third port positioned higher than the second port of the conduit,
• wherein circulation of a flow of fluid through the conduit and the receptor chamber removes at least some bubbles from the receptor chamber and transports at least some of said bubbles from the receptor chamber to the bubble trap.