Degassing liquid eluent of a preparative SFC fluid chromatography system
Methods, systems and apparatus are provided for degassing a supersaturated solution. An example degasser is described having a continuous body of gas-permeable tubing to remove an amount of a gas from the supersaturated solution below the gas's saturation point in the supersaturated solution. The degasser can be connected to at least one of a fraction collector or a detector. The example degasser is sized and/or positioned to cause a change in pressure (ΔP) across the degasser to drive removal of a dissolved gas from a supersaturated solution passing through the degasser. As a result of the reduction of gas, efficiencies in system flow and fraction collection are achieved.
1. A degasser for removing gas from a supersaturated solution, comprising:
(i) a continuous body of gas-permeable tubing having an interior portion and an exterior portion and an inlet and an outlet for conducting the supersaturated solution through the continuous body of gas-permeable tubing; and
(ii) a fraction collector in direct fluid communication with the outlet of the continuous body of gas-permeable tubing, wherein the degasser removes a portion of the gas below the saturation point of the gas in the supersaturated solution.
2. The degasser of claim 1 , wherein a partial pressure of a component of the supersaturated solution decreases between the inlet and the outlet of the continuous body of gas-permeable tubing.
3. The degasser of claim 1 , wherein the continuous body of gas-permeable tubing is comprised of a polymeric material.
4. The degasser of claim 3 , wherein the continuous body of gas-permeable tubing is formed from a material which expands upon intake of the supersaturated solution.
5. The degasser of claim 1 , wherein a change in pressure occurs between the interior portion and exterior portion of the continuous body of gas-permeable tubing.
6. The degasser of claim 1 , wherein the gas-permeable tubing is entangled.
7. The degasser of claim 1 , further comprising a vacuum source connected to the continuous body of gas-permeable tubing.
8. A method of degassing a solution within a system, the method comprising:
(i) flowing a solution through a degasser, the degasser comprising a continuous body of tubing, having an interior portion and an exterior portion, comprised of a gas permeable material, the degasser having an inlet and an outlet;
(ii) applying a change in pressure across at least a portion of the degasser to reduce a partial pressure of a component in the solution; and
(iii) conducting the solution from the outlet of the degasser directly to an inlet of a fraction collector.
9. The method of claim 8 , wherein the partial pressure of a component in the solution will be below the supersaturation point of the solution at operative temperature and pressure conditions at or about an inlet of a detector or inlet of the fraction collector.
10. The method of claim 8 , wherein a detector or the fraction collector are at ambient pressure and temperature.
11. The method of claim 8 , wherein a change in pressure occurs between the outlet of the degasser and an inlet of a detector or the inlet of the fraction collector.
12. The method of claim 11 , wherein the pressure decreases between the outlet of the degasser and an inlet of a detector or the inlet of the fraction collector.
13. The method of claim 8 , wherein a change in temperature occurs between the outlet of the degasser and an inlet of a detector or the inlet of the fraction collector.
14. The method of claim 13 , wherein the temperature increases between the outlet of the degasser and an inlet of the of a detector or the inlet of the fraction collector.
15. A method of degassing a supersaturated solution within a mixed fluid system, comprising:
(i) providing a gas-liquid separator fluidly connected to a degasser, the degasser comprising a continuous body of tubing, having an interior portion and an exterior portion, comprised of a gas permeable material, the degasser having an inlet connected to the gas-liquid separator and an outlet;
(ii) separating at least a portion of the supersaturated solution into a gas and a first liquid eluent within the gas-liquid separator;
(iii) introducing the first liquid eluent from the gas-liquid separator into the inlet of the degasser;
(iv) applying a differential pressure gradient across the degasser;
(v) separating an additional portion of the gas from the first liquid eluent, resulting in a second liquid eluent; and
(vi) conducting the second liquid eluent from an outlet of the degasser directly to an inlet of a fraction collector.
16. The method of claim 15 , wherein the second liquid eluent comprises a greater liquid to gas ratio by weight than the first liquid eluent.
17. The degasser of claim 1 wherein the continuous body has a residence time (g) adapted to remove the portion of the gas below the saturation point of the gas in the supersaturated solution.
18. The method of claim 8 , wherein the solution introduced to the degasser is a supersaturated solution.