US 4,958,529 AGranted

Interface for coupling liquid chromatography to solid or gas phase detectors

AssigneeVestec Corporation

InventorMarvin L. Vestal

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Abstract

An improved interface is provided for receiving effluent from a chromatographic device and outputting sample particles of interest to a detector for analysis. The interface includes a gas diffusion cell having a membrane therein separating the cell into an aerosol flow chamber and a sweep gas flow chamber. The effluent is sprayed as an aerosol into the aerosol flow chamber, and vaporized solvent diffuses through the gas membrane into the sweep gas flow chamber while particles of interest are output to the detector. Sweep gas is passed through the sweep gas flow chamber for removing the solvent vapor, and the flow rate of sweep gas is controlled to achieve little or no net flow of gas across the membrane. Efficient solvent removal may be achieved at room temperature for certain LC flow rates, and high detector resolution is possible by maintaining laminar flow of the carrier gas through the aerosol flow chamber.

Claims31

Dependent claims

An improved interface for receiving effluent including sample solute of interest and solvent from a liquid chromatographic device, and for outputting sample particles of interest to a detector for analysis of a sample, the interface comprising:

a gas diffusion device including a cell housing having an aerosol input port and an aerosol discharge port;
spraying means for passing the chromatographic effluent through the aerosol input port and for discharging the chromatographic effluent as an aerosol into the cell housing;
a gas diffusion membrane within the cell housing separating the cell housing into an aerosol flow chamber and an adjoining sweep gas flow chamber, the aerosol flow chamber being in fluid communication with both the aerosol input port and the aerosol discharge port for receiving and transmitting the aerosol to the detector, the sweep gas flow chamber having a sweep gas input port and a sweep gas discharge port for passing sweep gas through the sweep gas chamber in a direction counter to the flow of aerosol through the aerosol flow chamber;
and
sweep gas supply means for passing a sweep gas through the sweep gas flow chamber while the aerosol is passed through the aerosol flow chamber, such that solvent vapor released from the aerosol discharged by the spraying means is diffused from the aerosol flow chamber through the membrane and to the sweep gas flow chamber, and is removed from the gas diffusion device by the sweep gas.

2 more elements

An improved interface for receiving liquid effluent including sample solute of interest and solvent from a liquid chromatographic device, and for outputting sample particles of interest to a detector for analysis of a sample, the interface comprising:

a gas diffusion device including a first cell housing and a second cell housing in series with the first cell housing;
spraying means for discharging the liquid effluent as an aerosol into the first cell housing;
a first gas diffusion membrane within the first cell housing separating the first cell housing into a first aerosol flow chamber and an adjoining first sweep gas flow chamber;
first sweep gas supply means for passing a first sweep gas through the first sweep gas flow chamber while the aerosol is passed through the first aerosol flow chamber in a direction counter to the flow of the first sweep gas, such that solvent vapor released from the aerosol discharged by the spraying means is diffused from the first aerosol flow chamber through the first membrane and to the first sweep gas flow chamber, and is removed from the gas diffusion device by the first sweep gas;
a second gas diffusion membrane within the second cell housing separating the second cell housing into a second aerosol flow chamber in series communication with the first aerosol flow chamber and an adjoining second sweep gas flow chamber;
and
second sweep gas supply means for passing a second sweep gas through the second sweep gas flow chamber while the aerosol is passed through the second aerosol flow chamber in a direction counter to the flow of the second sweep gas, such that the first sweep gas in the second aerosol flow chamber is diffused through the second membrane and to the second sweep gas flow chamber, and is removed from the gas diffusion device by the second sweep gas.

4 more elements

An improved interface method for receiving effluent including sample solute of interest and solvent from a chromatographic device, and for outputting sample particles of interest to a detector for analysis of a sample, the improved interface method comprising:

providing a gas diffusion membrane within a cell housing to separate the cell housing into an aerosol flow chamber and a sweep gas flow chamber;
spraying the effluent as an aerosol into the aerosol flow chamber;
passing a carrier gas through the aerosol flow chamber to carry the aerosol through the aerosol flow chamber and toward the detector;
passing a sweep gas through the sweep gas flow chamber while the aerosol is carried through the aerosol flow chamber in a direction counter to the flow within the aerosol flow chamber;
controlling the sweep gas flow rate to complete vaporization of the solvent from the aerosol within the aerosol flow chamber while diffusing solvent vapor within the aerosol flow chamber through the membrane and into the sweep gas flow chamber;
controlling the carrier gas flow rate within the aerosol flow chamber to substantially equalize pressure across the gas diffusion membrane;
and
removing solvent vapor and sweep gas from the cell housing while outputting sample particles of interest to the detector.

5 more elements

An improved interface method for receiving liquid effluent including sample solute of interest and solvent from a liquid chromatographic device, and for outputting samples particles of interest to a detector for analysis of a sample, the improved method comprising:

providing a first gas diffusion cell including a first gas diffusion membrane within a first cell housing to separate the first cell housing into a first aerosol flow chamber and a first sweep gas flow chamber;
providing a second gas diffusion cell including a second gas diffusion membrane within a second cell housing to separate the second cell housing into a second aerosol flow chamber in series with the first aerosol flow chamber and a second sweep gas flow chamber;
spraying the liquid effluent as an aerosol into the first aerosol flow chamber;
passing a carrier gas through the first aerosol flow chamber to carry the aerosol through the first and second gas diffusion cells and toward the detector;
passing a first sweep gas through the first sweep gas flow chamber in a direction counter to the flow of aerosol through the first aerosol flow chamber such that solvent vapor released from the aerosol is diffused from the first aerosol flow chamber through the membrane and to the first sweep gas flow chamber, and is removed from the gas diffusion device by the first sweep gas;
controlling the first sweep gas flow rate through the first sweep gas chamber to complete vaporization of the solvent from the aerosol within the first aerosol flow chamber;
controlling the oarrier gas flow rate to the first aerosol flow chamber to substantially equalize the pressure across the first gas diffusion membrane;
removing solvent vapor and the first sweep gas from the first cell housing while outputting sample particles of interest to the second aerosol flow chamber;
passing a second sweep gas through the second sweep gas chamber in a direction counter to the flow of aerosol through the second aerosol flow chamber such that the solvent vapor, the carrier gas and the first sweep gas are diffused from the second aerosol flow chamber through the second gas diffusion membrane to the second sweep gas flow chamber, and are removed from the gas diffusion device by the second sweep gas;
and
removing solvent vapor and sweep gas from the second cell housing while outputting sample particles of interest to the detector.

8 more elements

providing a gas diffusion membrane within a cell housing to separate the cell housing into an aerosol flow chamber and a sweep gas flow chamber;
spraying the effluent as an aerosol into the aerosol flow chamber while maintaining the cell housing at ambient temperature;
passing a carrier gas through the aerosol flow chamber to carry the aerosol through the aerosol flow chamber and toward the detector;
passing a sweep gas through the sweep gas flow chamber while the aerosol is carried through the aerosol flow chamber in a direction counter to the flow within the aerosol flow chamber;
controlling the sweep gas flow rate to complete vaporization of the solvent from the aerosol within the aerosol flow chamber while diffusing solvent vapor within the aerosol flow chamber through the membrane and into the sweep gas flow chamber;
controlling the carrier gas flow rate within the aerosol flow chamber to substantially equalize pressure across the gas diffusion membrane and maintain laminar flow of carrier gas through the aerosol flow chamber;
and
removing solvent vapor and sweep gas from the cell housing while outputting sample particles of interest to the detector.

5 more elements

Dependencies are inferred from the claim text.