Automated sample concentrator for trace components
AssigneeHewlett-Packard Company
InventorsJohn S. Poole, Dennis R. Gere, Raymond J. Bell, Mark A. Nickerson
Life of this patent
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Abstract
Concentration of the solutes contained in a liquid solvent is effected by passing the solvent through a first trapping means that adsorbs them, flushing the first trapping means with supercritical fluid and reducing its solubility parameter in a second trapping means so that the latter can adsorb desired solutes.
Claims24
A method of concentrating solutes contained in a liquid solvent other than supercritical fluid before they are applied to chromatographic apparatus for analysis, the said method comprising:
- passing the liquid solvent to waste through a first trapping means that adsorbs and accumulates at least some of the solutes from the solvent,
- passing supercritical fluid through said first trapping means so as to adsorb at least some of the solutes therefrom and carry them into a second trapping means,
- reducing the solubility parameter of the supercritical fluid in said second trapping means, and
- permitting the fluid of reduced solubility parameter to escape from said second trapping means, thereby leaving at least some of the solutes in said second trapping means.
Apparatus for concentrating the solutes contained in a liquid solvent other than supercritical fluid before they are applied to chromatographic apparatus for analysis, comprising:
- a first trapping means containing material for adsorbing and accumulating at least some solutes from said liquid solvent other than supercritical fluid passing through it,
- means for causing the liquid solvent, when present, to flow through said first trapping means and out to waste,
- second trapping means,
- means for changing a liquid-gas combination into supercritical fluid and to cause said supercritical fluid to flow through said first trapping means and into said second trapping means, said means for changing a liquid-gas combination into supercritical fluid being operative when a source of liquid-gas is coupled thereto,
- said second trapping means being such as to reduce the density of any supercritical fluid entering it so as to reduce its solubility parameter and thus retain at least some of the solutes.
Apparatus for concentrating solutes contained in a liquid solvent other than supercritical fluid and conveying them to chromatographic detection means, comprising:
- trapping means for adsorbing and accumulating solutes from the liquid solvent when it passes therethrough,
- means for causing the liquid solvent, when present, to pass through said trapping means and out to waste,
- supercritical fluid chromatographic apparatus having a separation column, and
- means for causing supercritical fluid to pass through said trapping means and to the separation column of said chromatographic apparatus after the solutes have been accumulated in said trapping means.
In a chromatographic system, a method for deriving an amount of a solute that is above the minimum detectable level for the detector involved from a solvent other than a supercritical fluid in which the amount of solute contained in the largest sample volume of the solvent that can be injected is less than the minimum detectable level for the detector, the said method comprising:
- passing solvent through a first trapping means until the amount of solute accumulated therein is greater than the minimum detectable level,
- passing supercritical fluid through said first trapping means so as to adsorb at least a portion of the solute and then into a second trapping means, and
- reducing the solubility parameter of the supercritical fluid in said second trapping means so that an amount of the solute at least equal to the minimum detectable level is left in the second trapping means.
Apparatus for deriving an amount of solute that is above a given minimum detectable level for a given detector from a solvent in which the amount of solute contained in the largest sample volume of the solvent that can be used is less than the minimum detectable level for the detector, the said apparatus comprising:
- a first trapping means,
- means for causing solvent to pass through said first trapping means until the amount of solute contained therein exceeds the minimum detectable level,
- a second trapping means,
- a source of supercritical fluid and means for causing it to pass through said first trapping means and into said second trapping means, said second trapping means being such as to reduce the density of supercritical fluid entering it so as to reduce its solubility parameter.
Dependencies are inferred from the claim text.