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US 5,412,208 AGranted
Ion spray with intersecting flow
AssigneeMDS Health Group Limited
InventorsThomas R. Covey, Joseph F. Anacleto
Life of this patent
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AssigneeMDS Health Group Limited
InventorsThomas R. Covey, Joseph F. Anacleto
Estimating the term…
Liquid from a liquid chromatograph or other sample source, preferably assisted by a high velocity coaxial gas jet, is sprayed through a capillary tube producing a flow in a first direction of charged droplets. A flow of heated gas, in a second direction different from the first direction, intersects the droplet flow at a region upstream of an orifice. The flows mix turbulently, with the second flow helping to evaporate the droplets to produce ions and helping to move the evaporating droplets toward the orifice, providing a focusing effect. Ions are drawn through the orifice into a mass analyzer and analyzed. Alternatively the flows of liquid and heating gas can be directed toward each other and at right angles to the axis through the orifice, and the inhaling effect of the orifice can be used to draw droplets toward it, or a third gas flow can be used for this purpose. The heated intersecting gas flow typically provides an increase in sensitivity (ion counts per second) of between 10 and 100 times. Heating the droplet plume also allows controlled desaturation of ions and in increase in the number of charges on them, without degrading the ions.
A method of analyzing ions from trace sample molecules in a liquid, comprising the steps of:
In the method of analyzing ions from trace sample molecules in a liquid, said method comprising spraying said liquid in a first direction from an opening to form a plume of electrically charged droplets, the improvement comprising producing a flow of heated gas, and directing said flow in a second direction different from said first direction for said flow to intersect said plume of droplets at a selected region for turbulent mixing of said flow with said droplets in said region, thereby to increase the rate of emission of sample ions from said droplets.
Apparatus for analyzing ions from trace sample molecules in a liquid comprising:
In a method of analyzing ions from trace sample molecules in a liquid, said molecules being folded molecules, said method comprising spraying said liquid from an opening to form a plume of electrically charged droplets, each droplet containing said ions, the improvement comprising providing a flow of gas, causing said flow to mix with said plume to aid evaporation of said droplets and emission of ions therefrom, heating said gas to a controlled temperature to cause controlled rapid unfolding of said molecules in said droplets during evaporation of said droplets, and then drawing at least some of the ions emitted from said droplets out of the heated gas and into a vacuum chamber, and analyzing said ions.
Dependencies are inferred from the claim text.