Solvent susceptibility compensation for coupled LC-NMR
AssigneeWaters Investments Limited
InventorTheodore A. Dourdeville
Life of this patent
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Abstract
A method and apparatus in which the limitation upon analysis caused by variation of the magnetic susceptibility of the solvent conveying a sample to an NMR spectrometer can be addressed. The solvent composition which is used to bring about elution of analyte from devices such as chromatography columns can be varied without causing a corresponding variation of the solvent composition used to transport the analyte to the NMR spectrometer. The decoupling is achieved by the summing into the chromatographic stream, post column, a solvent composition which is complementary to the instantaneous composition emerging from the column, such that the magnetic susceptibility of the summed streams remains constant.
Claims19
An apparatus for limiting the variation in magnetic susceptibility of a liquid stream delivered to a nuclear magnetic resonance based detector, comprising:
- a system controller in communication with a first fluid stream, said first fluid stream having a first magnetic susceptibility;
- and
- said system controller in communication with at least one additional fluid stream, said at least one additional fluid stream having a differing magnetic susceptibility;
- wherein said at least one additional fluid stream is summed with said first fluid stream to compensate for the variation in magnetic susceptibility of said first fluid stream.
An apparatus for limiting the variation in magnetic susceptibility of a liquid stream delivered to a nuclear magnetic resonance detector comprising:
- a system controller being in communication with a first fluid stream having a first magnetic susceptibility;
- said system controller in communication with at least one additional fluid stream having a differing magnetic susceptibility;
- a first set of pumps conveying fluid within said first fluid stream;
- and
- an additional set of pumps conveying fluid within each said at least one additional fluid stream;
- wherein said first set of pumps creates said first fluid stream having a time varying magnetic susceptibility and where said additional set of pumps creates said at least one additional fluid stream having a time varying magnetic susceptibility which is complementary to that of said first fluid stream.
A method for compensation of magnetic susceptibility variation in a fluid stream directed to a nuclear magnetic resonance detection device, comprising the steps of:
- forming a first fluid stream having a first magnetic susceptibility;
- forming at least one additional fluid stream having a differing magnetic susceptibility;
- summing said first fluid stream into said at least one additional fluid stream, and forming an output stream;
- and
- modulating said at least one additional fluid stream to maintain a magnetic susceptibility of said output stream constant.
Dependencies are inferred from the claim text.