Focusing agents and calibration transportability
AssigneeThe United States of America as represented by the Secretary of the Air Force
InventorsH. Mitchell Rubenstein, Anthony Qualley
Life of this patent
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Abstract
A thermal desorption tube for chromatography and mass spectrometry analysis. The thermal desorption tube includes a sorbent and a plurality of focusing agents loaded at known, relative amounts onto the sorbent. Each focusing agent is a compound that chromatographically elutes within a retention time similar to a retention time of a target analyte and has a mass spectrum similar to a mass spectrum of the target analyte. The thermal desorption tube is configured to be further loaded with a sample having the target analyte.
Claims4
A method of comparing amounts of a target analyte using calibration transportability, the method comprising:
- obtaining first and second thermal desorption tubes, the first and second thermal desorption tubes comprising:
- a sorbent;
- and
- a plurality of focusing agents loaded at known, relative amounts onto the sorbent, focusing agents of the plurality comprising a compound that chromatographically elutes within a retention time the same as a retention time of a target analyte and having a mass spectrum similar to a mass spectrum of the target analyte,
- wherein the first and second thermal desorption tubes are configured to be further loaded with a sample having the target analyte, the first and second thermal desorption tubes having the same focusing agents at the same known, relative amounts;
- desorbing said focusing agents in a chromatography and mass spectrometry instrument;
- after desorbing, injecting an internal standard into the chromatography and mass spectrometry instrument, wherein the internal standard is not a focusing agent of the plurality;
- acquiring a first sample having the target analyte with the first thermal desorption tube;
- acquiring a second sample having the target analyte with the second thermal desorption tube;
- on separate instruments, analyzing an amount of target analyte in each of the first and second samples;
- and
- comparing the amounts of the target analyte in each of the first and second samples.
A method of comparing amounts of a target analyte using calibration transportability, the method comprising:
- obtaining first and second thermal desorption tubes, the first and second thermal desorption tubes comprising:
- a sorbent;
- and
- a plurality of focusing agents loaded at known, relative amounts onto the sorbent, focusing agents of the plurality comprising a compound that chromatographically elutes within a retention time the same as a retention time of a target analyte and having a mass spectrum similar to a mass spectrum of the target analyte,
- wherein the first and second thermal desorption tubes are configured to be further loaded with a sample having the target analyte, the first and second thermal desorption tubes having the same focusing agents at the same known, relative amounts;
- desorbing said focusing agents in a chromatography and mass spectrometry instrument;
- injecting an internal standard immediately prior to desorbing said focusing agents in a chromatography and mass spectrometry instrument, wherein the internal standard is not a focusing agent of the plurality;
- acquiring a first sample having the target analyte with the first thermal desorption tube;
- acquiring a second sample having the target analyte with the second thermal desorption tube;
- on separate instruments, analyzing an amount of target analyte in each of the first and second samples;
- and
- comparing the amounts of the target analyte in each of the first and second samples.
Dependencies are inferred from the claim text.