Compositions, methods, and kits for quantifying target analytes in a sample

• US 9,768,001 B2
• Filed: 06/06/2012
• Issued: 09/19/2017
• Est. Priority Date: 06/06/2011
• Status: Active Grant

• Current Assignee: Waters Technologies Corporation (Waters Corporation)
• Original Assignee: Waters Technologies Corporation (Waters Corporation)
• Inventors: Cooper, Donald Peter
• Primary Examiner(s): STOFFA, WYATT A
• Application Number:
  US14/124,061
• Publication Number:
  US 20140158881A1
• Time in Patent Office: 1,931 Days
• CPC Class Codes: G01N 2030/045 internal
• CPC Class Codes: G01N 30/72 Mass spectrometers mass spectrometers per se H01J49/00
• CPC Class Codes: G01N 30/8665 for calibrating the measuring apparatus
• CPC Class Codes: H01J 49/0009 Calibration of the apparatus

Abstract

A method of quantifying a target analyte by mass spectrometry includes obtaining a mass spectrometer signal comprising a first calibrator signal, comprising a second calibrator signal, and potentially comprising a target analyte signal from a single sample comprising a first known quantity of a first calibrator, comprising a second known quantity of a second calibrator, and potentially comprising a target analyte. The first known quantity and the second known quantity are different, and wherein the first calibrator, the second calibrator, and the target analyte are each distinguishable in the single sample by mass spectrometry. The method also includes quantifying the target analyte in the single sample using the first calibrator signal, the second calibrator signal, and the target analyte signal.

Claims

1. A method of quantifying a target analyte by mass spectrometry, the method comprising:

preparing a single sample by combining a first known quantity of a first calibrator, a second known quantity of a second calibrator, and a third known quantity of a third calibrator in a single sample comprising the target analyte,

wherein the target analyte is a steroid, an immunosuppressant, a thyroid marker, a vitamin or metabolite thereof, or an opioid, and wherein the target analyte has from 3 to 30 carbon atoms,

wherein the first calibrator, the second calibrator, and the third calibrator are each different stable isotope analogs of the target analyte,

wherein the target analyte is unlabeled,

wherein a quantity range defined by the first, second and third calibrators for the target analyte spans an expected analytical range of the target analyte in the sample and a ratio between a highest quantity calibrator and a lowest quantity calibrator is at least 10;

1;

generating a mass spectrometer signal from the single sample using a mass spectrometer comprising a first calibrator signal, comprising a second calibrator signal, comprising a third calibrator signal, and comprising a target analyte signal,

wherein the first known quantity, the second known quantity, and the third known quantity are different, and wherein the first calibrator, the second calibrator, the third calibrator and the target analyte are each distinguishable in the single sample by mass spectrometry due to differences in their mass, fragmentation pattern or combinations thereof;

obtaining a calibration curve, wherein the calibration curve is obtained from the first calibrator signal, the second calibrator signal and third calibrator signal; and

quantifying the target analyte using the calibration curve and the target analyte signal.

2. The method of claim 1, further comprising:

separating the first calibrator, the second calibrator, the third calibrator and the target analyte from other components of the single sample prior to obtaining the mass spectrometer signal.

3. The method of claim 2, wherein the separation comprises chromatography and the first calibrator, the second calibrator, the third calibrator and the target analyte co-elute.

4. The method of claim 2, wherein the separation comprises chromatography and the first calibrator, the second calibrator, the third calibrator and the target analyte elute separately.

5. The method of claim 2, wherein the separation comprises at least one of solid phase extraction, liquid chromatography, gas chromatography, affinity, immunoaffinity, and

supercritical fluid chromatography.

6. The method of claim 1, further comprising:

obtaining, from the mass spectrometer signal, a fourth calibrator signal, a fifth calibrator signal, a sixth calibrator signal, and an additional target analyte signal from the single sample comprising a fourth known quantity of a fourth calibrator, comprising a fifth known quantity of a fifth calibrator, comprising a sixth known quantity of a sixth calibrator, and comprising an additional target analyte,

wherein the additional target analyte is a steroid, an immunosuppressant, a thyroid marker, a vitamin or metabolite thereof, or an opioid, and wherein the additional target analyte has from 3 to 30 carbon atoms, and is unlabeled,

wherein the fourth calibrator, the fifth calibrator, and the sixth calibrator are each different stable isotope analogs of the additional target analyte,

wherein the fourth known quantity, the fifth known quantity and the sixth known quantity are different, wherein a quantity range defined by the fourth, fifth and sixth calibrators for the additional target analyte spans an expected analytical range of the additional target analyte in the sample and a ratio between a highest quantity calibrator and a lowest quantity calibrator is at least 10;

1, and

wherein the first calibrator, the second calibrator, the third calibrator, the fourth calibrator, the fifth calibrator, the sixth calibrator, the target analyte, and the additional target analyte are each distinguishable in the single sample by mass spectrometry due to differences in their mass, fragmentation pattern or combinations thereof; and

obtaining a second calibration curve, wherein the second calibration curve is obtained from the fourth calibrator signal, the fifth calibrator signal and sixth calibrator signal, and quantifying the additional target analyte using the second calibration curve and the additional target analyte signal.

7. The method of claim 1, further comprising

calculating a relative response factor for each calibrator, and

correcting the first known quantity of the first calibrator, the second known quantity of a second calibrator, and the third known quantity of a third calibrator using the relative response factor for each calibrator.

8. The method of claim 7, wherein the relative response factor for each calibrator is calculated by analyzing each calibrator using the mass spectrometer against a standard reference for the analyte.

9. The method of claim 1, wherein the quantity of the first calibrator is about 10% of an expected quantity of the target analyte, the quantity of the second calibrator is about 100% of the expected quantity of the target analyte, and the quantity of the third calibrator is about 1000% of the expected quantity of the target analyte.

10. The method of claim 1, wherein the first, second and third calibrators and target analyte have the same mass and empirical formula but generate fragments during mass spectrometry analysis having different masses.

11. The method of claim 1, wherein the target analyte is a steroid.

12. The method of claim 1, wherein the target analyte is testosterone.

13. The method of claim 1, wherein the target analyte is an immunosuppressant.

14. The method of claim 1, wherein the target analyte is an opioid.

15. The method of claim 1, wherein the target analyte is hydromorphone.

16. The method of claim 1, wherein the quantity range defined by the first, second and third calibrators for the target analyte comprises 2 ng/mL and 100 ng/mL.