Methods for detecting reverse triiodothyronine by mass spectrometry

Patent metadata

Field	Value
Publication number	US-9685311-B2
Application number	US-201514951203-A
Country	US
Kind code	B2
Filing date	Nov 24, 2015
Priority date	Dec 5, 2011
Publication date	Jun 20, 2017
Grant date	Jun 20, 2017

Abstract

Provided are methods for determining the amount of reverse T3 in a sample using mass spectrometry. The methods generally involve ionizing reverse T3 in a sample and detecting and quantifying the amount of the ion to determine the amount of reverse T3 in the sample.

First claim

That which is claimed is:

1. A method for determining the amount of reverse triiodothyronine (rT3) in a sample by tandem mass spectrometry, said method comprising:
a. adding an internal standard to the sample;
b. subjecting the sample to protein precipitation;
c. ionizing rT3 and the internal standard to generate at least one rT3 ion and at least one internal standard ion;
d. determining the amount of said at least one rT3 ion and the amount of said at least one internal standard ion by tandem mass spectrometry; wherein the amount of rT3 in the sample is determined from the amount of said at least one rT3 ion and the amount of said at least one internal standard ion.

2. The method of claim 1 , wherein the method further comprises subjecting the sample to liquid chromatography.

3. The method of claim 2 , wherein liquid chromatography comprises high performance liquid chromatography (HPLC), reverse phase liquid chromatography (RPLC), reverse-phase high performance liquid chromatography (RP-HPLC), or high turbulence liquid chromatography (HTLC).

4. The method of claim 1 , wherein said protein precipitation comprises organic solvent precipitation.

5. The method of claim 1 , wherein said protein precipitation comprises methanol precipitation.

6. The method of claim 1 , wherein said ionizing is by electrospray ionization (ESI) or atmospheric pressure chemical ionization (APCI).

7. The method of claim 1 , wherein said ionizing is in positive ion mode.

8. The method of claim 1 , wherein said ions are detected using multiple reaction monitoring (MRM).

9. The method of claim 1 , wherein the one or more rT3 ions detectable by mass spectrometry comprise one or more selected from the group consisting of ions with a mass/charge ratio of 649.9±0.5, 605.2±0.5 and 127.1±0.5.

10. The method of claim 1 , wherein the one or more rT3 ions detectable by mass spectrometry comprise one or more selected from the group consisting of ions with a mass/charge ratio of 649.9±0.5 and 605.2±0.5.

11. The method of claim 1 , wherein the internal standard is isotopically labeled.

12. The method of claim 1 , wherein the internal standard is 13 C-labeled rT3.

13. The method of claim 1 , wherein said sample comprises plasma or serum.

14. A method for determining the amount of reverse triiodothyronine (rT3) in a sample by tandem mass spectrometry, said method comprising:
a. adding a 13 C-labeled rT3 to the sample;
b. subjecting the sample to protein precipitation;
c. ionizing rT3 and the 13 C-labeled rT3 to generate at least one rT3 ion and at least one 13 C-labeled rT3 ion;
d. determining the amount of said at least one rT3 ion and the amount of said at least one 13 C-labeled rT3 ion by tandem mass spectrometry; wherein the amount of rT3 in the sample is determined from the amount of said at least one rT3 ion and the amount of said at least one 13 C-labeled rT3 ion.

15. The method of claim 14 , wherein the method further comprises subjecting the sample to liquid chromatography.

16. The method of claim 14 , wherein liquid chromatography comprises high performance liquid chromatography (HPLC), reverse phase liquid chromatography (RPLC), reverse-phase high performance liquid chromatography (RP-HPLC), or high turbulence liquid chromatography (HTLC).

17. The method of claim 14 , wherein said protein precipitation comprises organic solvent precipitation.

18. The method of claim 14 , wherein said protein precipitation comprises methanol precipitation.

19. The method of claim 14 , wherein said ionizing is by electrospray ionization (ESI) or atmospheric pressure chemical ionization (APCI).

20. The method of claim 14 , wherein said ionizing is in positive ion mode.

21. The method of claim 14 , wherein said ions are detected using multiple reaction monitoring (MRM).

22. The method of claim 14 , wherein the one or more rT3 ions detectable by mass spectrometry comprise one or more selected from the group consisting of ions with a mass/charge ratio of 649.9±0.5, 605.2±0.5 and 127.1±0.5.

23. The method of claim 14 , wherein the one or more rT3 ions detectable by mass spectrometry comprise one or more selected from the group consisting of ions with a mass/charge ratio of 649.9±0.5 and 605.2±0.5.

24. The method of claim 14 , wherein said sample comprises plasma or serum.

Assignees

• Quest Diagnostics Invest Inc

Inventors

• Banks J Fred
• Chou Peter P
• Matt Noriya M

Classifications

• H01J49/00

  Particle spectrometers or separator tubes · CPC title

• H01J49/004

  Combinations of spectrometers, tandem spectrometers, e.g. MS/MS, MSn · CPC title

• G01N33/78 Primary

  Thyroid gland hormones {, e.g. T3, T4, TBH, TBG or their receptors} · CPC title

• H01J49/10

  Ion sources; Ion guns · CPC title

• H01J49/0031

  Step by step routines describing the use of the apparatus (H01J49/0081 takes precedence) · CPC title