Mass spectrometric determination of eicosapentaenoic acid and docosahexaenoic acid

Patent metadata

Field	Value
Publication number	US-9696325-B2
Application number	US-201514816586-A
Country	US
Kind code	B2
Filing date	Aug 3, 2015
Priority date	Sep 16, 2010
Publication date	Jul 4, 2017
Grant date	Jul 4, 2017

Abstract

The invention relates to the detection of DHA and EPA. In a particular aspect, the invention relates to methods for detecting DHA and EPA by mass spectrometry and kits for carrying out such methods.

First claim

That which is claimed is:

1. A method for determining the amount of docosahexaenoic acid (DHA) in a human serum or plasma sample by mass spectrometry, the method comprising:
(i) ionizing DHA from the sample to generate one or more DHA ions detectable by mass spectrometry;
(ii) determining the amount of said one or more DHA ions by single mass spectrometry, wherein said one or more ions comprises an ion with a mass to charge ratio (m/z) of 327.2±0.5; and
(iii) relating the amount of DHA ions to the amount of DHA in the sample, wherein said method has a limit of detection for DHA in the sample of about 5 μmol/L or less.

2. The method of claim 1 , wherein said ionizing comprises atmospheric pressure chemical ionization (APCI).

3. The method of claim 2 , wherein said APCI is in negative ionization mode.

4. The method of claim 1 , wherein said ionizing comprises electrospray ionization (ESI).

5. The method of claim 1 , wherein said sample is subjected to a hydrolyzing agent prior to ionization.

6. The method of claim 5 , wherein said hydrolyzing agent is an acid.

7. The method of claim 1 , wherein DHA from said sample is subjected to liquid/liquid extraction prior to ionization.

8. The method of claim 1 , wherein DHA from said sample is subjected to a liquid chromatography prior to ionization.

9. The method of claim 8 , wherein said liquid chromatography comprises high performance liquid chromatography (HPLC).

10. The method of claim 1 , wherein said method comprises determining the amount of an internal standard.

11. The method of claim 10 , wherein said internal standard is a deuterated DHA.

12. The method of claim 11 , wherein said deuterated DHA is DHA- 2 H 5 .

13. The method of claim 1 , further comprising simultaneously determining the amount of EPA in said sample by:
(i) ionizing eicosapentaenoic acid (EPA) from the sample to generate one or more EPA ions detectable by single mass spectrometry;
(ii) determining the amount of said one or more EPA ions by single mass spectrometry and
(iii) relating the amount of ions determined in step (ii) to the amount of a EPA in the sample.

14. A method for determining the amount of eicosapentaenoic acid (EPA) in a human serum or plasma sample by mass spectrometry, the method comprising:
(i) ionizing EPA from the sample to generate one or more EPA ions detectable by mass spectrometry;
(ii) determining the amount of said one or more EPA ions by single mass spectrometry, wherein said one or more ions comprises an ion with a mass to charge ratio (m/z) of 301.2±0.5; and
(iii) relating the amount of one or more EPA ions to the amount of a EPA in the sample, wherein said method has a limit of detection for EPA in the sample of about 10 μmol/L or less.

15. The method of claim 14 , wherein said ionizing comprises atmospheric pressure chemical ionization (APCI).

16. The method of claim 15 , wherein said APCI is in negative ionization mode.

17. The method of claim 14 , wherein said ionizing comprises electrospray ionization (ESI).

18. The method of claim 14 , wherein said sample is subjected to a hydrolyzing agent prior to ionization.

19. The method of claim 18 , wherein said hydrolyzing agent is an acid.

20. The method of claim 14 , wherein EPA from said sample is subjected to liquid/liquid extraction prior to ionization.

21. The method of claim 14 , wherein EPA from said sample is subjected to a liquid chromatography prior to ionization.

22. The method of claim 21 , wherein said liquid chromatography comprises high performance liquid chromatography (HPLC).

Assignees

• Quest Diagnostics Invest Inc

Inventors

• Goldman Scott M
• Neidich Julie A

Classifications

• Y10T436/24

  Nuclear magnetic resonance, electron spin resonance or other spin effects or mass spectrometry · CPC title

• H01J49/165

  Electrospray ionisation · CPC title

• Y10T436/25375

  Liberation or purification of sample or separation of material from a sample [e.g., filtering, centrifuging, etc.] · CPC title

• H01J49/168

  field ionisation, e.g. corona discharge (atmospheric pressure corona discharge per se H01T19/00) · CPC title

• Y10T436/104165

  Lipid, cholesterol, or triglyceride standard or control · CPC title