Methods for detecting and quantifying non-polar analytes with high sensitivity

Patent metadata

Field	Value
Publication number	US-10520510-B2
Application number	US-201615349384-A
Country	US
Kind code	B2
Filing date	Nov 11, 2016
Priority date	Nov 13, 2015
Publication date	Dec 31, 2019
Grant date	Dec 31, 2019

Abstract

The technology of the present application is directed to methods and kits for detecting and quantifying a non-polar analyte in a plant-derived sample. The technology uses a simple extraction, e.g., a liquid-liquid extraction (LLE) or solid-phase extraction (SPE), to enrich a sample for a non-polar analyte of interest and to remove contaminants. After the extraction and clean-up steps, liquid chromatography and mass spectrometry are used to detect the non-polar analyte. In one embodiment, acequinocyl and/or its derivatives is analyzed using liquid chromatography and tandem mass spectrometry (LC-MS/MS) and the improved LC-MS/MS conditions allows detection limits of acequinocyl and/or its derivatives of 50 ppb or less.

First claim

What is claimed is:

1. A method for detecting and quantifying a non-polar analyte in a plant-derived sample, comprising:
(a) purifying said sample in a first purification step to obtain a first solution;
(b) purifying said first solution in a second purification step comprising extracting said first solution with liquid-liquid extraction (LLE) or solid phase extraction (SPE) using a non-polar solvent to obtain a second solution; and
(c) subjecting said second solution to detection and quantitative analysis;
wherein when LLE is used, said non-polar analyte is retained in a non-polar liquid phase, and said second solution is said non-polar liquid phase comprising said non-polar analyte; and
wherein when SPE is used, said non-polar analyte is initially retained on a non-polar solid phase and is then eluted from said non-polar solid phase in a separate elution step, and said second solution is said eluate from said non-polar solid phase comprising said non-polar analyte.

2. The method of claim 1 , wherein said method results in detection of said non-polar analyte at a detection limit that is equal to or lower than a threshold detection limit.

3. The method of claim 2 , further comprising:
(d) subjecting said second solution to an analysis by liquid chromatography (LC) followed by mass spectrometry (MS).

4. The method of claim 3 , wherein said liquid chromatography is ultra high pressure liquid chromatography (UHPLC).

5. The method of claim 3 , wherein a mobile phase for said liquid chromatography comprises ammonium acetate.

6. The method of claim 3 , wherein said mass spectrometry is tandem mass spectrometry (LC/MS/MS).

7. The method of claim 1 , wherein said non-polar solvent is selected from the group consisting of pentane, hexane, cyclohexane, benzene, toluene, chloroform, diethyl ether and 1,4-dioxane.

8. The method of claim 7 , wherein said non-polar solvent is hexane.

9. The method of claim 1 , wherein said first purification step comprises extraction with a solution comprising acetonitrile and at least one salt.

10. The method of claim 9 , wherein said salt is selected from the group consisting of sodium chloride, magnesium sulfate, trisodium citrate dehydrate and disodium hydrogen citrate sesquihydrate.

11. The method of claim 1 , wherein said plant-derived sample comprises hops or cannabis.

12. The method of claim 11 , wherein said non-polar analyte is acequinocyl, an acequinocyl derivative or a combination thereof.

13. The method of claim 12 , wherein said acequinocyl derivative is acequinocyl-OH.

14. The method of claim 2 , wherein said threshold detection limit is 1000 ppb or less.

15. The method of claim 1 , wherein the non-polar analyte is acenoquinocyl, an acequinocyl derivative or a combination, the plant-derived sample comprises cannabis, and the non-polar liquid phase is hexane.

16. The method of claim 15 , wherein said method results in detection of acequinocyl, an acequinocyl derivative or a combination thereof at a detection limit of 50 ppb or less.

17. The method of claim 6 , wherein said LC/MS/MS comprises multiple reaction monitoring (MRM) using an ion selected from the group consisting of an ion having an M/Z of 343 + , 385 + or 402 + .

18. The method of claim 1 , wherein the first solution consists of a supernatant from the first purification step.

19. The method of claim 14 , wherein said threshold detection limit is 100 ppb or less.

20. The method of claim 19 , wherein said threshold detection limit is 10 ppb or less.

Assignees

• Waters Technologies Corp

Inventors

• Young Michael S

Classifications

• G01N2560/00

  Chemical aspects of mass spectrometric analysis of biological material · CPC title

• G01N33/64 Primary

  involving ketones · CPC title

• G01N2030/027

  Liquid chromatography · CPC title

• G01N1/405

  by adsorption or absorption · CPC title

• B01D15/26

  characterised by the separation mechanism · CPC title