NMR method for differentiating complex mixtures

• US 20070055456A1
• Filed: 08/31/2006
• Published: 03/08/2007
• Est. Priority Date: 08/31/2005
• Status: Abandoned Application

• Current Assignee: Purdue Research Foundation (The Trustees of Purdue University (d/b/a Purdue University))
• Original Assignee: Purdue Research Foundation (The Trustees of Purdue University (d/b/a Purdue University))
• Inventors: Sandusky, Peter, Raftery, Daniel
• Application Number:
  US11/514,031
• Publication Number:
  US 20070055456A1
• Time in Patent Office: Days
• US Class Current: 702/19
• CPC Class Codes: G01N 24/08 by using nuclear magnetic resonance G01N24/12 takes precedence
• CPC Class Codes: G01R 33/4625 Processing of acquired signals, e.g. elimination of phase errors, baseline fitting, chemometric analysis
• CPC Class Codes: G01R 33/465 applied to biological material, e.g. in vitro testing

Abstract

A method for differentiating complex mixtures each having one or more chemical species is provided. The method comprises producing a sample NMR spectrum by subjecting a mixture to a selective spectroscopy process, wherein the NMR spectrum has individual spectral peaks representative of the one or more chemical species within the mixture. The one or more chemical species within the mixture are identified by analyzing the individual spectral peaks, and the individual spectral peaks are then subjected to a multivariate statistical analysis.

Claims

1. A method for differentiating complex mixtures each having one or more chemical species, comprising:

producing a sample NMR spectrum by subjecting a mixture to a selective spectroscopy process, the NMR spectrum having individual spectral peaks representative of the one or more chemical species within the mixture;

identifying the one or more chemical species by analyzing the individual spectral peaks within the mixture; and

subjecting the individual spectral peaks to a multivariate statistical analysis.

2. The method of claim 1, wherein the mixture comprises a biofluid mixture.

3. The method of claim 1, further comprising using the multivariate statistical analysis to determine purity of the individual spectral peaks and to assign the individual spectral peaks into spin systems.

4. The method of claim 1, wherein the selective spectroscopy analysis is a total correlation spectroscopy analysis.

5. The method of claim 1, wherein the multivariate statistical analysis comprises a Pearson product moment correlation test.

6. The method of claim 1, wherein the multivariate statistical analysis comprises a principal component analysis process.

7. The method of claim 1, wherein the multivariate statistical analysis comprises an orthogonal-partial least squares-discriminate analysis.

8. The method of claim 1, wherein subjecting the mixture to a selective spectroscopy process comprises optimizing the duration of an excitation pulse during the spectroscopy analysis to maximize sensitivity.

9. The method of claim 8, wherein the duration of the excitation pulse is about 5 to about 40 ms.

10. The method of claim 1, wherein subjecting the mixture to a selective spectroscopy process comprises optimizing a mixing pulse during the spectroscopy analysis.

11. The method of claim 1, further comprising classifying the individual spectral peaks by applying a frequency-domain multiplex scheme.

12. The method of claim 11, wherein the frequency-domain multiplex scheme comprises a Hadamard Transform NMR matrix.

13. A method for quantifying one or more chemical species within a complex mixture, comprising:

subjecting a first mixture to a total correlation spectroscopy analysis to produce a first spectrum composed of individual spectral peaks representative of the one or more chemical species within the first mixture;

acquiring a second spectrum from an isolated standard sample from a second mixture, the second spectrum being produced by subjecting the second mixture to a second total correlation spectroscopy analysis; and

comparing the first spectrum to the second spectrum to quantify the one or more chemical species within the first mixture.

14. The method of claim 13, further comprising subjecting the individual spectral peaks of the first mixture to a multivariate statistical analysis.

15. The method of claim 13, further comprising optimizing the duration of an excitation pulse during the spectroscopy analysis of the first mixture to maximize sensitivity.

16. The method of claim 13, wherein the first mixture comprises a biofluid mixture.

17. The method of claim 13, wherein the multivariate statistical analysis comprises a Pearson product moment correlation test.

18. The method of claim 13, wherein the multivariate statistical analysis comprises a principal component analysis process.

19. The method of claim 13, wherein the multivariate statistical analysis comprises an orthogonal-partial least squares-discriminate analysis.

20. The method of claim 15, wherein the duration of the excitation pulse is about 5 to about 40 ms.

21. The method of claim 13, further comprising classifying the individual spectral peaks by applying a frequency-domain multiplex scheme.

22. The method of claim 21, wherein the frequency-domain multiplex scheme comprises a Hadamard Transform NMR matrix.

23. The method of claim 13, further comprising using the multivariate statistical analysis to determine purity of the individual spectral peaks and to assign the individual spectral peaks into spin systems.

24. The method of claim 13, further comprising differentiating the complex mixture by analyzing the concentrations of the chemical species quantified during the total correlation spectroscopy analysis.

25. The method of claim 13, further comprising optimizing a mixing pulse during the spectroscopy analysis of the first mixture.

26. A method for quantifying one or more chemical species within a complex mixture, comprising:

subjecting the mixture to a first total correlation spectroscopy analysis to produce a first spectrum composed of individual spectral peaks representative of the one or more chemical species within the mixture;

acquiring a second spectrum from an isolated standard sample within the mixture, the second spectrum being produced by subjecting the mixture to a second total correlation spectroscopy analysis; and

comparing the first spectrum to the second spectrum to quantify the one or more chemical species within the mixture.

27. The method of claim 26, further comprising subjecting the individual spectral peaks of the mixture to a multivariate statistical analysis.

28. The method of claim 27, wherein the multivariate statistical analysis comprises a Pearson product moment correlation test.

29. The method of claim 26, wherein the mixture comprises a biofluid mixture.