System and method for liquid delivery evaluation using solutions with multiple light absorbance spectral features

• US 7,791,716 B2
• Filed: 04/07/2008
• Issued: 09/07/2010
• Est. Priority Date: 04/07/2008
• Status: Active Grant

• Current Assignee: Artel Incorporated (Conagra Brands, Inc.)
• Original Assignee: Artel Incorporated (Conagra Brands, Inc.)
• Inventors: Ewing, Charles A., Rogers, Alexis L., Curtis, Richard H., Bradshaw, John Thomas, McNally, Ceara, Albert, Keith J., Knaide, Tanya R.
• Primary Examiner(s): PUNNOOSE, ROY M
• Application Number:
  US12/098,875
• Publication Number:
  US 20090251681A1
• Time in Patent Office: 883 Days
• Field of Search: 356/36, 356/627, 356/432
• US Class Current: 356/36
• CPC Class Codes: G01F 22/00 Methods or apparatus for measuring volume of fluids or fluent solid material, not otherwise provided for
• CPC Class Codes: G01F 25/0084 for measuring volume

Abstract

A system and related method for improved liquid delivery evaluation using a solution containing one or more dyes such that the solution exhibits multiple distinct detectable light absorbance spectral features for calibrating or testing over extended volume or dilution ranges are described. The system includes: a photometric instrument capable of measuring optical absorbance at multiple wavelengths; one or more sample solutions to be dispensed using the liquid delivery system whose performance is being tested or calibrated; and vessels optionally pre-filled, or filled by the user, with diluent solution. The sample solutions contain one or more dyes, chosen so that multiple distinct detectable light absorbance spectral features, such as peaks and/or valleys and/or plateaus of the solution can be distinguished for volume or dilution ranges of interest. The concentrations of the dyes may be chosen so that a large volume delivery device is calibrated using a spectral feature in the solution with a low absorbance per unit pathlength, while a small volume delivery device is calibrated with the same sample solution but using a different spectral feature with a high absorbance per unit pathlength.

Claims

1. A method of measuring a liquid volume of a sample solution in a vessel, the method comprising the steps of:

a. adding to the vessel a known volume of diluent including a known concentration of a diluent dye which absorbs light at a wavelength unique to the diluent;

b. adding a volume of the sample solution to the vessel, wherein the sample solution includes a known concentration of one or more dyes, wherein the one or more dyes are selected to produce multiple distinct detectable light absorbance spectral features at a corresponding number of distinct wavelengths, each of which is distinct from the wavelength unique to the diluent, and wherein the sample solution does not include the diluent dye;

c. mixing the diluent and the sample solution in the vessel to produce a mixture of the sample solution and the diluent;

d. measuring the absorbance of the mixture of the sample solution and the diluent at one or more wavelengths at which the distinct detectable light absorbance spectral features can be detected; and

e. calculating the volume of the sample solution added to the vessel based on the measured absorbances, absorptivity of the diluent and the sample solution and the known volume of the diluent.

2. The method of claim 1 wherein the step of calculating the volume of the sample solution added to the vessel involves using the equation

3. The method of claim 1 wherein the one or more dyes of the sample solution comprise a first sample solution dye and a second sample solution dye, wherein each of the first sample solution dye and the second sample solution dye has a single distinct detectable light absorbance spectral feature.

4. The method of claim 1 wherein the one or more dyes of the sample solution comprises a single sample solution dye, wherein the single sample solution dye has a plurality of distinct detectable light absorbance spectral features.

5. The method of claim 1 wherein the diluent includes a plurality of distinct detectable light absorbance spectral features that do not overlap the distinct detectable light absorbance spectral features of the sample solution.

6. The method of claim 5 wherein the diluent includes a plurality of diluent dyes.

7. A method of measuring a liquid volume of a sample solution in a vessel, the method comprising the steps of:

a. adding to the vessel a known volume of diluent including a known concentration or concentrations of one or more diluent dyes, resulting in a diluent with multiple light absorbance spectral features at a corresponding number of distinct wavelengths;

b. adding a volume of the sample solution to the vessel, wherein the sample solution has no measurable absorbance at the distinct wavelengths of the multiple light absorbance spectral features of the diluent;

c. mixing the diluent and the sample solution in the vessel to produce a mixture of the sample solution and the diluent;

d. measuring measurable absorbances of the mixture of the sample solution and the diluent; and

e. calculating the volume of the sample solution added to the vessel based on the measured absorbances, absorptivities of the diluent and the sample solution and the known volume of the diluent.

8. The method of claim 7 wherein the sample solution contains no dyes.

9. The method of claim 7 wherein the sample solution contains one dye having one light absorbance spectral feature at a corresponding wavelength distinct from any wavelength of the distinct wavelengths of the multiple spectral features of the diluent.

10. The method of claim 7 wherein the sample solution contains one or more dyes producing a plurality of light absorbance spectral features at corresponding distinct wavelengths.

11. The method of claim 10 wherein the distinct wavelengths of the light absorbance spectral features of the one or more dyes of the sample solution are all different from the distinct wavelengths of the multiple spectral features of the diluent.

12. The method of claim 10 wherein the sample solution includes a plurality of dyes and wherein only one of the distinct wavelengths of the light absorbance spectral features of the plurality of dyes of the sample solution is the same as one of the distinct wavelengths of the multiple spectral features of the diluent.

13. A method of determining the dilution of a sample solution using a plurality of vessels, wherein the sample solution includes one or more dyes selected to produce multiple distinct detectable light absorbance spectral features at corresponding wavelengths, the method comprising the steps of:

a. measuring in the sample solution the absorbance values of the detectable light absorbance spectral features at the corresponding wavelengths, wherein the sample solution is contained in a first vessel of the plurality of vessels;

b. transferring a target volume of the sample solution from the first vessel to a second vessel of the plurality of vessels;

c. mixing into the sample solution in the second vessel a target volume of a diluent, wherein the diluent includes a diluent dye that is the same as one of the one or more sample solution dyes at a concentration substantially equivalent to the concentration of the corresponding dye of the sample solution;

d. measuring the absorbance values of the detectable light absorbance spectral features in the second vessel; and

e. calculating a dilution ratio for the sample solution contained in the second vessel based on the measured absorbance values, wherein the dilution ratio represents the extent to which the sample solution has been diluted by the diluent mixed into the second vessel.

14. The method of claim 13 wherein the calculation of the dilution ratio involves using the equation

15. The method of claim 14 further comprising the steps of:

a. repeating X more times the steps of i) transferring a target volume of the mixture of the sample solution and the diluent into a subsequent vessel, ii) mixing in a target volume of the diluent into the subsequent vessel, and iii) measuring the absorbance values for all spectral features for which measurable absorbance values may be obtained, wherein X is ≧

1, such that the last vessel of the plurality of vessels with the mixture of the sample solution and the diluent and the added diluent is vessel n and a preceding vessel is vessel m; and

b. calculating a dilution ratio for the mixture of the sample solution and the diluent contained in vessel n, wherein the dilution ratio represents the extent to which the mixture of the sample solution and the diluent has been diluted by the diluent mixed into vessel n.

16. The method of claim 15 wherein the step of calculating the dilution ratio for the mixture of the sample solution and the diluent of vessel m after mixing with the diluent in vessel n involves using the equation

17. The method of claim 13 wherein the one or more dyes of the sample solution comprises a first sample solution dye and a second sample solution dye, wherein each of the first sample solution dye and the second sample solution dye has a single distinct detectable light absorbance spectral feature.

18. The method of claim 13 wherein the one or more dyes of the sample solution comprises a single sample solution dye, wherein the single sample solution dye has a plurality of distinct detectable light absorbance spectral features.

19. The method of claim 18 wherein the diluent includes a plurality of diluent dyes.

20. A method of determining the dilution of a sample solution diluted with a diluent, wherein the sample solution includes known concentrations of one or more dyes selected to produce multiple distinct detectable light absorbance spectral features at corresponding wavelengths, the method comprising the steps of:

a. transferring a target volume of the sample solution from a source into a vessel;

b. mixing into the sample solution in the vessel a target volume of the diluent, wherein the diluent includes a diluent dye that is the same as one of the one or more sample solution dyes at a concentration substantially equivalent to the concentration of the corresponding dye of the sample solution;

c. measuring the absorbance values of the detectable light absorbance spectral features in the vessel; and

d. calculating a dilution ratio of the sample solution from the source based on the measured absorbance values, wherein the dilution ratio represents the extent to which the sample solution of the source has been diluted by the diluent mixed into the vessel.

21. The method of claim 20 further comprising the steps of:

a. repeating X more times the steps of i) transferring a target volume of the mixture of the sample solution and the diluent to a subsequent vessel, ii) adding a target volume of the diluent with the known concentration of the common dye to the mixture of the sample solution and the diluent in the subsequent vessel and iii) measuring the absorbance values, wherein X is ≧

1, such that any vessel but the source is vessel m and the source is represented as vessel 0; and

b. calculating a dilution ratio for the sample solution from the source, wherein the dilution ratio represents the extent to which the sample solution of the source has been diluted by the diluent through all mixing steps.

22. The method of claim 21 wherein the step of calculating the dilution ratio for the sample solution of vessel 0 after the addition of the diluent in vessel m involves using the equation

23. The method of claim 20 wherein the one or more dyes of the sample solution comprises a first sample solution dye and a second sample solution dye, wherein each of the first sample solution dye and the second sample solution dye has a single distinct detectable light absorbance spectral feature.

24. The method of claim 20 wherein the one or more dyes of the sample solution comprises a single sample solution dye, wherein the single sample solution dye has a plurality of distinct detectable light absorbance spectral features.

25. The method of claim 24 wherein the diluent includes a plurality of diluent dyes.

26. A method of determining the dilution achieved in diluting a solution originating from a source using a sample solution and a diluent, wherein the sample solution includes one or more sample solution dyes selected to produce multiple distinct detectable light absorbance spectral features, the method comprising the steps of:

a. transferring a target volume of the sample solution from a source into a first vessel;

b. mixing into the sample solution in the first vessel a target volume of the diluent;

c. transferring a target volume of the mixed sample and diluent from the first vessel into a second vessel;

d. mixing into the solution in the second vessel a target volume of the diluent;

e. measuring the absorbance values of the detectable light absorbance spectral features of the solution in the first and second vessels; and

f. calculating a dilution ratio for the sample solution contained in the second vessel based on the measured absorbance values, wherein the dilution ratio represents the extent to which the mixed sample and diluent from the first vessel has been diluted by the diluent mixed into the second vessel.

27. The method of claim 26 wherein the calculation of the dilution ratio involves using the equation

28. The method of claim 26 further comprising the steps of

a. repeating X more times the steps of i) transferring a target volume of the mixture of the sample solution and the diluent into a subsequent vessel, ii) mixing in a target volume of the diluent into the subsequent vessel, and iii) measuring the absorbance values for all spectral features for which measurable absorbance values may be obtained, wherein X is ≧

1, such that the last vessel of the plurality of vessels with the mixture of the sample solution and the diluent and the added diluent is vessel n and a preceding vessel is vessel m; and

b. calculating a dilution ratio for the mixture of the sample solution and the diluent contained in vessel n based on the absorbance measurements of the mixtures in vessels m and n, wherein the dilution ratio represents the extent to which the mixture of the sample solution and the diluent has been diluted by the diluent mixed into vessel n.

29. The method of claim 28 wherein the calculation of the dilution ratio involves using the equation: