Detection of formaldehyde in urine samples

• US 20080145947A1
• Filed: 12/14/2006
• Published: 06/19/2008
• Est. Priority Date: 12/14/2006
• Status: Active Grant

• Current Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Original Assignee: Kimberly-Clark Worldwide Incorporated (Kimberly-Clark Corporation)
• Inventors: Martin, Stephanie M., Boga, Rameshbabu, Smith, Molly K., McGrath, Kevin Peter
• Granted Patent: US 8,012,761 B2
• Time in Patent Office: Days
• US Class Current: 436/130
• CPC Class Codes: A61F 13/15 Absorbent pads, e.g. sanitary towels, swabs or tampons for external or internal application to the body non-absorbent catamenial receptacles A61F5/44; Supporting or fastening means therefor; Tampon applicators
• CPC Class Codes: A61F 13/42 with wetness indicator or alarm
• CPC Class Codes: A61F 13/8405 Additives, e.g. for odour, disinfectant or pH control
• CPC Class Codes: A61F 2013/8473 for diagnostic purposes
• CPC Class Codes: G01N 21/78 producing a change of colour
• CPC Class Codes: G01N 31/224 for investigating presence of dangerous gases
• CPC Class Codes: G01N 33/52 Use of compounds or compositions for colorimetric, spectrophotometric or fluorometric investigation, e.g. use of reagent paper and including single- and multilayer analytical elements immunological elements G01N33/54386; involving labelled immunochemicals G01N33/58; for haemoglobin or occult blood G01N33/72
• CPC Class Codes: Y10T 436/200833 Carbonyl, ether, aldehyde or ketone containing
• CPC Class Codes: Y10T 436/202499 Formaldehyde or acetone

Abstract

A method for rapidly detecting the presence of formaldehyde in a urine sample (e.g., urine or a urinary material associated therewith, such as headspace gas located associated with urine) is provided. The method includes contacting the urine sample with a substrate on which is disposed a colorant that is capable of undergoing a detectable color change in the presence of formaldehyde. Without intending to be limited by theory, it is believed that oxidation of the colorant by formaldehyde induces either a shift of the absorption maxima towards the red end of the spectrum (“bathochromic shift”) or towards the blue end of the spectrum (“hypsochromic shift”). The absorption shift provides a color difference that is detectable, either visually or through instrumentation, to indicate the presence of formaldehyde within the urine sample. For example, prior to contact with a urine sample, the colorant may be colorless or it may possess a certain color. However, after contacting the urine sample and reacting with formaldehyde, the colorant exhibits a color that is different than its initial color. The color change may thus be readily correlated to the presence of formaldehyde in the urine sample.

Claims

1. A method for detecting formaldehyde in a urine sample, the method comprising:

contacting the urine sample with a substrate, the substrate comprising a colorant configured for producing a spectral response when subjected to formaldehyde;

detecting the spectral response; and

correlating the spectral response to the presence of formaldehyde in the urine sample.

2. The method of claim 1, wherein the colorant includes a triarylmethane.

3. The method of claim 2, wherein the triarylmethane includes pararosanilin or an analog thereof.

4. The method of claim 2, wherein the colorant includes basic fuchsin.

5. The method of claim 2, wherein the triarylmethane is pre-reacted with a sulfur-containing compound.

6. The method of claim 1, wherein the colorant comprises an aromatic azo compound.

7. The method of claim 6, wherein the aromatic azo compound comprises chrysoidin.

8. The method of claim 1, wherein the substrate defines a detection zone within which the colorant is located.

9. The method of claim 8, wherein the substrate is a chromatographic medium of a lateral flow device.

10. The method of claim 1, wherein the spectral response is detected and compared to a control colorant.

11. The method of claim 1, wherein the spectral response is visually detected.

12. The method of claim 1, wherein the spectral response is correlated to the presence of formaldehyde at a concentration of about 10 parts per billion or more.

13. The method of claim 1, wherein the spectral response is produced in about 5 minutes or less after the substrate is contacted with the sample.

14. A device for detecting the presence of formaldehyde in a urine sample, the device comprising:

a container having an interior volume for the receipt of the liquid sample;

a lid configured for enclosing the interior volume of the container; and

a substrate affixed to the lid, the substrate comprising a colorant configured for producing a spectral response when subjected to formaldehyde in a vapor over the urine sample.

15. The device of claim 14, wherein the colorant includes a triarylmethane.

16. The device of claim 15, wherein the triarylmethane includes pararosanilin or an analog thereof.

17. The device of claim 15, wherein the colorant includes basic fuchsin.

18. The device of claim 15, wherein the triarylmethane is pre-reacted with a sulfur-containing compound.

19. The device of claim 14, wherein the colorant comprises an aromatic azo compound.

20. The device of claim 19, wherein the aromatic azo compound comprises chrysoidin.

21. The device of claim 14, wherein the substrate defines a detection zone within which the colorant is located.

22. The device of claim 14, wherein the substrate is a chromatographic medium of a lateral flow device.

23. The device of claim 14, wherein the colorant is configured for producing the spectral response when the vapor contains a formaldehyde concentration of about 10 parts per billion or more.

24. An absorbent article for receiving a bodily fluid suspected of containing formaldehyde, the article comprising:

a substantially liquid impermeable layer;

a liquid permeable layer;

an absorbent core positioned between the substantially liquid impermeable layer and the liquid permeable layer; and

a substrate integrated into the article and positioned such that the substrate is in fluid communication with the bodily fluid when provided by a wearer of the article, the substrate comprising a colorant configured for exhibiting a spectral response indicative of the presence of formaldehyde in the bodily fluid.

25. The absorbent article of claim 24, wherein the absorbent article defines a window through which the colorant is observable.

26. The absorbent article of claim 24, wherein the substrate is a chromatographic medium of a lateral flow assay device.

27. The absorbent article of claim 26, wherein the lateral flow device comprises a sample application zone comprised of at least part of the absorbent core.

28. The absorbent article of claim 24, wherein the substrate is positioned between the substantially liquid impermeable layer and the absorbent core.

29. The absorbent article of claim 24, wherein the substrate is adhered to the absorbent core.

30. The absorbent article of claim 24, wherein the substrate is positioned between the liquid permeable layer and the absorbent core.

31. The absorbent article of claim 24, wherein the bodily fluid is urine.

32. The absorbent article of claim 24, wherein the colorant includes a triarylmethane.

33. The absorbent article of claim 32, wherein the triarylmethane includes pararosanilin or an analog thereof.

34. The absorbent article of claim 32, wherein the colorant includes basic fuchsin.

35. The absorbent article of claim 32, wherein the triarylmethane is pre-reacted with a sulfur-containing compound.

36. The absorbent article of claim 24, wherein the at least one colorant comprises an aromatic azo compound.

37. The absorbent article of claim 36, wherein the aromatic azo compound comprises chrysoidin.

38. The absorbent article of claim 24, wherein the substrate defines a detection zone within which the colorant is located.

39. A method of testing for a bladder dysfunction in a patient, the method comprising contacting a urine sample of the patient with the absorbent article of claim 24, and thereafter correlating the spectral response of the colorant to the presence of absence of the bladder dysfunction.