Use of a fiber optic probe for organic species determination

• US 5,583,051 A
• Filed: 01/31/1995
• Issued: 12/10/1996
• Est. Priority Date: 02/03/1993
• Status: Expired due to Fees

• Current Assignee: United States Of America As Represented By The Department Of Energy
• Original Assignee: United States Of America As Represented By The Department Of Energy
• Inventors: Ekechukwu, Amy A.
• Primary Examiner(s): Snay, Jeffrey R.
• Application Number:
  US08/380,921
• Time in Patent Office: 679 Days
• Field of Search: 422/56, 422/82.06, 422/82.07, 422/82.08, 422/82.09, 422/82.11, 436/139-142, 436/143, 436/145, 436/146, 436/169, 436/171, 385/12
• US Class Current: 436/169
• CPC Class Codes: G01N 21/6428 Measuring fluorescence of fluorescent products of reactions or of fluorochrome labelled reactive substances, e.g. measuring quenching effects, using measuring "optrodes" in vivo A61B5/00; immunoassay G01N33/53
• CPC Class Codes: G01N 21/78 producing a change of colour

Abstract

A fiber optic probe for remotely detecting the presence and concentration organic species in aqueous solutions. The probe includes a cylindrical housing with an organic species indicator, preferably diaminonaphthyl sulfonic acid adsorbed in a silica gel (DANS-modified gel), contained in the probe'"'"'s distal end. The probe admits aqueous solutions to the probe interior for mixing within the DANS-modified gel. An optical fiber transmits light through the DANS-modified gel while the indicator reacts with organic species present in the solution, thereby shifting the location of the fluorescent peak. The altered light is reflected to a receiving fiber that carries the light to a spectrophotometer or other analysis device.

Claims

1. A method for the detection of organic species in a solution, said method comprising the steps of:

directing light through an indicator;

measuring a first absorption spectrum of said indicator;

contacting said solution with said indicator to form a mixture;

directing light through said mixture;

measuring a second absorption spectrum of said mixture;

comparing said fast absorption spectrum and said second absorption spectrum to determine a difference between said first and said second absorption specta; and

analyzing said difference to determine the presence of organics in said solution wherein said indicator is a 5-dimethylamino-1-naphthalene sulfonate salt.

2. A method as recited in claim 1, further comprising:

determining the magnitude of said difference, said magnitude being related to said difference.

3. A method as recited in claim 1, wherein said indicator is fixed in a housing, and wherein said contacting step takes place in said housing.

4. A method as recited in claim 1, wherein said indicator is fixed in a housing having a plurality of openings;

and

said method further comprises filtering foreign matter from said solution by passing said solution through said plurality of openings before said contacting step.

5. A method as recited in claim 1, wherein said indicator is fixed in a housing having a plurality of openings;

said method further comprises filtering foreign matter from said solution by passing said solution through said plurality of openings before said contacting step; and

wherein said contacting step takes place in said housing.

6. A method as recited in claim 1, further comprising the step of adsorbing said indicator on a substrate.

7. A method as recited in claim 1, further comprising the step of adsorbing said indicator on a modified silica gel substrate.

8. A method as recited in claim 1, wherein said indicator is a 5-dimethylamino-1-naphthalene sulfonate salt, said method further comprising absorbing said 5-dimethylamino-1-naphthalene sulfonate salt on a substrate.

9. A method as recited in claim 1, wherein said indicator is a 5-dimethylamino-1-naphthalene sulfonate salt, said method further comprising absorbing a 5-dimethylamino-1-naphthalene sulfonate salt on a modified silica gel substrate.

10. A method as recited in claim 1, wherein in each of said directing steps said light is directed through a optical focusing device.

11. A method as recited in claim 1, wherein in each of said directing steps said light is reflected to a means for measuring said first and said second absorption specta.

12. A method as recited in claim 1, wherein in each of said directing steps said light is directed through an optical focusing device and reflected to a means for measuring said first and said second absorption spectra.

13. A method for the determination of organic species in a solution, said method comprising the steps of:

adsorbing an indicator on a substrate, wherein said indicator adsorbed on said substrate is fixed in a housing having a plurality of openings;

directing light through said indicator;

measuring a first absorption spectrum of said indicator;

filtering foreign matter from said solution by passing said solution through said plurality of openings;

contacting said solution with said indicator in said housing to form a mixture;

directing light through said mixture;

measuring a second absorption spectrum of said mixture;

comparing said first absorption spectrum and said second absorption spectrum to determine a difference between said first and said second absorption spectra; and

analyzing said difference to determine the presence of organics in said solution wherein said indicator is a 5-dimethylamino-1-naphthalene sulfonate salt.