Calibration-free optical chemical sensors

Chemistry: analytical and immunological testing – Optical result

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C436S127000, C436S133000, C436S172000

Reexamination Certificate

active

07026165

ABSTRACT:
An apparatus and method for taking absorbance-based chemical measurements are described. In a specific embodiment, an indicator-based pCO2(partial pressure of CO2) sensor displays sensor-to-sensor reproducibility and measurement stability. These qualities are achieved by: 1) renewing the sensing solution, 2) allowing the sensing solution to reach equilibrium with the analyte, and 3) calculating the response from a ratio of the indicator solution absorbances which are determined relative to a blank solution. Careful solution preparation, wavelength calibration, and stray light rejection also contribute to this calibration-free system. Three pCO2sensors were calibrated and each had response curves which were essentially identical within the uncertainty of the calibration. Long-term laboratory and field studies showed the response had no drift over extended periods (months). The theoretical response, determined from thermodynamic characterization of the indicator solution, also predicted the observed calibration-free performance.

REFERENCES:
patent: 5116759 (1992-05-01), Klainer et al.
patent: 5434084 (1995-07-01), Burgess, Jr.
MacCraith, B.D.; McDonagh, C.; McEvoy, A.K.; Butler, T.; O'Keefe, G.; Murphy, V.J.Sol-Gel Sci. Tech.1998, 8, 1053-1061.
Spichiger-Keller, U.E.Chemical Sensors and Biosensors for Medical and Biological Applications, Wiley-VCH: Weinheim, 1998.
Berman, R.J.; Christian, G.D.; Burgess, L.W.Anal. Chem.1990, 62, 2066-2071.
DeGrandpre, M.D.anal. Chem.1993, 65,331-337.
DeGrandpre, M.D.; Hammar, T.R.; Smith, S.P.; Sayles, F.L.Iimnol. And Oceanog.1995, 40, 969-975.
Byrne, R.H.; Breland, J.A.Deap-Sea Res.1989,36,803-810.
Clayton, T.D.; Byrne, R.H.Deep-Sea Res.1993, 40, 2115-2129.
Goyet, C.; Walt, D.R.; Brewer, P.G.Deep-Sea Res.1992, 39, 1015-1026.
Goswami, K.; Kennedy, J.A.; Dandge, D.K.; Klainer, S.M.; Tokar, J.M.Proc. SPIE—Int. Soc. Opt. Eng.1990, 1172, 225-232.
Lefevre, N.; Ciabrini, J.P.; Michard, G.; Brient, B.; DuChaffaut, M.; Merlivat, L.Mar. Chem.1993, 42, 189-198.
Weeks, D.A.; Johnson, K.S.Anal. Chem.1996, 68, 2717-2719.
Peterson, J.L.; Goldstein, S.R.; Fitzgerald, R.V.; Buckhold, K.K.Anal. Chem.1980, 52, 864-869.
Zhou, Q.; Kritz, D.; Bonnell, L.; Sigel, G.App. Opt.1989, 28, 2022-2025.
Chau, L.K.; Porter, M.D.Anal. Chem.1990, 62, 1964-1971.
DeGrandpre, M.D.,Anal. Chem.1999, 71, 1152-1159.
Ingle, J.D.; Crouch, S.R.Spectrochemical Analysis.Prentice-Hall: New Jersey, 1998.
Thompson, R.B.; Jones, E.R.Anal. Chem.1993, 65, 730-734.
McDonagh, C.; MacCraith, B.D.; Mc envoy, A.K.Anal. Chem.1998, 70, 45-50.
Wolfbeis, O.S.; Posch, H.E.; Kroneis, H.W.Anal. Chem.1985, 57, 2556-2561.
Klimant, I.; Meyer, V.; Kuhl, M.Linmol. Oceanog.1995, 40, 1159-1165.
Draxler, S.; Lippitsch, M.E.Proc. SPIE-13 Int. Soc. Opt. Eng.1993, 2085, 61-67.
Tabacco, M.B.; Uttamial, M.; McAllister, M.; Walt, D.R.Anal. Chem.1999, 71, 154-161.
Burgess, L. W.Sensors and Actuators B 291995, 10-15.
Weigl, B.H.; Holobar, A.Analytica Chimica Acta282, 1993, 335-343.
Wolfbeis, O.S.; Weis, L. J.Anal. Chem.1988, 2028-2030.
Luo, S.; Walt, D.R.Anal. Chem.1989, 61, 174-177.
Walt, D.R.; Gabor, G.; Goyet, C.Analytica Chimica Acta274, 1993, 47-52.
DeGrandpre, M.D.; Hammar, T.R.; Wallace, D.W.R.; Wirick, C.D.Limnol. Oceanogr.42(1) 1997, 21-28.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Calibration-free optical chemical sensors does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Calibration-free optical chemical sensors, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Calibration-free optical chemical sensors will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-3547350

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.