Spectroscopic chemical analysis methods and apparatus
Inventors
Hug, William F. • Reid, Ray D.
Assignees
Interested in licensing this patent?
MTEC can help explore whether this patent might be available for licensing for your application.
Publication Number
US-7525653-B1
Publication Date
2009-04-28
Expiration Date
Abstract
Spectroscopic chemical analysis methods and apparatus are disclosed which employ deep ultraviolet (e.g. in the 200 nm to 300 nm spectral range) electron beam pumped wide bandgap semiconductor lasers, incoherent wide bandgap semiconductor light emitting devices, and hollow cathode metal ion lasers to perform non-contact, non-invasive detection of unknown chemical analytes. These deep ultraviolet sources enable dramatic size, weight and power consumption reductions of chemical analysis instruments. Chemical analysis instruments employed in some embodiments include capillary and gel plane electrophoresis, capillary electrochromatography, high performance liquid chromatography, flow cytometry, flow cells for liquids and aerosols, and surface detection instruments. In some embodiments, Raman spectroscopic detection methods and apparatus use ultra-narrow-band angle tuning filters, acousto-optic tuning filters, and temperature tuned filters to enable ultra-miniature analyzers for chemical identification. In some embodiments Raman analysis is conducted simultaneously with native fluorescence spectroscopy to provide high levels of sensitivity and specificity in the same instrument.
Core Innovation
The invention provides a method of providing a chemical analysis of a sample by applying excitation radiation from an electron beam pumped semiconductor source onto the sample to produce emission radiation. The excitation radiation has a wavelength less than about 250 nm in one method and less than about 300 nm in another. Emission radiation is received at a spectral filter capable of passing a selected range of wavelengths along a given optical path, and an amount of the selected emission radiation is measured using a detector located along the selected optical path.
The measured amount of selected emission radiation is correlated with data associated with at least one chemical compounds of interest to provide at least a partial chemical analysis of the sample. The approaches include correlating information concerning the amount measured by the detector with compound data to produce at least a partial chemical analysis. The spectral filtering is central to passing selected wavelength ranges along given optical paths for detection and correlation.
Integrated chemical analysis is provided by measuring different selected emission radiation using a 1st spectral filter and a 2nd spectral filter, with a 1st detector and a 2nd detector located along 1st and 2nd optical paths, respectively. The 1st chemical analysis comprises a selected one of native fluorescence or Raman analysis, while the 2nd chemical analysis comprises a different one of native fluorescence or Raman analysis. The excitation radiation is produced by a source selected from an electron-beam pumped semiconductor laser, a hollow cathode laser, an AlGaN semiconductor source having an aluminum content greater than 20%, a diamond semiconductor emission source, or a diamond-like carbon semiconductor emission source.
Claims Coverage
The document provides four independent claims. Each independent claim centers on supplying a sample, applying ultraviolet excitation radiation from a specified source category, spectrally filtering emission along an optical path, detecting and measuring an amount of selected emission radiation, and correlating the measurement with data for chemical compounds of interest to provide at least a partial chemical analysis, with independent Claim 27 further requiring integrated dual-path native fluorescence/Raman analysis.
Electron-beam pumped semiconductor excitation with tunable spectral filtering and correlation
Supplying a sample to be analyzed; applying excitation radiation from an electron beam pumped semiconductor source having a wavelength less than about 250 nm onto the sample; receiving emission radiation at a spectral filter capable of passing a selected range of wavelengths along a given optical path; measuring an amount of the selected emission radiation present using a detector located along the selected optical path; and correlating information concerning the amount of selected emission radiation measured by the detector with data associated with at least one chemical compounds of interest to provide at least a partial chemical analysis of the sample.
Electron-beam pumped semiconductor light emitting device excitation with spectral filtering and correlation
Supplying a sample to be analyzed; applying radiation from an electron beam pumped semiconductor light emitting device having a wavelength less than about 300 nm onto the sample; receiving emission radiation at a spectral filter capable of passing a selected range of wavelengths along a given optical path; measuring an amount of the selected emission radiation using a detector located along the selected optical path; and correlating information concerning the amount of selected emission radiation measured by the detector with data associated with at least one chemical compounds of interest to provide at least a partial chemical analysis of the sample.
Integrated dual spectral filter chemical analysis using different native fluorescence/Raman modalities
Supplying a sample to be analyzed; applying excitation radiation having a wavelength less than about 300 nm onto the sample to produce emission radiation; receiving the emission radiation at a 1st spectral filter capable of passing a 1st selected emission radiation along a 1st optical path; receiving the emission radiation at a 2nd spectral filter capable of passing a 2nd selected emission radiation along a 2nd optical path; measuring an amount of the 1st selected emission radiation using a 1st detector located along the 1st optical path; correlating information concerning the amount of selected emission radiation measured by the 1st detector with data associated with one or more chemical compounds of interest to provide at least a partial 1st chemical analysis of the sample; measuring an amount of the 2nd selected emission radiation using a 2nd detector located along the 2nd optical path; correlating information concerning the amount of 2nd selected emission radiation measured by the 2nd detector with data associated with one or more chemical compounds of interest to provide at least a partial 2nd chemical analysis of the sample; wherein the 1st chemical analysis comprises a selected one of native fluorescence or Raman analysis and the 2nd chemical analysis comprises a different one of native fluorescence or Raman analysis; and wherein the excitation radiation is produced by a source selected from the group consisting of (1) an electron-beam pumped semiconductor laser; (2) a hollow cathode laser; (3) a ALGaN semiconductor source having an aluminum content greater than 20%; (4) a diamond semiconductor emission source; and (5) a diamond-like carbon semiconductor emission source.
UV laser excitation with tunable spectral filtering and correlation
Supplying a sample to be analyzed; applying UV laser radiation onto the sample; receiving radiation from the sample at a tunable spectral filter capable of passing a selected radiation along a given optical path; measuring an amount of the selected radiation present using a detector located along the selected optical path; and correlating information concerning the amount of radiation measured by the detector with data associated with at least one chemical compounds of interest to provide at least a partial chemical analysis of the sample; wherein the UV laser radiation is produced by a source selected from the group consisting of (1) an electron-beam pumped semiconductor laser; (2) a hollow cathode laser; (3) a ALGaN semiconductor source having an aluminum content greater than 20%; (4) a diamond semiconductor emission source; and (5) a diamond-like carbon semiconductor emission source.
Across the independent claims, the inventive coverage is directed to UV/DUV excitation from electron-beam pumped semiconductor sources (including specified wavelength limits) and alternative UV laser sources, combined with spectral filtering along an optical path and detector measurement. The methods then correlate measured amounts of selected emission radiation with chemical compound data to obtain at least partial chemical analysis, with Claim 27 specifically requiring integrated dual analysis using different native fluorescence or Raman modalities along separate spectral filter/detector paths.
Stated Advantages
Documented Applications
No documented applications found
Interested in licensing this patent?