초록 ▼

A gas-sample collection device provides matrix isolation of individual gas bands from a gas chromatographic separation and for the spectroscopic analysis of the individual sample bands. The device includes a vacuum chamber containing a rotatably supported, specular carousel having at least one refle

A gas-sample collection device provides matrix isolation of individual gas bands from a gas chromatographic separation and for the spectroscopic analysis of the individual sample bands. The device includes a vacuum chamber containing a rotatably supported, specular carousel having at least one reflecting surface for holding a sample deposited thereon. A gas inlet is provided for depositing a mixture of sample and matrix material on the reflecting surface which is maintained at a sufficiently low temperature to cause solidification. A first parabolic mirror directs an incident beam of electromagnetic radiation, such as in the infrared (IR) spectrum, from a source onto the sample/matrix mixture while a second parabolic mirror directs a second beam of electromagnetic radiation reflected by the specular surface to an IR spectrometer for determining the absorption spectra of the sample material deposited on the reflecting surface. The pair of off-axis parabolic mirrors having a common focal point are positioned outside of the vacuum chamber and may be displaced in combination for improved beam positioning and alignment. The carousel is provided with an aperture for each reflecting surface to facilitate accurate positioning of the incident beam relative to the gas-samples under analysis. Improved gas-sample deposition is insured by the use of a long focal length stereomicroscope positioned outside of the vacuum chamber for monitoring sample formation through a window, while the sample collector is positioned outside of the zone bounded by the incident and reflected electromagnetic beams for improved sample access and monitoring.

대표청구항 ▼

Apparatus for the collection and spectroscopic analysis of a sample in a matrix, said apparatus comprising: an evacuated chamber having an optical window in a first wall portion thereof; a cryogenically cooled specular sample carrier rotatably supported along its longitudinal axis within said evacua

Apparatus for the collection and spectroscopic analysis of a sample in a matrix, said apparatus comprising: an evacuated chamber having an optical window in a first wall portion thereof; a cryogenically cooled specular sample carrier rotatably supported along its longitudinal axis within said evacuated chamber and including an external, reflecting lateral surface; inlet means positioned in a second wall portion of said evacuated chamber adjacent to said specular sample carrier for depositing a sample material intermixed with matrix material onto the lateral reflecting surface of said sample carrier whereupon the mixture of said sample material and said matrix material solidifies on said cooled specular sample carrier, wherein said first and second wall portions form facing sections of said evacuated chamber; illumination means for generating a beam of electromagnetic radiation; detection means positioned outside of said evacuated chamber and optically communicating with and responsive to a modulated beam of electromagnetic radiation incident thereon for measuring the spectral characteristics thereof; first and second coupled parabolic reflecting means having a common focal point and positioned outside of said evacuated chamber for respectively directing said beam of electromagnetic radiation through said optical window and onto the mixture of said sample and matrix materials and for directing the beam of electromagnetic radiation reflected from said lateral reflecting surface through said optical window to said detection means wherein the spectral characteristics of said beam are measured and said sample is analyzed; alignment means including an aperture located on the lateral reflecting surface of said sample carrier for proper positioning of said beam of electromagnetic radiation relative to the sample and matrix material mixture deposited thereon, whereby no input is provided to said detection means when said beam of electromagnetic radiation is incident upon said aperture; and displacement means coupled to the combination of said first and second parabolic reflecting means for adjusting the position and the focal point of said beam of electromagnetic radiation relative to said alignment means on said specular sample carrier for improved spectroscopic analysis of said sample.