Method and system for examining the composition of a fluid or solid sample using fluorescence and/or absorption spectroscopy
US5491344A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 1, 1993 |
| Grant date | Feb 13, 1996 |
| Priority date | — |
| Expiry date | Dec 1, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N30/74
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and system for examining the composition of a fluid or solid sample using fluorescence and/or absorption spectroscopy. In one embodiment, the system is adapted for use in examining liquid effluents as they elute from the end of a liquid chromatography column and comprises a Nd:YAG laser coupled to a harmonic generator. Pulses of the fourth harmonic therefrom are focused into a Raman shifter filled with a mixture of hydrogen and methane gases. The laser pulses have an intensity sufficient to produce an array of different-colored laser pulses by stimulated Raman scattering within the Raman shifter. These different-colored pulses are then dispersed according to their respective wavelengths and then launched into a plurality of optical fibers. The fibers tranmit the different-colored pulses to a specially-designed detection cell, where they simultaneously excite a flowing fluid sample contained within the cell at the same point of axial fluid flow. The fluid sample enters and exits the detection cell via tubes. Ultraviolet and visible lamp light is also used to illuminate the fluid sample, and the attenuation of this light is used to obtain an absorption spectrum of the sample…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.