Instrumentation of Fluorescence Spectroscopy ( spectrofluorometer ) and process

Instrumentation of Fluorescence Spectroscopy ( spectrofluorometer ) and process

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The basic instrument is a spectrofluorometer
 

- It contains a light source, two monochromators, a sample holder and a detector.
- There are two monochromators, one for selection of the excitation wavelength, another for analysis of the emitted light.
- The detector is at 90 degrees to the excitation beam.

- Upon excitation of the sample molecules, the fluorescence is emitted in all directions and is detected by photocell at right angles to the excitation light beam.
- The lamp source used is a xenon arc lamp that emits radiation in the UV, visible and near-infrared regions.
- The light is directed by an optical system to the excitation monochromator, which allows either preselection of wavelength or scanning of certain wavelength range.

- The exciting light then passes into the sample chamber which contains fluorescence cuvette
- A special fluorescent cuvette with four translucent quartz or glass sides is used.
- When the excited light impinges on the sample cell, molecules in the solution are excited and some will emit light.
- Light emitted at right angles to the incoming beam is analyzed by the emission monochromator.
- The wavelength analysis of emitted light is carried out by measuring the intensity of fluorescence at preselected wavelength.
- The analyzer monochromator directs emitted light of the preselected wavelength to the detector.
- A photomultiplier tube serves as the detector to measure the intensity of the light.
- The output current from the photomultiplier is fed to some measuring device that indicates the extent of fluorescence.