Fluroscence spectroscopy

What is fluroscence spectroscopy?

Fluorescence spectroscopy is a type of electromagnetic spectroscopy that analyzes fluorescence from a sample.

To watch video on fluroscence spectroscopy👇

Principle of fluoroscenc spectroscopy :

The principle of fluoroscence spectroscopy is based upon jablonski diagram.

Jablonski diagram👇

When radiation falls on electron it gets excited and moves from groud state to excited state.

When during relaxation it comes back to ground state it releases energy in the form of radiation which is fluroscence.

Instrumentation

Components of instrument:

1) light source 2) Excitation monochromator 3) sample 4) Emission monochromator 5) Detectors 6) Readout device

1) light source:

Xenon arc is mainly used as light source.

Beacuse xenon produces continuous spectrum.

2) Excitation monochromator:

It allows only the radiation which excites molecules/atoms to pass to sample.

3.) Sample holder:

Cuvette is used as sample holder. It is made up of quartz or glass.

4.) Emission monochromator:

It passes radiation only emitted by the sample molecules/atoms to detector

Note: Emission monochromator is always at 90° from excitation monochromator. It is because it reduces risk of transmitted or reflected incident light to fall on detector. Thus it minimise the error of detector.

5.) Detectors:

It will convert light energy into electrical signal that are displayed on readout devices.

PMT is most commonly used as detector in fluoroscence spectroscopy.

6.) Readout device:

The output current from detector is fed into measuring device that indicates the extent of fluroscence from the sample.

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