In this site we focused on the the areas of science incluod analytical chemisty, general chemistry, inorganic chemistry, organic chemistry, physical chemistry, and spectroscopy.(Online Chemistry Dictionary )

Yalla Science on Facebook

Follow @yallascience

Donate

Contact Form

Name

Email *

Message *

Followers

6.9.13

Instrumentation of Fluorescence Spectroscopy ( spectrofluorometer ) and process


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.
Instrumentation of Fluorescence Spectroscopy spectrofluorometer  and process

- 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.