Date post: | 29-Nov-2014 |
Category: |
Education |
Upload: | saurav-dutta |
View: | 2,645 times |
Download: | 4 times |
I express my heartful gratitude to MADAM MANIKA
DAS KOTOKI, HOD and s/t of DEPT. OF BIOTECHNOLOGY,
DARRANG COLLEGE, TEZPUR for giving me an opportunity
to present this presentation on
“SPECTROPHOTOMETRY” and helping me to
collect and organize the presentation data. I sincerely
hope tat the knowledge provided by her will be
beneficial in my future life.
Quantitative measurement of the reflection or transmission properties of a material as a function of wavelength.
A part of BIO-INSTRUMENTATION Involves the use of SPECTROPHOTOMETER
It is a photometer that can measure intensity as a function of the light source wavelength.
It is commonly used for the measurement of transmittance or reflectance of solutions, transparent or opaque solids, or gases.
Also designed to measure the diffusivity on any of the listed light ranges that usually cover around 200nm - 2500nm using different controls and calibrations.
A Spectrophotometer
Works upon the following principles-Beer’s LawLambert’s LawBeer-Lambert’s Law
The intensity of a ray of Monochromatic Light passing through an absorbing medium decreases exponentially as the concentration of absorbing medium increases.
I = I e-klc
AUGUST BEER
The intensity of light or a ray of Monochromatic Light that passes through an absorbing medium decreases exponentially as the length of absorbing medium increases.
I = I e-k2l
JOHANN HEINRICH LAMBERT
The Beer–Lambert law, also known as the Lambert–Beer law or the Beer–Lambert–Bouguer law (named after August Beer, Johann Heinrich Lambert, and Pierre Bouguer) relates the absorption of light to the properties of the material through which the light is travelling.
Two laws have been combined together as Beer – Lambert’s Law, which is stated below-
I = I o e -kcl
0.20
Light Source
Collimator(lens)
Monochromator(Prism or Grating)
Wavelengthselector
(slit)
Samplesolution
(in Cuvette)
Detector(Photo Cell)
DigitalDisplayor Meter
Five types of Spectrophotometer according to the range and type of light used-
UV-Vis absorption spectrophotometer (UV-Vis)FT-IR absorption/transmission spectrophotometer (FTIR)Atomic absorption spectrophotometer (AAS)Atomic fluorescence spectrophotometer (AFS)X-ray fluorescence spectrophotometer (XFS)
Two types according to the number of beams used-Single Beam SpectrophotometerDouble Beam Spectrophotometer
Manual Data Input
Computerised DataInput
The use of spectrophotometers spans various scientific fields, such as-
PhysicsMaterials ScienceChemistryBiochemistryMolecular Biology
Also used in industries including semiconductors, laser and optical manufacturing, printing and forensic examination, as well in laboratories for the study of chemical substances.