2. INTRODUCTION
• Raman Spectroscopy is a non-destructive
chemical analysis technique which
provides detailed information about
chemical structure, phase and polymorphy,
crystallinity and molecular interactions.
• It is based upon the interaction of light
with the chemical bonds within a material.
3. HISTORY
• This inelastic scattering of light was predicted
theoretically by Adolf Smekal in 1923.
• This was first observed experimentally by Sir
Chandrasekhara Venkata Raman in 1928,
which is why this inelastic scattering is called
Raman scattering (Raman effect).
• Noble prize in 1930.
5. (a) An electron is excited from the ground level and falls to
the original ground level. (b) An electron is excited from the
ground level and falls to a vibrational level. (c) An electron is
excited from a vibrational level and falls to the ground level.
9. 9
SAMPLE HOLDER
FILTER
•Optical filter
•Notch filter
•Edge filter
• Glass and silca tubes
• Water is regarded as good solvents for the
study of inorganic compounds in raman
spectroscopy
15. Advantages :
• Non-contact and non-destructive analysis
• High spatial resolution up to sub-micron scale
• No sample preparation needed.
• Both organic and inorganic substances can be
measured
• Samples in various states such as gas, liquid,
solution, solid, crystal, emulsion can be
measured
• Samples in a chamber can be measured
through a glass window
16. Disadvantages :
• The Raman effect is very weak. The detection
needs a sensitive and highly optimized
instrumentation.
• Fluorescence of impurities or of the sample
itself can hide the Raman spectrum. Some
compounds fluoresce when irradiated by the
laser beam.
• Sample heating through the intense laser
radiation can destroy the sample
18. • The use of SERS to detect and monitor the
chemical fungicide thiabendazole (TBZ) which
is used in the food industry against mold and
blight on citrus fruit and bananas.
19. Detection of pesticides in fruits by surface-
enhanced Raman spectroscopy coupled with
gold nanostructures
20. REFERENCE
• Jin, H., Lu, Q., Chen, X., Ding, H., Gao, H. and Jin, S. (2015). The use of
Raman spectroscopy in food processes: A review. Applied Spectroscopy
Reviews, 51(1), pp.12-22.
• Mabrouk, P. (2005). Modern Raman SpectroscopyA Practical Approach By
Ewen Smith (Strathclyde University, Glasgow, U.K.) and Geoffrey Dent
(Intertek ASG and UMIST, Manchester, U.K.). John Wiley & Sons,
Ltd: Chichester. 2005.Journal of the American Chemical Society, 127(33),
pp.11876-11877.
