This document provides an introduction to spectroscopy, explaining the electromagnetic spectrum and the interaction of light with matter. It covers key concepts such as ionizing radiation, wave energy equations, and the principles behind various types of spectroscopy including UV-visible and NMR spectroscopy. Additionally, it discusses foundational figures in the field and includes mathematical laws relevant to absorbance.

1. Introduction to Spectroscopy
M. Faisal Shahid
Department of Biosciences
Mohammad Ali Jinnah University
Karachi

2. Light
Light is electromagnetic radiation within a certain portion of the
electromagnetic spectrum.

3. The Electromagnetic Spectrum
The electromagnetic spectrum is the ENTIRE RANGE and of
FREQUENCIES of ELECTROMAGNETIC RADIATION* as per their
WAVELENGTHS AND PHOTON ENERGIES.
* LIGHT CAN EXIST AS BOTH PARTICLE AND WAVE (de’ Broglie hypothesis)

4. The Electromagnetic Spectrum
The electromagnetic spectrum (EMS) is the ENTIRE RANGE and of
FREQUENCIES of ELECTROMAGNETIC RADIATION as per their
WAVELENGTHS AND PHOTON ENERGIES.
Fig 1: The Electromagnetic Spectrum as per comparison with wave /photon energies

5. The EMS-Continued
Fig 2: The Electromagnetic Spectrum as per comparison with daily life examples

6. Spectroscopy
• Spectroscopy is a series of technique(s) that uses the interaction of
energy with a SAMPLE to perform analysis.
OR
• It is the study of matter and the changes it undergo(es) when it
interacts/subjected to a particular electromagnetic radiation (light).

7. Ionizing and Non Ionizing Radiations
Ionizing radiation refers to types of radiation that has ENOUGH
ENERGY TO REMOVE ATLEAST “ONE” ELECTRON from an atom.
Ionizing radiation is always HIGH ENERGY CARRIER WAVES/PHOTONS

8. The EMS-Continued
Fig 2: The Electromagnetic Spectrum as per comparison with daily life examples

9. Boundaries of EMS
Fig 3: The Electromagnetic Spectrum Regional Boundaries as per Wavelengths (ƛ) and Frequency

10. The Wave Energy Equation (Plank’s Equation)
E=h.ʋ
Here:
E: Energy
h: Plank’s Constant (6.63x10-34 J.s)
ʋ: Frequency of a wave [f= 1/(c/ƛ)] or [ f= 1/t(sec))

11. The UV Spectrum
• 150-380 nm (UV)
Fig 4: The UV Spectrum Regional Boundaries as per Wavelengths (ƛ) and Frequency
Here:
UV-A: Long wave UV (315-400 nm)
UV-B: Medium wave UV (280-315 nm)
UV-C: Short wave (100-280 nm)
Near UV: 300- 380, 400 nm

12. The Visible Spectrum
Fig 5: The Visible Spectrum Boundaries as per Wavelengths (ƛ) and Frequency

13. The Principle of Spectroscopy
Fig 6: The Fundamental Principle of Spectroscopy (Any Type)
A light source (of any wave length) passes the EM Radiation type from a Sample and the
Resultant Emission Wavelength/frequency is Detected by a Detector.

14. The Lambert Beer Law
• Lamber’s Statement:
“Absorbance of a material sample is directly proportional to its thickness”
• Beer’s Statement:
“Absorbance is proportional to the concentrations of the attenuating
species in the material sample”
• Mathematically (and MORE EMPERICALY &
Practically)

15. Some Basic Types of Spectroscopy in Research
and Applied Use
• UV-Visible Spectroscopy
• IR-Spectroscopy
• X-Ray Diffraction
• Fluorescent Spectrometery
• Mass Spectrometery
• NMR Spectroscopy

16. The Founders Behind This Science
Joseph Ritter von Fraunhofer
(Straubing, Germany)
Anders Jonas Ångström
(Uppsala, Sweden)

17. Heisenberg’s Uncertainty Principle
• “It is simultaneously impossible to PRECISELY MEASURE the POSITION
and ANGULAR MOMENTUM of a moving object at the same time.”
Werner Heisenberg
Nobel Prize in Physics-1932

18. Spectroscopy Stretched to It’s Limit
at Visualization of 4 states of a Hydrogen Atom
Fig 7: The Electromagnetic Spectrum Regional Boundaries as per Wavelengths (ƛ) and Frequency

19. Questions??