1. Atomic emissions and absorption
Instrumentation I
Atomic emissions and absorption
2/12/11

2. Atomic emission E = hv = h*c/l
When excited, an atom will absorb external energy and raise its
electrons above the ground state. This is a transient and unstable state.
The electrons will return to the ground state, but need to return the
energy they absorbed to reach the higher state in discrete quanta of energy.

3. Every element has a distinct pattern of allowable quanta based on
the electron configuration of that element.
h = Plank’s constant = x J*sec
The energy is typically given off as light
Hydrogen is the easiest to visualize

4. According to Plank’s equation, each transition can be related
to a wavelength

5. Each element will have a distinctive pattern of emission
Hydrogen nm
Iron

8. Note that all wavelength in a spectra do not have the same intensity
This can be caused by re-absorbtion or interference)
Hg spectrum

9. Prismatic dispersion

10. Diffraction. Close point sources

11. Reflective diffraction

13. Atomic emission spectroscopy

14. Getting the best excitation = ICP
Induction Coupled Plasma

15. ICP reduces sample induced interferences- 7000-8000 degree plasma
Primarily used in metals analysis
Sensitive to 1 part/billion range

16. Atomic absorption spectroscopy

17. Example AAS

18. Comparision

20. FTIR Absorption of broadband infrared and subsequent analysis
of interference

23. Typical FTIR spectrum

24. polypropylene
Comparison analysis