1. Chapter 9 Atomic Absorption and Atomic Fluorescence Spectrometry

2. 1. Atomic Absorption Spectrometry 2. Atomic Fluorescence Spectrometry

3. 9A SAMPLE ATOMIZATION TECHNIQUES 9A-1 Flame Atomization

4. Figure 9-1 Processes occurring during atomization.

5. Types of Flames

6. TABLE 9-1 Properties of Flames

7. Flame Structure

8. Figure 9-2 Regions in a flame.

9. Figure 9-3 Temperature profiles in C for a natural gas-air flame.

10. Figure 9-4 Flame absorbance profile for three elements.

11. Figure 9-5 A laminar flow burner.

12. Performance Characteristics of Flame Atomizers.
1. Reproducible (CV = 1% or better)
2. low sensitivity

14. 9A-2 Electrothermal Atomization

15. Figure 9-6 (a) Cross-sectional view of a graphite furnace
Figure 9-6 (a) Cross-sectional view of a graphite furnace. (b) The L’vov platform and its position in the graphite furnace.

16. Performance Characteristics of Electrothermal Atomizers.
1. high sensitivity ( DL = to g)
2. low relative precision ( CV = 5-10%)

17. 9A-3 Specialized Atomization Techniques Glow Discharge Atomization Hydride Atomization Cold-Vapor Atomization

18. Figure 9-8 (a) Cross section of a cell for glow-discharge atomization of solid samples. (b) Craters formed on sample surface by six jets of ionized argon.

19. Figure 9-9 A hydride generation and atomization system for Atomic Absorption Spectrometry.

20. ATOMIC ABSORPTION INSTRUMENTATION radiation source sample holder wavelength selector detector signal processor & readout

21. Figure 9-10 Absorption of a resonance line by atoms.

22. Figure 9-11 Schematic cross section of a hollow-cathode lamp.

23. Figure 9-12 Cutaway of an electrodeless discharge lamp.

24. 9B-2 Spectrophotometers Single-Beam Instruments Double-Beam Instruments

25. Figure 9-13 Typical flame spectrophotometers: (a) single-beam design and (b) double beam design.

26. 9C INTERFERENCES IN ATOMIC ABSORPTION SPECTROSCOPY Spectral Interferences Chemical Interferences

27. Formation of Compounds of Low Volatility releasing agents protective agents ( EDTA, 8-hydroxy quinoline, ammonium pyrrolidinedithiocarbamate)

28. Dissociation Equilibria MO M + O M(OH)2 M + 2OH NaCl Na + Cl Ionization Equilibria M M+ + e

29. TABLE 9-2 Degree of Ionization of Metals at Flame Temperatures

30. 9E ATOMIC FLUORESCENCE SPECTROSCOPY