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                  What is Atomic Spectroscopy? – Sec 20-1                  Atomic Absorption Spectroscopy (AAS) 
                                                                        versus Atomic Emission Spectroscopy (AES)
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                         Flame Atomization – Sec 20-2                                 Fuels and Flame Temperatures –Table 20-1
                   Atomization process =                                                  Fuel           Oxidant       Temperature 
                                                                                                                            (K)
                   Complete atomization results in ____________________              acetylene        air             2400 - 2700
                                                                                     acetylene        Nitrous oxide   2900 - 3100
                                                                                                      (N O)
                                                                                                        2
                                                                                     acetylene        oxygen          3300 - 3400
                                                                                     hydrogen         air             2300 - 2400
                                                                                     hydrogen         oxygen          2800 - 3000
                                                                                     Cyanogen         oxygen          4800
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                               Instrumentation – Sec 20-4
                      The Linewidth Problem – absorbance is proportional to                             Line Broadening Mechanisms
                      concentration (i.e. Beer’s Law holds) when the linewidth of 
                      the probing light is narrower than the absorption band
                                                                                                    Both mechanisms result in more line broadening 
                                                                                                    as the temperature increases.
                                                                                                   1. Doppler Effect – atom moving towards the 
                                                                                                   lamp samples EM wave more often = higher 
                                                                                                   frequency (shorter wavelength) absorbed
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                        2. Pressure Broadening – colliding atoms (and                                           Hollow Cathode Lamps
                        molecules) absorb a broader range of frequencies 
                        (wavelengths)                                                             Cathode composed of the same element as the analyte. 
                                                                                                  As long as line broadening within the cathode is less 
                                                                                                  than within the flame, the linewidth of the lamp is always 
                                                                                                  less than the linewidth of the absorbing atoms and Beer’s 
                                                                                                  Law is followed.
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