Non-Flame Absorption Cells

Non-flame atomization has been developed in recent years and has advantages over the flame under certain circumstances. Generally, nonflame methods have greater sensitivities and require smaller samples than flames. A number of non-flame techniques have been developed that can produce an atomic vapor from a liquid or solid sample. 

The atomic vapor is produced by an action similar to the action of a conventional hollow cathode source. Positive ions of the fill-gas strike the cathode, dislodging metal atoms into the optical path. The sensitivity is a function of the discharge current. Walsh used currents of up to 60 mA, but currents of 200-600 mA have been used by others. Higher currents cause some additional heating of the cathode and some additional atomic vapor is produced by the heating process. 

FIGURE 10-19. Hollow cathode sputtering chamber. [From B. M. Gatehouse and A. Walsh, Analysis of Metal Samples by Atomic Absorption Spectroscopy, Spectrochim. 

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