Summary of Atomic Techniques

We have spoken frequently in this chapter about sensitivity and detection limit in reference to advantages and disadvantages of the various techniques. Sensitivity and detection limit have specific definitions in atomic absorption. Sensitivity is defined as the concentration of an element that will produce an absorption of 1% (absorptivity percent transmittance of 99%). It is the smallest concentration that can be determined with a reasonable degree of precision. Detection limit is the concentration that gives a readout level that is double the electrical noise level inherent in the baseline. It is a qualitative parameter in the sense that it is the minimum concentration that can be detected, but not precisely determined, like a blip that is barely seen compared to the electrical noise on the baseline. It would tell the analyst that the element is present, but not necessarily at a precisely determinable concentration level. A comparison of detection limits for several elements for the more popular techniques is given in Table 9.2. 

The description and application of the techniques discussed in this chapter are given in Table 9.3. 

Element Flame AA Graphite Furnace AA ICP Cold Vapor Hg Hydride 

Source From Perkin Elmer Instruments literature. With permission. 

TABLE 9.3 Summary of the Techniques Described in This Chapter 

---