Environmental Engineering Reference
In-Depth Information
Figure 9.11
Typical relative purchase prices for atomic spectroscopy systems (Courtesy of Perkin-
Elmer, Inc.)
favored for lower concentrations. ICP-OES and ICP-MS are multi-element
techniques, favored where large numbers of samples are to be analyzed and cost
is not the primary concern (Fig. 9.12).
Whereas the cost of ICP-MS is still prohibitive for many labs, ICP-OES
appears to have become the dominant instrument for routine environmental metal
analysis and the role of other atomic absorption techniques has decreased.
Compared with FAA, ICP-OES offers several advantages: (a) Lower interelement
interference, which is a direct consequence of their higher temperatures; (b) Better
spectra for many elements under the same excitation conditions, and hence spectra
for many elements can be recorded simultaneously. This is why ICP can perform
sequential multielemental analysis; (c) Higher temperature allowing refractory
compounds (e.g., metal oxides) to be measurable; (d) Determination of nonmetals
such as Cl, Br, I, and S; and (e) A wider linear dynamic range of 4-6 orders of
magnitude.
High
ICP-
OES
ICP-
MS
Speed
Flame
AA
GFAA
Low
High
Low
Detection
limits
Figure 9.12
General selection guide for atomic spectroscopy instrumentation based on sample
throughput and concentration range (Courtesy of Perkin-Elmer, Inc.)
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