Discriminator atomic absorption spectrometry

In the determination of cadmium in seawater, for both operational reasons and ease of interpretation of the results it is necessary to separate particulate material from the sample immediately after collection. The dissolved trace metal remaining will usually exist in a variety of states of complexation and possibly also of oxidation. These may respond differently in the method, except where direct analysis is possible with a technique using high-energy excitation, such that there is no discrimination between different states of the metal. The only technique of this type with sufficiently low detection limits is carbon furnace atomic absorption spectrometry, which is subject to interference effects from the large and varying content of dissolved salts. 

Px/2 atoms can be expected. It appears feasible to determine the rates of recombination of both Pj/a and Pi/a chlorine atoms separately, using methods capable of state discrimination—e.p.r. spectrometry, or vacuum U.V. resonance line absorption (sections 4.2.9a, 4.2.lOe). 

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