For general introductory material on atomic absorption spectrometric methods, see Section 3111 A.
The two methods presented in this section are a manual method and a continuous-flow method especially recommended for selenium. Continuous-flow automated systems are preferable to manual hydride generators because the effect of sudden hydrogen generation on light-path transparency is removed and any blank response from contamination of the HCl reagent by the elements being determined is incorporated into the background baseline.