Metals that are introduced to the unsaturated zone and the saturated zone will most likely not be transported a long distance. Dissolved metals that are carried below the land surface will readily sorb to soil particles or lithic material in the unsaturated zone and the saturated zone. Metals introduced into the atmosphere may be carried to the land surface by precipitation and dry fallout. Additionally, because metals readily sorb to many sediment types, wind-borne sediment is a potential route for metal transport. Most samples will require digestion before analysis to reduce organic matter interference and to convert metal to a form that can be analyzed by Atomic Absorption Spectroscopy or Inductively Coupled Plasma Spectroscopy.
Digestion is complete when solution is clear or light-colored.
Digestion is complete when digestate is light in color. Digestion is complete when soultion is clear and white HClO4 fumes appear. Sample is aspirated into a flame and atomized. The amount of light emitted is measured. The high heat of a graphite furnace atomizes the element being determined.