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.
High temperature dissociates molecules, creating an ion emission spectra.
Physical interference from changes in sample viscosity and surface tension. Extracts are measured photometrically. At pH 8.5 to 9.5, dithizone complexes with bismuth, stannous tin, and monovalent thallium. Mercury ions react with dithizone solution to form an orange solution that is measured in the spectrophotometer.