Which method uses a flame as the atomization source?

• A. Flame Atomic Absorption (FAA) Spectrometry
• B. Graphite Furnace Atomic Absorption (GFAA) Spectrometry
• C. Inductively Coupled Plasma Optical Emission Spectrometry
• D. Mass Spectrometry

Answer: (A)

Flame AAS uses a flame to atomize the sample. The sample is aspirated into a flame, where the heat converts it into free atoms in the ground state. A light beam at the element’s wavelength passes through the flame, and those ground-state atoms absorb some of the light. The amount of absorption is proportional to the concentration, allowing quantification. The other methods use different atomization or excitation sources: a graphite furnace atomizes the sample in a miniature furnace rather than in a flame; inductively coupled plasma optical emission uses a high-temperature plasma to excite and emit light, not to absorb light from ground-state atoms; and mass spectrometry ionizes the sample and analyzes ions, not light absorption by ground-state atoms.