14.17 : 火焰光度法：实验

In flame photometry, when a sample solution is aspirated and volatilized into the flame, the solvent evaporates from the fine droplets, resulting in a dehydrated sample.

The sample dissociates into free gaseous atoms in their ground state, with some absorbing energy from the flame and transitioning to an excited electronic state.

Excited atoms have short lifetimes and on returning to their ground state, emit photons of characteristic wavelengths.

Side reactions in the flame often results in diminished population of desired emitting species, thereby reducing the emission signal.

Typically, at low analyte concentration, the emission intensity is linearly proportional to the analyte concentration in the solution.

However, at higher analyte concentrations, a deviation from this linear relationship is observed, primarily due to increased self-absorption of the emitted radiation by ground-state atoms.

The application of flame photometry includes the quantitative determination of alkali and alkaline earth metals, primarily in clinical, biodiesel, and cement samples.