Atomic Absorption Spectroscopy: Atomization Methods

AAS usually atomizes samples through flame or electrothermal atomization.

Flame atomization typically uses a nebulizer to continuously aerosolize the sample and a spray chamber assembly to mix it with fuel and oxidant.

Only about five percent of the aerosol droplets are fine enough to reach the flame, where they desolvate in the primary combustion zone, leaving behind bare particles that are atomized in the inner flame.

The gaseous atoms, ions, and molecular species swiftly flow through the interzonal region for analysis and out of the flame.

Because very little of the sample is successfully atomized and detected, flame atomization isn't good for samples with low analyte concentrations or limited volumes.

On the other hand, electrothermal atomization, also known as graphite-furnace atomization, uses a graphite tube to capture and concentrate analytes from small, discrete samples, which are dried, charred, and atomized at high temperatures.

Alternatively, some elements under milder chemical conditions convert to volatile hydride products first and then can be atomized. Additionally, mercury determination can use a unique cold-vapor method because of its natural volatility.