Atomic Absorption Spectroscopy (AAS) and Inductively Coupled Plasma Mass Spectrometry (ICP-MS) are both used to measure metals, but they differ in how they work and what they can do.
AAS measures the amount of light absorbed by atoms of a specific element. It usually tests one element at a time and is suitable for samples with moderate metal concentrations. It is simple, cheaper, and good for routine testing of a few elements.
ICP-MS, on the other hand, uses a very hot plasma to turn the sample into ions and then measures their mass. It can detect many elements at once and at extremely low levels—even parts per trillion. It is much more sensitive and faster but also more expensive and complex to operate.
In short:
- AAS is best for simple, low-cost, single-element analysis.
- ICP-MS is best for highly sensitive, multi-element, trace-level analysis.