Wood Ash Database

– Wood for Energy -

Analysis and extraction methods


ICP-AES is optical emission spectrometry with inductively coupled plasma. The plasma is formed by argon gas in a partly ionized state flowing through a radio frequency field, i.e. the gas contains charged particles. It then reaches a very high temperature of up to 10000 °C. At high temperatures, most chemical elements emit light of characteristic wavelengths that can be measured and used for content determination.

The sample that is to be analyzed is led into the plasma in the form of an aerosol of fine units of fluid. The light emitted by the various chemical elements are divided into separated wavelengths by a lattice and picked up by detectors sensitive to light. This makes it possible to get a simultaneous determination of up to 40-50 chemical elements.

ICP-AES is therefore a multi-element technique. Sensitivity-wise ICP-AES roughly equals atomic absorption by flame, by having detection limits typically at the level of µg/l in water solutions.