The Thermo Scientific Flash 2000 Series is designed for simultaneous determination of carbon, hydrogen, nitrogen, and sulfur (CHNS) in solid or liquid samples. An exothermic reaction of oxygen with the tin capsule raises the temperature in the reactor to 1800 °C for a few seconds. At this high temperature both organic and inorganic substances are converted into elemental gases which, after further reduction, are separated in a chromatographic column and finally detected by a highly sensitive thermal conductivity detector (TCD).

Alternatively, oxygen determination (O) is achieved in a separate run using an oxygen-specific pyrolysis reactor heated at a temperature slightly above 1060 °C.