- Typical instruments measure CHNO(S)
- Steps
- known mass of sample is combusted in pure O2 atmosphere
- CO, CO2, H2O, NOX and SO2 is formed
- The gases pass through a CuO and Cu catalyst conveting CO CO2 and NOX N2
- Via a He carrier, the gases are passed through 4 traps for H2O, CO2, N2, SO2
- Masses of each component determined and given as percentage of total mass. Residual mass is labelled as other elements
- Notes
- Exact mass of water needs to be known
- Isotopes not measured
- Widely accepted deviation from theoretical value is $\pm$0.04%
- For oxygen measurement, combustion is done in H2 atmosphere
- ICP is used to detect other elements. The sample is burned in plasma and the emitted light is analyzed for the elements.