elemental analysis carbon, hydrogen and nitrogen elemental analysis C,H,N analysis A type of elemental analysis accomplished by combustion of the sample at 1200 °C in a stream of unreactive gas and excess oxygen and collection of the products (CO2, H2O and NOx). The masses of these combustion products can be used to calculate the composition of the unknown sample. CHMO:0001076 C, H, N analysis C, H, N elemental analysis CHN analysis