Elemental analysis C,H,S,N

Service description

This technique provides the total content of carbon, hydrogen and nitrogen in a wide range of organic and inorganic solid samples. The technique is based on the complete and instantaneous oxidation of the sample by combustion with oxygen at a temperature of 925 ºC. Combustion products (CO2, H2O and N2) are transported by a carrier gas (He) via a reduction tube and then selectively separated in specific columns to be then thermally desorbed. Finally, the gases are passed separately by a thermal conductivity detector which gives a signal which is proportional to the concentration of each of the individual components of the mixture signal. For significant, repeatable and reliable quantitative determination, the sample must be free of any solvent traces and impurities. Also it is important that replicate samples exhibit high degree of homogenization and need to be finely ground or crushed to facilitate combustion. The recommended minimum amount for each sample is 50 mg, which should come in flat mouth vials (1.5 cm in diameter). The products to be analyzed must be perfectly dry to discard errors due to the presence of solvents or water moisture. It is recommended carry out at least two tests per sample to avoid errors due to the lack of sample homogenization. Samples to be analyzed must be free of mercury. Elemental analysis could be completed with the determination of total phosphorus (see nutrient water analysis).