CHNOS analysis of organic materials

Determination of carbon, hydrogen, nitrogen, sulfur, and oxygen content of the organic sample. CHNS analysis (”LECO analysis”) is performed using Dumas combustion method, where the sample is combusted at elevated temperature followed by gas chromatography separation and detection using thermal conductivity. Oxygen is analysed using Unterzaucher pyrolysis method, which utilizes high temperature thermal decomposition and conversion of sample's oxygen into carbon monoxide before gas chromatography separation and detection by thermal conductivity. The sample can be either solid or liquid, but water in the sample affects the result. In the case of aqueous samples, it is possible to dry the sample before analysis. The price includes two parallel measurements. The results are reported as wt-% of the initial sample. The analysis gives the total carbon, hydrogen, nitrogen, sulfur, and oxygen content of the material, but it does not identify any chemical structures. Can be combined with other methods, such as GC-MS, 1H, and 13C NMR, to perform substance structure identification. Possible element packages: CHN, CHNO, CHNS, and CHNOS.

Compositional analysisElements and ions

Suitable sample matrices

Solid and liquid organic materials

Minimum sample amount

20 mg

Typical turnaround time

2 weeks after receiving the samples

Detection limit

0.05 wt-% (500 ppm) for C, H and N, 0.100 wt-% for sulfur, and 0.050 wt-% for oxygen.

Quality system

Accredited test method

Device types

Elemental analyzer

Method expert

Juha Keskiväli