CHNOS analysis of organic materials

Determination of carbon, hydrogen, nitrogen, sulfur, and oxygen content of an organic sample. CHNS analysis (”LECO analysis”) is performed using a flash combustion method, where the sample is combusted under 25 kPa of O₂ at an elevated temperature (1000 °C), followed by gas chromatography separation and detection using a thermal conductivity detector.

Oxygen is analyzed by reduction on granulated carbon at 1480 °C, utilizing high-temperature thermal decomposition and conversion of oxygen into carbon monoxide before gas chromatography separation and detection with a thermal conductivity detector.

The sample can be either solid or liquid, but water in the sample affects the results. In the case of aqueous samples, it is possible to dry the sample before analysis.

The displayed price by includes the full CHNOS package with two parallel measurements and applies to conventional organic samples. The results are reported as wt-% of the initial sample. The ash, drying and dry loss measurements will increase the minimum required sample material need to 300 mg.

The analysis gives the total carbon, hydrogen, nitrogen, sulfur, and oxygen content of the material, but it does not identify any chemical structures. The measurement can be combined with other methods, such as GC-MS, 1H, and 13C NMR, to perform substance structure identification.

Analysis can be split into the following packages: CHN, O, and S.