The disguised chromatograph, part I: CHN analyzer

An important academic research tool that I rarely heard about in industry is the CHN anayser. Any Organic/Synthetic chemist know that in some applications CHN are so important as NMR or Mass Spectrometry, but what many people doesn't know is that CHN is a automatized chromatograph.

It works in following way:

The sample is heated at 1000 ºC and carbon, hydrogen and nitrogen converted to CO2, H2O and NO2, after reduction of NO2 to N2 through a cooper catalyst, the gases are separated and measured with a thermal conductivity detector.

In the end you have the final percentage of each element like: C: 45%, H: 8% and N: 47%.

Some models also detect Sulfur as SO2.