Non-Metal-Microanalytics (H, C, N, S, O; Organic)

Method
The simultaneous determination of hydrogen, carbon, nitrogen and sulfur is performed by combustion of the samples at approximately 1100^°C by adding oxygen to a helium gas stream. The released gases (in this process C, H, S are converted to CO₂, H₂O and SO₂, respectively, as well as N to N₂) are swept to high-selective IR-cells for H₂O, SO₂, and CO₂ and finally (after removal of all interfering gases) N₂ is swept into the thermal conductivity measuring cell for quantification. Samples being analyzed for oxygen are burnt in a high-carbon-content environment inside the pyrolysis furnace at T_max 1300^°C in a stream of helium to form CO. CO is swept from the furnace and converted to CO₂ before being measured with an IR-cell. The calibration succeeds by high-purity organic standards.

Sample preparation
No sample preparation is required.

Required amount of sample
Quantities of approximately 10 mg for major, minor, and trace components are required.

Instrumentation
LECO CHNS 932:
Carbon-, hydrogen-, nitrogen-, sulfur-analyzer with three IR measuring cells for the detection of CO₂, H₂O, and SO₂ and one thermal conductivity cell for the detection of N₂
VTF-900:
Pyrolysis furnace for oxygen analysis