Elemental Analysis (CHNS)

Elemental Analysis is a traditional, but rather essential means of determining the elemental composition of organic materials.

Principle :

The technique involves combustion of test sample in an oxygen rich environment. The products of combustion in a CHNS analysis (CO2, H2O, N2 and SO2) are carried through the system by He carrier gas. The combustion products are measured quantitatively by means of a non-dispersive IR absorption detection system, except for the N2 which is determined via a thermal conductivity detector (TC).

Oxygen is measured in a separate VTF furnace. Sample is combusted at high temperature in a carbon rich environment. Resulting CO2 is measured using the CO2 IR cell and the percentage of oxygen is determined.

Instrumentation :

LECO CHNS-932 Elemental Analyser


Sensitivity : ~ 0.001%
Accuracy : 0.01%
Range : 0.01 - 100%
Furnace temperature : up to 1100C
Detector : IR- and TC-based
Automation :
  -  fully automated unattended operation.
  -  selection of operation parameters by touch screen.
Sample nature : solid / liquid
Sample size : 5-10 mg / 1-2 mL



Operation modes : CHNS, CHN, CNS, CN, S, N, O (with TCD or IR detection). All for solid and liquid, organic and most inorganic samples.
Quantitative high temperature decomposition : Up to 1200oC, for special applications also selectable up to 1400oC (1800oC during combustion) for analytical accuracy also for difficult to combust samples. Jet injection of oxygen supplies high concentration at the place of combustion with very low total usage.
Elemental Concentration : up to 7mg C or 2mg N absolute (or 100 %)
Thermally controlled purge and trap technique results in baseline resolution of all analytical peaks regardless of relative concentration. Analysis time is automatically optimized.
Multipoint calibration is stable for many months and independent of sample matrix.

Automation :
All analytical results are automatically calculated and complete operating conditions for each sample are stored. Optional 21 CFR Part 11 compliant software is available. Easy operation and maintenance.

Sample nature : solid / liquid
Sample size : micro (< 1mg) to macro (1g) / Bulky samples of up to 1mL

Location :

Chemistry Dept., KH31, Room 145

Technician :

Lima Mathew    Phone : 4987389

Download Technique form

Applications :

  -  Determination of carbon, hydrogen, nitrogen, sulfur and oxygen content of organic and organo-     solids and liquids.
  -  Evaluation of tiyal organic content of soil and sediments.

CHARGES (typical for straight forward analysis)
LECO CHNS-932 - C, H, N   KD 5.000
LECO CHNS-932 - S KD 10.000
LECO CHNS-932 - O KD 20.000