CHNS Analysis

Perkin-Elmer 2400 Series II CHNS/O Analyser

The Perkin-Elmer 2400 (series II) CHNS analyser is an elemental analyser that uses to rapid determination of carbon, hydrogen, nitrogen and sulphur content in material or environmental samples. The analyser can operate in either CHN mode or CHNS mode. The CHN mode simultaneously detects Carbon, Hydrogen and Nitrogen whereas CHNS mode allows the simultaneous detection of Sulphur in addition to Carbon, Hydrogen and Nitrogen.

Principle

The instrument functions based on the Pregl-Dumas method where the sample combustion takes place in a high-temperature and oxygen-rich environment. During the combustion process, Carbon is converted to Carbon dioxide; Hydrogen to water; Nitrogen to Nitrogen gas/oxides of Nitrogen and Sulphur to Sulphur dioxide. The combustion products are then moved out of the combustion chamber by an inert carrier gas and passed through heated high purity Copper. The function of this Copper medium is to remove any Oxygen that is not consumed in the initial combustion and to convert any oxides of Nitrogen to Nitrogen gas. The gases are then passed through the absorbent traps to leave only Carbon dioxide, water, Nitrogen and Sulphur dioxide. Finally, the gasses are subjected to gas chromatographic (GC) separation and thermal conductivity detection (TCD).

Strengths

• Designed to analyse organic materials

Limitations

• Refractory materials cannot be used for analysis
• The maximum combustion temperature for a sample is limited to 950°C
• Cannot be used for the analysis of materials containing inorganic salts (Potassium and Sodium salts) in higher concentrations
• Sample has to be homogeneous as the sample quantity used is minute (Maximum: 2 mg)

Applications

• Determination of the weight percentage of C,H, N, S or O in a variety of sample types

Technical Specifications

• Analytical Range: