Elemental analysis is a field of analytical chemistry and is used for the quantitative and qualitative determination of organic and inorganic compounds in solid or liquid substances.
Particular attention is paid to the determination of carbon, hydrogen, nitrogen, oxygen and sulphur (CHNOS analysis). Knowledge about the content of these elements is of great importance for numerous sectors and industries.
There are various established methods for elemental analysis. Spectroscopic measurement methods such as optical emission spectroscopy (ICP-OES), atomic absorption spectrometry (AAS) or spark spectrometry are widely used and are preferred for the analysis of metallic samples.
In thermogravimetric analysis (TGA), the change in mass of the sample material is measured as a function of a change in temperature over time, which allows conclusions to be drawn about the composition of the substance being analysed.
Compared to these methods, the so-called combustion analysers offer a significantly wider range and can be used for the fast and reliable analysis of a wide variety of sample types.
Combustion analysis is basically a three-step process. In the first step, an oxygen stream is treated to remove any impurities that could affect the measurement results. In the next step, the sample material to be analysed is completely combusted in an oxygen atmosphere. Induction furnaces or resistance furnaces are generally used for this purpose. The gas components produced during combustion are processed in a final step and then analysed spectroscopically. Near-infrared sensors (NIR) or thermal conductivity sensors (TCD) are often used for analysis.
Due to the versatile use of elemental analysers, there are countless possible applications in a wide range of industries. For example, elemental analysers are often used in the steel and titanium industry for quality control purposes.
Carbon is also an important component of steel, and its content has a significant influence on the properties of the material. As the carbon content increases, the strength and hardenability of the steel increases, while other properties such as ductility and weldability decrease.
Hydrogen can have a considerable influence on the material properties of steel, titanium or even copper. High-strength steels with a high martensite content are particularly sensitive to hydrogen-induced damage. In the case of titanium, the hydrogen can be deposited in the metal matrix of the material, resulting in the formation of a metal hydride, which also has a considerable influence on the material properties.
The oxygen content of materials is also of major interest. In the case of titanium, an increased oxygen content results in a harder but also much more brittle material structure. An increasing oxygen content also has a similar negative effect on other materials such as iron, steel or copper.
In addition to determining carbon, analysing the sulphur content of a sample is one of the most important tasks in elemental analysis today. In the case of organic samples such as coal coming from mining industry, the sulphur content allows conclusions to be drawn about the quality of the fuel. Higher quality materials generally have a higher calorific value and a lower sulphur content. Analysing the sulphur content of various inorganic samples is also of particular interest.
In case of the food and feed industry the detection of nitrogen content is of special interest. Based on the nitrogen fraction, the protein content of the analysed sample can be determined.
Elemental analysis is a method for analysing various sample materials regarding their chemical composition. Particular attention is paid to the detection of carbon, hydrogen, nitrogen, oxygen and sulphur.
In general, the sample to be analysed is burned in a pure oxygen atmosphere. The resulting gas is then often analysed spectroscopically regarding its components.
Knowledge of the exact chemical composition of materials is of enormous importance for countless applications. In the steel and building materials industries, for example, elemental analysis is used for important quality control.
In addition to the steel and building materials industry, elemental analysis is used in many other areas. In the food sector, for example, this method is used for protein determination. In the mining sector, it is used to determine the carbon and sulphur content in the sample being analysed. In addition to these industries, elemental analysis is used in many other areas, such as automotive, additive manufacturing or in environmental and energy research.