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  • The BWB Team

Combustion and its Role in Flame Photometry: A Comprehensive Overview

Combustion, a widely known chemical reaction, is a process of releasing energy through the use of diatomic oxygen. This exothermic reaction generates carbon dioxide and water from a fuel source. In the field of analytical chemistry, specifically flame photometry, combustion plays a crucial role. Here we will delve into the concept of combustion, explore the combustion fuels utilised in flame photometry, explain the temperature differences between propane and butane, and discuss the application of combustion in flame photometry.


Understanding Combustion:


Combustion, as mentioned earlier, is an exothermic process that liberates heat energy by combining a fuel source with oxygen. This chemical reaction is widely recognised and utilised in various industrial, commercial, and domestic applications. It involves the rapid oxidation of the fuel source, releasing carbon dioxide and water vapour as by-products.



Combustion Fuels in Flame Photometry:


In the realm of flame photometry, where precise measurement of elements is required, combustion fuels like propane and butane, or a mixture of the two, are commonly employed. These fuels offer several desirable characteristics, including stability, controllability, and reproducibility.


Flame photometers are equipped with a mixing chamber, where a vortex efficiently blends the fuel and air in a predetermined ratio before combustion takes place in the burner head. The stoichiometric ratio between butane and propane combustion profiles is crucial to achieving optimal results. It is important to note that butane burns at a lower temperature compared to propane.


Temperature Differences between Propane and Butane:


The variation in burning temperatures between propane and butane is a notable factor when choosing a combustion fuel for flame photometry. Propane burns hotter than butane due to differences in their molecular structures and combustion properties.


The molecular structure of propane consists of three carbon atoms and eight hydrogen atoms (C3H8). This arrangement allows propane to achieve a higher combustion temperature, making it an excellent choice for applications where higher flame temperatures are required.


On the other hand, butane possesses four carbon atoms and ten hydrogen atoms (C4H10). The additional carbon atoms in butane lead to a lower heat of combustion and result in a comparatively lower burning temperature.


Application of Combustion in Flame Photometry:


Flame photometry utilises the combustion process to analyse the concentration of various elements in a sample. By introducing the sample into the flame, the heat of combustion excites the atoms present in the sample, causing them to emit characteristic wavelengths of light.


One key aspect in flame photometry is the temperature of the flame. Increasing the flame temperature leads to an increase in the quantity of emitted wavelengths. This occurs by altering the ratio of unexcited atoms to excited atoms, ultimately affecting the observed signal.



In flame photometers such as the BWB-Tech flame photometer, a built-in compressor is located inside the instrument. This innovative feature simplifies the setup process, allowing users to conveniently connect a gas source to the instrument. The slogan "Just Add Gas" reflects the ease of use and accessibility provided by this design.


Combustion, an exothermic chemical reaction, plays a vital role in flame photometry. By utilising combustion fuels like propane and butane, flame photometers are able to achieve precise and reliable measurements of elemental concentrations. Understanding the temperature differences between these fuels is essential in selecting the most suitable option for specific applications. Additionally, controlling the flame temperature in flame photometry can significantly impact the emitted wavelengths and, consequently, the accuracy of the analysis. With advancements in instrumentation, flame photometry has become more accessible and user-friendly, exemplified by the incorporation of compressors in modern flame photometers. As technology continues to evolve, flame photometry will remain a valuable analytical tool for elemental analysis in various scientific and industrial fields.




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