The field of nitrogen analysis underwent a sea change when Johan Kjeldahl published his New Method for the Determination of Nitrogen in Organic Bodies in the year 1883. This method established brand new benchmarks. Since that time, the technique has evolved to the point where it is now indispensable in fields such as the analysis of food and feed, soil and water, respectively. This versatile method can also be found in the industrial sector, the pharmaceutical industry, and anywhere else where the nitrogen content is considered to be significant. However, it is not limited to these areas in any way.
The Kjeldahl analysis is still widely regarded as the gold standard for a number of reasons, including the breadth of its potential applications, its accuracy, and the ease with which it can be carried out. mainly due to the fact that the Kjeldahl analysis can be applied to the determination of all nitrogen components. In addition to the total nitrogen content, it is possible to determine the individual components of a wide variety of sample matrices, such as ammonium, nitrate, nitrite, and organically bound nitrogen. This can be done regardless of the type of sample.
The flexibility of the matrices that can be analyzed is a significant advantage in particular. For instance, in addition to cereals, animal feed, dairy products, and other foodstuffs, the nitrogen content of slurry, sewage sludge, composts, and soils, as well as aqueous extracts and waste water, can also be analyzed. Because of the high sample weights, there is very little competition for the Kjeldahl method, particularly when dealing with highly inhomogeneous sample material.
Kjeldahl's investigation into the nitrogen and protein content
In the conventional method, manual laboratory heaters, round-bottom flasks for digestion, and Erlenmeyer flasks for distillation are utilized
In addition, the process is carried out in a beaker
Following the publication of the automatic kjeldahl nitrogen analyzer method, C
Gerhardt made it their mission to improve upon the performance of this time-honored application
In the course of the last few decades, a great variety of unique kinds of instruments have been designed specifically for the accomplishment of this goal
In the beginning, there were large cast-iron racks; today, there are highly accurate block digestion units and steam distillation units with automatic sample feeding and calculation of results
Therefore, only a minor adjustment has been made to the chemical composition, but the procedure as a whole is now fully automated and tailored to the requirements of contemporary research facilities. There are a lot of benefits for the user that come along with using a digestion block and a steam distillation system that comes with integrated titration.
The time spent at the equipment has been cut down, and it has been outfitted with a number of different safety features, which has made the daily work of the laboratory staff significantly safer. Additionally, the sample throughput has been substantially increased thanks to the automated processes that have been implemented. While this is going on, the reliability of the analysis is also being improved.
Compared to Total Nitrogen, the Total automatic kjeldahl nitrogen analyzer Nitrogen
When determining the nitrogen content, the terms Kjeldahl nitrogen (Total Kjeldahl Nitrogen, TKN) and total nitrogen (Total N) are frequently confused with one another or even considered to be the same. However, these terms actually refer to different values and should not be considered interchangeable.
Because of the differences in their names, many people incorrectly believe that total nitrogen and total nitrogen content are two distinct types of the same nitrogen compound. In point of fact, however, these two terms refer to different sum parameters in the analysis of nitrogen.
Total N takes into account nitrite (NO2) and nitrate (NO3) in addition to the total bound organic nitrogen and ammonium (NH4) that are present in a sample, whereas TKN describes the proportion of total bound organic nitrogen.
Because of this, the term Total Kjeldahl Nitrogen (TKN), also known as Kjeldahl nitrogen, is not derived from a particular nitrogen compound; rather, it is derived from the analytical method that was utilized, which is known as the Kjeldahl method.
Since the automatic kjeldahl nitrogen analyzer method can be used to determine not only Kjeldahl nitrogen but also ammonium nitrogen (NH4), nitrite nitrogen (NO2), and nitrate nitrogen (NO3), it is also possible to determine the two sum parameters TKN and total N in addition to the individual nitrogen compounds
This is because the automatic kjeldahl nitrogen analyzer method can be used to determine not only automatic kjeldahl nitrogen analyzer nitrogen but also ammonium nitrogen (NH4)
The various values are significant for the following categories of analytical endeavors:
TKN stands for total automatic kjeldahl nitrogen analyzer nitrogen.
Total Kjeldahl Nitrogen (TKN) Kjeldahl nitrogen is particularly important in the context of wastewater treatment due to the fact that the determination of TKN is required by many international regulations.
1. The parameter is continuously monitored throughout the various stages of the process, such as during biological wastewater treatment
2. This ensures that the whole process can be constantly checked for quality and altered as required
3. The amount of nitrogen that is present in the sample can also be used to calculate the sample's protein content (for more information, see the section titled "Protein")
Nitrogen in ammonium form
To begin with, the majority of the nitrogen that is introduced into the environment by means of excretions and the decomposition of organic material is present in the form of nitrogen that is organically bound. In the very first stage of the mineralization process, this substance is changed into ammonium (NH4). This process is also known as ammonification when referring to its technical name. The subsequent process, which is referred to as nitrification, involves the transformation of ammonium into nitrate (NO3) via the intermediate step nitrite (NO2).
Mineralization is a natural process that occurs in the soil when nitrogen is extracted from complex organic compounds that are inaccessible to plants and converted into a mineral nitrogen species. This process takes place when nitrogen is mineralized, or transformed, into a mineral form.
On the other hand, this method is also utilized in environmental analysis, such as in sewage treatment plants during the process of treating waste water, as this method results in the purification of the water. For example, the ammonium value in drinking water can provide information about the amount of pollution in the water.
Because plants are able to take in and use the nitrogen that is contained within ammonium, this element is also important to the field of agriculture. Fertilizers are applied to agricultural land because they promote healthy plant growth, which is why this type of land is used for agriculture. Ammonium nitrogen, which is readily available, is consequently added to the plants.
Nitrate is a form of nitrogen.
Nitrogen in nitrate form
Nitrate nitrogen (NO3), like ammonium nitrogen (NH4), can be particularly well absorbed by plants, which in turn encourages the growth of the plants. Modern agriculture makes use of fertilisers based on nitrates in order to make better use of the land that is available for agricultural production.
However, due to the fact that nitrate is only safe for human health up to a certain amount, there are stringent limits in place all over the world for things like drinking water. The overfertilization of agricultural land can result in an excessive amount of nitrate being leached into the groundwater and other bodies of water. As a result, the compliance with the limit values needs to be checked on a regular basis in areas where there is intensive agriculture.
Protein (determined using the factor for protein content)
The determination of the amount of protein present is especially important for both food and animal feed. Nitrogen that is organically bound, such as that found in amino acids, proteins, and nucleic acids (DNA), among other places, is critically important to the structure and metabolism of living organisms.
Because it is reasonable to assume that the Kjeldahl nitrogen in the majority of foods comes primarily from the proteins, the nitrogen content of a sample is directly related to the amount of protein that it contains. Because the nitrogen content of the proteins in the majority of the samples is 16%, the conversion factor that is calculated as the result of multiplying the nitrogen content percentage by the protein factor is 6.25. However, the proportion varies depending on the sample, which leads to a different protein factor (see the table below for more information).
