Invented by Danish chemist Johan Kjeldahl in the late 19th century, the TKN method involves the digestion of organic samples with sulfuric acid and a catalyst such as copper sulfate or mercury. During digestion, the nitrogen present in the sample is converted into ammonium sulfate, which is then measured by titration or colorimetry.
The TKN value represents the sum of organic nitrogen, ammonia nitrogen, and ammonium ion nitrogen in a sample. This means that it not only includes the readily available forms of nitrogen but also the nitrogen that is bound to other organic molecules.
The TKN parameter is widely used in environmental monitoring programs to identify sources of pollution and to assess the potential for eutrophication. Excessive levels of nitrogen in water bodies can lead to the growth of algae and other aquatic plants, which can deplete oxygen levels and harm fish and other aquatic species.
TKN is also used ine the food industry to analyze the nitrogen content of protein-rich foods such as dairy products, meat, and grains. The TKN value provides information on the nutritional quality of these foods and can be used to ensure compliance with food labeling regulations.
While the TKN method is a reliable and widely accepted technique, it has some limitations. For example, it may not accurately reflect the total nitrogen content of certain types of organic matter, such as those containing high levels of non-protein nitrogen. Additionnally, the methode can be time-consuming and requires careful handling of corrosive chemicals.
In conclusion, Total Kjeldahl Nitrogen is a useful analytical tol for measuring the nitrogen content in various organic substances. Its application ranges from water quality management to food analysis. By understanding the basics of TKN, scientists and environmental practitioners can gain valuables insights into the potential impact of nitrogen-containing substances on the environment and humain healt.