Nitrogen in soils and plants

Facilitating fast, reproducible and automatic Nitrogen determination in soils and plants

Thermo Fisher Scientific has a new application note for providing rapid, automatic and reproducible quantitative determination of nitrogen in soils and plants with the Thermo Scientific FLASH 4000 nitrogen/protein analyzer. The application note is entitled “Nitrogen Determination in Soils and Plants by the Thermo Scientific FLASH 4000 Elemental Analyzer.”

Nitrogen content in soils is an important evaluation parameter of organic matter. The analyses of nitrogen content provide valuable information regarding the deficiency or excess of nutritional elements important to plant growth. Nitrogen content analysis is also essential when determining the quality of various types of crops for feeding and processing, as well as for N-cycle and N-fixation monitoring in agricultural and environmental research.

For maximum analytical performance, nitrogen content determination in soils and plants must be performed using accurate instrumental analytical techniques while also avoiding the use of toxic chemicals. To achieve this, the classic Kjeldahl method has been replaced by the Dumas combustion method, a simple and automatic technique that does not require sample digestion of toxic chemicals and facilitates faster analysis combined with excellent reproducibility. The FLASH 4000 is based on the Dumas combustion method, providing significant advantages over the Kjeldahl method including laboratory staff safety, improved sample throughput, automation, reduced operational costs and quantitative determination of nitrogen in a large range of concentrations.

The new application note details the analytical configuration and analytical conditions required to achieve rapid, safe and reliable nitrogen content determination in soil and plant samples. The correct quantity of oxygen, correlated to the weight and type of sample, is determined automatically by the OxyTuneTM feature of Thermo Scientific Eager Xperience software which facilitates the complete combustion of the sample.

Experimental results demonstrate excellent reproducibility and no memory effect when changing the type of sample, indicating the complete detection of the nitrogen present in the sample. The FLASH 4000 is able to analyze nitrogen in a wide range of samples from low to high content without matrix effects. In addition, the nitrogen data obtained using the analyzer is within the tolerable levels set by WEPAL International Round Robin Tests, demonstrating the high-performance of the instrument.