Know your nitrogen fertilizers

The most advanced nitrogen fertilizer quality
control solution on the marker

How much nitrogen is in your fertilizers?

UAN-type liquid fertilizers (UAN-28, -30 and -32) are a nitrogen fertilizer commonly used in agriculture, which ensures an even and gradual release of nitrogen to the plants. Liquid fertilizers of the UAN type contain ammonium nitrate, urea and water. However, it is not easy to measure the exact concentration of ammonium nitrate and urea in the production, distribution and quality control of fertilizers and to calculate the optimal amount of fertilizer to be applied to the fields. Errors can lead to financial and environmental problems.

Currently, there are two main methods for measuring nitrogen – either pre-treatment and distillation of the sample using the Kjeldahl method, or a combined, carefully controlled measurement of the refraction and liquid density of the sample. Both methods are lengthy, cumbersome and expensive. We believe there is a need for a faster, cheaper and more robust method of measuring UAN fertilizer samples without sacrificing accuracy.

The solution
Determine the exact composition of the nitrogen compounds‘ in your fertilizers in just a few minutes


Senso N is a novel solution for the analysis of urea, ammonium nitrate and total nitrogen, suitable for quality control of UAN type fertilizers at the point of production, distribution or application with high accuracy. The measurement requires a single 10 µL sample and takes only 5 minutes! The concentrations of urea and nitrogen are measured by two sensors and the total amount of nitrogen is calculated from the readings of these components.

For ease of use, all necessary calculations are performed automatically by the software and displayed on a touch screen graphical user interface (GUI). The unit is equipped with an automatic dilution, washing and thermostatting system and requires no external hardware to operate.

Best features:

  • In contrast to light refraction and liquid density analysis, the measured values for urea and ammonium nitrate are independent of each other.
  • Easy calibration by UAN solutions with known ammonium nitrate and urea concentration. The exact calibration values can be set in the GUI.
  • The displayed measurement results can be expressed either in nitrogen % or in total concentration of the desired compound.
  • The sensors are immune to interferences such as technical oils or biuret.
  • Depending on use, the system will operate for weeks or months without major maintenance or cleaning.

Measuring parameters:

  • Measuring range: 10-45 % (total urea), 10-35 % (total ammonium nitrate).
  • Theoretical accuracy: 0.1% (urea), 0.1% (nitrate or ammonium nitrogen), 0.1% (total nitrogen).
  • Real accuracy tested in the laboratory with UAN 32: < 0.32 % (urea nitrogen), < 0.36 % (nitrate or ammonium nitrogen), < 0.29 % (total nitrogen).
  • Time to result: 3 min.
  • Time between measurements: 5 min.

Technical parameters:

  • Dimensions (H x L x W): 9 × 16 × 31 cm
  • Weight: 4.0 kg
  • Operating temperature: 20 – 30°C
  • Power requirements: 100 – 240 V, 50 – 60 Hz.


Senso N is based on the most advanced technology available on the market. Our scientific team has been working on a urea biosensor system for medical purposes to analyse blood samples from patients requiring haemodialysis for residual urea in the bloodstream. After discussions with technicians from the UAN fertilizer industry, a vision emerged for the application of medical technology in the chemical industry.

The technology is based on an electrochemical bi-potentiostat system that contains nitrate and urea biosensor membranes in its cell. The design works because of complex chemical reactions that occur near the surface of each thermally reduced graphene oxide-based sensor electrode, resulting in an electrochemical signal. Urea and nitrate concentrations are calculated from the increase in Faraday currents that occur due to such reactions. The system has two independent processors that control the sequences, perform calculations and make adjustments.

The Team of Senso N
Senso N was developed by a team of scientists


The company's activities relate to the production of solutions for industry and medicine, which include the development of biosensors and methods for chemical analysis. For example, the company is also currently developing two-parameter biosensors for the detection of L-amino acids and glucose for medical applications.

The company has close ties with Vilnius University, as most of the company's employees are also researchers at the university. This enables the company to engage not only in applications but also in science and to find solutions to significant technological challenges. To meet the needs of customers, the company offers various modifications of sensors and detection systems.