Detecting and Measuring Concentration of Urea in the Blood Using an Electronic Sensor

Abstract

People who suffer from chronic kidney disease require the use of hemodialysis. The
monitoring of blood urea concentration during therapy is important to evaluate the progress of
therapy. The higher the concentration of urea in the blood, the more lethal it is for the patient.
Urea is broken down into ammonia and carbon dioxide with the help of enzyme urease. High
concentrations of ammonia in the blood can further damage the kidneys. Ammonia ions
dissolved in the blood can be detected using a potentiometric conductivity sensor. The sensor
has two electrodes that detect changes in electrical potential difference between them. Results
show that as the concentration of ammonia dissolved in distilled water increases, the
conductivity of the solution increases. On the other hand, an increase in ammonia concentration
dissolved in diluted blood would show a decrease in conductivity. This shows that ammonia has
an effect on a solution’s overall conductivity, but not as much as the difference caused by blood.
The undetected changes made by ammonia in diluted blood can be calculated, and these values
can be referred as the fixed relation of ammonia concentration and solution conductivity.
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