Potentiometric detection of ammonium in biological fluids: reducing the interference from potassium

Identifier:  TFM:184

Handle: https://hdl.handle.net/20.500.11797/TFM184

Authors:  Chahin,Nassif

Abstract:
ABSTRACT: A novel approach to detect ammonium in biological samples is introduced here. The strategy combines the extraction of the main interfering cation, i.e. potassium, by functionalized polystyrene microbeads and the potentiometric detection of ammonium. Indeed the detection of ammonium in real samples is typically hampered by the strong interference coming from potassium. The potentiometric detection of ammonium in artificial urine was first carried out. Then, the extraction of potassium was optimized by tuning the amount of components and polystyrene microbeads. We reported an extraction efficiency as high as 77 % which then reduced significantly the interference from potassium. Noteworthy, we hypothesized that the amount of microbeads has to be tuned to the amount of potassium present in the sample. A general strategy was therefore proposed: first potentiometric detection of potassium, second extraction of potassium by the microbeads and third potentiometric detection of ammonium. Several artificial samples were then measured and their corresponding recovery calculated. The present strategy present significant advantages although limitations could be suffered in particularly high content of potassium.