Disposable potentiometric ammonia gas sensors for estimation of ammonia in blood

Why ammonium detection is particularly challenging but insightful with ionophore-based potentiometric sensors – an overview of the progress in the last 20 years

“…Beyond that, NH 4 + detection in the sample becomes difficult. The first implementation of nonactin in polymeric membranes was reported by Meyerhoff and co-workers, 38,39 who developed a potentiometric sensor for detecting ammonia gas in blood samples based on the use of a buffer solution phase placed between NH 4…”

Continuous monitoring of ambient ammonia with a membrane-electrode-based detector

“…We previously have been successful in devising sensitive and highly selective membrane-electrode-based systems suitable for direct measurement of low levels of dissolved ammonia in solutions (including blood) (17,18). We now describe how this original detection concept can be extended to design a very simple arrangement for monitoring gas-phase ammonia on a continuous basis.…”

Response properties, applications and limitations of carbonate-selective polymer membrane electrodes

“…For evaluation within the gas sensor arrangement., a small piece of the above membrane was affixed to the end of a plastic pipet-tygon tubing assembly as described previously for an ammonium-selective membrane [ 11,121. The rest of the gas sensor was also assembled in an analogous manner to the earlier ammonia probe [12] buffer. The pH of the buffer was simultaneously monitored with a glass electrode to determine whether responses observed were a result of pH changes caused by the addition of test reagents (a pH change shifts the CO:-/HCO; equilibrium and the electrode responds to OH-).…”