PURPOSE: To obtain a urea-sensor for the determination fo urea, by bonding an enzyme membrane immobilized with urease closely with a porous membrane immobilized with the cells of nitrifying bacteria, bonding the resultant membrane to an oxygen electrode diaphragm facing the porous membrane to the diaphragm, and covering the assembly with a semipermeable membrane.
CONSTITUTION: An enzyme mebrane immobilized with urease which is an enzyme to decompose urea into ammonia and carbon dioxide, is bonded closely with a porous membrane immobilized with the cells of nitrifying baceteria which consume oxygen and assimilate ammonia, to obtaine an immobilized enzyme-microofganism composite membrane. In the case of a urea sensor having a Galvani-type dissolved oxygen electrode, the electrode is composed of the supporting member 10, filled electrolyte liquid 12, lead anode 14, platinum cathode 16, and oxygen electrode diaphragm 18. The above composite membrane 20, 22 is attached to the diaphragm 18 contacting the bacterial cell side closely to the diaphragm, and the enzyme membrane is covered with the exterior dialyzing membrance 24. The obtained membrane is fixed to the supporting member 10 with an O-rincy 26 to obtain the objective urea sensor 28.
| JPH02100668 | LIQUID DETECTOR |
| JP4503151 | Urea nitrogen measurement method and measurement reagent |
| WO/2001/092889 | LOW-ENRICHED 13C-LABELLED UREA COMPOSITION FOR UREA BREATH TEST |
KARUBE MASAO
KUBO IZUMI
FUJI DENKI SOGO KENKYUSHO KK