| abstract |
Disclosed is a method and apparatus for the determination of urea in an aqueous specimen such as blood or urine. The specimen is passed through a bed of immobilized urease to hydrolyze the urea to ammonium ion. The ammonium ion is then converted to ammonia by reaction with a base. The resulting ammonia is then selectively passed as a gas through a hydrophobic, ammonia permeable membrane for potentiometric detection with a pH sensitive electrode. |