Spectrophotometric bioanalytical flow-injection system for control of hemodialysis treatment

A spectrophotometric flow-injection analysis (FIA) system for monitoring cl inical hemodialysis is demonstrated. The role of a dialysate urea detector incorporated in this bioanalytical system is played by an optical flow-thro ugh biosensor based on Prussian Blue film with chemically linked urease for ming a monomolecular layer of the enzyme. This pH-enzyme optode-FIA system is useful for the selective determination of post-dialysate urea in the ran ge of concentration corresponding to its level in real clinical samples (2- 16 mmol l(-1)). This bioanalytical system allows the analysis of about 15 s amples of spent dialysate per hour. The operational and storage stabilities of the applied biosensor are longer than 2 weeks and 2 months, respectivel y. Clinical evaluation of the bioanalytical system was performed.