An optimized optrode for continuous potassium monitoring in whole blood

An optrode for continuous monitoring of potassium to be used in whole blood was realized. Several commercial chromoionophores have been tried and comp osition of the membrane has been optimized in order to obtain the highest s ensitivity around pH 7.4 and maximum light stability. The sensor is sensiti ve to pH but a simple equation relates absorbance and the value (pH + log K ) and it was used in real experiments with cow whole blood. The analytical range is 1-10 mM of K+ and it matches the clinical requireme nts. (C) 1999 Elsevier Science B.V. All rights reserved.