title: Determination of creatine kinase activity using a co-immobilized auxiliary enzyme reactor coupled on-line with a flow injection system.
abstract: Two flow injection methods (based on spectrophotometric and spectrofluorimetric detection) were developed for the determination of over-all creatine kinase activity. Despite the complexity of the reactions involved (both include three enzyme-catalysed steps), the manifold is very simple because the two auxiliary enzymes which catalyse the two-step indicator reaction are co-immobilized on controlled-pore glass. The features of the proposed methods (calibration ranges between 0.1 and 2.0 and 0.01 and 1.0 U l-1, relative standard deviation 0.93 and 0.53% for the spectrophotometric and spectrofluorimetric methods, respectively) allow the successful determination of the analyte activity in serum samples (recoveries better than 95-105% for both methods).
authors.affiliation: Department of Analytical Chemistry, Faculty of Sciences, University of Córdoba, Spain.
authors.forename: J M
authors.initials: JM
authors.lastname: Fernández-Romero
authors.forename: M D
authors.initials: MD
authors.lastname: Luque de Castro
mesh_terms: D001322:Autoanalysis / Q000379:methods; D003402:Creatine Kinase / Q000097:blood*; D004800:Enzymes, Immobilized; D006801:Humans; D013050:Spectrometry, Fluorescence; D013056:Spectrophotometry, Ultraviolet
chemical_list: D004800:Enzymes, Immobilized; D003402:Creatine Kinase