Eg. Matveeva et al., DETERMINATION OF COPROPORPHYRIN IN URINE BY USING STOPPED-FLOW FLUOROIMMUNOASSAY, Analytica chimica acta, 361(1-2), 1998, pp. 27-32
A simple and fast stopped-flow fluoroimmunoassay method for the direct
determination of coproporphyrin in urine is described, which is the f
irst attempt to apply the immunoassay methodology for this analytical
purpose. The method is based on the use of the initial rate of the imm
unochemical reaction as the analytical parameter, which is measured in
only 0.5 s through the fluorescence quenching of the porphyrin caused
by its reaction with monoclonal antibodies. Stopped-flow mixing techn
ique allows this high initial rate to be easily measured and facilitat
es the automation of the method. The dynamic range of the calibration
graph is 7-100 nM and the relative standard deviation is 1.1-4.0%. Pot
ential interferences from the sample matrix an avoided or minimized by
the use of kinetic methodology, so that the pretreatment of the sampl
e is not required. The analytical recoveries obtained by applying the
method to urine samples ranged from SS to 113%. (C) 1998 Elsevier Scie
nce B.V.