the batch method. In the batch mode, the experimental parameters were kept constant. The typical response curve of uric acid
that reacted with DPA was recorded to study the kinetic characteristic of the CL reaction. Fig. 3 demonstrates that the CL reaction
was very quick. The CL intensity peak appeared within 0.3 s since
the uric acid solution was injected. The CL signal would also
decrease instantly to baseline at within 0.5 s. Therefore, the length
of the mixing tube of DPA and uric acid should be as short as
possible in the flow-injection method. The tube delivering uric
acid was inserted into the flow cell in order to obtain strong CL
intensity.