2.4. Procedure
The mobile phase was pumped through the column at a flow
rate of 1.0mLmin−1. The column effluent was mixed with the supporting
electrolyte (2.5mLmin−1) at a mixing-tee and then flowed
into the flow-cell. Until stable baseline was achieved, 20L standard solution
or sample solution was injected into the mobile phase.
The quantitative determination was based on the net ECL intensity
I = IS −I0, where IS is the ECL intensity in the presence of naproxen
and I0 is the intensity of blank signal.