Influence of parameters such as flow rate, compositions
of carrier solution and applied potentials (E1 is the applied
generator electrode potential and E2 is the applied detector
electrode potential) was individually examined on the FIA
signals of 50 lM DA. A steep decrease in the FIA signals
were noticed when the flow rate was greater than 300 lL/
min (E1 = 0.7 V, E2 = 0.1 V). The absence of signal sensitivity
at high flow rates is likely the kinetic limitation associated
with the addition reaction [3]. The concentrations of
ABSA (2–5 mM) showed no significant effects on the FIA
signals.