her flow rates caused overpressure in the system.
Lengths of both mixing reactors (d1 and d2) were optimized
separately, because no optimum conditions were found when
we tried to optimize them simultaneously. Distance between
the two connectors (d1) ranged from 5 to 125 cm, using a PTFE
tube of 0.5 mm of internal diameter. The effect of this length on
the analytical signal of the three analytes is illustrated in Fig. 4,
selecting 25 cm as optimum value. Subsequently, d2 was varied from the minimum length (5 cm) to 50 cm, obtaining higher
peak broadening and worse peak shapes. Therefore, 5 cm was
selected as appropriate length. In order to minimize the peak
broadening, a PTFE tube of 0.3 mm of internal diameter was
used for constructing d2.