Finally, the investigation of stirring speed (250 to 2500 rpm),
amplitude (10 to 100 mV), frequency (10 to 50 Hz) and step potential
(1 to 10 mV) showed that the use of 2250 rpm, 100 mV, 30 Hz
and 10 mV, respectively, displayed the best voltammetric stripping
signal for 50 μg L−1 Mn.