3.2.5. Effect of NaDC
To determine the impact of the amounts of surfactant on the sweeping efficiency, different concentrations (40–140 mM) of NaDC in the BGS were tested. The concentration of NaDC had a dual effect on the analytes electrophoresis. First, it affected the sweeping of analytes which manifested itself in peaks height and
separation efficiency. Too low concentration of NaDC (40 mM) in the BGS not only caused an overlap of ENRO and an unknown peak, but also resulted in a poor enrichment of CIP. As shown in Fig. 3E, the resolution of ENRO and the unknown peak and that of ENRO and CIP were improved with increasing NaDC concentration from 60 to 140 mM. Meanwhile, the peak heights of the two analytes decreased for peaks broadening. The level of NaDC also had a sig- nificant effect on the baseline noise. Too high concentration of NaDC (140 mM) in the BGS led to an awful baseline.