A New Sensitive Sensor for Simultaneous Differential Pulse Voltammetric Determination of Codeine and Acetaminophen Using a Hydroquinone Derivative and Multiwall Carbon Nanotubes Carbon Paste Electrode

Figure 4

Chronoamperometric current responses at HTP-MWCNT-CPE surface in a 0.15 M phosphate buffer solution (pH 7.0), at a step potential of 235 mV, for different concentrations of codeine. The numbers of 1–5 correspond to 0.02, 0.04, 0.06, 0.08, and 0.1 mM of codeine. Insets: (a) plots of versus obtained from chronoamperograms and (b) plot of the slopes of the straight lines against the codeine concentrations.