Nine E-64 Interaction Strategies
As it can be seen, the constructed modified electrode is superior in some cases, as compared to the previously reported modified electrodes. Figure 5 (a) and (b) show differential pulse voltammograms of HTP-MWCNT-CPE in a 0.15?M phosphate buffer solution (pH 7.0) containing different concentrations of codeine. The numbers of 1�C19 and 20�C34 correspond to 0.2�C31.4? ... Table 1 Comparison of the efficiency of different modified electrodes for the determination of codeine. The utility of the modified electrode was studied for the simultaneous determination of codeine and acetaminophen by simultaneously changing the concentrations of codeine and acetaminophen. The voltammetric responses show that the simultaneous determination of codeine and R428 nmr acetaminophen with two anodic peaks at potentials of 170 and 410?mV, corresponding to the oxidation of codeine and acetaminophen, is possible at HTP-MWCNT-CPE (Figure 6(a)). Figure 6(b) shows that the plot of corrected anodic peak current versus codeine concentration is linear in concentration range of 1.3�C168.2?��M. Also, Figure 6(c) demonstrates the linear correlation between corrected anodic peak current and acetaminophen concentration in concentration range 0.95�C125.8?��M while MWCNT-CPE could not separate the voltammograms of the mixed solution of 50.0?��M of codeine and Selleck JQ1 110.0?��M of acetaminophen (inset of Figure 6(a)). Also, the sameness of sensitivities of HTP-MWCNT-CPE to codeine in the absence (Figure 5(a); 0.0288?��A?��M?1) and presence (Figure 6(b); 0.0258?��A?��M?1) of acetaminophen indicates that the voltammetric responses of codeine and acetaminophen at HTP-MWCNT-CPE surface are independent of each other. Therefore, individual or simultaneous determination of codeine and acetaminophen is possible without any cross interferences. Figure 6 (a) Differential pulse voltammograms of HTP-MWCNT-CPE in a 0.15?M phosphate buffer solution (pH 7.0) containing different concentrations of codeine and acetaminophen. The numbers 1�C21 correspond to 1.3�C168.2?��M ... 3.4. Interference Study E-64 Applicability and selectivity of the developed procedure were also evaluated by studying the effect of some common species that often accompany codeine in real samples. The study was performed by analyzing of 40.0?��M of codeine in 0.15?M phosphate buffer solution (pH 7.0) containing concomitant species at different concentrations. The tolerance limit of coexisting species is defined as the largest amount that making variation of less than 5% in the recovery of the analyte. The results, given in Table 2, show that morphine and ascorbic acid have seriously interfering effect on the determination of codeine. Table 2 Interference study of some species for the determination of 40.0??M of codeine at HTP-MWCNT-CPE. 3.5.
