Voltammetric Behavior of Hydroxycamptothecinum at Single-Wall Carbon Nanotube Modified Electrode and Its Analytical Application

It was found that as compared with the bare glassy carbon electrode (GCE),the oxidation peak current of hydroxycamptothecinum (HCPT) was significantly increased at the single-wall carbon nanotube (SWCNT) modified GCE.Through optimization of various electrochemical parameters,a sensitive voltammetric method for direct determination of HCPT was proposed,giving a linear relationship between values of peak current (Ip) and concentration of HCPT in the range from 0.05 to 2.5 μmol·L-1.The detection limit (3S/N) was found to be 0.02 μmol·L-1 after enrichment for 3 min.Precision of the method was tested at the concentration level of 1.0 μmol·L-1 of HCPT with 10 determinations,and value of RSD found was 4.8%.Test for recovery was performed by adding standard solutions of HCPT of 3 different concentrations,values of recovery obtained were in the range of 95.5%-104.0%.In analyzing 3 samples of HCPT injections,the results obtained by this method were in conformity with the results found by UV-spectrophotometry.