Adsorptive Stripping Voltammetry of Bleomycin

Abstract

In 0.05 M H ₂ SO ₄ solution, two reductive peaks, P ₁ and P ₂ , of bleomycin were obtained. The peak potentials E _P1 and E _P2 were -0.83 and -1.09 V (versus Ag/AgCl), respectively. The sensitivity of P ₂ was much higher than that of P ₁ . The peak current of P ₂ was proportional to the concentration of bleomycin over the range 1.0 ×10 ^-9 –1.0 × 10 ^-7 M with a detection limit of 5.0 × 10 ^-10 M using adsorptive voltammetry at an accumulation time of 120 s (E _i = -0.80 V). The behaviour of the reduction wave was studied and applied to the determination of bleomycin in mouse serum. The reduction process of P ₁ was irreversible with adsorptive characteristics and the adsorption behaviour obeyed the Frumkin adsorptive isotherm.The adsorptive coefficient β was 8.9 × 10 ⁵ , the interaction factor α was 0.94 and the Gibbs energy of adsorption ΔG° was -33.93 kJ mol ^-1 . P ₂ was an irreversible adsorption peak with catalytic hydrogen properties.