Bismuth (III)-rutin complex based derivative-adsorption chronopotentiometry for the determination of bismuth (III)

An electroanalytical method for the determination of trace amounts of bismuth, based on derivative chronopotentiometry of bismuth (III)-rutin complex adsorptively accumulated on the surface of a hanging mercury drop electrode (HMDE) has been developed. Optimum experimental conditions include 0.015 mol/l HAc, 0.005 mol/l NaAc, 7.5 x 10(-7) mol/l rutin, and a pre-concentration potential of 0.10 V (vs. SCE). Under these conditions, the detection limit and linear range are 5 x 10(-11) mol/l and 1.0 x 10(-10-) 7.5 x 10(-8) mol/l, respectively, for an accumulation time of 3 min. The method has been used to determine the amount of bismuth in traditional Chinese medicine (medical herb) with satisfying result obtained. The main factors that affect the sensitivity of the system have been studied during the electrode processes. The electrochemical behavior of bismuth-rutin complex at the HMDE is also reported.