A highly sensitive and selective cathodic adsorptive stripping voltammetric method for determination of
rutin is presented. The method relies on the accumulation of a Cu(II)–rutin complex at a hanging mercury
drop electrode (HMDE), followed by its reduction during a differential pulse voltammetric scan. The
electrochemical behavior of the Cu(II)–rutin complex at HMDE was investigated by cyclic voltammetry.
Results show that the electrode process is adsorption-controlled and gradually becomes less reversible at
high scan rates where peak separation grows. Under the optimized conditions (phosphate buffer pH 6,
1.000 V accumulation potential, 180 s accumulation time, 70 mV pulse amplitude, 50 mV s1 scan rate
and 1.6 106 M Cu(II) concentration), the reduction peak current (Ipc) of the Cu(II)–rutin complex is
linear (Ipc (nA) = 10.070 + 1.9 108 [Rutina]) to rutin concentration in the range from 2.0 107 to
1.4 106 M, with a correlation coefficient of 0.999. The detection and quantification limits obtained
were 7.0 109 M and 2.2 108 M, respectively. The method was successfully applied to the
determination of rutin in soybean cultivars, with recoveries of 94–105%.