VOLTAMMETRIC BEHAVIOR OF PUERARIN AND ITS DETERMINATION BY SINGLE-SWEEP OSCILLOPOLAROGRAPHY

In 0.1 mol dm(-3) H2SO4 solution, a sensitive reductive wave of puerar in was obtained by single-sweep oscillopolarography. The peak potentia l was -1.00 V (versus SCE). The peak height was proportional to the co ncentration of purearin over the range 4.0 x 10(-7)-6.0 x 10(-6) mol d m(-3) and the detection limit was 5.0 x 10(-8) mol dm(-3). The behavio ur of the reduction wave was studied and applied to the determination of puerarin in tablets. The reduction process was irreversible with th e adsorptive characteristics and the behaviour obeyed the Frumkin adso rptive isotherm. The adsorption coefficient beta was 1.14 x 10(5) and the interaction factor alpha was 1.54.