DETERMINATION OF IRISQUINONE BY SINGLE SWEEP OSCILLOPOLAROGRAPHY

AIMTo propose a polarographic method for the determination of irisquinone. METHODSA reduction wave of irisquinone was recorded by single sweep oscillopolarography. RESULTSIn 8.0×10^-3 mol·L^-1 Na₂B₄O₇-1.6×10^-2 mol·L^-1 KH₂PO₄ (pH 7.7) supporting electrolyte, a reduction wave of irisquinone with peak potential -1.23 V (vs SCE) achieved high sensitivity. The 2nd-order derivative peak current of the reduction wave was proportional to irisquinone concentration in the range of 1.5×10^-7～5.2×10^-6 mol·L^-1 (γ=0.9992, N=9). The detection limit was 6.0×10^-8 mol·L^-1. Relative standard deviation (RSD) was 0.87% by performing 13 independent measurements on 2.0×10^-6 mol·L^-1 irisquinone. CONCLUSIONThe proposed method was sensitive, simple, rapid, and can be applied to the determination of irisquinone in raw medicine and capsule.