Solid Substrate-Room Temperature Phosphorescence Method for the Determination of Trace Mn(II) Based on Oxidizing Reaction of Hydrogen Peroxide Using α,α′-Bipyridine as Sensitizer

Abstract

A new solid substrate-room temperature phosphorescence (SS-RTP) method for the determination of trace manganese (II) has been established. It bases on the fact that fullerol (R) emits strong and stable room temperature phosphorescence (RTP) on filter paper substrate. H2O2 can oxidize R to cause the SS-RTP quenching. But manganese (II) can obstruct H2O2 to oxidize R, and enhance the RTP of R. alpha,alpha'-Bipyridine (Bipy) can sensitize the RTP. After adding Bipy, the DeltaI(p) enhances 7 times than that without Bipy. Under the optimum conditions, the linear dynamic range of this method is 0.016-1.12 pg spot(-1) with a detection limit (L.D.) of 4.6 fg spot(-1) (m(Mn(2+) is the absolute mass of Mn(2+)), and the regression equation of working curve is DeltaI(p)=25.20 + 63.55 m(Mn(2+) (pg spot(-1)), n=6, r=0.9983. For 0.016 and 1.12 pg spot(-1) Mn(2+), RSDS are 4.3 and 4.8%, respectively (n=7). This method has been applied to the determination of trace manganese (II) in actual sample with high sensitivity and good selection. And the reaction mechanism of SS-RTP is discussed.