Catalytic solid substrate-room temperature phosphorimetry for the determination of trace As(V) based on oxidising reaction between hydrogen peroxide and fullerenol using tween-80 as sensitizer

Abstract

A new catalytic solid substrate-room temperature phosphorimetry (SS-RTP) for the determination of trace arsenic(V) has been established. It is based on the fact that fullerenol (F-ol) emitted strong and stable room temperature phosphorescence (RTP) on nitric acid cellulose membrane (NCM) substrate. H₂O₂ could oxidise F-ol to cause the quenching of RTP. As(V) could catalyse H₂O₂ to oxidise F-ol and decrease the RTP signal of F-ol sharply. After adding tween-80 in the system, its ΔI _p enhanced 7.7 times compared with the without-tween-80 levels. Under the optimum conditions, the linear dynamic range of this method was 0.016−11.2 ag spot⁻¹ with a detection limit (LD) of 9.3 zg spot⁻¹ (corresponding concentration: 2.3 × 10⁻¹⁷ g mL⁻¹). This sensitive, simple and selective method has been successfully applied to the determination of trace As(V) in human hair and tea samples. The reaction mechanism for SS-RTP is also discussed.

Keywords:

• arsenic(V)
• fullerenol
• tween-80
• catalytic solid substrate-room temperature phosphorimetry

Acknowledgements

This work was supported by Fujian Province Science Foundation (Grant 2006J0269 (U0650025), D 0510027, 2006J0386).