RESUMEN
Bismuth modified boron doped diamond (BDD) film electrode was employed for simultaneous determination of trace ZnⅡ,CdⅡand PbⅡby anodic stripping voltammetry.BiⅢwas simultaneously in-situ deposited on bismuth modified boron doped diamond electrode with ZnⅡ,CdⅡ and PbⅡ by pre-concentration.In the presence of BiⅢ,the sensitivity for determination of ZnⅡ,CdⅡ and PbⅡ was remarkably enhanced.Influence factors such as bismuth concentration,boron doped concentrations of BDD electrode,pH,preconcentration potential were investigated and optimized.Under the optimal conditions,the stripping peak currents increased linearly with the increasing concentration of ZnⅡ,CdⅡ and PbⅡ in the range of 10-300 μg/L.The limit of detection was 0.56 μg/L for ZnⅡ,0.32 μg/L for CdⅡand 0.75 μg/L for PbⅡ (S/N=3),respectively.The interference experiments showed that common ions had little influence on the determination except CuⅡ.In addition,the developed electrode displayed a good repeatability.The method was successfully applied to determination of ZnⅡ,CdⅡ and PbⅡ in real water samples with the standard addition recoveries of 92.0%-114.0%.