| 摘 要： | The voltammetric and polarographic behaviours of 14 rare earth elements were investigated in anhydrousacetone.The influence of residual oxygen on their waves was examined.At a concentration lower than 6×10~(-4)mol/L,Eu~(3 ),Yb~(3 )and Sm~(3 ) produce two waves and other rare earth ions exhibit only one wave.When the concentration is greater than 8×10~(-4)mol/L,two waves could be observed on the reductionof Yb~(2 ),Sm~(2 )and other RE~(3 )ions except for Eu~(3 ).By adding 0.6% H_2O(or 1×10~(-4)mol/L NH_4ClO_4)one well-defined wave appears instead of two.The phenomenon is explained that a thin deposit film may beformed at electrode surface owing to the interaction of RE~(3 ) with O_2~-,which is the reduction product of traceoxygen in aprotic solvent.In the presence of a proton donor such as H_2O or NH_4~ ,oxygen reduces directly toH_2O_2 and eliminates the appearance of two waves.
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