酸性铬兰K固体石蜡碳糊修饰电极溶出伏安法测定痕量钴

DETERMINATION OF TRACE COBALT BY ANODIC STRIPPING VOLTAMMETRY METHOD(ASV) USING ACID CHROME BLUE K MODIFIED SOLID PARAFFIN WAX CARBON PASTER ELECTRODE

在pH为8.5，0．2mol／L，氨性缓冲底液中，以酸性铬兰K（ACBK）为修饰剂，固体石蜡为粘合剂，制备了ACBK碳糊修饰电极。在-1．0V电位下富集，将钴以Co－ACBK络合物的形式吸附在电极上，以阳极溶出伏安法制定Co2+，在十0．106V（VS．SCE，以下同）处有灵敏的氧化峰，其一次微分峰电流与Co2+浓度在1．0X10^-12～1．0X10~－5mol／L范围内的负对数呈良好的线性关系，此法的检测下限为5.0X10^13mol／L.

In this paper,solid paraffin wax carbon paste electrode modified by acid chrome blue K (ACBK)has been made. In 0. 2m/L NH3.HO2-NH4Cl solution (pH= 8. 5) cobalt was accumulated to form Co-ACBK cornplex onthe chemical modified electrode at the applied poten tial of - 1.0V. A sensitive oxidation peak of Co2+ was observedwith ASV method. The peak potential is 0. 106V(vs. SCE). The lst differential current/logarithm of concentration re lationship is linear from 1 X 10-12~ 1 X 10-5mol/L. The detect limit is 5 X 10-13mol/L.