电泳中介微分析法测定铁(Ⅱ)和铜(Ⅱ)

Determination of Iron (Ⅱ) and Copper (Ⅱ) by Electrophoretically Mediated Microanalysis

利用电泳中介微分析通过与邻菲罗啉的络合反应完成了对Fe2+与Cu2+的同时测定.在压差作用下,淌度较小的邻菲罗啉在金属离子区带之前首先进样,加高电压后,两区带电泳在磷酸缓冲液中(pH=4.5)混合、反应形成络合物并实现电泳分离.研究了缓冲液pH、试剂和样品区带长度对分离效果的影响.对于Fe2+与Cu2+两离子,方法的检出限(S/N=3)分别为1.6和11 μmol /L;线性范围分别为5.0×10-6～3.0×10-4 mol/L (r=0.9979)和8.0×10-5～3.0×10-4 mol/L (r=0.9996).采用标准矿样验证了测定Fe2+的可行性.

Simultaneous determination of two transition metal ions (Fe 2+ , Cu 2+ ) after complexation with o phenanthroline (phen) were investigated by electrophoretically mediated microanalysis (EMMA). The slower o phenanthroline zone was injected spatially before a faster analyte zone containing Fe 2+ and Cu 2+ in a fused silica capillary under pressure. Upon application of the high voltage, the analyte zone was electrophore tically mixed with the reagent zone, then the complexes were formed and separated in a phosphate buffer (pH=4.5). The separation behavior was investigated with respect to dependence on the buffer pH, analyte and reagent zone length. In this method, the linear calibration ranges were 5~300 ( r =0.9979) and 80～300 μmol/L ( r =0.9996) with detection limits of 1.6 and 11 μmol /L for Fe 2+ and Cu 2+ , respectively. The method was also validated by analysis of the standard reference mineral samples.