【摘要】 使用阴极溶出伏安法,利用2,3-二羟基苯丙氨酸(DHN)可以与Fe(Ⅲ)结合生成配合物,而BrO3-的加入可以催化该电化学反应的性质,系统研究了海水中溶解态Fe(Ⅲ)的最佳分析条件。结果表明,体系中添加20.0μmol/L DHN即可达到分析要求;添加BrO3-可以使溶出电流线性增大,选择的最终浓度为20.0mmol/L。当沉积电位为-0.20V,扫描速率为50.0mV/s,沉积时间为90s时,即可达到低铁海水的分析要求,在此条件下检测限为0.011nmol/L。紫外消解可以使测量灵敏度比未消解时提高13倍。用此方法测量得到的太平洋某处(158°15′E,22°23′N)海水表层水浓度为0.45nmol/L,75m处浓度为0.14nmol/L,1 500m处浓度为0.86nmol/L。更多还原

【Abstract】 The determination method of Iron in sea water is studied by Cathodic Stripping Voltammetry(CSV) in this work.The factors that may influence the sensitivity were studied by changing the electrochemical parameters and the concentrations of competing ligand,2,3-dihydroxynaphthalene(DHN) and catalytic reoxidation,BrO-3.It is demonstrated that with adsorptive collection of complexes with DHN,the sensitivity of the determination of iron in seawater is greatly enhanced by catalytic re-oxidation in the presence of Bromate(BrO-3).The limit of detection is lowered to 0.011 nmol/L Fe(using an adsorption time of 90 s).Open ocean water could be well determined by the experiment condition which included 20.0 mmol/L BrO-3 and 20.0 μmol/L DHN,with the electrochemical parameters of-0.20V deposition potential,50.0 mV/s scan rate and 90 s deposition time.The sensitivity was increased by 13 times in UV digested sea water.The method was applied to the samples from the Pacific Ocean and the concentrations of dissolved Fe of surface,75 m and 1500 m water are 0.45 nmol/L,0.14 nmol/L and 0.86 nmol/L,respectively.更多还原