示波催化极谱法测定高纯铅中痕量镍

Determination of trace nickel in high-purity lead by catalytic oscillopolarography

在 8 6× 1 0 -5 mol/L丁二酮肟— 0 4mol/L氯化铵— 3mol/L亚硝酸钠底液介质中 ,溶液的 pH 8 2左右 ,镍具有极灵敏的催化波 ,波形良好稳定。本法采用硫酸使铅生成硫酸铅沉淀分离主体铅 ,用示波极谱法测定。镍浓度在 1× 1 0 -2 ～ 1 2× 1 0 -1μg/mL范围内与峰电流呈线性关系。镍的加标回收率在 90 5%～ 1 1 4%。测定含量为 0 0 0 0 2 1 %的试样 ,相对标准偏差为 6 9%。本法具备选择性好、灵敏度高、准确度好的特点 ,适用于高纯铅中 0 0 0 0 0 5%～ 0 0 1 %镍的测定。

In the supporting electro lyte of sodium nitrite(3mol/L)and ammonium chloride(04mol/L,pH82±0 1)containing dimethylglyoxime(86 ×10 -5 mol/L)nickel has a sensitive and stable catalytic polarographic waveAfter separating matrix lead in the medium of sulfuric acid as precipitation of PbSO 4,nickel was determined by the method mentioned aboveThe peak currents were linea r with the concentrations of nicke l in the range from 000μg/mL to 0 12μg/mLThe recovery was in the ra nge from 905% to 114%The relativ e standard deviation(RSD)was 69% for the sample containing 000021% of NickelThe proposed method has the advantages of good selectivity ,high sensitivity,ease to operate and good accuracy,which can be emp loyed for the determination of Nickel (0 00005%-001%) in high-puri ty lead metal