单扫描示波极谱测定痕量银

Determination of Trace Amounts of Silver by Linear Scan Polarography

本文首次提出了运用单扫描极谱直接测定银的方法。在含N-烯丙基-N′-对苯磺酸钠硫脲及四乙烯五胺的硼砂缓冲液中,银离子在-0.66V(相对饱和甘汞电极)有一灵敏还原波。运用经典极谱或单扫描极谱,此波均可用于微量银的定量测定。“银波”的单扫描示波极谱波可在5×10^(-7)～3×10^(-5)mol/L范围内检测银。方法已用于废定影液中银含量的分析,结果满意。

A sensitive and selective method is presented for the direct determination of trace amounts of silver by lincar scan polarography(LSP). In a borax buffer solution containing Nallyl-N'-(sodium p-phenylsulphonate) thiourea and tetraethylenepentaamine, a sharp derivative LSP peak related to the concentration of silver ion appears at -0.66V (vs.SCE). Thepeak height is proportional to the concentration of silver ion over a range of 5×10^(-7)～3×10^(-5)mol/L. The detection limit is 8×10^(-8)mol/L. Several samples of fixer solution have been analyzed by the recommonded procedure and the results agree well With the statistical analysis.