差分脉冲溶出伏安法测定陶瓷器皿中铅和镉的溶出率

采用4%的乙酸浸泡陶瓷样品24 h,应用同位镀汞差分脉冲溶出伏安法测定了陶瓷样品中微量重金属铅、镉的溶出量。以0.1 mol/L的硝酸溶液做底液,0.1 mol/L的KCl溶液做支持电解质,2 g/L的Hg2+溶液做镀汞液,测得铅的溶出峰电位为-0.5 V(vsSCE),镉的溶出峰电位为-0.7 V(vsSCE),两者含量在5×10-4～1 mg/L和5×10-4～0.5 mg/L范围内峰电流和其含量呈良好的线性关系,检出限分别为2×10-4和4.3×10-3mg/L。

Determination of Dissolution Rate of Lead and Cadmium in Ceramic Ware by Differential Pulse Stripping Voltammetry

The determination of micro-amount of lead and cadmium in ceramic by differential pulse stripping voltammetry were developed when the samples were soaking 24 h with 4% acetic acid.A glassy carbon electrode was used as working electrode in the method.It was found that lead had a very sensitive ASV peak at the potential of-0.5 V（vs SCE）and cadmium at-0.7 V（vs SCE）in the solution of HNO3-KCl-Hg2＋.The peak current had a good relationship with concentration of lead and cadmium in 5×10-4 mg/L～1 mg/L and 5×10-4 mg/L～0.5 mg/L separately.The detection limit respectively is 3×10-4 mg/L and 4.3×10-3 mg/L.