DVD-Ag电极阳极溶出伏安法测定枸杞子中铅和镉残留

Determination of copper and cadmium in Fructus Lycii by anodic stripping voltammetry using DVD-Ag electrode

建立了利用DVD-Ag电极阳极溶出伏安法同时快速测定铅和镉的方法,并考察了I-对电极上的铅和镉溶出分析的影响。利用该方法测定了枸杞子中铅和镉的残留含量。结果表明,优化实验条件下,在5~50μg/L浓度范围内,Pb^2+和Cd^2+的溶出峰电流与Pb^2+和Cd^2+的浓度呈线性相关,相关系数分别为0.9923和0.9953,Pb^2+和Cd^2+的检出限分别为0.2μg/L和2.6μg/L(S/N=3)。对该方法进行了方法学考察,包括精密度、稳定性和回收率,结果均符合相关要求。枸杞子中Pb^2+和Cd^2+的残留含量测定结果与经典的电感耦合等离子体质谱法(ICP-MS)一致性较好,表明该方法可用于枸杞子中铅和镉的残留量的检测。

The use of a digital versatile disc(DVD)-Ag electrode for the square-wave anodic stripping voltammetric determination of Pb^2+and Cd^2+was described.The effect of I-on the stripping analysis of Pb^2+and Cd^2+at DVD-Ag electrodes was also studied.Residual of lead and cadmium in Fructus Lycii was determined by this method.The result showed that under the optimal test conditions,the anodic stripping voltammetry peak current was in proportional to Pb^2+and Cd^2+concentration at 5~50μg/L,r=0.9923 and r=0.9953.And the limits of detection(S/N=3)are estimated to be 0.2μg/L and 2.6μg/L for Pb^2+and Cd^2+,respectively.The precision,stability and recovery test showed well results.The method can be used for the determination of lead and cadmium in Fructus Lycii,as there was no significant difference(P>0.05)between the results from anodic stripping voltammetry and inductively coupled plasma mass spectrometry.