DPSV法快速测定茶叶中Pb的SPCE传感器的研究

Study on determination of lead in tea with SPCE sensor based on DPSV method

为探究出一种食品（茶）中Pb的快速检测新技术，研究以丝网印刷碳电极为支持电极，选用差分脉冲溶出伏安法和电极同位镀汞膜法，以多种绿茶作为固体有机物食物代表的检测对象，进行痕量Ph的快速检测研究。优化同位镀汞膜浓度、时间、最佳底液、沉积电位等6项最佳条件参数。在优化条件下，溶出峰电流与Pb浓度在10-300μg／L范围内呈现良好的线性关系，检出限为2．208μg/L。茶样检测结果其标准偏差小于8％，回收率达到85．2％～109．3％。实验结果表明：研究出的丝网印刷传感器差分脉冲伏安法测定茶叶中的Pb离子具有快速、灵敏、准确、经济等优点，所用丝网印刷传感器可实现一次性使用和批量生产。

Using a screen printed carbon electrode （SPCE） in situ plated in mercury（ Ⅱ ） the trace lead in tea（ as a representative of solid organic food ） based on differential pulse stripping vohammetry （DPSV） method is determinated in order to develop a rapid detection technique of lead in food （ tea ）. Several factors such as pretreatment of mercury film electrodes, the kind of buffer solution, and other parameters of electrochemistry are optimized. A detailed description of the systematic laboratory test carried out to optimize its performance is reported. Under the optimized condition, the study result showes that the calibration curve is linear in the range of 10 -300 μg/L,and the detection limits is 2. 208 μg/L,the standard deviation is less than 8 % and the recovery is between 85.2 % and 109.3 %. The method is sensitive,accurate,fast and suitable for disposable and batch usage of the determination of trace lead in tea.