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Journal of Tea Science ›› 2008, Vol. 28 ›› Issue (2): 93-100.doi: 10.13305/j.cnki.jts.2008.02.005

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Determination of Trace Lead in Tea with Screen-printed Carbon Electrodes

ZHAO Guang-ying, WU Yan-yan   

  1. Food safety key lab of Zhejiang, College of Food Science and Biotechnology Engineering, Zhejiang Gongshang University, Hangzhou 310035
  • Received:2007-07-25 Revised:2007-12-07 Online:2008-04-15 Published:2019-09-16

Abstract: The square wave anodic stripping voltammetric (SWASV) methodology using a screen printed carbon electrode (SPCE) in situ plated in mercury (Ⅱ) was developed by the authors to determine lead in tea. A detailed description of the systematic laboratory test carried out to optimize its performance is reported. A series of optimum parameter are as follows Hg2+concentration: 4×10-4 mol/L, Plating potential: -1.1 V, Estep: 3 mV, Frequency: 10 Hz, Amplitude: 60 mV, pH: 5, plating time: 280 s, balance time: 30 s. Under the optimized analytical condition, the obtained sensitivity, linearity, and detection limit are 22.7 nA/(μg/L), 10~225 μg/L (r=0.9986), and 0.74 μg/L(S/N=3),respectively. The interference effect was thoroughly studied with various metals in the determination of 120 μg/L Pb2+. Tea was digested using domestic microwave oven and PTFE sealed and pressurized microwave digestion tank. The standard method of analysis was used to detect the samples and comprised with the GB method, no significant deviation was found. The method was sensitive, accurate, fast and suitable for the determination of trace lead in tea.

Key words: square wave anodic stripping voltammetry, screen printed carbon electrode, tea

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