Square-wave voltammetric determination of lead(II) with a Nafion®/2,2-bipyridyl mercury film electrode

✍ Scribed by Jyh-Myng Zen; Sen-Yuan Huang

• Publisher: Elsevier Science
• Year: 1994
• Tongue: English
• Weight: 823 KB
• Volume: 296
• Category: Article
• ISSN: 0003-2670
• DOI: 10.1016/0003-2670(94)85152-2

✦ Synopsis

A chemically modified electrode (CME9 system consisting of a Nafion-coated mercury film electrode containing appropriate amounts of 2,2-bipyridyl for practical use in the analysis of lead(U) was investigated. The relative advantages of using square-wave stripping voltammetry (SWSV) in combination with the CME for the determination of the reversible lead(H)-2,2-bipyridyl complex was assessed. The main advantages of the CME are better mechanical stability of the mercury film, and improved resistance to interference from both surface-active compounds and those metals which commonly interfere in anodic stripping measurements. For a 5min preconcentration period in the presence of oxygen, a linear calibration curve from 1 to 100 pg 1-l was obtained, and the detection limit was 0.1 pg 1-l. A lower detection limit can be obtained when longer preconcentration times are used. The CME surface could be regenerated by exposure to acid. For 10 successive preconcentration/determination/renewal cycles, the SWSV response could be reproduced with 5% relative standard deviation. Rapid and convenient acid renewal allows the use of an individual modified electrode surface in continuous-monitoring environmental or clinical applications.