Voltammetric Identification of Lead(II) and (IV) in Mediaeval Glazes in Abrasion-Modified Carbon Paste and Polymer Film Electrodes. Application to the Study of Alterations in Archaeological Ceramic
✍ Scribed by A. Doménech-Carbó; M. T. Doménech-Carbó; J. V. Gimeno-Adelantado; M. Moya-Moreno; F. Bosch-Reig
- Publisher
- John Wiley and Sons
- Year
- 2000
- Tongue
- English
- Weight
- 141 KB
- Volume
- 12
- Category
- Article
- ISSN
- 1040-0397
No coin nor oath required. For personal study only.
✦ Synopsis
Direct identi®cation of lead(II) and (IV) in glazed ceramics by cyclic voltammetry and differential pulse voltammetry is described. Characteristic cathodic and anodic pro®les are obtained for microsample coatings in Paraloid B72-®lm electrodes immersed in NaCl and HAc/NaAc media. The electrochemical response of PbO, PbO 2 and Pb 3 O 4 , and a series of test specimens of glaze is compared with that of microsamples extracted from the glaze of blue and white decorated ceramic produced in Manises (Spain) in the 15th century which have been buried in a damp place. Under abrasive conditions, striping peaks at À0.12 and À0.25 V (vs. SCE) appear for Pb(IV) centers and, at À0.55 and À0.75 V, for Pb(II) centers. The weathering process is accompanied by a signi®cant decrease of the total lead content and an enhancement of the Pb(IV)/Pb(II) ratio suggesting that a signi®cant fraction of Pb(II) ions is released. Electrochemical data are compared with those obtained from SEM/EDX.