Document Type: Original research article
Department of Chemistry, Payame Noor University (PNU),19395-4697, Tehran, Iran
A differential pulse anodic stripping voltammetric method was developed for the determination of Ag(I) at a carbon paste electrode modified with 4,6-diaminopyrimidine-2-thiol and multi-walled carbon nanotubes. The analysis procedure consisted of an open circuit accumulation step in stirred sample solution for 9 min. This was followed by medium exchange to a clean solution where the accumulated Ag(I) was reduced for 15 s in −0.6V. Subsequently an anodic potential scan was affected from −0.2 to +0.3V to obtain the voltammetric peak. The detection limit of silver(I) was 0.08 µgL−1 and R.S.D. for 10 and 100 µgL−1 Ag(I) were 2.4 and 1.2%, respectively. The calibration curve was linear for 0.99–118.57 µgL−1 Ag(I). The procedure was applied to determination of Ag(I) in standard alloys and water samples.