A New Method for Stripping Voltammetric Determination of Ag(I) at Carbon Nanotube Paste Electrode Modified with 4,6-Diaminopyrimidine-2-Thiol

Abstract

<span style="color: black; font-size: 9pt; mso-bidi-font-family: 'Times New Roman';">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 <span lang="FA" dir="RTL">+</span>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.</span>