a new method for stripping voltammetric determination of ag(i) at carbon nanotube paste electrode modified with 4,6-diaminopyrimidine-2-thiol

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.