Chemical Speciation Measurements of Silver Ions in Alkaline Carbonate Electrolytes Using Differential Pulse Stripping Voltammetry on Glassy Carbon Compared With Ion Selective Electrode Measurements

摘要

Given the increasing incorporation of silver nanoparticles as an antibacterial additive in washing+ machines and textiles, sensitive methods for accurate determination of Ag ions in laundry relevantelectrolytes (alkaline carbonate) are required. The most widely reported method, the silver ionselective electrode (ISE), lacked sensitivity and accuracy and was affected by the concentration ofNa2CO3 in solution. Differential pulse stripping voltammetry (DPSV) on glassy carbon electrodes(GCE) was therefore investigated as an alternative technique. Surface preparation of the GCE surfacewas essential and a suitable procedure was developed. A linear response was observed from 0 to 180-1 -1 mg L with a lower detection limit of 500 ng L (5 nM). DPSV was shown to be significantly more+ sensitive and accurate in determining the Ag activity than the silver ISE technique, particularly below200 nM.