Potentiometric determination of trace silver based on the use of a carbon paste electrode

A carbon paste electrode used as a sensor for silver has been developed and electrode response characteristics have been investigated. The electrode exhibits linear response to the logarithm of the concentration of silver from 5 × 10 −7 M to 1 × 10 −2 M, with a response slope of 63 ± 2 mV. The detection limit according to IUPAC recommendations is 1 × 10 −7 M. This electrode has been used to determine trace silver in fixing solutions and waste electroplate solutions with good results.