A silver optical sensor based on 5(p-dimethylaminobenzylidene)rhodanine immobilized on a triacetylcellulose membrane

An optical sensor has been proposed for the determination of silver by spectrophotometry. The sensor was prepared by immobilizing 5(p-dimethylaminobenzylidene)rhodanine on a transparent triacetylcellulose membrane. The effect of different variables on the response of the sensor was studied and the optimum conditions were established. The sensor responded linearly in the range 1.8–55.6 μM of silver with a limit of detection of 0.8 μM and a response time range of 8–10 min depending on the concentration of the silver ions. The presented optode is reversible and stable if stored in water for more than one month without reagent leaching. The relative standard deviation for seven replicated measurement of 4.6 and 37 μM silver was 3.15 and 2.76%, respectively. The sensor was successfully applied to the determination of silver in a silver sulphadiazine cream, an ore sample, and a radiology film. The text was submitted by the authors in English.