Titrage potentiometrique des thiols en milieu organique a l'aide d'une electrode a monocristal de sulfure d'argent: Comparaison avec une electrode argent-sulfure d'argent classique

The responses of the silver sulfide membrane electrode (the so-called sulfideselective membrane electrode) to different primary and aromatic thiols and to hydrogen sulfide have been studied in an ethanol-benzene mixture. They have not been found in good agreement with the Nernst relationship. However, this electrode can readily be used to follow, by potentiometry, the precipitation of thiols and thiol-hydrogen sulfide mixtures with silver ions. The observed potential breaks are similar to those obtained with a conventional silver-silver sulfide electrode. As it needs neither pretreatment nor maintenance, the silver sulfide membrane electrode is therefore suitable for determining hydrogen sulfide and thiols in petroleum products by potentiometric titration.