In addition to the more conventional methods used in hydrometallurgy to determine the stoichiometry of ligand-metal species formed in solvent extraction, a few research efforts have been done to establish some spectroscopic techniques which call provide that information "in situ." In this work, nuclear magnetic resonance is used to confirm the Cyanex 471X-silver ratio when the metal is extracted from a concentrated chloride medium on the basis of the "coordination shift" detected in some nucleus of the organic ligand upon complexation. The same approach has also been applied successfully to estimation of the composition of triphenylphosphine-silver chloride species synthesized in one phase.