Utilizing a highly selective reaction between silver metal and cyanide ions, an apparatus and procedure for the analytical determination of aqueous cyanide species has been developed. The rapid analysis of free cyanide has been achieved through the use of pure silver filters as the reaction medium and atomic absorption spectroscopy as the detection method. This methodology has allowed for the quantitative detection of cyanide ions down to the sub-parts-per-billion level. By incorporating selective oxidation, kinetic equilibria, and photodissociation techniques, the silver-cyanide reaction technique has been adapted to provide a means of categorically speciating aqueous cyanide compounds. The complete system has been shown to be free from common chemical interferences, including thiocyanate. This detection system provides high speed cyanide determinations with little to no sample preparation or instrument supervision.