A selective membrane electrode for thiocyanate ion based on a copper-1,8-dimethyl-1,3,6,8,10,13-azacyclotetradecane complex as ionophore

An ion selective electrode for thiocyanate based on Cu(Il)-1,8-dimethyl-1,3,6,8,10,13-hexaazacyclotetradecane complex as an ionophore is described. At pH 4.5-10.5, the electrode based on this ionophore and cationic sites (40 percent of the ionophore) responds to thiocyanate in linear (E vs log [SCN(-)]) range from 1.0 x 10(-1) to 7.0 x 10(-6) M. Selectivity coefficients determined with the match potential method (MPM) indicate that interference from inorganic and organic anions is very small. The proposed sensor shows a fast response time of about 15 s. It was applied as an indicator electrode in titration of thiocyanate with Ag(+) and in potentiometric determination of thiocyanate in saliva and urine samples.