Аннотация:The possibility of using anion-selective electrodes with a liquid membrane based on the salts of quaternary phosphonium bases was investigated to determine the concentrations of nitrate, chloride, sulfate, and phosphate ions in acidic media. Solutions of tetraoctylphosphonium nitrate and chloride in decanol and tetraphenylphosphonium nitrate and chloride in nitrobenzene were used as sensing element.