Solid-phase spectrophotometric and test determination of silicate in natural water

► Anion-exchangers based on tetradecylammonium nitrate and lucigenine immobilized onto silica. ► Solid-phase extraction of silicate in the form of the reduced molybdo-silicic heteropoly anion. ► Sorption-spectrophotometric method of silicate determination in the form of ion associate. ► Visual on-site testing of the silicate in natural water.