by water , especially the Euphrates River . The letter listed the total supplies of explosives and industrial chemicals sent " to terrorists through Turkey in 2015 . " It said 2,500 tons of ammonium nitrate worth approximately $ 788,700 were sent along with 456 tons of potassium nitrate worth $ 468,700 , 75 tons of aluminum powder worth $ 496,500 , sodium nitrate worth $ 19,400 , glycerin worth $ 102,500 , and nitric acid worth $ 34,000 .