A note on the removal of silver from aqueous extracts of plant material

Abstract

Some difficulty has been experienced with the complete removal of silver from the aqueous extracts of plant material using the method of Johnson and Ulrich (1950). Because of this, tests were performed to determine the pH value at which silver is completely precipitated from solution as the phosphate, using weights of silver sulphate and potassium dihydrogen phosphate present in the extraction procedure. A modification of the Johnson and Ulrich method, involving precipitation at pH 10·5, is given.