Determination of low-level90Sr in environmental materials: A novel approach to the classical method

Abstract

A method was developed for the separation of strontium from large amounts of calcium which does not depend on fuming nitric acid. A sample in the form of mixed carbonates or oxides is stirred into concentrated nitric acid in the proportion 1∶7 w/v. Strontium forms insoluble nitrates while calcium remains in the solution. Two re-precipitation steps combined with an acetone wash yield a very pure strontium salt which is suitable for gravimetric determination of recovery. The method, devised originally for90Sr assay in sea water, can also be applied to solid samples which present analytical problems due to their high calcium content.