Rapid determination of strontium-90 in seawater with proportional counters

Abstract

A novel and rapid method to determine ⁹⁰Sr activity in seawater by proportional counter has been developed. Precipitation of ⁹⁰Sr and radiochemical separation were investigated. ⁹⁰Sr was precipitated in the form of oxalate to remove the dominant salts present in seawater and then radiochemical separation was performed by using Sr-resin. The chemical recovery of ⁹⁰Sr (75–95%) was determined gravimetrically using a stable primary Sr²⁺ solution. The minimum detectable activity (MDA) of ⁹⁰Sr was determined to be 0.025 Bq L⁻¹ for 1 L seawater sample for 2 h counting time using ultra-low background proportional counters. The validation of the method has been performed by using the samples from the IAEA-RML-2021 and IAEA-RML-2019 proficiency tests organized by International Atomic Energy Agency (IAEA).ı