Measurement of ⁹⁰Sr in Marine Biological Samples

Strontium-90 (90Sr) is one of the most hazardous radionuclides, and it contributes to radiation exposure by ingestion. The routine determination of 90Sr in marine biological samples is highly desirable given the development of the nuclear power industry. A fast, simple, and low-detection-limit method was developed for the measurement of 90Sr in marine biological samples based on determining 90Y by means of coprecipitation and solvent extraction with bis-2-ethylhexyl-phosphoric acid (HDEHP) in n-heptane. The interfering 210Bi is removed using Bi2S3 precipitation. The separation and purification of eight samples per day can be accomplished through this method. The detection limit of 90Sr for this method is 0.10 Bq/kg (ash weight). The radiochemical procedure was validated by fitting the decay curve of the sample source and by the determination of 90Sr standards