Determination of 90Sr–90Y activity in urine samples by using Cherenkov counting

Cherenkov counting of the 90Sr–90Y pure beta emitters in aqueous samples is an attractive method; but color quenching correction is needed, this being especially significant for urine which is characterized by a strong coloration. A quench correction method based on the external source of some liquid scintillation systems (named ESAR—External Source Area Ratio) was proposed for aqueous solutions. In the present work, the application of the ESAR method for determination of 90Sr–90Y in human urine samples is described.

► A new color quenching correction method (ESAR) was tested for Cherenkov counting.
► It uses the spectrum of the 152Eu outer source of a Quantulus 1220™ system.
► The method was applied for 90Sr–90Y determination in urine samples.
► Results within the range of 11.5% from target values were obtained in blind tests of urine samples.