A quick liquid scintillation counting technique for analysis of 90Sr in environmental samples

• An organic cocktail LSC counting method for 90Sr was developed, which can be completed in 8 h.
• Six environmental RMs which are spiked with 90Sr for reference were used to verify the performance.
• RMs were purified with a Sr-spec. column, and then measured by both Cerenkov and organic LSC.
• The organic LSC is quicker, higher efficiency and lower MDA than Cerenkov counting.
• The bias, precision and En number are agreed with the HPS N13.30 and ISO 13528.

In this study, to improve the problem of waiting for the growth of 90Y for Cerenkov counting and save the time of 90Sr analysis, an organic cocktail sample was counted by a liquid scintillation counting system immediately after the purification of 90Sr without waiting for the growth of 90Y. The chemical separation and the measurement procedures for 90Sr radioactivity analysis can be completed in 24 h. In order to verify the performance of the improved method, the activity of 90Sr in six environmental reference samples was determined after radiochemical purification with a crown-ether resin column, and subsequent measurement by both the Cerenkov and the organic cocktail liquid scintillation counting methods. The results revealed that the organic cocktail liquid scintillation counting was quicker and had higher efficiency and lower minimum detectable activity (MDA) than the Cerenkov counting.