Determination of plutonium isotopes in bilberry using liquid scintillation spectrometry and alpha-particle spectrometry

•Sample preparation methods for Pu using LSS and alpha spectrometry developed.•Complete separation of plutonium from interfering radionuclides.•Commercial bilberry was spiked with NPL 2011 (AH-B11144) proficiency test sample.•Results were checked using ζ test, z-test, rel. bias and rel. uncert. outlier tests.•Recommended procedures successfully applied to bilberry samples.

This paper presents α-particle spectrometry and liquid scintillation spectrometry methods to determine plutonium isotopes in bilberry. The analytical procedure involves sample preparation steps for ashing, digestion of bilberry samples, radiochemical separation of plutonium radioisotopes and their measurement. The validity of the method was checked for coherence using the ζ test, z-test, relative bias and relative uncertainty outlier tests. The results indicated that the recommended procedures for both measurement systems could be successfully applied for the accurate determination of plutonium activities in bilberry samples.