Simple 40K removal by acidified water leaching for estimating low levels of radiocesium in fishery products following Fukushima Dai-ichi Nuclear Power Plant accident.

We developed a simple method for 40 K removal by acidified water leaching combined with ammonium phosphomolybdate coprecipitation, for estimating low levels of radiocesium in Japanese flounder. 40 K removal from ashed samples was approximately 98%, with the radiocesium yield of ~98%. The treatment reduced the γ-spectral baseline to ~1/5 at ground and ~3/100 at underground levels (1.04 and 0.11 cph/keV, respectively). Faint signal of 134 Cs, which is embedded in the Compton continuum of 40 K in an untreated sample, was detected. [ABSTRACT FROM AUTHOR]