Nickel-63: radiochemical separation and measurement with an ion implanted silicon detector

A method was developed for the determination of 63Ni in environmental samples. Nickel is extraced as dimethyl glyoxime complex by chloroform and back-extracted with HCl then electroplated. The radiochemical yield is determined by atomic absorption measurements of stable Ni before and after electrodeposition. Nickel-63 on the discs is measured by beta spectrometry using solid state ion implanted detectors and a conventional windowless anti-coincidence shielded GM gas flow counter. The minimum detection limits were 8 and 1 mBq, respectively. The method was applied to a series of macroalgae (Fucus vesiculosus) collected at different distances from a nuclear power plant. There was a correlation between distance to the power plant and the 63Ni concentration in the algae. The relationship between 63Ni and 60Co, as well as that between 63Ni and stable nickel was also investigated. (author) 10 refs.; 3 figs