227Ac is the most appropriate parent nuclide to produce a solid 219Rn source. The paper describes methods to determinate the radiochemical purity of 227Ac extrated from uranium ore. The radiochemical purity of 227Ac is determined by relative measurement of 211Pb and quantitative measurement of 222Rn, 220Rn. The results show that the content of 222Rn, 220Rn in 227Ac product is lower than 0.2%, and...