1980 Volume 29 Issue 9 Pages 417-421
In order to detect a radioactive band on the paper strip developed by focusing chromatography, plate-making-film was used for the autoradiography and β-spots were photographed. Thereafter the film was etched with sodium hydroxide solution to find the a-tracks. Paper strip used for the sample was prepared by the precipitation focusing chromatography of 226Ra and its daughter nuclides using HCl-KF solution as a developer.
The film used was not high in its β-sensitivity, but because of its high resolution good photographic results were obtained according to the intensity of β-activity when the proper conditions of photographic development were fulfiled. The simple α-spectrometry was made possible by counting the numbers of tracks according to the ething depth of the film. The film was hard and thick enough for etching with 6M sodium hydroxide solution at 50°C for more than 50 hrs to measure the depth of tracks.