High-sensitivity autoionography

Ionography can replace conventional film autoradiography in the detection of radioactive spots on thin-layer chromatograms. The sensitivity of autoionography has been greatly increased by the use of thick charge receptors instead of the thin imaging foils used hitherto, and also, for some radio-nuclides, by the use of higher gas pressure. The sensitivity of the method is now such that the following activities of three commonly used isotopes can be imaged in 24 h with a resolution of at least 2 line pairs mm-1: for 3H, 5 nCi cm-1 (185 Bq cm-2); for 14C, 1 nCi cm-2(37 Bq cm-2); and for 32P, 0.05 nCi cm-2(1.85 Bq cm-2). (author)