A NOTE ON THE QUANTITATIVE DETERMINATION OF C¹⁴-RADIOACTIVITY ON PAPER CHROMATOGRAMS

The accuracy of measuring radioactivity on paper chromatograms by direct counting with a Geiger counter has been determined. It has been shown that satisfactory accuracy can only be obtained when the chromatograms are dried in still air. When chromatograms are allowed to dry in a draft, substances in the spots tend to concentrate erratically at the surfaces of the paper causing errors of up to 25% in counting.