Pentylenetrazole‐10‐14C was synthesized by reacting hydrazoic acid with cyclohexanone‐1‐14C. Purification was carried out using sublimation and thick layer chromatography. Proof of radiochemical purity was determined using thin layer chromatography and autoradiography. The specific activity was found using liquid scintillation counting.

SUMMARYPolyvinyl acetate ~h t h a l a t e -~"~ (PVAP) was prepared by condensing radioactive phthalic anhydride with polyvinyl alcohol *.The radioactive anhydride was prepared from ethyl anthranilate The chemical purity and the authenticity of the PVAP so prepared was ascertained by a comparison of its acid number and thin layer chromatography to an authentic sample. The speciji c activity was determined using liquid scintillation counting.