▎ 摘　　要

NOVELTY - Planar carbon form comprises a set of atoms of tritium that are covalently associated with the form. USE - The planar carbon form is useful as a carbon nanotube e.g. single-walled or multi-walled carbon nanotube and graphene (all claimed), and is useful in diagnostic studies, environmental studies, and biodistribution studies. ADVANTAGE - The directly labeled planar carbon form can be prepared in a simple manner. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for: (1) Producing a tritiated planar carbon form comprising reacting a planar carbon form including carboxylic acid groups on a surface of the planar carbon form, with a reducing agent capable of reducing a carboxylic acid to produce a tritiated planar carbon form with an atom of tritium associated with the surface; and (2) detecting a planar carbon form in a sample comprising supplementing a planar carbon form source with a tritiated planar carbon form to produce a labeled source, and detecting the presence or absence of a planar carbon form in a test sample derived from the labeled source by measuring the presence or absence of a beta particle emission from the sample.