Microscopic tracing of deuterium.

The development of the ion microprobe analyser has made it possible to follow stable isotopes with microscopic resolution in biological and other materials. An ion microprobe using an oxygen primary beam has been found to produce relatively few mass 2 ions (+ or -) on organic samples. This technique should permit the use of deuterium as a practical tracer with a resolution of about 1 mum in the plane of the section and 2 nm in the depth dimension with available instruments.