Trägerisotops

Trägerisotops, in German often translated as tracer isotopes, are isotopes used to follow the distribution, transformation, or fate of a substance in a system. They can be radioactive (radioisotopes) or stable. Radioisotopes emit detectable radiation and enable sensitive tracking of processes such as uptake, metabolism, or transport in biological, chemical, and environmental contexts. Stable isotopes are measured by mass spectrometry or isotope ratio analysis and are used when radioactivity must be avoided.

In practice, tracer studies rely on the tracer principle: a small amount of labeled substance behaves chemically like the unlabeled material and thus traces the same pathways. Radiotracers are chosen for suitable half-lives and emission types (for example, 18F for PET imaging, 3H or 14C for metabolic studies, 32P for phosphorus tracing). Stable tracers use isotopes such as 13C, 15N, or 18O and are detected via mass spectrometry or related techniques.

The term Trägerisotop can also relate to the concept of a carrier isotope in radiochemistry, where a non-radioactive isotope of the same element is added to increase the total amount and reduce the specific activity. This affects measurement, purification, and chemical behavior of the labeled compound.

Applications of tracer isotopes span medicine (diagnostic imaging and radiopharmaceutical development), biology and environmental science (metabolic studies, nutrient fluxes, hydrological tracing), and industrial research (process analytics). Safety and regulatory requirements govern the handling, use, and disposal of radioactive tracers.