AbstractOntario Hydro Research Division has carried out an experimental program co-funded by Canadian Fusion Fuels Technology Project to develop the gas chromatographic technique to separate hydrogen isotopes. Two novel GC techniques were optimized or developed in the pilot system, namely, the heart-cutting technique for removing the hydrogen-containing species from a fusion fuel and the temperature programming technique for separating all six hydrogen isotope species. The experimental results showed that these techniques improved not only the separation but also the throughput significantly for these applications and will be discussed in detail in the paper.