  High-resolution gas phase spectroscopy techniques in the microwave,
millimeter-wave and terahertz spectral ranges can be used to study complex
organic molecules desorbed from interstellar ice analogues surface with a high
sensitivity. High-resolution gas phase spectroscopy gives unambiguous
information about the molecular composition, the molecular structure, and
transition frequencies needed for their detection by radio telescopes in
various interstellar and circumstellar environments. The results will be useful
not only for interpreting astronomical spectra and understanding astrophysical
processes, but also for more general studies of gas-surface chemistry. This
paper presents a new experimental approach based on a combination of a
chirped-pulse Fourier transform microwave spectrometer detection and a low
temperature surface desorption experiment. The experimental set-up is
benchmarked on the desorption of ammonia ice detected by high-resolution gas
phase microwave spectroscopy.
