Through the confinement of gas in nanoporous materials it is possible to significantly increase the path length for light-gas interaction. This enables the observation of much stronger absorption features for the confined gas molecules. This approach, also known as gas in scattering media absorption spectroscopy (GASMAS) [1], allows to use the porous material as a miniaturized random-scattering multipass cell [2]. Thanks to the strong scattering of light in the samples it is possible to achieve long interaction path lengths, minimal sample gas volume and extremely easy alignment. This is particularly advantageous in industrial and medical fields where it is necessary to minimize the sampled volume for the gas measurement.