Time-of-flight mass spectrometry (TOF-MS) combined with an ion trap front end (IT -TOF) is a potentially powerful tool for in situ sample analysis in space. We have developed a compact hybrid instrument by combining a 3D ion trap with a highly-miniaturized TOF mass spectrometer. The IT -TOF configuration was investigated with gas-phase laser ionization internal to the ion trap. We demonstrated that the precursor ion trap in the setup can be utilized to store and accumulate ions prior to analysis. Selected semi-volatile aromatic compounds of ethyl-naphthalene and phenanthrene were tested, and the results showed that using and tuning with available parameters in the IT -TOF combination, the mass resolution was increased, and through accumulation of ions, the sensitivity and duty cycle could be improved.