If two electrically neutral materials are brought into contact, an exchange of charge can occur. This effect is called tribocharging and has been known for over 2500 years, yet it is still poorly understood. Perhaps the most important unresolved issue is the unknown identity of the charge-carrier itself. While it is often assumed that the carriers are electrons, they could also be ions, and different experiments in different circumstances provide suggestive evidence for both cases. In order to address this fundamental issue, an experiment whose aim is to clearly identify the carrier responsible for tribocharging is being built. For this, tribocharging experiments with insulating samples in vacuum are being carried out. After contact and charge exchange, we heat one sample near the entrance to a single-charge sensitive quadrupole mass spectrometer (QMS), which can measure ionic charges leaving the sample in real time and with single ion sensitivity. Simultaneously, a charge measurement with a Faraday cup is used to cross check the QMS measurement. If the charge leaving the sample corresponds to the amount of ions detected by the QMS, the ions in question can be identified. In the case of no particle detection a charge exchange through electrons is strongly suggested.