Modern gasification technologies need to have low concentrations of impurities in the process gas for their failure-free operation. Therefore, hot gas cleaning is required. Molecular beam mass spectrometry was used to determine the gas purity downstream different materials for the sorption of arsenic at 800 degrees C Additionally, thermodynamic calculations regarding the release and the removal of arsenic using SimuSage were performed. The calculations showed that copper-containing sorbents Should be suitable for cleaning of arsenic laden gases. This could be confirmed by sorption experiments, where also high surface alumina appeared as an adequate sorbent material. Fly ash from lignite combustion is also capable for arsenic retention, whereas zeolites, clay minerals, and lime did not interact with arsenic.