Using the TANDY AMS facility (600kV) at ETH Zurich the seawater-derived (authigenic) 10 Be/ 9 Be ratio of marine sediment samples is measured without the addition of 9 Be carrier. This novel method reduces systematic uncertainties because the 10 Be/ 9 Be ratio of a sample is determined in only one (AMS) measurement. A challenge of carrier-free AMS is to avoid any contamination of the sample with 9 Be during the chemical preparation. Further, the leaching procedure has to be reproducible and ideally should attack the authigenic Be of the sediments only, leaving the detrital Be untouched. The low amount of stable 9 Be in the unspiked samples causes low currents during the AMS measurement. This requires a good stability and sensitivity of the AMS setup. Our first results show that the new preparation method is reliable and that background from stable 9 Be is avoided.For a comparison study, sediment samples from two cores located in the Arctic Ocean (HLY0503-09JPC, HLY0503-14JPC) were used. The authigenic 10 Be/ 9 Be ratio of these samples had been determined previously applying the conventional method where 10 Be and 9 Be concentrations are measured separately by AMS and ICP-MS, respectively. The resulting sedimentation rates are in discrepancy with values derived from biomarkers. To cross check the 10 Be/ 9 Be based age model two samples from each core were measured again with the new carrier-free method. The carrier-free results show systematically higher authigenic 10 Be/ 9 Be ratios. The calculated sedimentation rates of about 0.2cm/kyr, however, are consistent for the carrier free and the conventional method.