During PS85 (in 2014) and PS93.2 (in 2015) sediment cores were recovered by a Multiple corer. A sodium bromide solution of similar density as seawater (1028 g/L) replaced the overlying water of the cores. Three subsamples of water were taken during an incubation at three different times (t0, t1, t2) and stored at 4 °C. Removed water volume of the subsampling at t1 was replaced with the NaBr-seawater solution. The bromide concentrations were measured using ion chromatography. The dilution of the t2-sample, due to the sampling procedure, was corrected by the known bromide concentration in the removed and the added water. The solute exchange is represented by the bromide flux