Dissolved organic carbon concentration of PeCaBeau water samples

The water sampling was performed using a CTD Rosette system, consisting of 12 L Niskin bottles. The samples were filtered using a 0.7 μm Whatman GF/F syringe filter (filter was rinsed with 50 mL before filtrate was used), filled into 20 mL glass vials and acidified using 20 μL HCl (37%) and stored dark and cool at +4°C until analysis. Concentration of DOC was measured using high-temperature catalytic oxidation (TOC-VCPH, Shimadzu) at the Alfred-Wegener-Institute (AWI) Potsdam, Germany. Blanks (Milli-Q water) and certified reference standards (Battle-02, Mauri-09 or Super-05 from the National Laboratory for Environmental Testing, Canada) were measured for quality control.