Gradients1-KOK1606-HPLC_2020-03-23_v1.0

Cruise: Gradients 1, KOK1606 Project Name: Simons Foundation, Gradients NPSG Method: Samples were processed to detect and quantify phytoplankton pigments using a modified version of the high-performance liquid chromatography (HPLC) method of Wright et al. (1991) as described by Bidigare et al. (2005). Sample water was concentrated onto Whatman GF/F filters (0.7 µm nominal pore size) and stored at -80°C until analysis. Filters were extracted in 100% acetone for 24 h at 4°C. Extracts were processed in reverse-phase on a 250 mm C18 column using a Waters separations module and photodiode detector array. Empower chromatography software was used for integration and pigment quantification. The instrument was calibrated using chlorophyll a from Anacystis nidulans (Sigma USA) and mixed pigment standards were obtained from DHI in Denmark.