Dataset: Chloro HPLC
Deployment: GF222_BATS

Fluorometric chlorophyll and HPLC phytoplankton pigments - Fluorometric chlorophyll samples were collected on both pre-dawn and midday casts in seasoned, well-rinsed 500 ml amber Nalgene bottles and gently vacuum filtered (<5 mm Hg) onto 25 mm diameter Whatman GF/F filters (nominal pore size ~0.7 µm) for “total” chlorophyll. Samples were extracted into 7 ml 100% methanol [Jeffrey et al., 1997] for 24 h in the dark at -20°C and read on a Turner 700 fluorometer equipped with narrow band excitation and emission filters [Welschmeyer, 1994] and calibrated with a commercial chlorophyll standard (Sigma) and checked against a solid standard daily.

Phytoplankton HPLC pigment samples were collected on both pre-dawn and midday casts in seasoned, well-rinsed 2L amber Nalgene bottles and gently vacuum filtered (<5 mm Hg) onto 25 mm diameter Whatman GF/F filters (nominal pore size ~0.7 µm). Samples were immediately frozen in liquid N and stored in liquid N until analyzed by the Horn Point Analytical Laboratory (Univ. of MD) according to established methods for high pressure liquid chromatography (HPLC) for phytoplankton pigments [Hooker et al., 2005]