Gradients 2 - MGL1704 - PCPN

Cruise: Gradients 2, MGL1704 Project Name: Simons Foundation Gradient NPSG The carbon and nitrogen content of particulate material (PC and PN) was collected from rosette niskin bottles at specific depths and filtered at low vacuum through a combusted glass fiber filter. Following filtration, filters were folded in half and placed in combusted aluminum foil and stored at -80°C for later analysis. Post-cruise, all filters were thawed and dried overnight at 60°C. Samples were then balled into Sn boats and plated for analysis. Organic carbon and total nitrogen content was analyzed using high-temperature combustion (1020 C) on a ThermoQuest NC 2500 elemental analyzer. Three standards with known %C and %N were weighed, folded in tin boats, and analyzed with the samples to develop the calibration equation for each run. The calibration equation was then used to calculate the mass (mg) of carbon and nitrogen in each sample using EAS Clarity Chromatography Station software. The standards are Cystine (Elemental Microanalysis, B2035, 11.66 %TN, 29.99 %TC), Atropine (Elemental Microanalysis, B2002, 4.84 %TN, 70.56%TC), and GoniLab Secondary Standard (low %C)-A1 (an internal standard of sediment from the Gulf of Mexico, MV0803, with low carbon - 0.12 %N, 1.3 %C).