Dataset: GP15 d13C-DIC Leg 2
Deployment: RR1815

Niskin seawater samples were collected in 250 ml bottles and poisoned with 100 µl of mercuric chloride. In the lab, approximately 100 ml was transferred from the bottle to a bubbler attached to a high vacuum line. Samples were acidified with 1 ml of 50% phosphoric acid before stripping with He gas at 200 ml min⁻¹. CO₂ gas was collected cryogenically in a liquid nitrogen cold trap after removal of water vapor. CO₂ yield was calculated manometrically (1σ = 5 µmol kg⁻¹) before transfer to a vacuum flask for isotopic analysis.