I will be taking part in an Antarctic expedition to the Ross Sea in January and will be using Rhizon samplers to extract pore water from kasten and piston cores for pH, dissolved oxygen, salinity and d18O analysis. However I am concerned about sample contamination with regard to DO and d18O and would like your advice.
In the original proposal the extracted pore waters were going to be injected into septa capped glass vials under a Helium filled portable glove bag, however there were concerns using pressurized glass vials and needles on a ship. It was advised that we use HDPE bottles (or centrifuge vials) to store the pore water after extraction. I am unsure if the pore water will be contaminated by the atmosphere during extraction (using a syringe as a vacuum attached to a hydrophobic tube and filter placed inside of the core) and if there is a method for storing pore water that will minimize possible gas exchange.
I would imagine that unless the extraction and analysis is done under an anoxic environment, the pore water will be compromised. Is this true?