I. Pre-Expedition
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- Headspace sampling tools and containers (vials, septa, headspace tool, plunger, crimper). The septum has a shiny thin creamy color PTFE layer and a thick white matte silicone layer. The shiny PTFE side goes against the vial.
- Gas void assemblies (50 mL syringe and three-way stopcock, with male luer lock, attached to the core liner puncturing tool).
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- Take a 5 cc headspace sample from every sediment core (non-basement), at the top of a section (try to be consistent). This sample is taken until the total depth objective is met. If doing multiple holes, you do not have to repeat the sampling if a headspace sample has already been taken at that depth but just continue after the prior hole's bottom depth.
- For cores with IW samples, always take the headspace sample adjacent to IW, best from the top of the section immediately below the IW sample. Note the core, section and interval of the headspace sample and write it on the Curator's logsheet. The interval will need to be entered into SampleMaster by the Curator/ALO.
- Make sure nobody sprays acetone on the catwalk before sampling is completed. Acetone will contaminate the sample.
- It is recommended to occasionally take a sample of the air on the core deck, so that any change in the headspace sample analysis can be correlated to changes in volatilized acetone.
- Inject a standard (corresponding to concentrations seen in the recent cores) every fifty injections or so, to check on the instrument calibration.
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- Set the pressure to 3000 lbs and simultaneously push and hold both green (CLOSE) buttons on the hydraulic unit's base until the auto-pressure engages.
- After the first drops flow from the hole in the squeezer's base plate, insert the syringe into the hole. Keep an eye on the syringe to make sure the pressure doesn't push out the syringe or plunger (especially for the first few cores). Keep incrementing the hydraulic unit pressure in steps of 1000 lbs until 10000 lbs; after 10000 lbs, increase in steps of 2000. Do not ever increase the pressure above 30000 lbs.
- Select the correct core, section and sample in SampleMaster. Upload the IW sample splits (using the Excel template) into SampleMaster and distribute the labels.
- When porewater yield is sufficient/no more water is trickling, release the hydraulic unit pressure by pressing the red OPEN button and remove the syringe from the squeezer.
- Start sample distribution (splits).
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