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Link to US Geological Survey
Coastal and Marine Geology Program
Woods Hole Field Center

Geochemical Sediment Analysis Procedures

RUNNING SAMPLES IN THE COULOMETER


LOADING SAMPLES IN THE COULOMETER
Materials Required:
  • Coulometer
  • Samples
  • Standards
  • Empty Vials for Blanks
  • Chemical Sorbent Pad
  • Gloves
  • Safety Goggles/Shield
  • Lab Coat
 Preparation materials; link to larger image

Attach an empty "blank" vial to the bottom of the reaction tube.

 Screwing blank vial into cap; link to larger image
Lower the tube into the heating unit so the plastic connector does not touch the heating unit. Lowering vial into heating unit; link to larger image
Hit the reset button on the coulometer. Reset button; link to larger image

Inject 3mL of 2N Sulfuric Acid using the auto-pipet.

This is considered a blank run.
Continue running blanks until the blank values stabilize and are below 4 µg of carbon.

After the first sample (2mg) has been run, repeat with other samples by raising the sample out of heater, unscrewing it from connector, and screwing a new sample to it.

After the blanks stabilize, the Coulometer is calibrated.

 Auto injecting acid; link to larger image

Start the run sequence: Blank, CaCO3 Standard, Mess-2 Standard, 8 Samples, Blank, etc.
(See attached Excel Spreadsheet).

After each run, record the raw data on the spreadsheet.

During the run sequence, in between each sample, check to make sure bubbles are still streaming to the titration cell (this checks for leaks where the sample attaches).

 Inorganic Excel spreadsheet

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