Snow sample lab processing

Filtering samples for Kiowa lab

Materials list

  • Thawed snow samples in their nalgene bottles
  • A data entry spreadsheet that includes their sample numbers and a place to enter notes, sample bottle tare weights, and sample weights.
  • This can be derived from the sample log
  • 3 250ml Filter flasks (Erlenmeyer type with sideport)
  • 2 Millipore filters
  • 47mm Nuclepore filter membranes
  • 2 vacuum hoses
  • Clean 125ml nalgenes
  • Labeling tape
  • Sharpie

Filtration procedure

  1. Thaw samples
  2. Put on clean gloves, and change them often
  3. Set up a clean lab bench:
  4. Clean all filter flasks with soap, and give them a good rinse in DI water.
  5. Clean both Millipore filters.
  6. Rinse rubber stoppers
  7. Lay out clean lab mats (2) across the bench.
  8. Place Nuclepore membrane on the plate of the Millipore filter.
  9. Screw the top onto the plate and slide the rubber stopper over the filtrate outlet
  10. Place the Millipore assembly on the opening of a filter flask.
  11. Attach the vaccuum hose to the sideport of the flask.
  12. Turn on the vaccuum about halfway
  13. Run 120-150 ml of DI water through the filter
  14. Detach the filter flask, throw this filtrate away, then reattach the flask.
  15. Turn the vaccuum back on
  16. Filter roughly 80-100 ml of sample through the filter
  17. Weigh and label a clean 125ml nalgene with the sample id number
  18. Also label the original sample nalgene with the sample id number
  19. Pour the filtered sample from the filter flask into the nalgene
  20. Weigh the nalgene + sample and record this on the spreadsheet.