LALman wrote:
What sort of sample sizes can you extract using the 6 mL SPE columns? Are you using the 500mg beds and are you using some sort of adapter to let you pull from 100-1000 mL bottles? I really have no idea how much SPE bed is required for typical groundwater samples.
We are going by method EPA525.3, which should also work for groundwaters. We use 500mg packing in the cartridges and you can find adapters and tubes from several suppliers to allow the cartridge to draw directly from a 1L bottle of sample.
From EPA525.3
"Use of a transfer tube system (Supelco “Visiprep”, #57275 or equivalent), which transfers the sample directly from the sample container to the SPE cartridge is recommended."
I believe we bought ours from Restek or UCT (
https://www.unitedchem.com/product-category/spe )
When using the transfer lines, fill the cartridge full of DI before inserting the adapter so you will have water in the cartridge after the air in the line has pulled through, it makes them flow better than if a slug of air passes through the cartridge.