A Waters Sep-Pak C18 solid phase extraction cartridge (Milford, MA) was activated with 3 mL methanol and 3 mL water, and loaded with 2 mL of supernatant.
A Waters Sep-Pak C18 solid phase extraction cartridge (Milford, MA)was activated with 3 mL methanol and 3 mL water, and loadedwith 2 mL of supernatant.