Chromatography Forum

I'm trying to use Phenomenex Strata X-A SPE cartridges for the extraction of Endothall from drinking water. I've been following the instructions ( https://phenomenex.blob.core.windows.ne ... 77a61a.pdf ) exactly as published by Phenomenex themselves. However, each time I come to the partitioning step a thick white precipitate forms in my separatory funnel, and there is no obvious separation of the polar (MeOH/H2SO4/Na2SO4 in H2O) and non-polar (CH2Cl2) phases.

I've been running this method for over a year successfully using Empore extraction disks, which have sadly been discontinued.

Have any of you encountered this problem, and, if so, how did you correct it?

Thanks,
Ben