column cleaning

[gincot]

column care

When I do a light cleaning of my columns, going high water and high organic, I turn the colums inverse flow.

My guess was getting rid of contamination on head of column. My resolution is returning fine.

But I am second guessing this pratice. In every cleaning procedure that I have read so far it is never mentionned.

thank you

[Consumer Products Guy]

Lots of column manufacturers recommend doing just that. Contact your column manufacturer for their instructions if that's not included with the column. As long as the inlet frit is same size as the outlet frit, usually OK to backflush.

[sam.pedraglio]

As long as the inlet frit is same size as the outlet frit, usually OK to backflush.

I.e. this is not case for Waters BEH column.

[gincot]

HI

what BEH means.
and if it is BEH could it be backflush

thank you

[Uwe Neue]

BEH means Bridged-Ethyl Hybrid, and is the core of the packing material. It is different from silica, and contains ethyl groups in the matrix. This gives it a pH stability to pH 12, while silica starts to struggle above pH 8.

The use for different inlet and outlet frits with the Waters columns is not associated with a particular packing but with the particle size. All columns with particle sizes 3 and lower have a larger frit at the inlet than at the outlet. This prevents premature plugging of the frit. Agilent uses the same trick, but I am not familar with the particle sizes for which this is used.

[kerri]

Ahh ha! That Waters column tidbit is _VERY_ useful! Thanks!!!