Restoring Columns

[XiZ]

Hi all.

Sorry to bring this subject back, but I really need some help, and I didn´t find what I need.

I have some C8 and C18 columns (phenomenex - kromasil silica) that need some restoring procedure. Talking with some people, and taking in consideration what we run at these columns, we find one solution (consider that we wash them very well with MeOH 10%, and use MeOH 65% to store them every times after use):

Flow = 1,0 ml/min
0-30 mins - 100% MeOH
30-40 mins - 100% Isopropanol
40 - 70 mins - 100% Chloroform
70 - 80 mins - 100% Isopropanol
80 - 110 mins - 100% MeOH
110 - 125 - 100% MeOH 10%
125 - 140 - ACN 75%

And then make a test with toluen

My real question is about Chloroform 100% - This couldn´t damage all seals and polymer based parts inside the HPLC?

Thx all your help!!

Guilherme.

[Consumer Products Guy]

We were told by Alltech telephone tech support to do essentially the same for one of their columns, except it was methylene chloride instead of chloroform. And we have done that several times, and have not noticed any effects on the HPLC. That restoring process did work on their column.

[JGK]

From "Practical High-Performance Liquid Chromatography"by Veronika R. Meyer :

Flow rate 0.5 - 2 mL/min

75 mL water + 4 x 100 µL DMSO injected
75 mL Methanol
75 mL Chloroform
75 mL Methanol

Water then 0.1 M sulphuric acid the water is an alternative.