Chromatography Forum

Dear Friends,

We have found a couple of Hyper REZ XP Carbohydrate columns (Ag+ and Ca++) (Thermo) in the lab. Due to the high cost of these we would like to try to wash and/or regenerate them, however we have no information as to how to do it, and how to test them properly.

We know how to regenerate similar columns from BIORAD, and we wonder if we could follow similar procedures. If anyone of you has information about these columns, their care, regeneration, and testing, we would like to hear about it.

Thanks,

josebenjamin

As far as I know, all of the Ca++/Ag++/Pb++ form carbohydrate columns are "descended" from the Bio-Rad HPX87-series columns (which were introduced almost 30 years ago!). The same regeneration procedures should apply.

Hi Josebenjamin,

Here is some information about cleaning of HyperREZ XP ligand exchange columns for you, hopefully it will be of use. This information is taken from a user guide for such a column.

Initially, the column should be flushed with HPLC grade water in the reverse direction for at least 12 hours at the appropriate operating temperature (in your case, for the Ag+ and Ca++ columns this is in the region of 80-90 °C). This may remove particulate contamination at the inlet of the column.

For strongly retained contaminants, the addition of a small amount of organic modifier to the mobile phase can be beneficial (<30% v/v acetonitrile, <5% v/v methanol or other alcohol).

These types of HPLC column can become contaminated with other counter-ions (i.e. the Ag+ and Ca++ ions that are usually associated with the stationary phase become displaced by another positively charged ion), and this is a more serious problem! Extensive flushing of the column with a 0.1M solution of the appropriate nitrate salt (or 0.05M sulfuric acid in the case of Hydrogen counter-ion columns) can help to regenerate the resin in this case.

In terms of caring for these columns, users need to ensure that they are not run at too high a pressure and to gradually increase flow rate to the desired level once its operating temperature has been reached. This will avoid accidental compression of the packing material, and therefore a void inside the column (usually accompanied by a substantial increase in back pressure). If the columns are to be stored for extended periods of time, it is advisable that they are flushed with 100% HPLC grade water beforehand.

Finally, a good way of testing the performance of the column is to inject a 10mg/ml solution of Glucose.

Best Regards,

Steve.

Dear Steve,

Thanks very much for your message. It is obvious that you have the right information. We will follow your recomendations trying to restore the columns.

josebenjamin