Prep Column Problems

[HUH?]

I have recently experienced column failure (bed compression) on four 50 x 250 mm prep columns. These columns come from the same manufacturer and the failures were all the same. We use these prep scale columns for approximately 10 - 20 prep separations per month (low usage). In the past, columns have lasted 4 - 6 years. These columns did not last 6 months. Has anyone else experienced anything like this? The manufacturer, with whom we have a 14+ year relationship is not accepting any responsibility. They have left us high and dry on this 25K investement (two of the columns were replacements for the originals that failed immediatley). Please let me know if you have had any early failures and how you dealt with the manufacturer. Thanks

[Bruce Hamilton]

In reply to your other post I do occassional 50mmm column work, but now most is 20-30mm x 250um x 4-5um work with 100-500mg load because separations are usually difficult.

I've found that my prep column manufacturer seems to manufacture column on order, rarther than hold stock, so if that's the case, your columns may be from a small batch, without other endusers to substantiate claims.

In general, my approach is to contact the vendor, describe the problem, and ask if they can check their records whilst I investigate further.

I always make the assumption that I've screwed up and don't take anything for granted.

I start with the solvents, ensure they are from the correct supplier, of suitable grade, that all containers and filters are clean. I test filter some through 0.45um to confirm, especially if buffers of unusual solvents have been used. With buffers.

I allow them to stand and ensure they filter OK, as precipitation on the column could be an issue. I confirm that my column storage is as per recommendations.

I then confirm that my pump is OK, and seals/valves aren't disintergrating in solvents. If I have column logs and pressure/flow histories, I summarise those.

I confirm that the sample solution is clear and bright and is completely miscible with the mobile phase hasn't decomposed or dropped out in the injector or column. I confirm that no changes have been made to sample prepartion or quality.

If I'm using a guard, I check the effect of a replacement

I retest the column using the same conditions as on the CoA, and then compile a report of my data and conclusions and send it to the column manufacturer for their review, and also suggestions of any further work that could explain the failure.

Generally, the suppliers look it over, decide I'm not a total bunny, and give me a significant discount on the replacement, if not a free one.

I've recently replaced a 250x30x4um reverse phase column as the earlier column had failed after a couple of years of occasional usage. I decided the root cause was the recommended storage solvent, and switched to 100% CH3CN, and advised the supplier accordingly.

They were a little cagey about blaming storage solvent, but I got a very worthwhile discount on the replacement, and they are aware I've changed the storage solvent - in case I have future issues.

I find mutual respect for column manufacturers is better than hostility, and I avoid suppliers who can't/won't investigate issues.

I hope you can resolve your issues, and please keep having fun,

Bruce Hamilton