High pressure and quick aging in Metrosep IC columns

[ANeria]

Hello Everybody!
I’m just getting started on the forum

We have the Metrohm-Applikon’s Monitor for Aerosols and Gases in Air (MARGA). The current matter is about the IC columns’ pressure. The instrument uses an Anion A Supp 10-75/4 column (Polystyrene-divinylbenzene copolymer with quaternary ammonium groups) and a Cation C 4 100/4 column (Silica gel with carboxyl groups).

As soon as we install the columns, the pressure starts rising but there’s also a quick aging of the stationary phase, since the RTs get smaller and the peak quality decreases. The current anion columns are lasting about 7 days, meanwhile the cation columns 20 days. According to the operation manual, they should last 2 months for the anion column and 4 months for cation column.

We are using tridistilled water with conductivity lower than 1 uS/cm, we have done lots of system cleaning procedures with H2O2, and even if we change all the filters and columns, the pressure keeps rising.

I would really appreciate all your comments regards this, I feel I have proved everything and nothing seems to work…

Thank you so much for you attention. Best regards & much success! Angelica

[Markus Laeubli, Metrohm]

Dear Angelica

I am sorry to hear your negative experiences with our columns in MARGA. And I assure you that this is absolutly not what you should get.
You mention tridistilled water for eluents. I my experience this might not be good enough for IC. W actually recommend to use ultrapure water from repsective water purification equipment. Best actually is to have an UV station within the equipment.
You also mention H2O2 rinsing. Did you rinse the system with the column or did you tak the colum out for rinsing. The latter definitely would be better.
Please check-back with you Applikon representative for further details and do not hesitate to contact me directly (lae@metrohm.com) in case of further problems.

[ANeria]

Dear Dr. Markus
Thank you so much for your kind answer!

We are really concern, The MARGA is such an amazing instrument, the data is very accurate and interesting, actually we wanted to use it for a PM precursors campaign here in Mexico City before this happened. Last year we had a very good campaign, the columns were excellent, really good separation and peak definition in a very small time and they lasted what should do.

When we install a brand new column, the initial pressure is higher than it used to be with the old columns and rises very quick. We talked to our Applikon representative and he mentioned that the current batch of columns does have a slight increment in working pressure due to small differences in manufacturing, but that doesn’t explain the pressure rising, he thinks is a bacterial infection and he recommend a peracetic acid rinsing also through the columns, what do you think?

We buy tridistilled water and pass it through a Millipore purifier system, but in fact it doesn’t have an UV station. It would be a very good idea to try it, thank you.

About the H2O2 rinsing, we did it according to the manual, in Standby Mode where there’s no injection to the columns, the rinsing is only for the Sample Box and doesn’t reach the ICs, so the manual says.

Thank you so much again!
Best regards! Angelica

[Markus Laeubli, Metrohm]

Dear Angelica
It would be helpfull if you could send me serial numbers of the columns (good and bad). I then could check their differences.
I am not sure whether MARGA is able to export chromatograms. If, yes it would goo to get example chromatograms as well.

Best regards
Markus

[ANeria]

Dear Dr Markus:

I just wanted to confirm your reception of the email I sent you with chromatograms and pressure graphics of the old and new batch of columns

Thanks for all your help. Best regards!

Angelica