Column degrading in GCMS

[versitian]

We are running Chlorinated organic carriers (COC) application on our GCMS (Shimadzu). The procedure involve simple extraction by sonication in acetone and then filtered solution injected in GCMS.

Problem is with our disperse dyes, it dissolve in acetone and pass through filters and degrade the column gradually, resulting in peak tailing and low signals. We are using DB-35 MS (25m,0.2mm, 0.33µm) J&W column.

Recommended filters for this application from our global headquarter is Acrodisc GHP with glass fiber prefilter, PALL . But the disperse dye molecule even pass from this special filter. We also try other filter like 0.45 and 0.2 but same result.
I have also try guard column, but it also works poor and the low intensity and peak tailing can be seen.

one more observation is that after some injections, the reproducibility also effected and the first injection of the day shows better intensity as compare to other injections of same concentration.

Now I want to do some modification in our method, either with column, solvent, filters or anything which can save my column. My column take 4-5 months to degrade.

[gcguy]

Have you tried cleaning up the samples with a micro-centrifuge? We use one and in certain cases it gives us cleaner solutions than filtering.

GCguy

[Peter Apps]

Try a series of solvents to see if there is one that does not dissolved your dyes, then check whether it will extract your COCs.

Peter

[KipDM]

if filtering that small doesn't help and microcentrifuging don't help you may need to see if there is any form or liquid-liquid protocol or even go to a short solid phase extraction process.

sorry to not have any good news.
otherwise you may want to see if you there is a better column alternate that is not as reactive.


KDM