Column degrading in GCMS
Posted: Wed Aug 12, 2015 4:42 am
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.
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.