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Two Peaks with same retention time
Posted: Tue Oct 23, 2012 2:48 am
by andzzle
Hi. I have two compounds that are coming off of the column at the same time. One of the peaks is my compound of interest and the other I don't care about and is very small. Is there a way to separate the peaks with out a new column or a way to subtract the smaller peak from my peak of interest with in the Chemstation software?
Thank you
Re: Two Peaks with same retention time
Posted: Tue Oct 23, 2012 3:54 am
by cleh
Please post a chromatogram and your GC parameters. Can probably make some changes in the oven temp ramp or flows to seperate them.
Re: Two Peaks with same retention time
Posted: Tue Oct 23, 2012 5:02 am
by chromatographer1
If difference in carrier flow and oven temperature do not separate the peaks, then a change is column will probably work.
If you are using a methyl silicone, then try a OV1301 or a OV275 or a Wax column.
If your analytes are small (smaller than six carbons, try a porous polymer column.
best wishes,
ROd
Re: Two Peaks with same retention time
Posted: Tue Oct 23, 2012 6:28 am
by Peter Apps
If the retention times really are the same - i.e. the peaks are completely overlapped then it is very unlikely that you will be able to separate them by changing temperatures and flows unless your current conditions are very badly chosen - but if that is the case, how would you know that you have two peaks eluting together unless you have an MS ? If you do have an MS, then you might be able to find ions that are specific to each compound, and use those to select which peak you look at on an extracted ion chromatogram.
Peter