Hi all. I am currently using 1260 with RID and GPC columns to analyze our polymer MW, and I found there are some unknown peaks after my main peak, not the solvent peak. I think they are monomer or solvent residuals, so I tried solvent and monomer spike tests, but the GPC column shows poor resolution on those components. Therefore, I am thinking about setting up another dimension of LC to do some qualitative and quantitative analysis on the peaks after the main peak. I wonder is it practicable? If so, what are the best column and detector for the second dimension? Or will it be easier to just set up a headspace GC for the test?