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- Posts: 12
- Joined: Tue Apr 28, 2020 2:55 pm
I have noticed some changes during last analyses. I want to quantify BTEX, but with benzene there is coelution of something that (I think) is present in n-hexane (before and also after extraction - used to microextraction of BTEX).
I use GC-MS 6890, HP-5MS column (30m, 250 um, 0,25 um); flow during analysis 0,7 ml/min (He), splitless mode, front inlet - initial temperature 250°C, 1 rate 6 min 80, run time 17,50 min.
Calibration curves of xylenes and styren are ok, toluene is worse, benzene is horrible (unable to quantify with or without extraction process there are some peaks with large area), there is such low sensitivity and I think that peak in RT of benzene is something coelutioning from n-hexane.
Please, do you have any suggestion what to try to separate impurities and benzene - what conditions do I should try with HP-5MS column? With described method (below) sometimes it was possible to determinate benzene and also toluen without any problems.
Thank a lot.