Re: Sample dilutions for splitless injections
Posted: Wed Sep 20, 2017 5:50 pm
by James_Ball
The initial ramp rate from just below boiling point of solvent to just above should be as fast as the oven will ramp. You want to flash evaporate what is condensed on the column.
Below are a couple of articles dealing with a similar subject to give you an idea of what is possible with splitless.
http://blog.restek.com/?p=10311
http://www.restek.com/Technical-Resourc ... AN1548-UNV
Re: Sample dilutions for splitless injections
Posted: Wed Sep 27, 2017 7:42 pm
by Peter Apps
I would find out some of the solvents which would elute after my analytes after trying with hexane. Thank you so much for providing this useful information.
A solvent that elutes late in the chromatogram is unlikely to be anywhere near volatile enough for flash injections, it will recondense on the column, and cause all sorts of horrible peak shapes.
If you are really serious about this, carbon disulphide is nearly invisible to an FID, but it stinks and is toxic.
Fixing the splitter still seems like the best option - what is the problem with it ?
Peter
Hey Peter,
The pressure is not getting stabilized with split on. Thus, the status is always equilibrating and not ready. However, there is no such problem when split is off.
It sounds as if the split line and filter are partly blocked - replacing the filter and cleaning the line will probably fix it.
Peter