Chromatography Forum

Hi!
I have heard that Thermo's injector (split/splitless inlet) gives better results because the whole unit is heated up, vs. Agilent's system (6890) which only heats up a part of the inlet - and this could result in poor volatilization and hence poor reproducibility.
Have anyone experienced this kind of issue?
Thanks!

The guess is correct. If you do not have you injector fully heated, the results would not be satisfactory.

The only doubt that comes to me is that Agilent engineers would be that stupid to made a top-selling instrument with that serious "defect"?

I think the guy that told you this is a Thermo salesman...

The Thermo Split/splitless was designed for them by K Grob and papers do exist from around 1990 onwards detailing the improved transfer of less volatile materials onto the column and the ability to use lower temperatures with as good vapourisation to improve transfer of Thermally labile compounds. When looked at in profile the temperature on the Thermo injector is constant over the injection/vapourisation zone, the Agilent is not. This makes little difference unless the temperature at the exteme (top or bottom) is low enough to stop the componds vaporising. Will it make a difference for your analysis, probably not. Is it a better injector, IMO yes.

Does CE instruments stand for Carlo Erba?

Is the owner of CE instruments Thermo?

One thing I know is that the septa are exposed to a much higher temperature with the Thermo injector compared to an Agilent one set at the same injection temperature.

This can lead to problems with septum bleed & even physical breakdown of the septa. Most septa suppliers temperature ratings seem to be based on Agilent injectors, not on Thermo injectors.

Regards

Tony

Does CE instruments stand for Carlo Erba?

CE Instruments was a name used by Fisons on products made from the factory formally known as Carlo Erba when the agreement to continue to use the name ran out. Fisons then decided to rebadge everything Fisons and concentrate on core business (Pharmaceuticals)
One little slip and the group was split with Instruments being bought by Thermo.

CE Instruments Ltd is an independent company operating with the permission of Thermo to use the name. We are UK agents for the Milan factory Microstructure and OEA business. However I worked for Fisons/Thermo from 91-02 in GC and GC/MS and as a company we are factory trained in the current products and can back up the factory for service support if requested.

Should you want to see what we do visit www.ceinstruments.co.uk

In fact there is much more septum bleeding with the Thermo !
For the "better results" of Thermo injector, I am not sure at all...
I'am trying to transfer a method to quantify MeOH in NH3 on a Volamine column.
I don't have any problem and good RSD on the Agilent (0,3%).
For the Thermo (AS2000) i got RSD of about 10% :/ make it impossible to validate it on the Trace.
Same conditions different equipment, for me the Agilent injector system is beter

i would never inject a thermo-labile compound on a thermo system