Chromatography Forum

Hi,

Currently I use a GCMS-FID with a Tee at the column outlet (HP-5MS 30mx250µx0.25µ) and 2 inert columns.
* 1 inert column of 5.70 m x 0.18 mm towards the MS
* 1 inert column of 2.5m x 0.18mm towards the FID
The lengths have been determined by the installer and the flow rate is 1.1 mL/min

I want to change column for another (30m x 320µ x 1µm).

Is it necessary to change the lengths between the detectors since the diameter of the column is different?
How to calculate the lengths?
Using the Hagen-Poiseuille law?

In a previous post "GC FID MS", a user mentions a file for the calculation but the link is broken.

In another post "Simultaneous MS and FID runs on GC", a user mentions the Swafer Utility program
Software

Thank you in advance for your help.

Cordially

The ratio of the lengths of the transfer lines sets of the ratio of the flows to the MS and FID, and so there will be no need to change them.

Thanks