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Flow rates on an Agilent 6890
Posted: Tue Jan 31, 2012 5:42 pm
by mdooley
Have a method for caffeine analysis and it says to use a flow rate of 10ml/min
this sounds high to me
Any suggestions guys
MD
Re: Flow rates on an Agilent 6890
Posted: Tue Jan 31, 2012 7:07 pm
by walter
Depends on the column , packed or capillary, id, etc.
Re: Flow rates on an Agilent 6890
Posted: Tue Jan 31, 2012 9:42 pm
by GasMan
It can also depend on the carrier gas. Using hydrogen allows higher flow rates.
Gasman
Re: Flow rates on an Agilent 6890
Posted: Wed Feb 01, 2012 9:30 am
by mdooley
Hi Guys
Its a Capillary column (HP -17 from J&W Agilent) carrier gas is Nitrogen detector is FID
Thanks
Re: Flow rates on an Agilent 6890
Posted: Wed Feb 01, 2012 10:03 am
by Johnny Rod
What is the diameter of the column?
Depending on how easy the separation is you can go away from the ideal flow to speed things up, this could be one reason for the flow rate given. Or it could be wrong.
Re: Flow rates on an Agilent 6890
Posted: Wed Feb 01, 2012 11:49 am
by Peter Apps
Have a method for caffeine analysis and it says to use a flow rate of 10ml/min
this sounds high to me
Any suggestions guys
MD
Maybe that's the total flow; 1 ml down the column and about a 10:1 split ???
Peter
Re: Flow rates on an Agilent 6890
Posted: Fri Feb 03, 2012 7:15 pm
by Bigbear
Could be all of the above. I used about 10 cc/min with a 30M X 0.53 column. Worked fine for years. Switched to a 0.45 column and reduced the flow down to about 7.
Depends on the column ID.
Re: Flow rates on an Agilent 6890
Posted: Fri Feb 03, 2012 7:27 pm
by mdooley
thanks guy for your help
MD