PTV carryover when changing liner type
Posted: Tue Nov 09, 2010 1:24 pm
I analyze pesticideresidues on Waters quattro micro GC with a PTV from gerstel. I have recently changed the type of liner i use from one packed with PDMS foam to one with a carbo frit and now I am experiencing some carryover of the late eluting pesticides. The carryover lasts for several injections. I never had this problem with my old liner.
This is my method:
Solvent: Ethyl acetate
Inj volume: 10 µl
Flow: 1.3 ml/min
Inj speed: 0.25 µl/s
Initial inlet time: 0.9 min
PTV ramp: 720 C/min from 20 to 270 (hold 10 min)
Pressure: 6 kPa
Vent flow: 40 l/min
Vent end time: 0.9 min
Purge flow: 100
Time 2.05
What can i change to prevent carryover?
This is my method:
Solvent: Ethyl acetate
Inj volume: 10 µl
Flow: 1.3 ml/min
Inj speed: 0.25 µl/s
Initial inlet time: 0.9 min
PTV ramp: 720 C/min from 20 to 270 (hold 10 min)
Pressure: 6 kPa
Vent flow: 40 l/min
Vent end time: 0.9 min
Purge flow: 100
Time 2.05
What can i change to prevent carryover?