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- Posts: 35
- Joined: Wed Dec 21, 2016 12:38 am
The issue is very poor sensitivity for the heavier PAH, like BGP, ICP...NAP and PHE are fine.
The 6 ring PAH area counts are about 50x lower than before.
The standard is new from Sigma and I made multiple dilutions to test.
This is an Agilent 5977 ms with 7890 gc
I replaced:
liner
column
gold seal
septum
cleaned the inlet metal with meoh
increased xfer line and source temps
= no improvement
anything left to try here?
thanks!
method settings:
Mode Pulsed Splitless
Injection pulse pressure 50 psi until 0.7 minutes
Purge flow to split vent 50 mL/min at 0.75 minutes
Septum purge flow mode Standard
Injection volume 1.0 µL
Inlet temperature 320 °C
Carrier gas Helium
Inlet liner Agilent 4 mm single taper, with glass wool
Quadrupole temperature 150 °C
Source temperature 320 °C
Transfer line temperature 320 °C