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- Posts: 4
- Joined: Wed Oct 11, 2017 3:36 pm
We have spiked the IS right into water and bypassed the IS valves and still see the same drop. In soil mode, the IS's seem to be holding better. We have tried baking the MSD and direct injecting the IS into the GC and numbers still drop as you go.
The Atomx purge and trap is connected to the GC via transfer line.
Here is some of our instrument info:
5973 MSD Hewlett Packard
6890 Agilent GC
Column: 1st column was DB-624 Agilent 60m x 250um x 1.40um
Pressure: 16.1, Flow: 1, Carrier gas: Helium, Constant flow
Inlet: Split
Temperature: 250, Pressure: 16.1, Split ratio 40:1, Split flow: 39.7, Total flow: 43.2, Gas saver off
Oven:
Initial 35 for 5 mins
Ramp 1: 104
Ramp 2: 142
Ramp 3: 230
for total of 30 mins
Internal standards used in Atomx: d4-dichloroethane, tolene-d8, and bromoflurobenzene.
Any help is appreciated. I am going to start by replacing the drawout plate and filaments in the MSD.