This note describes the Pressure Controlled Tee (PCT) configuration for rapid and universal GC/MS backflushing applied to selected reaction monitoring experiments on the Agilent 7890 GC used with the Agilent 7000 Series Triple Quadrupole Mass Spectrometer. This means that rapid backflushing and quick column and inlet maintenance without venting the MS system can be incorporated without a loss in detection limits using a simple PCT configuration.
This document presents the results of an experiment using the Pressure Controlled Tee (PCT) configuration for rapid and universal GC/MS backflushing on the Agilent 7890 GC coupled with the Agilent 7000 Series Triple Quadrupole Mass Spectrometer. The study aimed to determine if adding this plumbing configuration would compromise signal sensitivity or detection limits in multiple reaction monitoring (MRM) mode.
The results indicate that implementing the PCT configuration maintains signal height and area without degrading compound retention time reproducibility or other performance metrics. Consequently, rapid backflushing and service of the injection port and column can be introduced without compromising analytical integrity or requiring the mass spectrometer to be vented.
| Target Compound | octafluoronaphthalene (OFN) |
|---|---|
| Concentration | 100 fg |
| Column 2 Length | 15 m |
| Carrier Gas | helium |
| Post run Temperature | 200 °C |
No, the results show no loss in sensitivity as measured for peak area, height, or signal-to-noise ratio.
No, rapid backflushing and service can be performed without venting the MS system.
Retention time reproducibility is unaffected, achieving a standard deviation of less than 0.1 seconds.