This Application Note describes a rapid method for analysis of polynuclear aromatic hydrocarbons (PAHs) in soil and sediment samples by GC-MS using an Agilent Low Thermal Mass (LTM) GC/MS system and Capillary Flow Technology QuickSwap for Backflush. The cycle time for GC-MS analysis of PAHs was dramatically improved through the combined use of a narrow-bore (180-µm id) column installed in an LTM module and capillary column back-flushing with QuickSwap. Improvements were achieved while maintaining resolution. Agilent Capillary Flow Technology enabled column backflushing to remove low-volatili- ty material from the capillary column, reducing bakeout and maintenance time. The method resulted in increased sample throughput and lab productivity, while maintain- ing analytical performance.
This document details a method to improve the cycle time for GC-MS analysis of polynuclear aromatic hydrocarbons (PAHs) in soil and sediment samples. The method combines a narrow-bore column installed in an LTM module with capillary column backflushing using the QuickSwap device. This approach reduces bakeout and maintenance time while maintaining resolution and increasing sample throughput.
The note demonstrates the translation of a standard PAH method to a fast method using a 20 m x 180 µm id x 0.18 µm J&W DB-5MS column. The system configuration includes an Agilent 7890A GC and 5975C Series MSD equipped with an S/SI inlet, QuickSwap device, AUX EPC module, and LTM column module. Specific setpoints for injection, pressure programming, oven temperature, and MS SIM/scan modes are provided to achieve analysis times of approximately 18 minutes.
| Transfer line temperature | 280 °C |
|---|---|
| MS Source temperature | 300 °C |
| MS Quad temperature | 150 °C |
| Oven final temperature | 300 °C |
The analysis is performed on an Agilent 7890A GC — Agilent 5975C Series MSD system.
The QuickSwap device is used for column backflushing to remove low-volatility material from the capillary column, reducing bakeout and maintenance time.
The analysis time is reduced by a factor of 2, with the fast method taking approximately 18 minutes compared to the reference method.