Full-Scan Low-Level Polynuclear Aromatic Hydrocarbon Analysis Using the Agilent Technologies 6890/5973 inert Gas Chromatograph/Mass Selective Detector

Importance of the Topic

The analysis of polynuclear aromatic hydrocarbons (PAHs) is critical due to their widespread environmental presence and potential carcinogenicity. Accurate, sensitive, and robust analytical methods are required to monitor these compounds in air, water, soil, and consumer products.

Objectives and Study Overview

This application study evaluates the performance of the Agilent 6890/5973 inert gas chromatograph/mass selective detector (GC/MSD) for full-scan analysis of 13 priority PAHs over a calibration range of 0.1 to 10.0 ppm. The goal is to demonstrate linearity and sensitivity comparable to traditional Selected Ion Monitoring (SIM) approaches while maintaining confirmation capabilities provided by full-scan data.

Methodology

Calibration standards were prepared in dichloromethane at seven levels (0.1, 0.2, 0.5, 1.0, 2.0, 5.0, 10.0 ppm). Each level received a perylene-d12 internal standard and two surrogates. A pulsed splitless injection at 300 °C ensured efficient transfer of heavy PAHs, and a direct-connect inlet liner minimized adsorption losses.

Used Instrumentation

• Gas chromatograph: Agilent 6890 with EPC split/splitless inlet, pulsed injection, 300 °C inlet temperature
• Column: HP-5MS, 30 m × 0.25 mm × 0.25 µm, constant helium flow
• Inlet liner: Direct Connect deactivated, 4 mm id
• Mass selective detector: Agilent 5973 inert, ultralarge aperture draw-out lens, source at 300 °C, transfer line at 280 °C, full scan 45–450 amu at 3.6 scans/s

Main Results and Discussion

Linearity was excellent across the full range, with relative standard deviations of response factors below 5% for all PAHs. A 0.01 ppm spike quantified against the same calibration yielded recoveries near target levels, demonstrating system inertness and sensitivity at ten-times below the lowest standard. Full-scan data provided confirmation of compound identity without sacrificing quantitative performance.

Benefits and Practical Applications

• Consolidates quantitation and identification in a single full-scan analysis
• Eliminates the need for SIM in routine low-level PAH monitoring
• Enhances laboratory throughput and data confidence for environmental and industrial QA/QC

Future Trends and Opportunities

Advances in inert materials and high-temperature sources will further reduce analyte adsorption and broaden mass range capabilities. Integration with high-resolution MS and automated sample handling will enable real-time PAH monitoring and lower detection limits for emerging contaminants.

Conclusion

The Agilent 6890/5973 inert GC/MSD system delivers reliable quantitative performance for low-level PAH analysis in full-scan mode, matching or exceeding the linearity of SIM. This approach streamlines workflows and strengthens confirmatory power for environmental and industrial applications.

References

Agilent Technologies, Inc. Application Note 5989-0264EN, November 2003.