PAH Analysis Using an Agilent J&W DB-5ms Ultra Inert Capillary GC Column

Significance of the topic

Trace- and ultra-trace-level analyses of polycyclic aromatic hydrocarbons (PAHs) are essential for monitoring environmental contamination and ensuring food safety. High inertness in gas chromatography columns minimizes analyte–surface interactions, improving sensitivity, accuracy, and reproducibility in challenging trace analyses.

Goals and overview of the study

This application brief evaluates the performance of an Agilent J&W DB-5ms Ultra Inert capillary GC column for the separation and quantification of 16 priority PAHs. The study aims to demonstrate rapid (15-minute) analysis with excellent sensitivity and linearity at sub-nanogram levels using electron impact single quadrupole scanning mass spectrometry.

Methodology

A standard mixture of 16 PAHs was prepared at concentrations ranging from 0.05 to 5 µg/mL. One‐microliter splitless injections delivered on‐column loadings of 0.05–5 ng per component. Chromatographic separation was achieved in a 30 m × 0.25 mm, 0.25 µm DB-5ms Ultra Inert column with a temperature program from 55 °C (1 min) to 320 °C at 25 °C/min (3 min hold). Detection employed EI scanning from 45 to 450 amu.

Instrumentation used

• Gas chromatograph: Agilent 6890N coupled to a 5973B or 5975B mass selective detector
• Autosampler: Agilent 7683B with a 5 µL syringe (p/n 5188-5246)
• Column: Agilent J&W DB-5ms Ultra Inert, 30 m × 0.25 mm, 0.25 µm (p/n 122-5532UI)
• Carrier gas: Helium at constant flow of 45 cm/s
• Injection: Pulsed splitless at 300 °C, 40 psi for 0.2 min, purge at 30 mL/min from 0.75 min
• Oven program: 55 °C (1 min) to 320 °C at 25 °C/min, hold 3 min
• MS parameters: EI source at 300 °C, quadrupole at 180 °C, transfer line at 280 °C, scan range 45–450 amu

Main results and discussion

All 16 PAHs were detected with excellent sensitivity and linearity (R² ≥ 0.995) down to 0.05 ng on‐column. The total ion chromatogram in a 15-minute run showed baseline resolution for most analytes; only indeno[1,2,3-cd]pyrene and dibenz[a,h]anthracene were partially resolved. Signal-to-noise for benzo[a]pyrene at 0.05 ng exceeded 9:1, underscoring the benefits of the inert column surface.

Benefits and practical applications

• Reliable detection of trace-level PAHs for environmental monitoring and food quality control
• Improved quantitative accuracy due to minimized analyte adsorption
• High throughput with rapid 15-minute analyses
• Compatibility with standard single quadrupole GC/MS setups in QA/QC laboratories

Future trends and potential applications

Advances may include coupling ultra-inert columns with high-resolution or tandem MS for enhanced selectivity, integration with comprehensive two-dimensional GC for complex mixtures, adoption of greener carrier gases, and development of field-deployable systems for on-site PAH screening. Miniaturization and automation will further increase laboratory efficiency.

Conclusion

The Agilent J&W DB-5ms Ultra Inert capillary column enables robust, sensitive, and linear trace-level PAH analyses in under 15 minutes. Its low-surface-activity profile delivers reliable results crucial for environmental and food safety applications.

Reference

Lynam K, Smith D. PAH Analysis Using an Agilent J&W DB-5ms Ultra Inert Capillary GC Column. Agilent Technologies Application Brief; 2011 Feb 11;5990-5652EN.