Rely on Rxi®-PAH Columns to Ensure Successful Polycyclic Aromatic Hydrocarbon (PAH) Analysis

Importance of the Topic

Polycyclic aromatic hydrocarbons (PAHs) present in food are a major concern for public health due to their potential genotoxic and carcinogenic effects. Regulatory bodies, such as the EFSA, define PAH4 limits that must be monitored. Accurate identification and quantification of these hazardous PAHs are often challenged by coeluting isobaric interferences, which can lead to false positives or biased results if not chromatographically resolved.

Objectives and Study Overview

This study evaluates Restek’s Rxi®-PAH gas chromatography columns designed to optimize efficiency, selectivity, and robustness for comprehensive PAH analysis in food matrices. Comparative assessments against competitor columns address run time, resolution of critical PAH pairs, and column longevity under demanding conditions.

Methodology and Used Instrumentation

Studies employed Rxi®-PAH columns with dimensions ranging from 30 m to 60 m, inner diameters of 0.18–0.25 mm, and film thicknesses of 0.07–0.10 µm. Key instrumentation and conditions included:

• Injection: Pulsed splitless (0.5–2.5 µL) with Restek liners at 275 °C
• Carrier gases: Helium (1.4 mL/min) or hydrogen (2.4 mL/min)
• Oven programs: Ramps from 70–110 °C to 350 °C at variable rates
• Detectors: Single-quad MS in SIM mode, TOFMS, and FID

Main Results and Discussion

Rxi®-PAH columns achieved up to 30 % faster analyses than competitor PAH columns while using simpler oven programs. Their proprietary arylene phase delivers beta values above 600, yielding 14 000–98 000 more theoretical plates per column. Critical isobaric pairs such as triphenylene/chrysene and benzo[b]/benzo[j]fluoranthenes were baseline-separated. Robustness testing demonstrated consistent resolution after over 464 injections and 116 hr at 350 °C, including analyses of oyster and paprika extracts.

Benefits and Practical Applications

These columns enable rapid, confident reporting of toxic PAHs without interference bias, reduce column replacements, and support compliance with food-safety regulations. Laboratories benefit from heightened throughput, lower maintenance, and improved trace-level sensitivity.

Future Trends and Opportunities

Emerging developments include integration with two-dimensional GC, coupling to high-resolution MS, and further refinement of stationary phases to expand PAH target lists. Automation and real-time monitoring will enhance routine food safety analysis.

Conclusion

Restek’s Rxi®-PAH columns combine exceptional efficiency, selectivity, and robustness, outperforming alternatives in the chromatographic separation of PAHs. Their proven longevity and resolution capabilities ensure reliable compliance with regulatory standards.

References

[1] EFSA Scientific Opinion on Polycyclic Aromatic Hydrocarbons in Food, EFSA Journal 724 (2008).