Ultrafast Total Petroleum Hydrocarbon Analysis by the Agilent 8850 GC with FID

Significance of the Topic

Total petroleum hydrocarbons (TPHs) are widespread contaminants in soil and water resulting from industrial operations, leaks, and spills. Rapid and reliable screening of TPHs is essential for environmental risk assessment and remediation planning.

Objectives and Study Overview

This study demonstrates an ultrafast gas chromatographic method using the Agilent 8850 GC with flame ionization detection (FID) to screen total petroleum hydrocarbons in soil and water samples. The method was benchmarked against ISO 16703, HJ 1021-2019, and HJ 894-2017 standards to verify performance metrics and throughput improvement.

Methodology and Instrumentation

Key instrumental setup:

• Agilent 8850 GC with compact air-bath oven (ramp rates up to 300 °C/min)
• 7650A autosampler with split/splitless inlet (310 °C, splitless)
• Agilent J&W DB-5ht column, 5 m × 0.32 mm, 0.1 µm
• Flame ionization detector at 340 °C
• Carrier gases: helium (6.0 mL/min) or hydrogen (5.5 mL/min)

Calibration was performed with mineral oil standards (ISO 16703) and n-alkane mixtures (HJ methods), covering 100–8 000 mg/L and 31–9 300 mg/L ranges, respectively.

Main Results and Discussion

System suitability showed baseline separation of n-C10 to n-C40 with inlet discrimination ratios exceeding 96%. Retention time repeatability (%RSD) remained below 0.07% for n-C10 and 0.69% for n-C40. Response precision for individual alkanes was under 0.91%, and integration precision for the TPH hump was 0.32–0.69%. Calibration curves exhibited R²>0.9998, with quantitation accuracy within 102–107%. Carryover was negligible (<0.05% blank/sample ratio). Ultrafast cycles of 8.5 min (He) and ≈9 min (H2) enabled high throughput. On-board peak evaluation automatically monitored n-C40/n-C20 response ratios, triggering user-configurable actions upon performance drift and guiding inlet maintenance after ~40 injections of complex samples.

Benefits and Practical Applications

The method delivers:

• Rapid screening of soil and water TPHs in under 9 minutes
• High precision and linearity compliant with international standards
• Reduced carrier gas consumption and power use
• Automated performance checks via peak evaluation to enhance lab productivity and uptime

Future Trends and Potential Applications

Further integration of hydrogen carrier gas workflows may alleviate helium shortages while maintaining performance. Advancements in GC automation and software-driven diagnostics will expand real-time quality control. Applications could extend to on-site screening, high-throughput environmental monitoring, and coupling with mass spectrometry for compound-specific analysis.

Conclusion

The Agilent 8850 GC with FID provides a robust ultrafast screening approach for total petroleum hydrocarbons, meeting or exceeding ISO and HJ method requirements while boosting laboratory efficiency through intelligent automation.

Reference

• ISO 16703:2004 Soil Quality—Determination of Content of Hydrocarbon in the Range C10 to C40 by Gas Chromatography.
• HJ 1021-2019 Soil and Sediment—Determination of Petroleum Hydrocarbons (C10-C40)—Gas Chromatography.
• HJ 894-2017 Water Quality—Determination of Extractable Petroleum Hydrocarbons (C10-C40)—Gas Chromatography.
• McCurry JD. Analysis of Total Petroleum Hydrocarbons in Environmental Samples Using Ultrafast Gas Chromatography. Agilent Technologies Application Note 5991-7367EN, 2018.