Analysis of diesel oil by using GC x GC-HRTOFMS (FI) with 2 different sets of column combinations

Importance of the Topic

Comprehensive two-dimensional gas chromatography (GC×GC) coupled with high-resolution time-of-flight mass spectrometry (HRTOFMS) provides exceptional separation and accurate mass measurements, essential for analyzing complex hydrocarbon mixtures like diesel fuel. Such capabilities support detailed compositional profiling for quality control, environmental monitoring, and industrial applications.

Objectives and Study Overview

This work compares two distinct GC×GC column configurations using field ionization (FI) detection to evaluate their performance in separating diesel oil components, focusing on polarity and boiling point differences.

Used Instrumentation

JMS-T100GCV GC×GC-HRTOFMS system (JEOL Ltd.)
Zoex KT2004 thermal modulator (Zoex Corporation)

Methodology

Sample and Conditions:

• Sample: Diesel oil
• Injection: Split 100:1, 0.2 µL at 280 °C
• Oven program: 50 °C (2 min), ramp 3 °C/min to 300 °C
• Modulation period: 6 s
• Ionization: Field ionization at –10 kV
• Mass range: m/z 35–500, acquisition 25 Hz

Column Sets:

• Normal set: 1st BPX-5 non-polar (30 m×0.25 mm, 0.25 µm), 2nd BPX-50 polar (2 m×0.1 mm, 0.1 µm)
• Reverse set: 1st DB-WAXETR polar (30 m×0.25 mm, 0.1 µm), 2nd DB-1 non-polar (1 m×0.1 mm, 0.1 µm)

Results and Discussion

The normal column sequence effectively separated aromatic hydrocarbons and polar compounds, resolving n-paraffins, naphthenes, and mono- and di-aromatic species. Short second-dimension columns limited resolution of mono- versus polycyclic naphthenes. In contrast, the reverse set leveraged boiling point differences on a non-polar second column to distinctly resolve mono- and polycyclic naphthenes and paraffins. Field ionization enabled direct observation of molecular ions with mass accuracy below 1.2 mDa, improving identification reliability.

Benefits and Practical Applications

• High-resolution separation of complex hydrocarbon classes
• Precise molecular ion confirmation
• Adaptable column configurations for targeted analyses
• Enhanced compositional profiling for fuel quality and environmental studies

Future Trends and Opportunities

Advancements may include integrating GC×GC-HRTOFMS with alternative ionization sources, developing automated data interpretation with machine learning, and expanding applications in petrochemical, environmental, and forensic research.

Conclusions

Column polarity order critically influences GC×GC separation of diesel oil constituents. The JMS-T100GCV system with FI detection delivers high sensitivity and accurate mass data, with normal and reverse column sets offering complementary separation strategies for comprehensive hydrocarbon analysis.

References

JEOL Ltd. JMS-T100GCV Application Data No. 154, 2009. Zoex Corporation KT2004 Modulator Datasheet.