Hydrocarbon Analysis Solutions with JMS-T2000GC AccuTOF™ GC-Alpha 2.0

Diversifying Hydrocarbon Sources for a Sustainable Future

Hydrocarbons are essential not only as fuels but also as feedstocks for many of the chemicals used in everyday life. To help protect the environment and reduce our carbon footprint, it is increasingly important to diversify hydrocarbon sources -- from conventional petroleum to more sustainable alternatives such as biomass, agricultural waste, recycled plastics, and synthetic hydrocarbons produced from carbon dioxide and hydrogen.

To use petroleum efficiently, detailed characterization of both hydrocarbon and non-hydrocarbon components in crude oil is required. Similarly, for hydrocarbons derived from alternative sources, comprehensive analysis is critical -- not only to determine hydrocarbon composition but also to detect and identify unexpected or unknown trace components that may aff ect performance, safety, or environmental impact.

JEOL offers unique solutions for hydrocarbon analysis across diverse sources using a high-resolution time-of- flight mass spectrometer combined with proprietary soft ionization technologies: field ionization (FI) and photoionization (PI).

JMS-T2000GC AccuTOF™ GC-Alpha 2.0
-the ideal mass spectrometer for hydrocarbon analysis

The JMS-T2000GC AccuTOF™ GC-Alpha 2.0 is a gas chromatograph - high resolution time-of-flight mass spectrometer (GC-HRTORMS) providing high mass-resolving power, high mass accuracy, high sensitivity, high speed data acquisition capability, wide dynamic range, and wide mass range. It can be equipped with soft ionization techniques suitable for hydrocarbons and other easy-to-fragment compounds.

Soft Ionization Techniques

Softest Ionization: FI for GC and FD for Direct MS

Field Ionization (FI) and Field Desorption (FD) are well suited for hydrocarbon analysis, because they generate molecular ions with minimal fragmentation for almost all compounds including saturated hydrocarbons.

FI is for volatile and semi-volatile analytes eluted from GC. FD is a direct MS method suitable for high-boiling point analytes, since the sample is directly applied to the FD emitter and does not have to be vaporized.

JEOL's unique EI/FI/FD combination ion source allows switching between EI, FI and FD without breaking the vacuum in the ion source chamber.

Good for Aromatic Hydrocarbons: PI for GC

While FI is still the softest ionization technique available, Photoionization (PI) can also be used to generate molecular ions for many analytes including hydrocarbons. In particular, aromatic hydrocarbons, which strongly absorb UV light, are preferentially ionized with PI.

JEOL's unique EI/PI combination ion source allows switching between EI and PI with no physical user intervention.

Regarding the advantages of PI and FI for hydrocarbons, please refer to the Ionization Methods for JEOL Mass Spectrometers - a Guidebook and JEOL GC-MS Soft Ionization Mass Spectra Collection.

Four Analytical Methods for Hydrocarbon Mixtures

Blank Tube FI (Field Ionization)

This method employs a short (3-5 meter), deactivated, non-separating fused silica tube positioned between the GC injection port and the mass spectrometer. The sample solution is injected, vaporized, and transferred directly to the ion source without chromatographic separation. When paired with Field Ionization (FI) -- a soft ionization technique particularly suited for hydrocarbons -- and a high-resolution time-of-flight mass spectrometer, this configuration enables rapid group-type analysis of complex hydrocarbon mixtures in under one minute. The presence of non-hydrocarbon species and hydrocarbons with varying degrees of unsaturation can be effectively visualized with a Kendrick Mass Defect (KMD) plot using the msRepeatFinder software. This approach supports a broad volatility range, from light C5 compounds to high-boiling components with boiling points up to 550 °C.

FD (Field Desorption)

Field Desorption is well-suited for analyzing samples with extremely high boiling points. The sample solution is directly applied to an activated carbon emitter and introduced into the ion source. Since complete vaporization is not required, components with boiling points above 550° C can be readily detected. However, low boiling point compounds (below approximately 200° C) may evaporate in a vacuum prior to analysis and thus may not be detected. The acquired high resolution mass spectrum is effectively visualized with a KMD plot.

GC Separation with EI (Electron Ionization) and Soft Ionization

In order to separate and identify structural isomers, gas chromatographic separation is essential. Under identical GC conditions, two datasets are acquired -- one using EI and the other using Soft Ionization. The msFineAnalysis AI software then performs integrated analysis and AI-driven structural elucidation, leveraging both datasets for comprehensive characterization.

Comprehensive Two-Dimensional GC (GCxGC) with EI and Soft Ionization

GCxGC is the most advanced gas-phase separation technique, capable of resolving thousands of components simultaneously. The msFineAnalysis AI software applies AI-driven structural analysis to all components separated by GCxGC, enabling detailed characterization of highly complex hydrocarbon mixtures.

Analysis of Crude Oil (MSTips No. 452)

Crude oil is a highly complex mixture -- it is not possible to obtain all the necessary information from a single analysis. The blank tube FI method allows comprehensive hydrocarbon group-type analysis with measurement times of 1 minute or less. With the GC-EI/FI analysis, minor components with heteroatoms can be determined. Finally, with comprehensive two-dimensional GC, the most comprehensive information for the sample can be determined.

Group-type analysis by Blank Tube FI and FD

The blank tube FI method is appropriate for a wide range of hydrocarbon mixtures. FD, a direct MS method, is useful for analyzing high boiling-point compounds that cannot pass through the deactivated fused silica tube.

msRepeatFinder

KMD Analysis Software

msRepeatFinder can visualize soft ionization mass spectra of highly complex hydrocarbon mixtures using KMD (Kendrick mass defect) plots. KMD plots make it possible to group hydrocarbons with different degrees of unsaturation and easily calculate the number average molecular weight, weight average molecular weight, polydispersity, etc. for each group.

Click here for more information regarding the msRepeatFinder.

One-dimensional GC-EI/FI Analysis

Using an EI/FI/FD combination ion source, GC-EI and GCFI data can be measured without breaking the vacuum in the ion source chamber. Integrated analysis is possible when combining hard ionization (EI) data with soft ionization (FI) data. The AccuTOF™ GC-Alpha 2.0 is compatible with a wide range of GC conditions -- from fast separation with a short, narrow-bore column to high resolution separation with a 100 m column, as shown below.

msFineAnalysis AI

Unknown Compounds Structure Analysis Software

GCxGC can analyze complex samples containing many compounds with high separation by using two different types of columns. Ultra-high GCxGC separation chromatography combined with an AI structural analysis provides a new qualitative analysis solution.

Click here for more information regarding the msFineAnalysis AI.

Multifaceted crude oil analysis using GC-EI/FI, blank tube-FI, and FD on JMS-T2000GC (MSTips No. 452).

Comprehensive two-dimensional GC (GCxGC): the ultimate chromatographic separation technique

The msFineAnalysis AI supports GCxGC data analysis in addition to the regular GC-MS data analysis. In highly complex mixtures, including crude oils and other complex hydrocarbon samples, the ultra-high separation of GCxGC and the structural analysis of unknown compounds using msFineAnalysis AI will prove to be very effective.

Detailed Analysis of Pyrolysis Oil (MSTips No. 511)

Pyrolysis oil generated from a mixture of polyethylene (PE), polypropylene (PP), and polyvinyl chloride (PVC) was measured by JMS-T2000GC AccuTOF™ GC-Alpha 2.0 GCxGC-TOFMS and the AI structural analysis was performed with the msFineAnalysis AI. Alkanes and alkenes derived from PE/PP, which are difficult to separate by an ordinary 1-dimensional GC, are clearly separated. The molecular formula of each component was identified with field ionization (FI), a soft ionization method. For unknown compounds that were not registered in the NIST database, the structural formulas were obtained using an AI structural analysis.

GCxGC data analysis of msFineAnalysis AI Ver. 3 ③ Pyrolysis oil (MSTips No. 511).

Analysis of Biomarker Compounds in Crude Oil

Fragment ions from electron ionization (EI) can cause interferences for biomarker detection. For example, fragments resulting from loss of a methyl group have isotope peaks that can be confused with molecular ions from related compounds. FI solves this problem because it does not produce fragment ions. We clearly identified 20 isomers of cholestane C₂₇H₄₈ in a crude oil sample by GCxGC/FI. The GCxGC/FI extracted ion chromatograms made it easy to interpret the data and correctly assign the biomarker peaks.

Biomarker Analysis in Petroleum Samples Using GC×GC-HRTOFMS with an Ion Source Combining Electron Ionization (EI) and Photo Ionization (PI)

Comprehensive analysis of commercially-available pyrolysis oil by combining Blank Tube - FI, KMD analysis, GC-EI/FI-MS, and AI structural analysis (MSTips No. 468)

When analyzing pyrolysis oil, it is important to quickly obtain the following information:

Molecular weight distribution and unsaturation distribution of hydrocarbons, which are expected to be the main components (group-type analysis).
Identification of non-hydrocarbon components, especially those that are not present in natural crude oils and may impede upcycling.

In the following example, pyrolysis oil derived from waste plastic was analyzed using the blank tube - FI method. FI (field ionization) is a soft ionization method, and most of the peaks in the mass spectrum are assumed to be the molecular ions M^{+ •} of the constituents.

By converting this mass spectrum into a KMD plot and grouping ions consisting only of carbon and hydrogen, information on hydrocarbons and other components can be easily separated. The KMD plot of the hydrocarbon molecular ions allows for a group-type analysis of the hydrocarbons.

From the KMD plot of the other components, it was possible to estimate the elemental composition of each component from the exact mass of each ion, and it was confirmed that this pyrolysis oil contains highly unsaturated sulfur-containing compounds that are not found in crude oil. By measuring the same sample using GC/EI and GC/FI methods and performing an integrated analysis and an AI structural analysis, we were able to estimate the structures of these components.

Rapid analysis of pyrolysis oil using blank tube-FI method and GC-EI/FI method of JMS-T2000GC (MSTips No. 468).

Key Specifications

JMS-T2000GC AccuTOF™ GC-Alpha 2.0
Mass Resolution	30,000 @ m/z 614
Mass Accuracy	1 ppm with internal reference and standard EI ion source
Mass Range	m/z 4 - 6,000
Ionization Methods	EI, CI, PI, FI, FD, DEI, DCI

Benefits of High Mass-Resolving Power

When comparing the mass spectra of crude oil from the first generation AccuTOF™ GC and the latest JMS-T2000GC AccuTOF™ GC-Alpha 2.0, each ion is clearly separated and detected with the data obtained using the AccuTOF™ GC-Alpha 2.0.

The difference in resolution is clearly evident in the KMD (Kendrick Mass Defect) plot for the FD mass spectrum of crude oil. The lower resolution of the first generation AccuTOF™ GC resulted in poor mass accuracy for unresolved peaks involving isobaric compounds at higher masses.

On the other hand, with the KMD plot drawn for the JMS-T2000GC AccuTOF™ GC-Alpha 2.0, peaks are separated and detected even at a high mass, and good results are obtained even for components with high degrees of unsaturation (high KMD values).

Effect of JMS-T2000GC high mass resolution on the analysis result-KMD Plot comparison using msRepeatFinder (MSTips No. 332).

Benefits of High Mass Accuracy

With accurate mass analysis, it is common to consider the mass error and specify an "error tolerance". If the error tolerance is large, the number of candidate elemental compositions increases, thus making it difficult to judge which is the correct elemental composition among multiple candidates.

The higher mass accuracy of the AccuTOF™ GC-Alpha 2.0 makes it possible to use a smaller mass tolerance, which in turn reduces the number of candidate elemental compositions. As a result, the user can more easily determine the correct compositions!

Comparison of integrated analysis result of trilaurin

Error tolerance: 5 mDa

#	Elemental formula	DBE	Calculation m/z	Error [mDa]	EI Fragment Coverage
1	C₄₀ H₇₀ N₄ O₂	8.0	638.54933	0.07	100
2	C₃₉ H₇₄ O₆	3.0	638.54799	1.41	100
3	C₃₆ H₆₆ N₁₀	9.0	638.54664	2.76	100
4	C₂₉ H₇₀ N₁₀ O₅	0.0	638.55252	-3.12	100
5	C₃₅ H₇₀ N₆ O₄	4.0	638.54531	4.09	100

Error tolerance: 2 mDa

#	Elemental formula	DBE	Calculation m/z	Error [mDa]	EI Fragment Coverage
1	C39 H74 O6	3.0	638.54799	1.41	100
2	C40 H70 N4 O2	8.0	638.54933	0.07	85

With error tolerance of 5 mDa, 5 candidates have 100% EI fragment coverage.
With error tolerance of 2 mDa, only 1 candidate has 100% EI fragment coverage.

Effect of high mass accuracy on the analysis result by JMS-T2000GC-Effect to narrow down the result of msFineAnalysis integrated analysis (MSTips No. 331).

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